3,136 research outputs found
Predicting PANCE Outcomes from First Year Evaluative Measures in a PBL Curriculum
Purpose: Previous research has explored various Physician Assistant (PA) student evaluative measures to see if they have predictive validity with regard to Physician Assistant National Certifying Exam (PANCE) scores. Recent literature has begun to evaluate how measures from the first year of didactic education might be helpful in identifying at-risk individuals early in the program. The purpose of this paper was to extend work in that area within a problem-based learning (PBL) curriculum. Method: Participants included 140 students from two consecutive PA classes. Data were imported regarding each studentâs evaluative measures of multiple choice question (MCQ) examinations, patient management assessments (PMA), a form of modified essay question (MEQ) examination, and facilitator evaluation ratings (FERs) from the end of each of six curricular units that comprise the didactic year. Results: Correlational analyses revealed all MCQ and MEQ (PMA) scores correlated significantly with PANCE scores. Regression analyses revealed that scores from two specific MCQ unit exams and one specific MEQ unit exam produced a three-factor model that accounted for 57% of variance in PANCE scores. FERs, though significantly correlated with PANCE scores, did not add to the predictive power. Conclusions: Use of MCQ and MEQ scores from the first year of didactic training in PA programs can successfully predict PANCE scores and may therefore be helpful in identifying students who are at risk for poor PANCE performance on their first attempt. Having such information available can direct faculty to students who need extra help early in their educational programs to increase likelihood of their success. With the significant correlations between FERs and PANCE scores, it is clear that faculty who facilitate PBL are also able to identify students who might be at risk based on their interactions during PBL sessions and can also utilize this information to assist studen
P09-15. Selection of higher avidity HLA-restricted T cell responses as a viral adaptation strategy
Loss of immune reactivity due to HIV mutational escape is well described. Data generated from a large population-based study (n>800) suggested that certain CD8 T cell epitopes are created as a result of HIV adaptation and are associated with enhanced viral replication. Here we sought to investigate the HLA-restricted T-cell responses associated with seven such adaptations
Improving Language Model Prompting in Support of Semi-autonomous Task Learning
Language models (LLMs) offer potential as a source of knowledge for agents
that need to acquire new task competencies within a performance environment. We
describe efforts toward a novel agent capability that can construct cues (or
"prompts") that result in useful LLM responses for an agent learning a new
task. Importantly, responses must not only be "reasonable" (a measure used
commonly in research on knowledge extraction from LLMs) but also specific to
the agent's task context and in a form that the agent can interpret given its
native language capacities. We summarize a series of empirical investigations
of prompting strategies and evaluate responses against the goals of targeted
and actionable responses for task learning. Our results demonstrate that
actionable task knowledge can be obtained from LLMs in support of online agent
task learning.Comment: Submitted to ACS 202
Improving Knowledge Extraction from LLMs for Task Learning through Agent Analysis
Large language models (LLMs) offer significant promise as a knowledge source
for task learning. Prompt engineering has been shown to be effective for
eliciting knowledge from an LLM, but alone it is insufficient for acquiring
relevant, situationally grounded knowledge for an embodied agent learning novel
tasks. We describe a cognitive-agent approach, STARS, that extends and
complements prompt engineering, mitigating its limitations and thus enabling an
agent to acquire new task knowledge matched to its native language
capabilities, embodiment, environment, and user preferences. The STARS approach
is to increase the response space of LLMs and deploy general strategies,
embedded within the autonomous agent, to evaluate, repair, and select among
candidate responses produced by the LLM. We describe the approach and
experiments that show how an agent, by retrieving and evaluating a breadth of
responses from the LLM, can achieve 77-94% task completion in one-shot learning
without user oversight. The approach achieves 100% task completion when human
oversight (such as an indication of preference) is provided. Further, the type
of oversight largely shifts from explicit, natural language instruction to
simple confirmation/discomfirmation of high-quality responses that have been
vetted by the agent before presentation to a user.Comment: 7 pages, 8 figures, 3 tables, bibliography, appendix (34 pages
total). Accepted to AAAI 202
Thiolated Janus silsesquioxane tetrapod : new precursors for functional materials
Herein, we report synthetic strategies for the development of a bifunctional Janus T4 tetrapod (Janus ring), in which the orthogonal silsesquioxane and organic faces are independently functionalized. An allâcis T4 tetrasilanolate was functionalized to introduce thiol moieties on the silsesquioxane face and naphthyl groups on the organic face to introduce luminescent and selfâorâ
ganization properties. The stepwise synthesis conditions required to prepare such perfectly defined oligomers via a suite of wellâdefined intermediates and to avoid polymerization or reactions over all eight positions of the tetrapod are explored via 29Si, 13C and 1H NMR, FTIR and TOFâESI mass spectroscopy. To the best of our knowledge, this is one of the few reports of Janus T4 tetrapods, with different functional groups located on both faces of the molecule, thus expanding the potential range of applications for these versatile precursors
The connexin 30 A88V mutant reduces cochlear gap junction expression and confers long-term protection against hearing loss
Mutations in the genes that encode the gap junction proteins connexin 26 (Cx26, encoded by GJB2) and Cx30 (GJB6) are the leading cause of hereditary hearing loss. That said, the Cx30 p.Ala88Val (A88V) mutant causes Clouston syndrome, but not hearing loss. Here, we report that the Cx30-A88V mutant, despite being toxic to inner ear-derived HEI-OC1 cells, conferred remarkable long-term protection against age-related high frequency hearing loss in Cx30(A88V/A88V) mice. During early development, there were no overt structural differences in the cochlea between genotypes, including a normal complement of hair cells; however, the supporting cell Cx30 gap junction plaques in mutant mice were reduced in size. In adulthood, Cx30(A88V/A88V) mutant mice had a reduction of cochlear Cx30 mRNA and protein, yet a full complement of hair cells. Conversely, the age-related high frequency hearing loss in Cx30(+/+) and Cx30(+/A88V) mice was due to extensive loss of outer hair cells. Our data suggest that the Cx30-A88V mutant confers long-term hearing protection and prevention of hair cell death, possibly via a feedback mechanism that leads to the reduction of total Cx30 gap junction expression in the cochlea
Progressive Bidirectional Age-Related Changes in Default Mode Network Effective Connectivity across Six Decades
The default mode network (DMN) is a set of regions that is tonically engaged during the resting state and exhibits task-related deactivation that is readily reproducible across a wide range of paradigms and modalities. The DMN has been implicated in numerous disorders of cognition and, in particular, in disorders exhibiting age-related cognitive decline. Despite these observations, investigations of the DMN in normal aging are scant. Here, we used blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) acquired during rest to investigate age-related changes in functional connectivity of the DMN in 120 healthy normal volunteers comprising six, 20-subject, decade cohorts (from 20â29 to 70â79). Structural equation modeling (SEM) was used to assess age-related changes in inter-regional connectivity within the DMN. SEM was applied both using a previously published, meta-analytically derived, node-and-edge model, and using exploratory modeling searching for connections that optimized model fit improvement. Although the two models were highly similar (only 3 of 13 paths differed), the sample demonstrated significantly better fit with the exploratory model. For this reason, the exploratory model was used to assess age-related changes across the decade cohorts. Progressive, highly significant changes in path weights were found in 8 (of 13) paths: four rising, and four falling (most changes were significant by the third or fourth decade). In all cases, rising paths and falling paths projected in pairs onto the same nodes, suggesting compensatory increases associated with age-related decreases. This study demonstrates that age-related changes in DMN physiology (inter-regional connectivity) are bidirectional, progressive, of early onset and part of normal aging
Progressive Bidirectional Age-Related Changes in Default Mode Network Effective Connectivity across Six Decades
The default mode network (DMN) is a set of regions that is tonically engaged during the resting state and exhibits task-related deactivation that is readily reproducible across a wide range of paradigms and modalities. The DMN has been implicated in numerous disorders of cognition and, in particular, in disorders exhibiting age-related cognitive decline. Despite these observations, investigations of the DMN in normal aging are scant. Here, we used blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) acquired during rest to investigate age-related changes in functional connectivity of the DMN in 120 healthy normal volunteers comprising six, 20-subject, decade cohorts (from 20â29 to 70â79). Structural equation modeling (SEM) was used to assess age-related changes in inter-regional connectivity within the DMN. SEM was applied both using a previously published, meta-analytically derived, node-and-edge model, and using exploratory modeling searching for connections that optimized model fit improvement. Although the two models were highly similar (only 3 of 13 paths differed), the sample demonstrated significantly better fit with the exploratory model. For this reason, the exploratory model was used to assess age-related changes across the decade cohorts. Progressive, highly significant changes in path weights were found in 8 (of 13) paths: four rising, and four falling (most changes were significant by the third or fourth decade). In all cases, rising paths and falling paths projected in pairs onto the same nodes, suggesting compensatory increases associated with age-related decreases. This study demonstrates that age-related changes in DMN physiology (inter-regional connectivity) are bidirectional, progressive, of early onset and part of normal aging
Ozone Depletion from Nearby Supernovae
Estimates made in the 1970's indicated that a supernova occurring within tens
of parsecs of Earth could have significant effects on the ozone layer. Since
that time, improved tools for detailed modeling of atmospheric chemistry have
been developed to calculate ozone depletion, and advances have been made in
theoretical modeling of supernovae and of the resultant gamma-ray spectra. In
addition, one now has better knowledge of the occurrence rate of supernovae in
the galaxy, and of the spatial distribution of progenitors to core-collapse
supernovae. We report here the results of two-dimensional atmospheric model
calculations that take as input the spectral energy distribution of a
supernova, adopting various distances from Earth and various latitude impact
angles. In separate simulations we calculate the ozone depletion due to both
gamma-rays and cosmic rays. We find that for the combined ozone depletion
roughly to double the ``biologically active'' UV flux received at the surface
of the Earth, the supernova must occur at <8 pc. Based on the latest data, the
time-averaged galactic rate of core-collapse supernovae occurring within 8 pc
is ~1.5/Gyr. In comparing our calculated ozone depletions with those of
previous studies, we find them to be significantly less severe than found by
Ruderman (1974), and consistent with Whitten et al. (1976). In summary, given
the amplitude of the effect, the rate of nearby supernovae, and the ~Gyr time
scale for multicellular organisms on Earth, this particular pathway for mass
extinctions may be less important than previously thought.Comment: 24 pages, 4 Postscript figures, to appear in The Astrophysical
Journal, 2003 March 10, vol. 58
- âŠ