107 research outputs found
PERCEIVED CHALLENGES AND SATISFACTION OF EDUCATION STUDENTS IN ONLINE DISTANCE LEARNING
The study aimed to determine the perceived challenges and satisfaction levels of Bachelor of Elementary Education in online distance learning. The descriptive-correlational design was used in this study. The investigations were conducted at Notre Dame of Midsayap College on fifty (50) BEED students who are enrolled in online distance learning for School Year 2021-2022 and the majority of them were female students. A researcher-modified survey questionnaire was used in data gathering, Frequency and percentage distribution, mean and standard deviation, t-test and ANOVA, and Pearson-r correlation were used in treating the data. The study revealed that the students have challenges in online distance learning. The study found out that the highest challenges encountered by the students in online distance learning are slow internet connection due to their location and facing many interruptions when learning at home such as household chores and other errands. The students are highly satisfied with how teachers showed interest in helping students to learn and the teacher’s accessibility and availability. Moreover, the respondents are least satisfied with how timely teachers give feedback on their performance. The study also revealed that there was a significant difference in the satisfaction level of the students in terms of their sex. Article visualizations
CLEAR: Spatially Resolved Emission Lines and Active Galactic Nuclei at
We investigate spatially-resolved emission-line ratios in a sample of 219
galaxies () detected using the G102 grism on the \emph{Hubble Space
Telescope} Wide Field Camera 3, taken as part of the CANDELS Ly
Emission at Reionization (CLEAR) survey, to measure ionization profiles and
search for low-luminosity active galactic nuclei (AGN). We analyze \OIII\ and
\Hb\ emission-line maps, enabling us to spatially resolve the \OIIIHb\
emission-line ratio across the galaxies in the sample. We compare the \OIIIHb\
ratio in galaxy centers and outer annular regions to measure ionization
gradients and investigate the potential of sources with nuclear ionization to
host AGN. We investigate some of the individual galaxies that are candidates to
host strong nuclear ionization and find that they often have low stellar mass
and are undetected in X-rays, as expected for low-luminosity AGN in low-mass
galaxies. We do not find evidence for a significant population of off-nuclear
AGN or other clumps of off-nuclear ionization. We model the observed
distribution of \OIIIHb\ gradients and find that most galaxies are consistent
with small or zero gradients, but 6-16\% of galaxies in the sample are likely
to host nuclear \OIIIHb\ that is 0.5~dex higher than in their outer
regions. This study is limited by large uncertainties in most of the measured
\OIIIHb\ spatial profiles, therefore deeper data, e.g, from deeper
\textit{HST}/WFC3 programs or from \textit{JWST}/NIRISS, are needed to more
reliably measure the spatially resolved emission-line conditions of individual
high-redshift galaxies.Comment: 16 pages, 13 figures, 2 table
Maximizing CRISPR/Cas9 phenotype penetrance applying predictive modeling of editing outcomes in Xenopus and zebrafish embryos
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Naert, T., Tulkens, D., Edwards, N. A., Carron, M., Shaidani, N. I., Wlizla, M., Boel, A., Demuynck, S., Horb, M. E., Coucke, P., Willaert, A., Zorn, A. M., & Vleminckx, K. Maximizing CRISPR/Cas9 phenotype penetrance applying predictive modeling of editing outcomes in Xenopus and zebrafish embryos. Scientific Reports, 10(1), (2020): 14662, doi:10.1038/s41598-020-71412-0.CRISPR/Cas9 genome editing has revolutionized functional genomics in vertebrates. However, CRISPR/Cas9 edited F0 animals too often demonstrate variable phenotypic penetrance due to the mosaic nature of editing outcomes after double strand break (DSB) repair. Even with high efficiency levels of genome editing, phenotypes may be obscured by proportional presence of in-frame mutations that still produce functional protein. Recently, studies in cell culture systems have shown that the nature of CRISPR/Cas9-mediated mutations can be dependent on local sequence context and can be predicted by computational methods. Here, we demonstrate that similar approaches can be used to forecast CRISPR/Cas9 gene editing outcomes in Xenopus tropicalis, Xenopus laevis, and zebrafish. We show that a publicly available neural network previously trained in mouse embryonic stem cell cultures (InDelphi-mESC) is able to accurately predict CRISPR/Cas9 gene editing outcomes in early vertebrate embryos. Our observations can have direct implications for experiment design, allowing the selection of guide RNAs with predicted repair outcome signatures enriched towards frameshift mutations, allowing maximization of CRISPR/Cas9 phenotype penetrance in the F0 generation.Research in the Vleminckx laboratory is supported by the Research Foundation—Flanders (FWO-Vlaanderen) (Grants G0A1515N and G029413N), by the Belgian Science Policy (Interuniversity Attraction Poles—IAP7/07) and by the Concerted Research Actions from Ghent University (BOF15/GOA/011). Further support was obtained by the Hercules Foundation, Flanders (Grant AUGE/11/14) and the Desmoid Tumor Research Foundation and the Desmoid Tumour Foundation Canada. T.N. is funded by “Kom op tegen Kanker” (Stand up to Cancer), the Flemish cancer society and previously held PhD fellowship with VLAIO-HERMES during the course of this work. D.T. and M. C. hold a PhD fellowship from the Research Foundation-Flanders (FWO-Vlaanderen). The Zorn Lab is supported by Funding from NIH National Institute of Child Health and Human Development (NICHD) P01 HD093363. A.W. and A.B. are supported by the Ghent University (Universiteit Gent) Methusalem grant BOFMET2015000401 to Anne De Paepe. The National Xenopus Resource and Horb lab is supported by funding from the National Institutes of Health (P40 OD010997 and R01 HD084409)
CLEAR: The Gas-Phase Metallicity Gradients of Star-Forming Galaxies at 0.6 < z < 2.6
We report on the gas-phase metallicity gradients of a sample of 264
star-forming galaxies at 0.6 < z < 2.6, measured through deep near-infrared
Hubble Space Telescope slitless spectroscopy. The observations include 12-orbit
depth Hubble/WFC3 G102 grism spectra taken as a part of the CANDELS Lya
Emission at Reionization (CLEAR) survey, and archival WFC3 G102+G141 grism
spectra overlapping the CLEAR footprint. The majority of galaxies (84%) in this
sample are consistent with a zero or slightly positive metallicity gradient
across the full mass range probed (8.5 < log M_*/M_sun < 10.5). We measure the
intrinsic population scatter of the metallicity gradients, and show that it
increases with decreasing stellar mass---consistent with previous reports in
the literature, but confirmed here with a much larger sample. To understand the
physical mechanisms governing this scatter, we search for correlations between
the observed gradient and various stellar population properties at fixed mass.
However, we find no evidence for a correlation with the galaxy properties we
consider---including star-formation rates, sizes, star-formation rate surface
densities, and star-formation rates per gravitational potential energy. We use
the observed weakness of these correlations to provide material constraints for
predicted intrinsic correlations from theoretical models.Comment: 19 pages, 10 figures (v2: typo fixed in Figure 10 label); submitted
to Ap
CLEAR: Paschen- Star Formation Rates and Dust Attenuation of Low Redshift Galaxies
We use \Pab\ (1282~nm) observations from the Hubble Space Telescope (\HST)
G141 grism to study the star-formation and dust attenuation properties of a
sample of 29 low-redshift () galaxies in the CANDELS Ly
Emission at Reionization (CLEAR) survey. We first compare the nebular
attenuation from \Pab/\Ha with the stellar attenuation inferred from the
spectral energy distribution, finding that the galaxies in our sample are
consistent with an average ratio of the continuum attenuation to the nebular
gas of 0.44, but with a large amount of excess scatter beyond the observational
uncertainties. Much of this scatter is linked to a large variation between the
nebular dust attenuation as measured by (space-based) \Pab to (ground-based)
\Ha to that from (ground-based) \Ha/\Hb. This implies there are important
differences between attenuation measured from grism-based / wide-aperture
\Pab fluxes and the ground-based / slit-measured Balmer decrement. We next
compare star-formation rates (SFRs) from \Pab to those from dust-corrected
UV. We perform a survival analysis to infer a census of \Pab\ emission implied
by both detections and non-detections. We find evidence that galaxies with
lower stellar mass have more scatter in their ratio of \Pab\ to
attenuation-corrected UV SFRs. When considering our \Pab\ detection limits,
this observation supports the idea that lower mass galaxies experience
"burstier" star-formation histories. Together, these results show that \Pab\ is
a valuable tracer of a galaxy's SFR, probing different timescales of
star-formation and potentially revealing star-formation that is otherwise
missed by UV and optical tracers.Comment: 19 pages, 14 figures, 2 table
CLEAR: High-Ionization [Ne V] 3426 Emission-line Galaxies at
We analyze a sample of 25 [Ne V] 3426 emission-line galaxies at
using Hubble Space Telescope/Wide Field Camera 3 G102 and G141
grism observations from the CANDELS Lyman- Emission at Reionization
(CLEAR) survey. [Ne V] emission probes extremely energetic photoionization
(97.11-126.21 eV), and is often attributed to energetic radiation from active
galactic nuclei (AGN), shocks from supernova, or an otherwise very hard
ionizing spectrum from the stellar continuum. In this work, we use [Ne V] in
conjunction with other rest-frame UV/optical emission lines ([O II]
3726,3729, [Ne III] 3869, H, [O III]
4959,5007, H+[N II] 6548,6583, [S II]
6716,6731), deep (2--7 Ms) X-ray observations (from Chandra),
and mid-infrared imaging (from Spitzer) to study the origin of this emission
and to place constraints on the nature of the ionizing engine. The majority of
the [Ne V]-detected galaxies have properties consistent with ionization from
AGN. However, for our [Ne V]-selected sample, the X-ray luminosities are
consistent with local () X-ray-selected Seyferts, but the [Ne V]
luminosities are more consistent with those from X-ray-selected QSOs.
The excess [Ne V] emission requires either reduced hard X-rays, or a 0.1
keV excess. We discuss possible origins of the apparent [Ne V] excess, which
could be related to the ``soft (X-ray) excess'' observed in some QSOs and
Seyferts, and/or be a consequence of a complex/anisotropic geometry for the
narrow line region, combined with absorption from a warm, relativistic wind
ejected from the accretion disk. We also consider implications for future
studies of extreme high-ionization systems in the epoch of reionization () with JWST.Comment: 17 pages + 5 (appendix), 7 figures + 2(appendix
Using [Ne V]/[Ne III] to Understand the Nature of Extreme-Ionization Galaxies
Spectroscopic studies of extreme-ionization galaxies (EIGs) are critical to
our understanding of exotic systems throughout cosmic time. These EIGs exhibit
spectral features requiring >54.42 eV photons: the energy needed to fully
ionize helium into He2+ and emit He II recombination lines. They are likely key
contributors to reionization, and they can also probe exotic stellar
populations or accretion onto massive black holes. To facilitate the use of
EIGs as probes of high ionization, we focus on ratios constructed from strong
rest-frame UV/optical emission lines, specifically [O III] 5008, H-beta, [Ne
III] 3870, [O II] 3727,3729, and [Ne V] 3427. These lines probe the relative
intensity at energies of 35.12, 13.62, 40.96, 13.62 eV, and 97.12,
respectively, covering a wider range of ionization than traced by other common
rest-frame UV/optical techniques. We use ratios of these lines ([Ne V]/[Ne III]
= Ne53 and [Ne III]/[O II]), which are closely separated in wavelength, and
mitigates effects of dust attenuation and uncertainties in flux calibration. We
make predictions from photoionization models constructed from Cloudy that use a
broad range of stellar populations and black hole accretion models to explore
the sensitivity of these line ratios to changes in the ionizing spectrum. We
compare our models to observations from the Hubble Space Telescope and James
Webb Space Telescope of galaxies with strong high-ionization emission lines at
z ~ 0, z ~ 2, and z ~ 7. We show that the Ne53 ratio can separate galaxies with
ionization from 'normal' stellar populations from those with AGN and even
'exotic' Population III models. We introduce new selection methods to identify
galaxies with photoionization driven by Population III stars or
intermediate-mass black hole accretion disks that could be identified in
upcoming high-redshift spectroscopic surveys.Comment: 16 pages, 5 figures, 1 table. Accepted in Ap
α-Arrestins Aly1 and Aly2 Regulate Intracellular Trafficking in Response to Nutrient Signaling
Arrestins, known regulators of endocytosis, take on novel functions in nutrient-regulated endosomal recycling. Yeast α-arrestins, Aly1 and Aly2, redistribute the Gap1 permease from endosomes to the cell surface and interact with clathrin/AP-1. Aly2 is regulated by the Npr1 kinase and acts through mechanisms distinct from Aly1
NGDEEP Epoch 1: Spatially Resolved H Observations of Disk and Bulge Growth in Star-Forming Galaxies at 0.6-2.2 from JWST NIRISS Slitless Spectroscopy
We study the H equivalent width, EW(H), maps of 19 galaxies
at in the Hubble Ultra Deep Field (HUDF) derived from NIRISS
slitless spectroscopy as part of the Next Generation Deep Extragalactic
Exploratory Public (NGDEEP) Survey. Our galaxies mostly lie on the
star-formation main sequence with a stellar mass range of , and are therefore characteristic of "typical" star-forming
galaxies at these redshifts. Leveraging deep HST and JWST broad-band images,
spanning 0.4-4 m, we perform spatially-resolved fitting of the spectral
energy distributions (SEDs) for these galaxies and construct specific star
formation rate (sSFR) and stellar-mass-weighted age maps. We compare these to
the EW(H) maps with a spatial resolution of 1 kpc. The
pixel-to-pixel EW(H) increases with increasing sSFR and with decreasing
age, with the average trend slightly different from the relations derived from
integrated fluxes of galaxies from the literature. Quantifying the radial
profiles of EW(H), sSFR, and age, the majority (84%) of galaxies show
positive EW(H) gradients, positive sSFR gradients, and negative age
gradients, in line with the the inside-out quenching scenario. A few galaxies
(16%) show inverse (and flat) trends possibly due to merging or starbursts.
Comparing the distributions of EW(H) and sSFR to the star formation
history models as a function of galactocentric radius, the central region of
galaxies (e.g., their bulges) have experienced, at least one, rapid
star-formation episodes, which leads to the formation of bulge, while their
outer regions (e.g., disks) grow in a more steady-state. These results
demonstrate the ability to study resolved star formation in distant galaxies
with JWST NIRISS.Comment: 22 pages, 11 figure
Systematic Mutational Analysis of the Intracellular Regions of Yeast Gap1 Permease
The yeast general amino acid permease Gap1 is a convenient model for studying the intracellular trafficking of membrane proteins. Present at the plasma membrane when the nitrogen source is poor, it undergoes ubiquitin-dependent endocytosis and degradation upon addition of a good nitrogen source, e.g. ammonium. It comprises 12 transmembrane domains (TM) flanked by cytosol-facing N- and C-terminal tails (NT, CT). The NT of Gap1 contains the acceptor lysines for ubiquitylation and its CT includes a sequence essential to exit from the endoplasmic reticulum (ER).Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe
- …