72 research outputs found

    Phosphorylation of the alternative mRNA splicing factor 45 (SPF45) by Clk1 regulates its splice site utilization, cell migration and invasion

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    Alternative mRNA splicing is a mechanism to regulate protein isoform expression and is regulated by alternative splicing factors. The alternative splicing factor 45 (SPF45) is overexpressed in cancer, although few biological effects of SPF45 are known, and few splicing targets have been identified. We previously showed that Extracellular Regulated Kinase 2 (ERK2) phosphorylation of SPF45 regulates cell proliferation and adhesion to fibronectin. In this work, we show that Cdc2-like kinase 1 (Clk1) phosphorylates SPF45 on eight serine residues. Clk1 expression enhanced, whereas Clk1 inhibition reduced, SPF45-induced exon 6 exclusion from Fas mRNA. Mutational analysis of the Clk1 phosphorylation sites on SPF45 showed both positive and negative regulation of splicing, with a net effect of inhibiting SPF45-induced exon 6 exclusion, correlating with reduced Fas mRNA binding. However, Clk1 enhanced SPF45 protein expression, but not mRNA expression, whereas inhibition of Clk1 increased SPF45 degradation through a proteasome-dependent pathway. Overexpression of SPF45 or a phospho-mimetic mutant, but not a phospho-inhibitory mutant, stimulated ovarian cancer cell migration and invasion, correlating with increased fibronectin expression, ERK activation and enhanced splicing and phosphorylation of full-length cortactin. Our results demonstrate for the first time that SPF45 overexpression enhances cell migration and invasion, dependent on biochemical regulation by Clk1

    Students’ perception towards behavioral intention of audio and video teaching styles : an acceptance study

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    Recently audio and video material has been used significantly in various online platforms. The audio-video materials enhance the teaching and learning process by facilitating the transformation of the data and providing a richer interactive environment, hence gaining wide intention within the educational realm. However, empirical studies have not examined the acceptance of the audio and video material depending on a conceptual model where acceptance is the key factor. The present study attempts to overcome this gap in the literature review by investigating the effects of media richness, speed and vividness, perceived concentration, perceived ease of use, perceived usefulness on the acceptance of audio-video material. What distinguishes the current study is the fact that content richness is considered as a mediator that affects all other factors in the conceptual model. The data is collected by distributing the online survey to college students. The results provide mostly insight and support for students’ intention to use audio-visual resources in a conceptual model. The technology characteristics of speed and vividness as well as TAM constructs were significant predictors of technology acceptance. However, it is concluded that the external factor of the perceived concentration has no impact on the students’ perception and intention to use audio-visual resources. In the recommendation, some theoretical and practical implications are stated along with the focus on technology designers, change managers, and users

    Binding energies of ground and isomeric states in neutron-rich ruthenium isotopes: measurements at JYFLTRAP and comparison to theory

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    We report on precision mass measurements of 113,115,117^{113,115,117}Ru performed with the JYFLTRAP double Penning trap mass spectrometer at the Accelerator Laboratory of University of Jyv\"askyl\"a. The phase-imaging ion-cyclotron-resonance technique was used to resolve the ground and isomeric states in 113,115^{113,115}Ru and enabled for the first time a measurement of the isomer excitation energies, Ex(113E_x(^{113}Rum)=100.5(8)^{m})=100.5(8) keV and Ex(115E_x(^{115}Rum)=129(5)^{m})=129(5) keV. The ground state of 117^{117}Ru was measured using the time-of-flight ion-cyclotron-resonance technique. The new mass-excess value for 117^{117}Ru is around 36 keV lower and 7 times more precise than the previous literature value. With the more precise ground-state mass values, the evolution of the two-neutron separation energies is further constrained and a similar trend as predicted by the BSkG1 model is obtained up to the neutron number N=71N=71.Comment: 12 pages, 9 figures, submitted to Physical Review

    The effectiveness of online platforms after the pandemic : will face-to-face classes affect students’ perception of their Behavioural Intention (BIU) to use online platforms?

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    The purpose of this study is to investigate students’ intention to continue using online learning platforms during face-to-face traditional classes in a way that is parallel to their usage during online virtual classes (during the pandemic). This investigation of students’ intention is based on a conceptual model that uses newly used external factors in addition to the technology acceptance model (TAM) contrasts; hence, it takes into consideration users’ satisfaction, the external factor of information richness (IR) and the quality of the educational system and information disseminated. The participants were 768 university students who have experienced the teaching environments of both traditional face-to-face classes and online classes during the pandemic. A structural equation modelling (SEM) test was conducted to analyse the independent variables, including the users’ situation awareness (SA), perceived ease of use, perceived usefulness, satisfaction, IR, education system quality and information quality. An online questionnaire was used to explore students’ perceptions of their intention to use online platforms accessibly in a face-to-face learning environment. The results showed that (a) students prefer online platforms that have a higher level of content richness, to be able to implement the three dimensions of users’ situation awareness (perception, comprehension and projection); (b) there were significant effects of TAM constructs on students’ satisfaction and acceptance; (c) students are in favour of using a learning platform that is characterised by a high level of educational system quality and information quality and (d) students with a higher level of satisfaction have a more positive attitude in their willingness to use the online learning system

    High-precision measurements of low-lying isomeric states in 120−124^{120-124}In with JYFLTRAP double Penning trap

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    Neutron-rich 120−124^{120-124}In isotopes have been studied utilizing the double Penning trap mass spectrometer JYFLTRAP at the IGISOL facility. Using the phase-imaging ion-cyclotron-resonance technique, the isomeric states were resolved from ground states and their excitation energies measured with high precision in 121,123,124^{121,123,124}In. In 120,122^{120,122}In, the 1+1^+ states were separated and their masses were measured while the energy difference between the unresolved 5+5^+ and 8−8^- states, whose presence was confirmed by post-trap decay spectroscopy was determined to be ≀15\leq15 keV. In addition, the half-life of 122^{122}Cd, T1/2=5.98(10)T_{1/2} = 5.98(10) s, was extracted. Experimental results were compared with energy density functionals, density functional theory and shell-model calculations.Comment: 11 pages, 7 figure

    First investigation on the isomeric ratio in multinucleon transfer reactions: Entrance channel effects on the spin distribution

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    The multinucleon transfer (MNT) reaction approach was successfully employed for the first time to measure the isomeric ratios (IRs) of 211^{211}Po (25/2+^+) isomer and its (9/2+^+) ground state at the IGISOL facility using a 945 MeV 136^{136}Xe beam impinged on 209^{209}Bi and nat^{\rm nat}Pb targets. The dominant production of isomers compared to the corresponding ground states was consistently revealed in the α\alpha-decay spectra. Deduced IR of 211^{211}Po populated through the 136^{136}Xe+nat^{\rm nat}Pb reaction was found to enhance ≈\approx1.8-times than observed for 136^{136}Xe+209^{209}Bi. State-of-the-art Langevin-type model calculations have been utilized to estimate the spin distribution of an MNT residue. The computations qualitatively corroborate with the considerable increase in IRs of 211^{211}Po produced from 136^{136}Xe+nat^{\rm nat}Pb compared to 136^{136}Xe+209^{209}Bi. Theoretical investigations indicate a weak influence of target spin on IRs. The enhancement of the 211^{211}Po isomer in the 136^{136}Xe+nat^{\rm nat}Pb over 136^{136}Xe+209^{209}Bi can be attributed to the different proton (pp)-transfer production routes. Estimations demonstrate an increment in the angular momentum transfer, favorable for isomer production, with increasing projectile energy. Comparative analysis indicates the two entrance channel parameters, projectile mass and pp-transfer channels, strongly influencing the population of the high-spin isomer of 211^{211}Po (25/2+^+). This is the first experimental and theoretical investigation on the IRs of nuclei produced via different channels of MNT reactions, with the latter quantitatively underestimating the former by a factor of two.Comment: 5 figure

    Nuclear charge radius of 26m^{26m}Al and its implication for Vud_{ud} in the quark-mixing matrix

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    Collinear laser spectroscopy was performed on the isomer of the aluminium isotope 26m^{26m}Al. The measured isotope shift to 27^{27}Al in the 3s^{2}3p\;^{2}\!P^\circ_{3/2} \rightarrow 3s^{2}4s\;^{2}\!S_{1/2} atomic transition enabled the first experimental determination of the nuclear charge radius of 26m^{26m}Al, resulting in RcR_c=\qty{3.130\pm.015}{\femto\meter}. This differs by 4.5 standard deviations from the extrapolated value used to calculate the isospin-symmetry breaking corrections in the superallowed ÎČ\beta decay of 26m^{26m}Al. Its corrected Ft\mathcal{F}t value, important for the estimation of VudV_{ud} in the CKM matrix, is thus shifted by one standard deviation to \qty{3071.4\pm1.0}{\second}.Comment: 5 pages, 2 figures, submitted to Phys. Rev. Let

    Racial Disparity in Utilization of High-Volume Hospitals for Surgical Treatment of Esophageal Cancer

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    © 2018 The Society of Thoracic Surgeons Background: Utilization of high-volume hospitals (HVH) for esophagectomy has been associated with improved perioperative outcomes and reduced mortality. We aimed to test the hypothesis that black-white racial disparities exist in HVH utilization and identify predictors of in-hospital surgical outcomes of esophageal cancer while adjusting for HVH utilization patterns. Methods: We queried the New York Statewide Planning and Research Cooperative System database (1995 to 2012) for esophageal cancer patients who underwent surgical resection exclusively. Only records for patients with self-reported white or black race and a valid New York State ZIP code were included (n = 2,895). Analysis was performed to identify factors associated with HVH hospital (≄20 esophagectomies/year) utilization and determine predictors of complications and in-hospital mortality. Results: Black patients (361 [12.5%]) were significantly different (p \u3c 0.001) than their white counterparts in the proportion of women, Medicaid, income distribution, and privately insured individuals. Although 55% patients overall utilized an HVH, blacks were significantly less likely to utilize an HVH than whites (odds ratio [OR], 0.18; 95% confidence interval [CI], 0.14 to 0.24), even though 74.5% resided within 8.9 miles of one. Operations performed at HVHs were associated with lower in-hospital mortality (OR, 0.48; 95% CI, 0.35 to 0.65); however, mortality remained higher for blacks (OR, 2.04; 95% CI, 1.65 to 3.30; propensity matched OR, 2.45; 95% CI, 1.5 to 4.03). Conclusions: Black patients were less likely to undergo esophagectomy at an HVH and experienced higher mortality. Efforts should be made to understand factors influencing patients’ decision process and improve referral practices to ensure optimal care is provided across all segments of the population, irrespective of race, insurance, or income status
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