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Effect of PEDOT:PSS on the performance of solution-processed blue phosphorescent organic light-emitting diodes with an exciplex host
Get PDFIn this study, efficient solution-processed organic light-emitting diodes (OLEDs) based on a light-emitting layer composed of a blue emissive phosphorescent dendrimer and exciplex host were investigated. Employing poly(styrene sulfonic acid) doped poly(ethylenedioxythiophene):poly(styrenesulfonate) (m-PEDOT:PSS) as the hole injection layer resulted in devices with external quantum efficiencies (EQEs) over 20% for luminances of up to 100 cd m−2. A feature of these devices was a relatively slow electroluminescence turn-on for the initial voltage scan, which was absent when m-PEDOT:PSS was replaced with molybdenum oxide as the hole injection layer. The initial turn-on rate was found to decrease with increasing PSSH content, with the results suggesting that proton migration from (m-)PEDOT:PSS is the cause of the change in the device performance. The overall device performance was found to be scan dependent, with sequential voltage scans leading to a decrease in EQE, which is ascribed at least in part to electromer formation. We also demonstrate solution-processed OLEDs with the same exciplex host and bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III) (FIrpic) as the emitter, that have maximum EQE and power efficiencies of 17.0% and 25.3 lm W−1, respectively
Limitations and challenges of adapting subjective keeper questionnaires to non-Western sanctuary settings
No full textIn the past decade, there has been substantial growth in the number of animal personality studies published, however relatively little work has been conducted on different species of bears. Personality structure can provide insight into individual differences in behavioural responses, and in the context of captive management, may be valuable for improving welfare through individualised monitoring and care. The goal of this study was to assess the relationship between personality and welfare in Asiatic black bears (‘moon bear’, Ursus thibetanus) and sun bears (Helarctos malayanus). In collaboration with bear behaviour specialists, we adapted existing personality, subjective well-being, and welfare surveys originally designed for other captive mammal species to be appropriate and specific for bears. Surveys were written in English and translated to Khmer, with backtranslation checked for retention of the original meaning. The surveys were delivered verbally to 16 experienced bear keepers working within a bear rescue centre in Cambodia. In total, 36 Asiatic black bears and 41 sun bears were rated. Each bear was assessed by two keepers who were familiar with the individual animal. Although this approach has been successfully used with an array of captive species, in the current study, observer agreement was found to be very low as determined by intraclass correlations of rating scores. Because of this, we were unable to determine the personality structures in these species and thus could not examine the relationship between personality and welfare. The cause of this low agreement is unclear however in this paper we discuss potential cross-cultural or logistical reasons, and suggest that future studies using questionnaires to assess animal personality, welfare, or subjective well-being may benefit from consideration of these challenges in their study design
The role of gender and employment status in MOOC learning: An exploratory study
Get PDFBackground
Learners in a given massive open online course (MOOC) are usually provided with the same learning materials, guided by the same syllabus, and assessed in the same format. This “one-size-fits-all” approach constrains learners' ability to reap the optimal benefits from online learning.
Objectives
This study aims to characterize learners' differences in MOOC learning. Specifically, it examines how learners might vary in their enrolment motivation and the development of continuance intention to learn in a MOOC because of their gender and employment status.
Methods
Data were collected via a questionnaire survey. Quantitative and qualitative methods were used to analyse data from 664 learners in a Chinese MOOC.
Results and Conclusion
The research revealed significant differences in learners' enrolment motivation across groups defined by employment status, but not for gender groups. Learner groups defined by gender and employment status experienced variant psychological processes when deciding to continue to learn in the MOOC.
Major Takeaways
Working adults stressed the instrumental values derived from MOOC learning; therefore, it is vital to design and integrate additional features into the MOOC to satisfy their needs. Besides, it would be critical to understand female learners' and working adults' expectations of MOOC learning, as they are more sensitive to confirmation in determining their attitudes toward learning in a MOOC. A short pre-course survey of learners' expectations would serve the purpose
Unpacking Public Perceptions of Effectiveness in Anti-Corruption Agencies: The Case of Hong Kong
No full textAnti-corruption agencies (ACAs) serve the important function of protecting society’s moral and legal standards. How does the public perceive their effectiveness? What variables influence these perceptions? To what extent does perceived effectiveness interact with the level of trust in a government institution? Using the Independent Commission Against Corruption (ICAC) in Hong Kong as a case and based on a disaggregated approach, this study attempts to unpack and understand public perceptions of ACA’s effectiveness in controlling corruption. It argues that the perceived effectiveness of the ICAC has two dimensions: an organizational dimension reflecting public perceptions of its structure, functions, procedures, and the integrity of personnel and an environmental dimension focusing on its ability to deal effectively with the changing social environment. The study also shows that trust may serve as a moderating variable to substitute or complement the impact of these dimensions on perceptions of institutional effectiveness. The data of this study are drawn mainly from a large-scale original survey conducted in Hong Kong in June 2019 and from official documents of the ICAC and the Hong Kong government
Genome-Wide Identification and Expression of FAR1 Gene Family Provide Insight Into Pod Development in Peanut (Arachis hypogaea)
Get PDFThe far-red-impaired response 1 (FAR1) transcription family were initially identified as important factors for phytochrome A (phyA)-mediated far-red light signaling in Arabidopsis; they play crucial roles in controlling the growth and development of plants. The reported reference genome sequences of Arachis, including A. duranensis, A. ipaensis, A. monticola, and A. hypogaea, and its related species Glycine max provide an opportunity to systematically perform a genome-wide identification of FAR1 homologous genes and investigate expression patterns of these members in peanut species. Here, a total of 650 FAR1 genes were identified from four Aarchis and its closely related species G. max. Of the studied species, A. hypogaea contained the most (246) AhFAR1 genes, which can be classified into three subgroups based on phylogenic relationships. The synonymous (Ks) and non-synonymous (Ka) substitution rates, phylogenetic relationship and synteny analysis of the FAR1 family provided deep insight into polyploidization, evolution and domestication of peanut AhFAR1 genes. The transcriptome data showed that the AhFAR1 genes exhibited distinct tissue- and stage-specific expression patterns in peanut. Three candidate genes including Ahy_A10g049543, Ahy_A06g026579, and Ahy_A10g048401, specifically expressed in peg and pod, might participate in pod development in the peanut. The quantitative real-time PCR (qRT-PCR) analyses confirmed that the three selected genes were highly and specifically expressed in the peg and pod. This study systematically analyzed gene structure, evolutionary characteristics and expression patterns of FAR1 gene family, which will provide a foundation for the study of genetic and biological function in the future
Recipients of 2021 CSSA Editor's Citation for Excellence Named
Get PDFThe editorial board of The Plant Genome is pleased to announce the recipients of the 2021 Editor's Citation for Excellence. These awards recognize the outstanding professional commitment and dedication of volunteer reviewers and/or editors who, through their excellent insights and comments, have helped maintain the high standard and quality of papers published in the journal. Recipients were nominated based on their thorough, competent, and timely reviews or editing of manuscripts. Each will receive a certificate of appreciation, an ASA-CSSA-SSSA gift certificate, and recognition in CSA News
Effect of essential oil of seven medicinal plants on longevity, nongermination, qualitative and quantitative traits of Solanum tuberosum cv. Agria
No full textThere is increasing interest in the application of natural plant extracts for the postharvest management of food crops. This study investigates the potential for hydro-distilled natural essential oils to inhibit the germination of potato tubers in storage. Four completely randomized design experiments were undertaken with extracts of seven medicinal plants [(Zataria multiflora L.), peppermint (Mentha piperita L.), fennel (Foeniculum vulgare L.), summer savory (Satureja hortensis L.), cloves (Eugenia caryophylium L.), lavender (Lavandula officinalis L.), and black cumin (Bunium persicum L.)], at four concentrations (0, 150, 300, and 450 μl/L) and three replications. Tubers were treated with essential oil vapor and then stored for 6 months at 8°C in the dark. Peppermint and fennel essential oils, at a concentration of 300 μl/L, completely inhibited tuber germination. In pregermination experiments, the dimensional and mass weight of tubers before germination increased by 18.4% and 21.11%, respectively, in the control treatment compared with the treated tubers with a concentration of 150 μl/L. However, the highest rate for the mentioned parameters in postgermination experiments was observed at a concentration of 300 μl/L fennel treatments. Peppermint and fennel essential oil with a concentration of 300 μl/L completely inhibited germination and tubers had acceptable volume, mass, dry matter, protein, and potassium. Also, the highest concentration of sugar (44.44 mg/g) occurred in tubers treated with fennel (300 μl/L), but the starch levels were lower than in tubers treated with the other essential oils. From these results, peppermint essential oil was identified as the best treatment and it is recommended for use in commercial harvests
Whole genome sequencing and molecular epidemiology of paediatric Staphylococcus aureus bacteraemia
Get PDFObjectives
The role Staphylococcus aureus antimicrobial resistance genes and toxins play in disease severity, management and outcome in childhood is an emerging field requiring further exploration.
Methods
A prospective multisite study of Australian and New Zealand children hospitalised with S. aureus bacteraemia (SAB) occurred over 24 months (2017–2018). Whole genome sequencing (WGS) data were paired with clinical information from the ISAIAH cohort.
Results
353 SAB isolates were sequenced; 85% methicillin-susceptible S. aureus ([MSSA], 301/353) and 15% methicillin-resistant S. aureus ([MRSA], 52/353). There were 92 sequence types (STs), most commonly ST5 (18%) and ST30 (8%), grouped into 23 clonal complexes (CCs), most frequently CC5 (21%) and CC30 (12%). MSSA comprised the majority of healthcare-associated SAB (87%, 109/125), with principal clones CC15 (48%, 11/21) and CC8 (33%, 7/21). Panton-Valentine leukocidin (PVL)-positive SAB occurred in 22% (76/353); predominantly MSSA (59%, 45/76), community-onset (92%, 70/76) infections. For community-onset SAB, the only microbiological independent predictor of poor outcomes was PVL positivity (aOR 2.6 [CI 1.0–6.2]).
Conclusion
From this WGS paediatric SAB data, we demonstrate the previously under-recognized role MSSA has in harbouring genetic virulence and causing healthcare-associated infections. PVL positivity was the only molecular independent predictor of poor outcomes in children. These findings underscore the need for further research to define the potential implications PVL-producing strains may have on approaches to S. aureus clinical management
Mount Merapi in drawings and paintings; A dynamic reflection of nature, 1800-1930
Get PDFMount Merapi in Central Java is one of the world’s most studied volcanoes. The frequent eruptions of this volcano and the densely populated areas on its slopes make Merapi particularly important to scholars of the natural and social sciences. Considerable attention has been devoted to contemporary aspects of this volcano, including research into forecasting and monitoring possible volcanic activity and eruptions. However, research investigating artistic representations of Merapi in a historical context, particularly local artworks referring to how people responded to a natural hazard such as a volcanic eruption, is still rare. In this paper, I explore how artists in the period 1800-1930 have portrayed the volcanic activities in their drawings and paintings. Various historical data, including newspapers, reports, and records of volcanic eruptions, will be used to help interpret the accuracy of the paintings which depict Merapi at different moments in time. I argue that artists in the period under investigation were acutely aware of Merapi’s volcanic activities and depicted these in their drawings and paintings, because of the influence of science, which invokes interest in Merapi, landscape art, and a sense of humanitarianism. Their artworks are dynamic visual historical reflections of Merapi which testify to the power and beauty of nature
Constraints, crashes and conservation: Were historical African savanna elephants Loxodonta africana densities relatively high or lower than those seen in protected areas today?
No full textAfrican savanna elephants (Loxodonta africana) are significant ecosystem engineers – having profound effects on the vegetation when at high population densities. To provide a context for modern conservation decisions it would be useful to know the ‘natural’ population densities prior to the arrival of firearms in Africa. Here, we use botanical and archaeological arguments to suggest a lower density of elephant populations than in some present protected areas over at least the last few millennia, and arguably much longer. This suggests that elephant population densities seen in some protected areas during the second half of the twentieth century are likely higher than those seen in the past and so have the potential to result in significant negative impacts on associated fauna and flora