bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue resistance of rotary endodontic files subjected to planar and non-planar curvatures induced by in vitro tooth canals
Authors: Martins Rui F. , Fernandes Alexandre , Lóios Gonçalo , Ginjeira António
Published: October 2017

Purpose

The purpose of this paper is to assess the fatigue life of different sizes of HyFlex CM™ endodontic files when submitted to planar or to non-planar curvatures, and to two different rotational speeds, namely 500 rpm or 250 rpm. The influence of superimposing back and forth motion to rotational bending of endodontic files was also assessed.

Design/methodology/approach

In all, 64 HyFlex CM™ files of different sizes, namely ref. 0.04/20, 0.06/20, 0.04/35 and 0.06/35, were submitted to rotational bending tests at two different rotational speeds. The planar radius of curvature imposed to the endodontic files was about 4.5 mm, along an angle of 45°, in order to simulate an apical canal that would induce severe loading to the files during clinical treatment. Additionally, 11 Hyflex CM™ files ref. 0.04/20 were submitted to rotational bending tests at 500 rpm inside a mandible first molar manufactured through selective laser melting (SLM), aiming to simulate non-planar curvatures of a real tooth canal.

Findings

When considering planar curvature, the endodontic file ref. 0.06/20, tested at 250 rpm, has shown the highest fatigue resistance (4,185 revolutions, 1,004 seconds), while the lowest fatigue resistance was registered for instrument ref. 0.04/35 submitted to 500 rpm (747 revolutions, 89 seconds). Hence, depending on the rotational speed, surface finish and the size of the endodontic files tested (taper and tip’s diameter), significant differences in fatigue resistance were noticed. If non-planar curvatures were considered, the minimum fatigue resistance was equal to 107 seconds, and back and forth motion allowed extending the minimum fatigue lifetime to 140 seconds.

Originality/value

The fatigue resistance of endodontic files is frequently determined through in vitro fatigue tests carried out under single planar curvature or eventually under double planar curvatures. However, non-planar loadings are frequently induced on endodontic instruments when treating root canals with severe multiplanar curvatures. In the research herein presented, a mandible first molar was 3D printed by using the SLM technique in an AISI 316 L stainless steel and more realistic experimental fatigue tests were carried out.
Fatigue of adhesively bonded epoxy-AA6061T651 joints
Authors: Campos António A.M.A. , Jesus Abílio M.P. de , Correia José A.F.O. , Morais José J.L.
Published: October 2017

Purpose

Adhesively bonded joints are gaining importance in the structural joining processes competing against welding and bolting processes. However, long-term behaviour of adhesively bonded joints is still an open question. Due to the increasing interest in adhesively bonded joints, mainly in the transports industry, there is a need to deep the knowledge about the fatigue behaviour of adhesive joints with metallic substrates allowing the development of reliable joints to resist cyclic loadings. The paper aims to discuss these issues.

Design/methodology/approach

An experimental research aiming at characterizing the fatigue behaviour of adhesively bonded aluminium substrates is presented in this paper, covering both fatigue crack propagation and global S-N behaviours. Double cantilever beam (DCB), end notch flexure (ENF) and double lap joints (DLJ) specimens built using the AA6061T651 substrate and epoxy adhesive were used to evaluate the pure modes I and II fatigue crack propagation rates and the S-N fatigue behaviours.

Findings

DCB and ENF specimens allowed the formulation of pure modes I and II fatigue crack propagation laws including the propagation thresholds. DLJs showed higher static shear strength than recommended by the manufacturer for aluminium substrates, but fatigue resistance of the DLJs was lower than suggested by the manufacturer. The fatigue damage process in the DLJs was dominated by a fatigue crack initiation process.

Originality/value

A consistent fatigue research on adhesively bonded aluminium substrates is presented covering in the same study aspects of fatigue crack propagation and fatigue crack initiation. Data reduction schemes involving both numerical and analytical procedures were followed. Proposed work constitutes a rigorous basis for future fatigue prediction models developments.
Fatigue limit prediction of A356-T6 cast aluminum alloys with different defect sizes sampled from an actual large-scale component
Authors: Uematsu Yoshihiko , Kakiuchi Toshifumi , Tajiri Akiko , Nakajima Masaki
Published: October 2017

Purpose

The purpose of this paper is the proposal of fatigue-life-prediction curve for cast aluminum alloy A356-T6 with different casting defect sizes.

Design/methodology/approach

Four kinds of A356-T6 fatigue specimens were sampled from the actual large-scale cast component, where the cooling rates were different. In addition, three kinds of A356 were casted under different casting conditions to simulate different defect sizes in the actual component. Subsequently, rotating bending fatigue tests were conducted using those samples. The maximum sizes of casting defects were quantitatively evaluated through microstructural observation and extreme value statistics. The fatigue limits of all samples were predicted using hardness and defect sizes based on modified Murakami’s equation.

Findings

The modified equation for fatigue limit prediction in A356-T6 was proposed. Fatigue limits were successfully predicted using the proposed equation.

Originality/value

Fatigue limit prediction method using hardness and maximum defect size was limited to steels. This paper proposed the modified method for A356-T6 aluminum alloy with lower elastic modulus. The method was valid for A356-T6 with different defect sizes.
The assessment of quality maturity levels in Nigerian university libraries
Authors: Egberongbe Halima , Sen Barbara , Willett Peter
Published: October 2017

Purpose

Organizations constantly evaluate their activities to ensure that they are attaining their management goals. Maturity assessment enables organizations to examine their capabilities, support innovation and evaluate development. The aim of this paper is to evaluate the maturity statuses of a selection of Nigerian university libraries in a study to investigate their quality management (QM) approaches. The study provides recommendations for means to attain the required statuses in academic library development.

Design/methodology/approach

The study involved a multisite case study in which interviews were conducted with 15 university librarians (or their representatives) and ten focus groups were conducted with non-management library staff. The resulting qualitative data were analyzed using an aspect of framework analysis – charting, while a maturity model from the field of project management (Prince 2 Maturity Model, P2MM) was used to assess maturity in QM of the libraries.

Findings

The results of the maturity assessment indicate a basic knowledge of the concept of QM implementation among the libraries. The scores obtained on the P2MM capability scale placed the libraries studied mainly on Level 1 (awareness level) of the model.

Practical implications

This paper demonstrates that the culture of QM in academic libraries in Nigeria is at a low level with considerable potential for development. It is suggested that future adoption of quality maturity models to assess performance and organizational effectiveness would aid improvements for value-added services.

Originality/value

This is the first study to attempt the assessment of quality maturity levels in Nigerian academic libraries for identification of the organization’s positioning in QM and strategy.
Is thymomectomy sufficient for non‐myasthenic early stage thymoma patients? A retrospective, single center experience
Authors: Rusidanmu Aizemaiti , Huang Sha , Lv Xiayi
Published: October 2017

Background

Thymic complete resection is considered the standard treatment for all thymic tumors; however, the ideal resection for non‐myasthenic early stage thymic tumors has not yet been determined. We conducted a retrospective study to examine this unique scenario.

Methods

We retrospectively analyzed the data of 118 early stage thymoma patients who underwent thymectomy (TM) or thymomectomy (TMM) with curative intent between January 2003 and December 2013 at our institution. Patients with myasthenia, thymic carcinomas, tumors with undetermined histology, and more advanced stage thymoma patients were excluded. We compared overall survival (OS) and disease‐free survival (DFS) according to the extent of thymic resection, tumor staging, and size.

Results

One hundred and eighteen patients were staged as early thymoma.TMwas performed in 43 (35.6%) patients andTMMin 75 (64.4%). Forty‐nine (65.3%) patients with a tumor ≤ 3 cm underwentTMM, and 9 (20.9%)TM. Twenty‐six (34.7%) patients with a tumor > 3 cm underwentTMM, and 34 (79.1%)TM. Seventy‐four patients were categorized as stageI: 57 (76%) underwentTMMand 17 (39.5%)TM. Forty‐four patients were categorized as stageII: 18 (24%) underwentTMMand 26 (60.5%)TM. There was no statistically significant difference in recurrence between the groups (P= 0.250).

Conclusion

No difference in the rate of recurrence was observed in early stage non‐myasthenic patients following thymic resection andMasaoka–Koga staging. However, TM is considered a better option for early stage thymoma patients with tumors > 3 cm.
Optimal Treatment Assignment to Maximize Expected Outcome with Multiple Treatments
Authors: Lou Zhilan , Shao Jun , Yu Menggang
Published: October 2017

When there is substantial heterogeneity of treatment effectiveness, it is crucial to identify individualized treatment assignment rules for comparative treatment selection. Traditional approaches directly model clinical outcome and define optimal treatment rule according to the interactions between treatment and covariates. This approach relies on the success of separating the main effects from the covariate–treatment interaction effects, which may not be easy. To overcome this shortcoming, a recent approach, called outcome weighted learning, focuses on building an optimal treatment rule by maximizing the expected clinical outcome related with differential treatments. However, there seems to be a lack of approaches to explicitly deal with three or more treatments. In this article, we propose an outcome weighted learning method that extends estimating individualized treatment rules to multi-treatment case by using a vector hinge loss as a target function. Consistency of the resulting estimator is shown in the article. We demonstrate the performance of our approach in simulation studies and in a real data analysis.
Using machine learning to disentangle homonyms in large text corpora
Authors: Roll Uri , Correia Ricardo A. , Berger‐Tal Oded
Published: October 2017

Systematic reviews are an increasingly popular decision‐making tool that provides an unbiased summary of evidence to support conservation action. These reviews bridge the gap between researchers and managers by presenting a comprehensive overview of all studies relating to a particular topic and identify specifically where and under which conditions an effect is present. However, several technical challenges can severely hinder the feasibility and applicability of systematic reviews, for example, homonyms (terms that share spelling but differ in meaning). Homonyms add noise to search results and cannot be easily identified or removed. We developed a semiautomated approach that can aid in the classification of homonyms among narratives. We used a combination of automated content analysis and artificial neural networks to quickly and accurately sift through large corpora of academic texts and classify them to distinct topics. As an example, we explored the use of the word reintroduction in academic texts. Reintroduction is used within the conservation context to indicate the release of organisms to their former native habitat; however, a Web of Science search for this word returned thousands of publications in which the term has other meanings and contexts. Using our method, we automatically classified a sample of 3000 of these publications with over 99% accuracy, relative to a manual classification. Our approach can be used easily with other homonyms and can greatly facilitate systematic reviews or similar work in which homonyms hinder the harnessing of large text corpora. Beyond homonyms we see great promise in combining automated content analysis and machine‐learning methods to handle and screen big data for relevant information in conservation science.
Association between increased small airway obstruction and asbestos exposure in patients with asbestosis
Authors: Yang Xiaoli , Yan Yongji , Xue Changjiang , Du Xuqin , Ye Qiao
Published: October 2017

Background

Asbestos exposure may cause asbestos‐related lung diseases including asbestosis, pleural abnormalities and malignancies. The role of asbestos exposure in the development of small airway obstruction remains controversial. Anatomic and physiologic small airway abnormalities may develop as part of the pathophysiologic process of asbestosis. We hypothesized that inhalation of asbestos may induce small airway defects in addition to asbestosis and pleural abnormalities.

Methods

In total, 281 patients with newly diagnosed asbestosis were evaluated. Clinical data were collected from the patients' medical charts. The patients were classified into various stages according to their chest X‐ray findings using the International Labour Organization classification. Pulmonary function was evaluated by plethysmography and the forced oscillation technique.

Results

Expiratory flow, including the predicted values of the maximum expiratory flow between 25% and 50% of the forced vital capacity (MEF25‐50), was significantly lower in the different stages of asbestosis. Accordingly, the predicted percentage ofR5–R20was significantly higher with increasing stages of asbestosis. Furthermore, the duration of exposure to asbestos was significantly associated with the forced expiratory volume in the first second (FEV1)/forced vital capacity (FVC) ratio and the predicted percentage of MEF25or MEF50according to the regression analysis in non‐smoking patients with asbestosis. The predicted percentage of FEV1or the FEV1/FVC ratio was significantly lower and the predicted percentage ofR5–R20was significantly higher in smokers than non‐smokers.

Conclusions

The patients with asbestosis have small airway obstructive defects that are significantly associated with asbestos exposure.
Immunohistochemical markers informing the diagnosis of sebaceous carcinoma and its distinction from its mimics: Adipophilin and factor XIIIa to the rescue?
Authors: Tetzlaff Michael T.
Published: October 2017

Sebaceous carcinoma typically presents a diagnostic challenge because it mimics other more common, locally invasive carcinomas, including squamous cell carcinoma and basal cell carcinoma—particularly when one of these tumors exhibits concomitant clear‐cell changes. Immunohistochemical studies offering high sensitivity and specificity are critical for accurate diagnosis.
Calciphylaxis with pseudoxanthoma elasticum‐like changes: A case series
Authors: Penn Lauren A. , Brinster Nooshin
Published: October 2017

Background

Calciphylaxis and pseudoxanthoma elasticum (PXE) are rare, clinically distinct disorders that share a common feature of cutaneous calcification and that vary widely in their cutaneous presentation.

Methods

We conducted a descriptive, retrospective review of biopsy specimens collected over a 2‐year period. Only specimens with a histologic and clinical diagnosis of calciphylaxis were included in the review. Specimens were then histologically examined for features of PXE in the dermis and/or subcutaneous fat, utilizing hematoxylin and eosin staining. Von Kossa and Verhoeff‐Van Gieson special stains were also performed to examine calcification and elastic fibers, respectively.

Results

We reviewed 13 biopsy specimens from 9 patients with known clinical and histologic evidence of calciphylaxis, both uremic and non‐uremic types. Upon re‐examination, we found that 46.2% (n = 6/13) of the specimens showed concomitant PXE‐like changes uniquely localized to the subcutaneous fat.

Conclusion

The presence of PXE‐like changes in the subcutis may heighten suspicion for a diagnosis of calciphylaxis in the appropriate clinical setting and be helpful when classic histologic features are subtle or absent.
PHYTOPLANKTON ABUNDANCE AND COMPOSITION IN THE SOUTHERN OCEAN
Authors: Schuback Nina , Thomalla Sandy J. , Antoine David
Published: October 2017

The Russian research vessel Akademik Treshnikov, circumnavigated Antarctica in the summer of 2016–2017. The authors describe some of the findings of their research on phytoplankton, and contrast their voyage with that made by J.D. Hooker in 1839–1843.
WALTER HOOD FITCH AND THE HOOKERS – THE CONTINUING TRADITION OF BOTANIST AND ARTIST COLLABORATION AT KEW GARDENS
Authors: Smith Lucy T.
Published: October 2017

The relationship between the W.H. Fitch, the botanical artist, and the Hookers, William and his son Joseph, is described. The role of the botanical artist in science and the work of some recent artists at Kew is examined.
Exploring the administrative mechanism of China's Paired Assistance to Disaster Affected Areas programme
Authors: Zhong Kaibin , Lu Xiaoli
Published: October 2017

The Paired Assistance to Disaster Affected Areas (PADAA) programme is a mutual aid initiative with Chinese characteristics, which speeded up the process of restoring and reconstructing regions affected by the Wenchuan earthquake on 12 May 2008. The PADAA is an efficient instrument for catastrophe recovery, yet it remains a mysterious mechanism to many members of disaster management communities. This paper aims to lift the veil on it by assessing its origins and evolution. It draws on the multi‐level moderated competition model to explain how the PADAA functions within the Chinese administrative system. The country's top‐down political system allows the central authority to mandate provincial and local governments from more economically developed regions to assist devastated areas with post‐disaster reconstruction. The practices of local accountability complement vertical control by giving leaders from donor regions strong incentives to accomplish assigned reconstruction tasks, resulting in intense competition between them.
Does Involved Fathering Produce a Larger Total Workload for Fathers Than for Mothers? Evidence from Norway
Authors: Kitterød Ragni Hege , Rønsen Marit
Published: October 2017

Objective

To compare mothers' and fathers' total workloads within couples with different work‐time arrangements in a social democratic welfare state (Norway) and explore possible changes in the 1990s and 2000s.

Background

Women's double workload in families with two full‐time jobs has been well documented. However, some argue that fathers, too, may experience the double burden of market and domestic work as they become more involved in parenting.

Method

The data are from the Norwegian Time Use Surveys conducted in 1990, 2000, and 2010 among representative samples of the adult population. A subsample of coupled other‐sex‐parents with at least one child younger than age 20 years were used in the present study. Total workload is the sum of paid and unpaid work activities reported in a time diary. Standard multivariate ordinary least square regressions were used to explore gender differences.

Results

Full‐time work for both parents entailed approximately equal total workloads for fathers and mothers. However, fathers' total workload exceeded mothers' in full‐time and part‐time couples with school‐aged children.

Conclusion

Despite equal total workloads and reduced specialization, mothers still do less paid work and more family work than fathers in couples where both work full‐time in Norway. This is partly related to the gender‐segregated labor market. In full‐time and part‐time couples with school‐aged children, fathers' longer working hours are not fully offset by more family work for mothers.

Implications

Work–family reconciliation policies promoting mothers' employment and fathers' family work may have the potential to reduce gender imbalances in parent's total workloads and moderate gendered specialization patterns.
Global value chains and the rise of the Global South: unpacking twenty‐first century polycentric trade
Authors: HORNER RORY , NADVI KHALID
Published: October 2017

A growing body of research points to the ‘Rise of the South’ and the growth of South–South trade. In this article, we consider the implications of the shifting dynamics of global trade and the greater prominence of Southern actors for the conceptualization of global value chains (GVCs) and global production networks (GPNs). We use trade data analysis to explore the changing geography of global trade and to highlight the emergence of more polycentric trade. We argue that our understanding of GVCs and GPNs, in a context where Southern actors and Southern end markets have more prominent roles, requires greater attention to the existence of multiple value chains (VCs) and production networks (PNs) serving different end markets – including domestic, regional and global. Consequently, there is a need to refine our understanding of both governance dynamics – lead firm strategies and standards requirements – and upgrading prospects through recognizing this shifting trade geography. We conclude by raising several new research questions regarding the conceptualization of VCs and PNs in a world where Southern actors and Southern markets are increasingly important.
Characterization of a novel HLA‐B*39:01:01‐related allele, HLA‐B*39:130, by cloning and phasing
Authors: Li L. X. , Tian W. , Zhu F. M. , Wang W. Y. , Cai J. H.
Published: October 2017

A novel HLA‐B*39:01:01‐related variant, HLA‐B*39:130, has been identified in a normal individual of Han ethnicity in Hunan province, southern China. Following Sanger polymerase chain reaction–sequence‐based typing (PCR‐SBT), this new allele was further confirmed by cloning, phasing and sequencing. Aligned with HLA‐B*39:01:01, HLA‐B*39:130 has a nonsynonymous thymine substitution at nucleotide position 94 in exon 4, resulting in amino acid change from threonine to isoleucine at codon 214 (ACA→ATA) of the mature HLA‐BmRNA molecule.
Long‐term retention of adalimumab treatment and associated prognostic factors for 1189 patients with Crohn's disease
Authors: Tanaka Hiroki , Kamata Noriko , Yamada Akihiro , Endo Katsuya , Fujii Toshimitsu , Yoshino Takuya , Sugaya Takeshi , Yokoyama Yoko , Bamba Shigeki , Umeno Junji , Yanai Yuka , Ishii Manabu , Kawaguchi Takaaki , Shinzaki Shinichiro , Toya Yosuke , Kobayashi Taku , Nojima Masanori , Hibi Toshifumi ,   The ADJUST study group
Published: October 2017

Background and Aim

There are few studies on the long‐term efficacy of adalimumab treatment for patients with Crohn's disease. We have conducted a large, multicenter, retrospective cohort study to evaluate the long‐term retention rate and prognostic factors associated with the discontinuation of adalimumab treatment in patients with Crohn's disease.

Methods

Data were collected from all patients with Crohn's disease who had received at least one induction dose of 160 mg of adalimumab between October 2010 and December 2013 at 41 institutions. The cumulative retention rates of adalimumab treatment following the first administration were estimated using the Kaplan–Meier method. Prognostic factors related to the cumulative retention rates were evaluated by log‐rank tests and multivariate Cox regression analysis.

Results

A total of 1189 patients were included in the study. The 1‐, 2‐, 3‐, and 4‐year cumulative retention rates of adalimumab were 81%, 72%, 65%, and 62%, respectively. The multivariate Cox regression analysis confirmed female sex, previous infliximab use, perianal disease, concomitant treatment with prednisolone at baseline, higher C‐reactive protein levels, and lower albumin levels as significant independent predictors of poor retention rate of adalimumab treatment. Significantly, more female patients than male patients discontinued adalimumab because of adverse events, especially skin reactions, infections, and arthralgia.

Conclusions

Our data demonstrated a good retention rate of adalimumab in patients with Crohn's disease over a 4‐year period. Female sex, perianal disease, concomitant treatment with prednisolone at baseline, previous infliximab use, higher C‐reactive protein levels, and lower albumin levels were associated with poor retention of adalimumab treatment.
Clenbuterol reduces GABAergic transmission in prefrontal cortex layer 5/6 pyramidal neurons of juvenile rat via reducing action potentials firing frequency of GABAergic interneurons
Authors: Luo F. , Zhou H.
Published: October 2017

Beta‐adrenoceptors (β2‐ARs) have beneficial effects on prefrontal cortex (PFC) working memory, however, the cellular and molecular mechanisms are unclear yet. In this study, we probed the effect of β2‐AR‐selective agonist clenbuterol (Clen) on synaptic transmission in layer 5/6 pyramidal neurons of PFC. Bath application of Clen reduced spontaneous IPSC (sIPSC) frequency without effects on sEPSCs. Clen did not alter the frequency and amplitude of miniature IPSCs (mIPSCs), but exerted heterogeneous effects on evoked IPSCs (eIPSCs) recorded from PFC layer 5/6 pyramidal neurons. Clen decreased the firing rate of action potentials of fast‐spiking GABAergic interneurons. Clen‐induced hyperpolarization of fast‐spiking GABAergic interneurons required potentiation of an inward rectifier K+ channels. Clen‐induced hyperpolarization of fast‐spiking interneurons was dependent on Gs protein rather than cAMP and protein kinase A. Our findings demonstrate that Clen (10 μM) enhances inward rectifier K+ channels via Gs protein to cause membrane hyperpolarization of fast‐spiking GABAergic interneurons resulting in reduction of action potentials firing rate to reduce GABAergic transmission.

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Tooth Color as a Predictor of Oral Health‐Related Quality of Life in Young Adults
Authors: Kovacevic Pavicic Daniela , Pavlic Andrej , Kinkela Devcic Maja , Lajnert Vlatka , Spalj Stjepan
Published: October 2017

Purpose

Smiling plays an important role in social interaction. The purpose of this research was to explore the extent to which objective parameters of color of one's own teeth affected the social and emotional dimensions of young adults’ lives.

Materials and Methods

The sample included 134 subjects—students of the University of Rijeka, Croatia (65% female) aged 19 to 28 years (median 21). All subjects had six intact maxillary anterior teeth without restorations or severe malocclusions and healthy gingiva with no signs of inflammation. Tooth color was assessed intraorally using a spectrophotometer. Lightness, chroma, and translucency of the right maxillary central incisors (the reference teeth) were calculated and used for analysis. Subjects reported dimensions of their oral health‐related quality of life (OHRQoL) using the Oral Health Impact Profile (OHIP), Orofacial Esthetic Scale (OES), and the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ). Linear relationships between elements of tooth color and OHRQoL were explored using Pearson correlations. Multiple linear regression, while controlling for the influence of age and gender, was also calculated. ANOVA with a Tukey post hoc test was employed to test whether nonlinear relationships existed between OHRQoL and categories of color elements.

Results

Dental self‐confidence, esthetic concerns, orofacial appearance, social impact and psychological impact were not related to lightness, chroma, or translucency of the subjects’ teeth. Neither linear nor nonlinear relationships were detected between those aspects. Satisfaction with smile esthetics was only related to translucency where subjects with moderate translucency were least likely to be satisfied (p = 0.033). Women tended to report greater psychosocial impacts than men (p < 0.05), regardless of their tooth color.

Conclusion

According to the results of this study objective, measurable, quantitative parameters of tooth color did not accurately predict psychosocial dimensions of OHRQoL in dentate young adults.
Geographically widespread honeybee‐gut symbiont subgroups show locally distinct antibiotic‐resistant patterns
Authors: Ludvigsen Jane , Porcellato Davide , L'Abée‐Lund Trine M. , Amdam Gro V. , Rudi Knut
Published: October 2017

How long‐term antibiotic treatment affects host bacterial associations is still largely unknown. The honeybee‐gut microbiota has a simple composition, so we used this gut community to investigate how long‐term antibiotic treatment affects host‐associated microbiota. We investigated the phylogenetic relatedness, genomic content (GC percentage, genome size, number of genes and CRISPR) and antibiotic‐resistant genes (ARG) for strains from two abundant members of the honeybee core gut microbiota (Gilliamella apicola and Snodgrassella alvi). Domesticated honeybees are subjected to geographically different management policies, so we used two research apiaries, representing different antibiotic treatment regimens in their apiculture: low antibiotic usage (Norway) and high antibiotic usage (Arizona, USA). We applied whole‐genome shotgun sequencing on 48 G. apicola and 22 S. alvi. We identified three predominating subgroups of G. apicola in honeybees from both Norway and Arizona. For G. apicola, genetic content substantially varied between subgroups and distance similarity calculations showed similarity discrepancy between subgroups. Functional differences between subgroups, such as pectin‐degrading enzymes (G. apicola), were also identified. In addition, we identified horizontal gene transfer (HGT) of transposon (Tn10)‐associated tetracycline resistance (Tet B) across the G. apicola subgroups in the Arizonan honeybees, using interspace polymorphisms in the Tet B determinant. Our results support that honeybee‐gut symbiont subgroups can resist long‐term antibiotic treatment and maintain functionality through acquisition of geographically distinct antibiotic‐resistant genes by HGT.
Know your farmer: Ancient origins and multiple independent domestications of ambrosia beetle fungal cultivars
Authors: Vanderpool Dan , Bracewell Ryan R. , McCutcheon John P.
Published: October 2017

Bark and ambrosia beetles are highly specialized weevils (Curculionidae) that have established diverse symbioses with fungi, most often from the order Ophiostomatales (Ascomycota, Sordariomycetes). The two types of beetles are distinguished by their feeding habits and intimacy of interactions with their symbiotic fungi. The tree tissue diet of bark beetles is facilitated by fungi, while ambrosia beetles feed solely on fungi that they farm. The farming life history strategy requires domestication of a fungus, which the beetles consume as their sole food source. Ambrosia beetles in the subfamily Platypodinae originated in the mid‐Cretaceous (119–88 Ma) and are the oldest known group of farming insects. However, attempts to resolve phylogenetic relationships and the timing of domestication events for fungal cultivars have been largely inconclusive. We sequenced the genomes of 12 ambrosia beetle fungal cultivars and bark beetle associates, including the devastating laurel wilt pathogen, Raffaelea lauricola, to estimate a robust phylogeny of the Ophiostomatales. We find evidence for contemporaneous diversification of the beetles and their associated fungi, followed by three independent domestication events of the ambrosia fungi genus Raffaelea. We estimate the first domestication of an Ophiostomatales fungus occurred ~86 Ma, 25 million years earlier than prior estimates and in close agreement with the estimated age of farming in the Platypodinae (96 Ma). Comparisons of the timing of fungal domestication events with the timing of beetle radiations support the hypothesis that the first large beetle radiations may have spread domesticated “ambrosia” fungi to other fungi‐associated beetle groups, perhaps facilitating the evolution of new farming lineages.
Distinct microbial communities in the active and permafrost layers on the Tibetan Plateau
Authors: Chen Yong‐Liang , Deng Ye , Ding Jin‐Zhi , Hu Hang‐Wei , Xu Tian‐Le , Li Fei , Yang Gui‐Biao , Yang Yuan‐He
Published: October 2017

Permafrost represents an important understudied genetic resource. Soil microorganisms play important roles in regulating biogeochemical cycles and maintaining ecosystem function. However, our knowledge of patterns and drivers of permafrost microbial communities is limited over broad geographic scales. Using high‐throughput Illumina sequencing, this study compared soil bacterial, archaeal and fungal communities between the active and permafrost layers on the Tibetan Plateau. Our results indicated that microbial alpha diversity was significantly higher in the active layer than in the permafrost layer with the exception of fungal Shannon–Wiener index and Simpson's diversity index, and microbial community structures were significantly different between the two layers. Our results also revealed that environmental factors such as soil fertility (soil organic carbon, dissolved organic carbon and total nitrogen contents) were the primary drivers of the beta diversity of bacterial, archaeal and fungal communities in the active layer. In contrast, environmental variables such as the mean annual precipitation and total phosphorus played dominant roles in driving the microbial beta diversity in the permafrost layer. Spatial distance was important for predicting the bacterial and archaeal beta diversity in both the active and permafrost layers, but not for fungal communities. Collectively, these results demonstrated different driving factors of microbial beta diversity between the active layer and permafrost layer, implying that the drivers of the microbial beta diversity observed in the active layer cannot be used to predict the biogeographic patterns of the microbial beta diversity in the permafrost layer.
Familial social structure and socially driven genetic differentiation in Hawaiian short‐finned pilot whales
Authors: Van Cise Amy M. , Martien Karen. K. , Mahaffy Sabre D. , Baird Robin W. , Webster Daniel L. , Fowler James H. , Oleson Erin M. , Morin Phillip A.
Published: October 2017

Social structure can have a significant impact on divergence and evolution within species, especially in the marine environment, which has few environmental boundaries to dispersal. On the other hand, genetic structure can affect social structure in many species, through an individual preference towards associating with relatives. One social species, the short‐finned pilot whale (Globicephala macrorhynchus), has been shown to live in stable social groups for periods of at least a decade. Using mitochondrial control sequences from 242 individuals and single nucleotide polymorphisms from 106 individuals, we examine population structure among geographic and social groups of short‐finned pilot whales in the Hawaiian Islands, and test for links between social and genetic structure. Our results show that there are at least two geographic populations in the Hawaiian Islands: a Main Hawaiian Islands (MHI) population and a Northwestern Hawaiian Islands/Pelagic population (FSTand ΦSTp < .001), as well as an easternMHIcommunity and a westernMHIcommunity (FSTp = .009). We find genetically driven social structure, or high relatedness among social units and clusters (p < .001), and a positive relationship between relatedness and association between individuals (p < .0001). Further, socially organized clusters are genetically distinct, indicating that social structure drives genetic divergence within the population, likely through restricted mate selection (FSTp = .05). This genetic divergence among social groups can make the species less resilient to anthropogenic or ecological disturbance. Conservation of this species therefore depends on understanding links among social structure, genetic structure and ecological variability within the species.
Divergence of species‐specific protein sex pheromone blends in two related, nonhybridizing newts (Salamandridae)
Authors: Treer Dag , Maex Margo , Van Bocxlaer Ines , Proost Paul , Bossuyt Franky
Published: October 2017

In animals that use chemical communication during courtship and reproduction, speciation is often associated with divergence of their sex pheromones. In multicomponent pheromone systems, divergence can be obtained either by adding or deleting components, or by altering the relative contribution of individual components to the mixture. Protein pheromone systems can additionally evolve by amino acid sequence divergence to produce pheromones with a species‐specific effect. The sodefrin precursor‐like factor (SPF) pheromone system, a blend of proteins that essentially enhances receptivity in salamanders, has had a long and dynamic evolution of gene duplications, but the mechanisms that govern interspecific divergence and the role they play in reproductive isolation remain elusive. Here, we use transcriptomics and proteomics to characterize the SPF protein repertoire of the alpine newt (Ichthyosaura alpestris), and compare it to the previously identified repertoire of SPF proteins of the palmate newt (Lissotriton helveticus), a related but nonhybridizing species. Subsequent phylogenetic analyses indicate that, despite the availability of multiple SPF gene copies, both species predominantly express the same subset of orthologs. Our study demonstrates that species specificity in the SPF protein pheromone system can be established by gradual sequence divergence of the same set of proteins alone.
Breakdown of a defensive symbiosis, but not endogenous defences, at elevated temperatures
Authors: Doremus Matthew R. , Smith Andrew H. , Kim Kyungsun L. , Holder Angela J. , Russell Jacob A. , Oliver Kerry M.
Published: October 2017

Environmental factors, including temperature, can have large effects on species interactions, including mutualisms and antagonisms. Most insect species are infected with heritable bacterial symbionts with many protecting their hosts from natural enemies. However, many symbionts or their products are thermally sensitive; hence, their effectiveness may vary across a range of temperatures. In the pea aphid, Acyrthosiphon pisum, the bacterial symbiont Hamiltonella defensa and its associated APSE bacteriophages confer resistance to this aphid's dominant parasitoid, Aphidius ervi. Here, we investigate the effects of temperature on both endogenous and symbiont‐based protection against this parasitoid. We also explored the defensive properties of the X‐type symbiont, a bacterium hypothesized to shape aphid defence when co‐occurring with H. defensa. We show that H. defensa protection fails at higher temperatures, although some aphid genotype and H. defensa strain combinations are more robust than others at moderately warmer temperatures. We also found that a single X‐type strain neither defended against parasitism by A. ervi nor rescued lost H. defensa protection at higher temperatures. In contrast, endogenous aphid resistance was effective across temperatures, revealing that these distinct defensive modes are not equally robust to changing environments. Through a survey of field‐collected pea aphids, we found a negative correlation between H. defensa frequencies and average daily temperatures across North American locales, fitting expectations for reduced symbiont benefits under warm climates. Based on these findings, we propose that rising global temperatures could promote the widespread breakdown of defensive mutualisms, a prospect with implications for both human and ecosystem health.
Recent insights into cotton functional genomics: progress and future perspectives
Authors: Ashraf Javaria , Zuo Dongyun , Wang Qiaolian , Malik Waqas , Zhang Youping , Abid Muhammad Ali , Cheng Hailiang , Yang Qiuhong , Song Guoli
Published: October 2017

Functional genomics has transformed from futuristic concept to well‐established scientific discipline during the last decade. Cotton functional genomics promise to enhance the understanding of fundamental plant biology to systematically exploit genetic resources for the improvement of cotton fibre quality and yield, as well as utilization of genetic information for germplasm improvement. However, determining the cotton gene functions is a much more challenging task, which has not progressed at a rapid pace. This article presents a comprehensive overview of the recent tools and resources available with the major advances in cotton functional genomics to develop elite cotton genotypes. This effort ultimately helps to filter a subset of genes that can be used to assemble a final list of candidate genes that could be employed in future novel cotton breeding programme. We argue that next stage of cotton functional genomics requires the draft genomes refinement, re‐sequencing broad diversity panels with the development of high‐throughput functional genomics tools and integrating multidisciplinary approaches in upcoming cotton improvement programmes.
Spermatic and oxidative profile of domestic cat (Felis catus) epididymal sperm subjected to different cooling times (24, 48 and 72 hours)
Authors: Angrimani DSR , Nagai KK , Rui BR , Bicudo LC , Losano JDA , Brito MM , Francischini MCP , Nichi M
Published: October 2017

Contents

Cooling stored epididymal samples for several days allows facilities to transport and process genetic material post‐mortem. Improvements to this practice allow the preservation of sperm from domestic cats, which are the ideal study model for wild felids. However, the modifications in spermatic features and the oxidative profile are not fully understood in cats. This information is necessary for the development of biotechniques, such as new extenders for cryopreservation. Therefore, the purpose of this study was to evaluate the spermatic and oxidative profile in samples from the epididymal cauda of domestic cats cooled at 5°C for 24, 48 and 72 hr. Spermatozoa were collected from the epididymis cauda. Evaluations consisted of computer‐assisted sperm analysis (CASA), plasma membrane integrity (eosin/nigrosin), acrosome integrity (fast green/rose bengal), sperm morphology, sperm DNA integrity (toluidine blue), mitochondrial activity (3′3 diaminobenzidine), activity of the antioxidant enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD), measurement of lipid peroxidation (TBARS) and protein oxidation. A decrease in sperm motility parameters was observed after 72 hr of cooling (i.e. total and progressive) with a higher percentage of minor (37.7 ± 6.3%) and total defects (53.4 ± 6.3%). Additionally, a decrease in high mitochondrial activity (Class I: 16.6 ± 2.2%) occurred after 72 hr. The decrease in motility rates after a long cooling time probably was caused by the increase in sperm abnormalities. A long cooling time causes cold shock and mitochondrial exhaustion, but there was no observed change with the oxidative stress condition. Therefore, cat epididymal sperm stored at 5°C appear to maintain a high quality for up to 48 hr of cooling time.
Identification and functional characterization of diterpene synthases for triptolide biosynthesis from Tripterygium wilfordii
Authors: Su Ping , Guan Hongyu , Zhao Yujun , Tong Yuru , Xu Meimei , Zhang Yifeng , Hu Tianyuan , Yang Jian , Cheng Qiqing , Gao Linhui , Liu Yujia , Zhou Jiawei , Peters Reuben J. , Huang Luqi , Gao Wei
Published: October 2017

Tripterygium wilfordii, which has long been used as a medicinal plant, exhibits impressive and effective anti‐inflammatory, immunosuppressive and anti‐tumor activities. The main active ingredients are diterpenoids and triterpenoids, such as triptolide and celastrol, respectively. A major challenge to harnessing these natural products is that they are found in very low amounts in planta. Access has been further limited by the lack of knowledge regarding their underlying biosynthetic pathways, particularly for the abeo‐abietane tri‐epoxide lactone triptolide. Here suspension cell cultures of T. wilfordii were found to produce triptolide in an inducible fashion, with feeding studies indicating that miltiradiene is the relevant abietane olefin precursor. Subsequently, transcriptome data were used to identify eight putative (di)terpene synthases that were then characterized for their potential involvement in triptolide biosynthesis. This included not only biochemical studies which revealed the expected presence of class II diterpene cyclases that produce the intermediate copalyl diphosphate (CPP), along with the more surprising finding of an atypical class I (di)terpene synthase that acts on CPP to produce the abietane olefin miltiradiene, but also their subcellular localization and, critically, genetic analysis. In particular, RNA interference targeting either both of the CPP synthases, TwTPS7v2 and TwTPS9v2, or the subsequently acting miltiradiene synthase, TwTPS27v2, led to decreased production of triptolide. Importantly, these results then both confirm that miltiradiene is the relevant precursor and the relevance of the identified diterpene synthases, enabling future studies of the biosynthesis of this important bioactive natural product.
MOS1 functions closely with TCP transcription factors to modulate immunity and cell cycle in Arabidopsis
Authors: Zhang Ning , Wang Zhixue , Bao Zhilong , Yang Leiyun , Wu Dianxing , Shu Xiaoli , Hua Jian
Published: October 2017

Emerging evidence indicates a close connection between cell‐cycle progression and the plant immune responses. In Arabidopsis, MODIFIER OF snc1‐1 (MOS1) modulates a number of processes including endoreduplication and plant disease resistance, but the molecular mechanism underlying this modulation was not fully understood. Here, we provide biochemical and genetic evidence that TEOSINTE BRANCHED 1, CYCLOIDEA, PCF1 (TCP) transcription factors TCP15 and its homologues are mediators of MOS1 function in the immune response and are likely to be also involved in cell‐cycle control. MOS1 and TCP proteins have a direct physical interaction. They both bind to the promoter of the immune receptor gene SUPRESSOR OF npr1‐1, CONSTITUTIVE 1 (SNC1) and modulate its expression and consequently immune responses. MOS1 and TCP15 both affect the expression of cell‐cycle genes D‐type CYCLIN 3;1 (CYCD3;1), which may mediate the MOS1 function in cell‐cycle modulation. In addition, CYCD3;1 overexpression upregulates immune responses, and SNC1 expression. This study investigated and revealed a role for MOS1 in transcriptional regulation through TCP15 and its homologues. This finding suggests the coordination of cell‐cycle progression and plant immune responses at multiple levels.
An Innovative Learning Model in Digital Age: Flipped Classroom
Authors: Çevikbaş Mustafa , Argün Ziya
Published: October 2017

The study aimed to emphasize that digital revolution has crucial influences on the field of education as in many other fields. The relevant influences have led to radical changes in terms of teaching and learning approaches approved in the field of education. The students in our age have quite different characteristics when compared to the past, and their expectations have been shaped accordingly. Hence, it is quite difficult to draw interest and curiosity of the students today to learning activities through the traditional teaching approaches. Moreover, it is not easy to overcome some problems regarding teaching and learning by obsolete approaches. In this regard, the educators today show highly much interest in the innovative teaching approaches that address the needs of this age. One of those approaches is flipped classroom model. In this study, the conceptual and historical foundations of the flipped classroom model as being one of the popular instructional models in recent years, theoretical background of the model, and the advantages and disadvantages of the model in teaching processes were highlighted. Furthermore, interpretations concerning what kind of a role flipped classroom model would play to get over some problems in the field of education were included.