Browsing by Author "Zhang S"

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    Evolutionary history of rabies in Ghana
    (Public Library of Science, 2011) Hayman DTS; Johnson N; Horton DL; Hedge J; Wakeley PR; Banyard AC; Zhang S; Alhassan A; Fooks AR
    Rabies virus (RABV) is enzootic throughout Africa, with the domestic dog (Canis familiaris) being the principal vector. Dog rabies is estimated to cause 24,000 human deaths per year in Africa, however, this estimate is still considered to be conservative. Two sub-Saharan African RABV lineages have been detected in West Africa. Lineage 2 is present throughout West Africa, whereas Africa 1a dominates in northern and eastern Africa, but has been detected in Nigeria and Gabon, and Africa 1b was previously absent from West Africa. We confirmed the presence of RABV in a cohort of 76 brain samples obtained from rabid animals in Ghana collected over an eighteen-month period (2007-2009). Phylogenetic analysis of the sequences obtained confirmed all viruses to be RABV, belonging to lineages previously detected in sub-Saharan Africa. However, unlike earlier reported studies that suggested a single lineage (Africa 2) circulates in West Africa, we identified viruses belonging to the Africa 2 lineage and both Africa 1 (a and b) sub-lineages. Phylogeographic Bayesian Markov chain Monte Carlo analysis of a 405 bp fragment of the RABV nucleoprotein gene from the 76 new sequences derived from Ghanaian animals suggest that within the Africa 2 lineage three clades co-circulate with their origins in other West African countries. Africa 1a is probably a western extension of a clade circulating in central Africa and the Africa 1b virus a probable recent introduction from eastern Africa. We also developed and tested a novel reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of RABV in African laboratories. This RT-LAMP was shown to detect both Africa 1 and 2 viruses, including its adaptation to a lateral flow device format for product visualization. These data suggest that RABV epidemiology is more complex than previously thought in West Africa and that there have been repeated introductions of RABV into Ghana. This analysis highlights the potential problems of individual developing nations implementing rabies control programmes in the absence of a regional programme.
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    Games Literacy for Teacher Education: Towards the Implementation of Game-based Learning
    (International Forum of Educational Technology & Society, 2020-04) Chen S; Zhang S; Qi GY; Yang J
    Game-based learning (GBL) has been widely recognised in research, and evidently benefited for learners. However, what GBL is perceived by teachers and learners has been a concern that might impact on quality of teaching and learning in the GBL environment. Game-based pedagogy meticulously designed from a teacher's perspective was regarded as harping on the same string without fun by learners. This paper aims to explore games literacy capabilities in supporting teachers to implement GBL that meets learners’ needs and expectations. Semi-structured interviews and surveys with experienced teachers of GBL and experts in the relevant field were conducted, followed by an Analytic Hierarchy Process seeking perceptions of a group of academics and researchers. Findings suggested five key capabilities in game literacy required by teachers in implementing GBL. They are (1) basic games literacy, (2) high-level games literacy, (3) instructional design for GBL, (4) organisation and management for GBL, and (S) evaluation of GBL. Amongst the five, instructional design for GBL and high-level games literacy were rated highly impacting on the quality of teaching. Based on the findings, aiming at informing teacher education and professional development, we proposed a framework providing a guidance to improve game-based design and pedagogical practices for teachers in the implementation of GBL in their classrooms. It concludes that teachers’ capabilities in games literacy require specific attention to instructional design – that demands a thought-provoking process for GBL.
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    Obligate mutualism within a host drives the extreme specialization of a fig wasp genome
    (BioMed Central Ltd, 20/12/2013) Xiao J-H; Yue Z; Jia L-Y; Yang X-H; Niu L-H; Wang Z; Zhang P; Sun B-F; He S-M; Li Z; Xiong T-L; Xin W; Gu H-F; Wang B; Werren JH; Murphy RW; Wheeler D; Niu L-M; Ma G-C; Tang T; Bian S-N; Wang N-X; Yang C-Y; Wang N; Fu Y-G; Li W-Z; Yi SV; Yang X-Y; Zhou Q; Lu C-X; Xu C-Y; He L-J; Yu L-L; Chen M; Zheng Y; Wang S-W; Zhao S; Li Y-H; Yu Y-Y; Qian X-J; Cai Y; Bian L-L; Zhang S; Wang J-Y; Yin Y; Xiao H; Wang G-H; Yu H; Wu W-S; Cook JM; Wang J; Huang D-W
    Background: Fig pollinating wasps form obligate symbioses with their fig hosts. This mutualism arose approximately 75 million years ago. Unlike many other intimate symbioses, which involve vertical transmission of symbionts to host offspring, female fig wasps fly great distances to transfer horizontally between hosts. In contrast, male wasps are wingless and cannot disperse. Symbionts that keep intimate contact with their hosts often show genome reduction, but it is not clear if the wide dispersal of female fig wasps will counteract this general tendency. We sequenced the genome of the fig wasp Ceratosolen solmsi to address this question. Results: The genome size of the fig wasp C. solmsi is typical of insects, but has undergone dramatic reductions of gene families involved in environmental sensing and detoxification. The streamlined chemosensory ability reflects the overwhelming importance of females finding trees of their only host species, Ficus hispida, during their fleeting adult lives. Despite long-distance dispersal, little need exists for detoxification or environmental protection because fig wasps spend nearly all of their lives inside a largely benign host. Analyses of transcriptomes in females and males at four key life stages reveal that the extreme anatomical sexual dimorphism of fig wasps may result from a strong bias in sex-differential gene expression. Conclusions: Our comparison of the C. solmsi genome with other insects provides new insights into the evolution of obligate mutualism. The draft genome of the fig wasp, and transcriptomic comparisons between both sexes at four different life stages, provide insights into the molecular basis for the extreme anatomical sexual dimorphism of this species. © 2013 Xiao et al.; licensee BioMed Central Ltd.
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    Potential rapid intraoperative cancer diagnosis using dynamic full-field optical coherence tomography and deep learning: A prospective cohort study in breast cancer patients
    (Elsevier B V on behalf of the Science China Press, 2024-06-15) Zhang S; Yang B; Yang H; Zhao J; Zhang Y; Gao Y; Monteiro O; Zhang K; Liu B; Wang S
    An intraoperative diagnosis is critical for precise cancer surgery. However, traditional intraoperative assessments based on hematoxylin and eosin (H&E) histology, such as frozen section, are time-, resource-, and labor-intensive, and involve specimen-consuming concerns. Here, we report a near-real-time automated cancer diagnosis workflow for breast cancer that combines dynamic full-field optical coherence tomography (D-FFOCT), a label-free optical imaging method, and deep learning for bedside tumor diagnosis during surgery. To classify the benign and malignant breast tissues, we conducted a prospective cohort trial. In the modeling group (n = 182), D-FFOCT images were captured from April 26 to June 20, 2018, encompassing 48 benign lesions, 114 invasive ductal carcinoma (IDC), 10 invasive lobular carcinoma, 4 ductal carcinoma in situ (DCIS), and 6 rare tumors. Deep learning model was built up and fine-tuned in 10,357 D-FFOCT patches. Subsequently, from June 22 to August 17, 2018, independent tests (n = 42) were conducted on 10 benign lesions, 29 IDC, 1 DCIS, and 2 rare tumors. The model yielded excellent performance, with an accuracy of 97.62%, sensitivity of 96.88% and specificity of 100%; only one IDC was misclassified. Meanwhile, the acquisition of the D-FFOCT images was non-destructive and did not require any tissue preparation or staining procedures. In the simulated intraoperative margin evaluation procedure, the time required for our novel workflow (approximately 3 min) was significantly shorter than that required for traditional procedures (approximately 30 min). These findings indicate that the combination of D-FFOCT and deep learning algorithms can streamline intraoperative cancer diagnosis independently of traditional pathology laboratory procedures.