151 research outputs found
Simultaneous VLBI Astrometry of H2O and SiO Masers toward the Semiregular Variable R Crateris
We obtained, for the first time, astrometrically registered maps of the 22.2
GHz H2O and 42.8, 43.1, and 86.2 GHz SiO maser emission toward the semiregular
b-type variable (SRb) R Crateris, at three epochs (2015 May 21, and 2016
January 7 and 26) using the Korean Very-long-baseline Interferometry Network.
The SiO masers show a ring-like spatial structure, while the H2O maser shows a
very asymmetric one-side outflow structure, which is located at the southern
part of the ring-like SiO maser feature. We also found that the 86.2 GHz SiO
maser spots are distributed in an inner region, compared to those of the 43.1
GHz SiO maser, which is different from all previously known distributions of
the 86.2 GHz SiO masers in variable stars. The different distribution of the
86.2 GHz SiO maser seems to be related to the complex dynamics caused by the
overtone pulsation mode of the SRb R Crateris. Furthermore, we estimated the
position of the central star based on the ring fitting of the SiO masers, which
is essential for interpreting the morphology and kinematics of a circumstellar
envelope. The estimated stellar coordinate corresponds well to the position
measured by Gaia
ChEDDAR: Student-ChatGPT Dialogue in EFL Writing Education
The integration of generative AI in education is expanding, yet empirical
analyses of large-scale, real-world interactions between students and AI
systems still remain limited. In this study, we present ChEDDAR, ChatGPT & EFL
Learner's Dialogue Dataset As Revising an essay, which is collected from a
semester-long longitudinal experiment involving 212 college students enrolled
in English as Foreign Langauge (EFL) writing courses. The students were asked
to revise their essays through dialogues with ChatGPT. ChEDDAR includes a
conversation log, utterance-level essay edit history, self-rated satisfaction,
and students' intent, in addition to session-level pre-and-post surveys
documenting their objectives and overall experiences. We analyze students'
usage patterns and perceptions regarding generative AI with respect to their
intent and satisfaction. As a foundational step, we establish baseline results
for two pivotal tasks in task-oriented dialogue systems within educational
contexts: intent detection and satisfaction estimation. We finally suggest
further research to refine the integration of generative AI into education
settings, outlining potential scenarios utilizing ChEDDAR. ChEDDAR is publicly
available at https://github.com/zeunie/ChEDDAR
RECIPE: How to Integrate ChatGPT into EFL Writing Education
The integration of generative AI in the field of education is actively being
explored. In particular, ChatGPT has garnered significant interest, offering an
opportunity to examine its effectiveness in English as a foreign language (EFL)
education. To address this need, we present a novel learning platform called
RECIPE (Revising an Essay with ChatGPT on an Interactive Platform for EFL
learners). Our platform features two types of prompts that facilitate
conversations between ChatGPT and students: (1) a hidden prompt for ChatGPT to
take an EFL teacher role and (2) an open prompt for students to initiate a
dialogue with a self-written summary of what they have learned. We deployed
this platform for 213 undergraduate and graduate students enrolled in EFL
writing courses and seven instructors. For this study, we collect students'
interaction data from RECIPE, including students' perceptions and usage of the
platform, and user scenarios are examined with the data. We also conduct a
focus group interview with six students and an individual interview with one
EFL instructor to explore design opportunities for leveraging generative AI
models in the field of EFL education
Asymmetric distributions of H2O and SiO masers towards V627 Cas
We performed simultaneous observations of the H2O 6(1,6) - 5(2,3) (22.235080
GHz) and SiO v= 1, 2, J = 1 - 0, SiO v = 1, J = 2 - 1, 3 - 2 (43.122080,
42.820587, 86.243442, and 129.363359 GHz) masers towards the suspected D-type
symbiotic star, V627 Cas, using the Korean VLBI Network. Here, we present
astrometrically registered maps of the H2O and SiO v = 1, 2, J = 1 - 0, SiO v =
1, J = 2 - 1 masers for five epochs from January 2016 to June 2018.
Distributions of the SiO maser spots do not show clear ring-like structures,
and those of the H2O maser are biased towards the north-north-west to west with
respect to the SiO maser features according to observational epochs. These
asymmetric distributions of H2O and SiO masers are discussed based on two
scenarios of a bipolar outflow and the presence of the hot companion, a white
dwarf, in V627 Cas. We carried out ring fitting of SiO v = 1, and v = 2 masers
and estimated the expected position of the cool red giant. The ring radii of
the SiO v = 1 maser are slightly larger than those of the SiO v = 2 maser, as
previously known. Our assumption for the physical size of the SiO maser ring of
V627 Cas to be the typical size of a SiO maser ring radius (\sim4 au) of red
giants yields the distance of V627 Cas to be \sim1 kpc.Comment: 7 pages, 4 figures, 1 table, Published in MNRA
Large-scale metabolic interaction network of the mouse and human gut microbiota
The role of our gut microbiota in health and disease is largely attributed to the collective metabolic activities of the inhabitant microbes. A system-level framework of the microbial community structure, mediated through metabolite transport, would provide important insights into the complex microbe-microbe and host-microbe chemical interactions. This framework, if adaptable to both mouse and human systems, would be useful for mechanistic interpretations of the vast amounts of experimental data from gut microbiomes in murine animal models, whether humanized or not. Here, we constructed a literature-curated, interspecies network of the mammalian gut microbiota for mouse and human hosts, called NJC19. This network is an extensive data resource, encompassing 838 microbial species (766 bacteria, 53 archaea, and 19 eukaryotes) and 6 host cell types, interacting through 8,224 small-molecule transport and macromolecule degradation events. Moreover, we compiled 912 negative associations between organisms and metabolic compounds that are not transportable or degradable by those organisms. Our network may facilitate experimental and computational endeavors for the mechanistic investigations of host-associated microbial communities
Recommended from our members
Dysregulated protocadherin-pathway activity as an intrinsic defect in induced pluripotent stem cell-derived cortical interneurons from subjects with schizophrenia.
We generated cortical interneurons (cINs) from induced pluripotent stem cells derived from 14 healthy controls and 14 subjects with schizophrenia. Both healthy control cINs and schizophrenia cINs were authentic, fired spontaneously, received functional excitatory inputs from host neurons, and induced GABA-mediated inhibition in host neurons in vivo. However, schizophrenia cINs had dysregulated expression of protocadherin genes, which lie within documented schizophrenia loci. Mice lacking protocadherin-α showed defective arborization and synaptic density of prefrontal cortex cINs and behavioral abnormalities. Schizophrenia cINs similarly showed defects in synaptic density and arborization that were reversed by inhibitors of protein kinase C, a downstream kinase in the protocadherin pathway. These findings reveal an intrinsic abnormality in schizophrenia cINs in the absence of any circuit-driven pathology. They also demonstrate the utility of homogenous and functional populations of a relevant neuronal subtype for probing pathogenesis mechanisms during development
- …