92 research outputs found
Constructing a Stochastic Model of Bumblebee Flights from Experimental Data
No full textPMCID: PMC3592844This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
An Investigation into Factors Affecting Concentration of University Students
No full textConcentration is one of the most influential decisive factors in student’s learning quality. The higher the student\u27s level is, the less concentration they pay in class, especially university students. Owing to this low level of concentration ability, many lecturers find it hard to maintain their enthusiasm when teaching students from this level, and also those students find it hard to achieve the best outcome when graduating from university. For that reason, this article will provide an understanding of all the distractions that undergraduate students may have during their class. Also, the roles of a teacher will be put into a discussion so that readers as teachers from all levels can have a better and deeper look into this academic job, with the hope that they may find it useful for any of their changes later if they think it is necessary so that their learners can have better experiment with them in class. And after all the analysis, this article will suggest some good and applicable solutions that can be applied to improve the situation. Hopefully, this would advance the teaching and learning quality in the university environment
Functionals of exponential Brownian motion and divided differences
No full textWe provide a surprising new application of classical approximation theory to a fundamental asset-pricing model of mathematical finance. Specifically, we calculate an analytic value for the correlation coefficient between
exponential Brownian motion and its time average, and we find the use of divided differences greatly elucidates formulae, providing a path to several new results. As applications, we find that this correlation coefficient is always at least 1/p2 and, via the Hermite–Genocchi integral relation, demonstrate that all moments of the time average are certain divided differences of the exponential function. We also prove that these moments agree with the somewhat more complex formulae obtained by Oshanin and Yor
Study on parental involvement in Vietnamese primary students’ learning: insights from the era of educational reform
Get PDFIn light of Vietnam’s recent educational reforms emphasizing competency-based learning, this research explores how Vietnamese parents engage in their children’s education and the relationship between this involvement and students’ academic performance. Employing both quantitative (surveys) and qualitative (interviews) methods, the study focuses on three critical aspects of parenting and the family environment, based on Epstein’s theory: communication between parents and teachers, volunteering, and collaboration with the community. Quantitative data, analyzed using SPSS software, revealed the frequency of parental involvement activities, providing a comprehensive picture of both common and less frequent activities. Pearson correlation results confirmed a positive relationship between active parental involvement and student performance. The qualitative findings further highlight the challenges parents face when engaging in their children’s education and offer suggestions for improving parental participation. Overall, the paper provides valuable insights into the dynamics of parental involvement in Vietnamese schools and proposes practical, contextually appropriate solutions to enhance educational quality by strengthening cooperation between schools and parents
Changes in total phenol, flavonoid contents and anti-Lactobacillus activity of Callisia fragrans due to extraction solvent
No full textContrast-enhanced CMR in patients after percutaneous closure of the left atrial appendage: A pilot study
Get PDFAbstract Background To evaluate the feasibility and value of first-pass contrast-enhanced dynamic and post-contrast 3D CMR in patients after transcatheter occlusion of left atrial appendage (LAA) to identify incorrect placement and persistent leaks. Methods 7 patients with different occluder systems (n = 4 PLAATO; n = 2 Watchman; n = 1 ACP) underwent 2 contrast-enhanced (Gd-DOTA) CMR sequences (2D TrueFISP first-pass perfusion and 3D-TurboFLASH) to assess localization, artifact size and potential leaks of the devices. Perfusion CMR was analyzed visually and semi-quantitatively to identify potential leaks. Results All occluders were positioned within the LAA. The ACP occluder presented the most extensive artifact size. Visual assessment revealed a residual perfusion of the LAA apex in 4 cases using first-pass perfusion and 3D-TurboFLASH indicating a suboptimal LAA occlusion. By assessing signal-to-time-curves the cases with a visually detected leak showed a 9-fold higher signal-peak in the LAA apex (567 ± 120% increase from baseline signal) than those without a leak (61 ± 22%; p Conclusion This CMR pilot study provides valuable non-invasive information in patients after transcatheter occlusion of the LAA to identify correct placement and potential leaks. We recommend incorporating CMR in future clinical studies to evaluate new device types.</p
New ophthalmosaurid ichthyosaurs from the European lower cretaceous demonstrate extensive ichthyosaur survival across the Jurassic–Cretaceous boundary
Get PDFBackground
Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood.
Methodology/Principal Findings
Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval.
Conclusions/Significance
There is currently no evidence that ichthyosaurs were affected by the JCB extinction event, in contrast to many other marine groups. Ophthalmosaurid ichthyosaurs remained diverse from their rapid radiation in the Middle Jurassic to their total extinction at the beginning of the Late Cretaceous
Colorectal Neoplasms in Young Vietnamese Individuals with First-degree Relatives Diagnosed with Colorectal Cancer
Get PDFObjective: Colorectal cancer (CRC) is increasingly prevalent, particularly among individuals with first-degree relatives (FDRs) diagnosed with CRC. Delayed colonoscopy beyond the recommended age increases the risk of advanced neoplasia and late-stage CRC. This study aims to characterize colorectal neoplasms in adults under 50 years of age with an FDR history of CRC.
Materials and Methods: A cross-sectional study was conducted on outpatients aged 18–49 years with an FDR history of CRC who presented with lower gastrointestinal symptoms and underwent colonoscopy at a tertiary hospital in Vietnam. All endoscopic lesions suspected of colorectal neoplasia were removed and subsequently reviewed for histopathological examination.
Results: Among 76 patients with FDRs diagnosed with CRC, the mean age was 40.2 ± 6.5 years, with a male-tofemale ratio of 1:1.3. A total of 27 neoplastic lesions were identified in 20 patients, including 22 adenomas (81.5%), 3 sessile serrated lesions (11.1%), and 2 adenocarcinomas (7.4%). Overall, colorectal neoplasms were detected in 26.3% (20/76) of patients, with advanced colorectal neoplasia accounting for 9.2% (7/76), including 2.6% (2/76) adenocarcinomas. The incidence of advanced colorectal neoplasms was higher but not significantly different in the delayed colonoscopy group than in the screening group in terms of adherence to the guidelines (11.8% vs. 4%, p = 0.41).
Conclusion: The prevalence of colorectal neoplasms in young Vietnamese individuals with an FDR history of CRC is significantly high
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