72 research outputs found
Phosphorylation of the alternative mRNA splicing factor 45 (SPF45) by Clk1 regulates its splice site utilization, cell migration and invasion
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
Studentsâ perception towards behavioral intention of audio and video teaching styles : an acceptance study
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 studentsâ 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 studentsâ 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
We report on precision mass measurements of 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 Ru and enabled for the first time a measurement of the
isomer excitation energies, Ru keV and
Ru keV. The ground state of Ru was measured
using the time-of-flight ion-cyclotron-resonance technique. The new mass-excess
value for 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 .Comment: 12 pages, 9 figures, submitted to Physical Review
The effectiveness of online platforms after the pandemic : will face-to-face classes affect studentsâ perception of their Behavioural Intention (BIU) to use online platforms?
The purpose of this study is to investigate studentsâ 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 studentsâ 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 usersâ 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 usersâ situation awareness (SA), perceived ease of use, perceived usefulness, satisfaction, IR, education system quality and information quality. An online questionnaire was used to explore studentsâ 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 usersâ situation awareness (perception, comprehension and projection); (b) there were significant effects of TAM constructs on studentsâ 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 In with JYFLTRAP double Penning trap
Neutron-rich 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 In. In In, the states were
separated and their masses were measured while the energy difference between
the unresolved and states, whose presence was confirmed by
post-trap decay spectroscopy was determined to be keV. In addition,
the half-life of Cd, 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
The multinucleon transfer (MNT) reaction approach was successfully employed
for the first time to measure the isomeric ratios (IRs) of Po
(25/2) isomer and its (9/2) ground state at the IGISOL facility using a
945 MeV Xe beam impinged on Bi and Pb targets. The
dominant production of isomers compared to the corresponding ground states was
consistently revealed in the -decay spectra. Deduced IR of Po
populated through the Xe+Pb reaction was found to enhance
1.8-times than observed for Xe+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 Po produced from Xe+Pb compared to Xe+Bi. Theoretical investigations indicate
a weak influence of target spin on IRs. The enhancement of the Po
isomer in the Xe+Pb over Xe+Bi can be
attributed to the different proton ()-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
-transfer channels, strongly influencing the population of the high-spin
isomer of 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 Al and its implication for V in the quark-mixing matrix
Collinear laser spectroscopy was performed on the isomer of the aluminium
isotope Al. The measured isotope shift to 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 Al, resulting in =\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
decay of Al. Its corrected value, important for the
estimation of 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
© 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 (â„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 patientsâ 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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