455 research outputs found
A layered abduction model of perception: Integrating bottom-up and top-down processing in a multi-sense agent
A layered-abduction model of perception is presented which unifies bottom-up and top-down processing in a single logical and information-processing framework. The process of interpreting the input from each sense is broken down into discrete layers of interpretation, where at each layer a best explanation hypothesis is formed of the data presented by the layer or layers below, with the help of information available laterally and from above. The formation of this hypothesis is treated as a problem of abductive inference, similar to diagnosis and theory formation. Thus this model brings a knowledge-based problem-solving approach to the analysis of perception, treating perception as a kind of compiled cognition. The bottom-up passing of information from layer to layer defines channels of information flow, which separate and converge in a specific way for any specific sense modality. Multi-modal perception occurs where channels converge from more than one sense. This model has not yet been implemented, though it is based on systems which have been successful in medical and mechanical diagnosis and medical test interpretation
Reducing uncertainty by using explanatory relationships
Explanatory relationships can be used effectively to reduce the uncertainty that remains after diagnostic hypotheses have been scored using local matching
Cardiac Rehabilitation Intervention and Quality of Life Indicators: A Validation Estimate of Ware's Model
Author Institution: Dept. of Counseling & Mental Health Services, University of Toledo, OHAuthor Institution: Dept. of Educational Foundations & Leadership, University of Akron, OHAuthor Institution: Dept. of Counseling, Summa Health System, University of Akron, OHAuthor Institution: Cardiac Rehabilitation Institute, Summa Health System, University of Akron, OHThe present study tests Ware’s (1987, 1990) prediction that patient evaluations of quality of life (QOL) are related to physical ability. QOL data from 302 patients were collected prior to initiation and upon completion of a 12-week cardiac rehabilitation program. Physical ability was measured in metabolic equivalents (METS). Pearson product moment correlation coefficients were calculated for the variables under study. Multiple regression analyses were conducted to test these relationships covarying patient diagnosis, and pre-treatment QOL score and patient demographics. Significant improvements from
pre- to post-CR were found for METs and all QOL variables. Improvements in physical ability were significantly correlated with improvements in physical health related QOL indices, but not with mental health QOL indices. These relationships were present even when moderating variables were co-varied. Improvements in physical ability were predictive of decreased expectations that physical health would interfere with work or other daily activities. As the physical capabilities of our patients increased, they reported feeling less physical pain and were less limited by any pain they did experience. And, increased
physical ability was associated with a brighter outlook on current and expected future health status. These findings provide support for Ware’s theory of QOL
Compositeness, Triviality and Bounds on Critical Exponents for Fermions and Magnets
We argue that theories with fundamental fermions which undergo chiral
symmetry breaking have several universal features which are qualitatively
different than those of theories with fundamental scalars. Several bounds on
the critical indices and follow. We observe that in four
dimensions the logarithmic scaling violations enter into the Equation of State
of scalar theories, such as , and fermionic models, such as
Nambu-Jona-Lasinio, in qualitatively different ways. These observations lead to
useful approaches for analyzing lattice simulations of a wide class of model
field theories. Our results imply that {\it cannot} be a good
guide to understanding the possible triviality of spinor .Comment: 12 pages, 3 figures (not included), ILL-(TH)-93-2
Universal Properties of Chiral Simmetry Breaking
We discuss chiral symmetry breaking critical points from the perspective of
PCAC, correlation length scaling and the chiral equation of state. A scaling
theory for the ratio of the pion to sigma masses is presented. The
Goldstone character of the pion and properties of the longitudinal and
transverse chiral susceptibilities determine the ratio which can be
used to locate critical points and measure critical indices such as .
We show how PCAC and correlation length scaling determine the pion mass'
dependence on the chiral condensate and lead to a practical method to measure
the anomalous dimension . These tools are proving useful in studies of
the chiral transition in lattice QED and the quark-gluon plasma transition in
lattice QCD.Comment: 19 pages, 4 figures. CERN-TH.6630/92 ILL-(TH)-92-1
Looking for the Logarithms in Four-Dimensional Nambu-Jona-Lasinio Models
We study the problem of triviality in the four dimensional Nambu-Jona-Lasinio
model with discrete chiral symmetry using both large-N expansions and lattice
simulations. We find that logarithmic corrections to scaling appear in the
equation of state as predicted by the large-N expansion. The data from
lattice simulations is sufficiently accurate to distinguish logarithmically
trivial scaling from power law scaling. Simulations on different lattice sizes
reveal an interesting interplay of finite size effects and triviality. We argue
that such effects are qualitatively different for theories based on fundamental
scalar rather than fermion fields. Several lessons learned here can be applied
to simulations and analyses of more challenging field theories.Comment: 25 pages, 14 ps figure
A Pilot Randomized Clinical Trial of a Teamwork Intervention for Heart Failure Care Dyads
Background: Dyadic heart failure (HF) management can improve outcomes for patients and caregivers and can be enhanced through eHealth interventions. Objective: To evaluate the feasibility, acceptability, and preliminary efficacy of an eHealth dyadic teamwork intervention, compared to an attention control condition. Methods: We recruited 29 HF patient-caregiver dyads from inpatient units and randomized dyads to an intervention or a control group. We calculated enrollment and retention rates, described acceptability using interview and questionnaire data, and computed intervention effect sizes. Results: 37% of eligible dyads agreed to participate and 93% of randomized participants completed follow-up questionnaires. Participants found both study conditions to be acceptable. Between-group effect sizes suggested that the intervention led to improvements in relationship quality, self-efficacy, and quality of life for patients and caregivers. Conclusions: Dyadic recruitment from acute care settings is challenging. Findings provide initial evidence that our intervention can contribute to better health outcomes for HF dyads
Response of thin-film SQUIDs to applied fields and vortex fields: Linear SQUIDs
In this paper we analyze the properties of a dc SQUID when the London
penetration depth \lambda is larger than the superconducting film thickness d.
We present equations that govern the static behavior for arbitrary values of
\Lambda = \lambda^2/d relative to the linear dimensions of the SQUID. The
SQUID's critical current I_c depends upon the effective flux \Phi, the magnetic
flux through a contour surrounding the central hole plus a term proportional to
the line integral of the current density around this contour. While it is well
known that the SQUID inductance depends upon \Lambda, we show here that the
focusing of magnetic flux from applied fields and vortex-generated fields into
the central hole of the SQUID also depends upon \Lambda. We apply this
formalism to the simplest case of a linear SQUID of width 2w, consisting of a
coplanar pair of long superconducting strips of separation 2a, connected by two
small Josephson junctions to a superconducting current-input lead at one end
and by a superconducting lead at the other end. The central region of this
SQUID shares many properties with a superconducting coplanar stripline. We
calculate magnetic-field and current-density profiles, the inductance
(including both geometric and kinetic inductances), magnetic moments, and the
effective area as a function of \Lambda/w and a/w.Comment: 18 pages, 20 figures, revised for Phys. Rev. B, the main revisions
being to denote the effective flux by \Phi rather than
Robust Meta-Model for Predicting the Need for Blood Transfusion in Non-traumatic ICU Patients
Objective: Blood transfusions, crucial in managing anemia and coagulopathy in
ICU settings, require accurate prediction for effective resource allocation and
patient risk assessment. However, existing clinical decision support systems
have primarily targeted a particular patient demographic with unique medical
conditions and focused on a single type of blood transfusion. This study aims
to develop an advanced machine learning-based model to predict the probability
of transfusion necessity over the next 24 hours for a diverse range of
non-traumatic ICU patients.
Methods: We conducted a retrospective cohort study on 72,072 adult
non-traumatic ICU patients admitted to a high-volume US metropolitan academic
hospital between 2016 and 2020. We developed a meta-learner and various machine
learning models to serve as predictors, training them annually with four-year
data and evaluating on the fifth, unseen year, iteratively over five years.
Results: The experimental results revealed that the meta-model surpasses the
other models in different development scenarios. It achieved notable
performance metrics, including an Area Under the Receiver Operating
Characteristic (AUROC) curve of 0.97, an accuracy rate of 0.93, and an F1-score
of 0.89 in the best scenario.
Conclusion: This study pioneers the use of machine learning models for
predicting blood transfusion needs in a diverse cohort of critically ill
patients. The findings of this evaluation confirm that our model not only
predicts transfusion requirements effectively but also identifies key
biomarkers for making transfusion decisions
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