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Attention, Perception & Psychophysics Apr 2021There has been a recent surge of research examining how the visual system compresses information by representing the average properties of sets of similar objects to...
There has been a recent surge of research examining how the visual system compresses information by representing the average properties of sets of similar objects to circumvent strict capacity limitations. Efficient representation by perceptual averaging helps to maintain the balance between the needs to perceive salient events in the surrounding environment and sustain the illusion of stable and complete perception. Whereas there have been many demonstrations that the visual system encodes spatial average properties, such as average orientation, average size, and average numerosity along single dimensions, there has been no investigation of whether the fundamental nature of average representations extends to the temporal domain. Here, we used an adaptation paradigm to demonstrate that the average duration of a set of sequentially presented stimuli negatively biases the perceived duration of subsequently presented information. This negative adaptation aftereffect is indicative of a fundamental visual property, providing the first evidence that average duration is encoded along a single visual dimension. Our results not only have important implications for how the visual system efficiently encodes redundant information to evaluate salient events as they unfold within the dynamic context of the surrounding environment, but also contribute to the long-standing debate regarding the neural underpinnings of temporal encoding.
Topics: Adaptation, Physiological; Humans; Illusions; Orientation; Orientation, Spatial; Photic Stimulation; Visual Perception
PubMed: 33033988
DOI: 10.3758/s13414-020-02134-8 -
Malaysian Family Physician : the... Nov 2022Evidence-based medicine is the foundation of current medical practice. Suitable evidence is needed to support the holistic approach in clinical practice. Quantitative...
Evidence-based medicine is the foundation of current medical practice. Suitable evidence is needed to support the holistic approach in clinical practice. Quantitative research produces some evidence needed for disease treatment based on probabilities or averages. However, the practice of evidence-based medicine should be personalised to individual patients without relying solely on an average perspective. Beliefs, values and expectations are unique for each individual and may differ significantly from the average. Therefore, understanding individual differences requires evidence from qualitative research. This is particularly important in family medicine practice, which focuses on holistic care for the person, family and community. Findings from properly conducted qualitative research can offer in-depth and comprehensive accounts on healthcare issues from patient and practice perspectives. Qualitative research also provides explanatory power and analytical transferability, which can be applied into daily family medicine practice. In conclusion, evidence from qualitative research should be rightfully equally acknowledged in family medicine and healthcare.
PubMed: 36606174
DOI: 10.51866/cm0004 -
Vision Research Oct 2021Viewers can summarize redundant features in groups of objects into an ensemble percept. There appears to be separate mechanisms underlying ensemble perception of low-...
Viewers can summarize redundant features in groups of objects into an ensemble percept. There appears to be separate mechanisms underlying ensemble perception of low- and high-level visual features, but it is unclear whether ensemble perception of different low-level features is supported by common mechanisms. Yörük and Boduroglu, in Attention, Perception, & Psychophysics 82 (2020) 852-864, investigated whether length and orientation summarization tap common mechanisms by examining the correlation between errors on length- and orientation-averaging tasks and concluded that because they did not find any correlations, the two features are summarized by different, feature-specific mechanisms. However, their study was conducted with a small sample size and included sources of individual performance variance that may have diminished correlations. We report two studies that tested the correlation between performance in the length- and orientation-averaging tasks, with larger samples and modifications that sought to reduce the sources of variance. Study 1 used ensembles that varied in both feature dimensions and Study 2 used ensembles that only varied in the task-relevant dimension. Both studies showed that errors in length- and orientation-averaging are correlated, suggesting that ensemble perception of these low-level features is supported, at least to some extent, by a common ability.
Topics: Attention; Humans; Orientation; Orientation, Spatial; Psychophysics
PubMed: 34237691
DOI: 10.1016/j.visres.2021.04.010 -
ELife Sep 2021Actions often require the selection of a specific goal amongst a range of possibilities, like when a softball player must precisely position her glove to field a...
Actions often require the selection of a specific goal amongst a range of possibilities, like when a softball player must precisely position her glove to field a fast-approaching ground ball. Previous studies have suggested that during goal uncertainty the brain prepares for all potential goals in parallel and averages the corresponding motor plans to command an intermediate movement that is progressively refined as additional information becomes available. Although intermediate movements are widely observed, they could instead reflect a neural decision about the single best action choice given the uncertainty present. Here we systematically dissociate these possibilities using novel experimental manipulations and find that when confronted with uncertainty, humans generate a motor plan that optimizes task performance rather than averaging potential motor plans. In addition to accurate predictions of population-averaged changes in motor output, a novel computational model based on this performance-optimization theory accounted for a majority of the variance in individual differences between participants. Our findings resolve a long-standing question about how the brain selects an action to execute during goal uncertainty, providing fundamental insight into motor planning in the nervous system.
Topics: Adolescent; Adult; Brain; Decision Making; Female; Humans; Male; Models, Biological; Movement; Uncertainty; Young Adult
PubMed: 34486520
DOI: 10.7554/eLife.67019 -
PNAS Nexus Nov 2022A typical model for a gyrating engine consists of an inertial wheel powered by an energy source that generates an angle-dependent torque. Examples of such engines...
A typical model for a gyrating engine consists of an inertial wheel powered by an energy source that generates an angle-dependent torque. Examples of such engines include a pendulum with an externally applied torque, Stirling engines, and the Brownian gyrating engine. Variations in the torque are averaged out by the inertia of the system to produce limit cycle oscillations. While torque generating mechanisms are also ubiquitous in the biological world, where they typically feed on chemical gradients, inertia is not a property that one naturally associates with such processes. In the present work, seeking ways to dispense of the need for inertial effects, we study an inertia-less concept where the combined effect of coupled torque-producing components averages out variations in the ambient potential and helps overcome dissipative forces to allow sustained operation for vanishingly small inertia. We exemplify this inertia-less concept through analysis of two of the aforementioned engines, the Stirling engine, and the Brownian gyrating engine. An analogous principle may be sought in biomolecular processes as well as in modern-day technological engines, where for the latter, the coupled torque-producing components reduce vibrations that stem from the variability of the generated torque.
PubMed: 36712376
DOI: 10.1093/pnasnexus/pgac251 -
Southern Medical Journal May 2023Current evidence favors plasma to be effective against coronavirus disease 2019 (COVID-19) in critically ill patients in the early stages of infection. We investigated... (Review)
Review
OBJECTIVES
Current evidence favors plasma to be effective against coronavirus disease 2019 (COVID-19) in critically ill patients in the early stages of infection. We investigated the safety and efficacy of convalescent plasma in specifically late-stage (designated as after 2 weeks of hospital admission) severe COVID-19 infection. We also conducted a literature review on the late-stage use of plasma in COVID-19.
METHODS
This case series examined eight COVID-19 patients admitted to the intensive care unit (ICU) who met criteria for severe or life-threatening complications. Each patient received one dose (200 mL) of plasma. Clinical information was gathered in intervals of 1 day pretransfusion and 1 hour, 3 days, and 7 days posttransfusion. The primary outcome was effectiveness of plasma transfusion, measured by clinical improvement, laboratory parameters, and all-cause mortality.
RESULTS
Eight ICU patients received plasma late in the course of COVID-19 infection, on average at 16.13 days postadmission. On the day before transfusion, the averaged initial Sequential Organ Failure Assessment (SOFA) score, PaO:FiO ratio, Glasgow Coma Scale (GCS), and lymphocyte count were 6.5, 228.03, 8.63, and 1.19, respectively. Three days after plasma treatment, the group averages for the SOFA score (4.86), PaO:FiO ratio (302.73), GCS (9.29), and lymphocyte count (1.75) improved. Although the mean GCS improved to 10.14 by posttransfusion day 7, the other means marginally worsened with an SOFA score of 5.43, a PaO:FiO ratio of 280.44, and a lymphocyte count of 1.71. Clinical improvement was noted in six patients who were discharged from the ICU.
CONCLUSIONS
This case series provides evidence that convalescent plasma may be safe and effective in late-stage, severe COVID-19 infection. Results showed clinical improvement posttransfusion as well as decreased all-cause mortality in comparison to pretransfusion predicted mortality. Randomized controlled trials are needed to conclusively determine benefits, dosage, and timing of treatment.
Topics: Humans; COVID-19; SARS-CoV-2; Blood Component Transfusion; Plasma; COVID-19 Serotherapy; Immunization, Passive
PubMed: 37137479
DOI: 10.14423/SMJ.0000000000001546 -
Gait & Posture Oct 2022Balance is often affected after stroke, severely impacting activities of daily life. Conventional testing methods to assess balance provide limited information, as they...
BACKGROUND
Balance is often affected after stroke, severely impacting activities of daily life. Conventional testing methods to assess balance provide limited information, as they are subjected to floor and ceiling effects. Instrumented tests, for instance using inertial measurement units, offer a feasible and promising alternative.
RESEARCH QUESTION
We examined whether postural sway can reliably be measured in sitting and standing balance in people after stroke in clinical rehabilitation using a single inertial measurement unit. Additionally, we assessed to what extent averaging two measurements would improve test-retest reliability compared to a single measurement, and if sway features can potentially be used to monitor progression.
METHOD
Forty participants performed two assessments with a test-retest interval of 24 h. Each assessment consisted of one sitting and four standing balance conditions (eyes open, feet together, eyes closed and foam). The standing balance conditions were performed twice during both assessments. In total, 35 sway features were calculated for each condition. For the standing balance conditions, these were calculated for both single test-retest measurement and the average of the two test and retest measurements. We determined the reliability using the intraclass correlation coefficient for both single and averaged measurements. Additionally, the minimal detectable change and the relative minimal detectable change were computed.
RESULTS
The single and averaged measurements resulted in 22 sitting, 30 & 32 eyes open, 27 & 22 feet together, 28 & 33 eyes closed and 23 & 13 foam sway features with good-excellent reliability. Overall, the difference between intraclass correlation coefficient values of the single and averaged measurements was small and inconsistent. The relative minimal detectable change ranged between 0.5 and 1.5 standard deviation.
SIGNIFICANCE
Sitting and standing balance can reliably be assessed in people after stroke in clinical rehabilitation with a single measurement using one inertial measurement unit.
Topics: Humans; Stroke Rehabilitation; Reproducibility of Results; Postural Balance; Stroke
PubMed: 36055184
DOI: 10.1016/j.gaitpost.2022.08.005 -
PloS One 2021The purpose of this study was to determine the energy partition of pregnant F1 Holstein x Gyr with average initial body weight (BW) of 515.6 kg and Gyr cows with average... (Comparative Study)
Comparative Study
The purpose of this study was to determine the energy partition of pregnant F1 Holstein x Gyr with average initial body weight (BW) of 515.6 kg and Gyr cows with average initial BW of 435.1 kg at 180, 210 and 240 days of gestation, obtained using respirometry. Twelve animals in two groups (six per genetic group) received a restricted diet equivalent to 1.3 times the net energy for maintenance (NEm). The proportion of gross energy intake (GEI) lost as feces did not differ between the evaluated breeds and corresponded to 28.65% on average. The daily methane production (L/d) was greater for (P<0.05) F1 HxG compared to Gyr animals. However, when expressed as L/kg dry matter (DM) or as percentage of GEI there were no differences between the groups (P>0.05). The daily loss of energy as urine (mean of 1.42 Mcal/d) did not differ (P>0.05) between groups and ranged from 3.87 to 5.35% of the GEI. The metabolizable energy intake (MEI) of F1 HxG animals was greater (P < 0.05) at all gestational stages compared to Gyr cows when expressed in Mcal/d. However, when expressed in kcal/kg of metabolic BW (BW0,75), the F1 HxG cows had MEI 11% greater (P<0.05) at 240 days of gestation and averaged 194.39 kcal/kg of BW0,75. Gyr cows showed no change in MEI over time (P>0.05), with a mean of 146.66 kcal/kg BW0. 75. The ME used by the conceptus was calculated by deducting the metabolizable energy for maintenance (MEm) from the MEI, which was obtained in a previous study using the same cows prior to becoming pregnant. The values of NEm obtained in the previous study with similar non-pregnant cows were 92.02 kcal/kg BW0.75 for F1 HxG, and 76.83 kcal/kg BW0.75 for Gyr (P = 0.06). The average ME for pregnancy (MEp) was 5.33 Mcal/d for F1 HxG and 4.46 Mcal/d for Gyr. The metabolizability ratio, averaging 0.60, was similar among the evaluated groups (P>0.05). The ME / Digestible Energy (DE) ratio differed between groups and periods evaluated (P<0.05) with a mean of 0.84. The heat increment (HI) accounted for 22.74% and 24.38% of the GEI for F1 HxG and Gyr cows, respectively. The proportion of GEI used in the basal metabolism by pregnant cows in this study represented 29.69%. However, there were no differences between the breeds and the evaluation periods and corresponded to 29.69%. The mean NE for pregnancy (NEp) was 2.76 Mcal/d and did not differ between groups and gestational stages (P>0.05).
Topics: Animal Feed; Animals; Body Composition; Body Weight; Cattle; Diet; Energy Intake; Energy Metabolism; Female; Gestational Age; Hybridization, Genetic; Methane; Pregnancy
PubMed: 33539434
DOI: 10.1371/journal.pone.0246208 -
Cureus Oct 2023Hirschsprung disease in newborns can be a potentially life-threatening condition, with risks for complications such as Hirschsprung-associated enterocolitis. Accessing...
OBJECTIVE
Hirschsprung disease in newborns can be a potentially life-threatening condition, with risks for complications such as Hirschsprung-associated enterocolitis. Accessing health information in a readable format for complex diseases demonstrates an important outlet for families to address concerns. While it is important to seek out information from trusted providers, many individuals seek out ways to educate themselves further by using common search engines and turning to the internet. This article will evaluate the readability of relevant articles on Hirschsprung disease and information accessibility to the average health literacy individual.
METHODS
A readability analysis of the first 20 Google search results from the keywords "Hirschsprung disease" and "aganglionic megacolon" was performed. Results were documented and averaged using standardized scoring systems. Scoring systems included an Automated Readability Index, Coleman Liau index, SMOG index, Gunning Fog score, Flesch Kinkaid grade level, Flesch Kinkaid reading ease, and average readability across all scoring systems. The number of sentences, number of words, number of complex words, percent of complex words, average words per sentence, and average syllables per word were included as a sample of criteria within scoring systems.
RESULTS
The average readability score for the first 20 search results of keywords "Hirschsprung disease" and "aganglionic megacolon" was 9.4, indicating a reading level just above the ninth grade. Readability ease was scored separately due to its unique scoring system on a scale of 0-100. Flesch Kincaid Readability ease score was averaged and resulted in a score of 46.4, which is considered "college level" or "difficult."
CONCLUSIONS
The average health consumer will turn to Google to find information about their own health, as well as the health of their loved ones. Hirschsprung disease in newborns presents a complex disease process and can be potentially life-threatening. Current resources available to the average health consumer averaged at a grade level of 9.4 relative to search results from keywords "Hirschsprung disease" and "aganglionic megacolon." Depending on the target audience for online information, more work needs to be done to improve readability for the average health information consumer.
PubMed: 37954798
DOI: 10.7759/cureus.46806 -
Methods of Information in Medicine Dec 2022Automated clinical decision support for risk assessment is a powerful tool in combating cardiovascular disease (CVD), enabling targeted early intervention that could...
BACKGROUND
Automated clinical decision support for risk assessment is a powerful tool in combating cardiovascular disease (CVD), enabling targeted early intervention that could avoid issues of overtreatment or undertreatment. However, current CVD risk prediction models use observations at baseline without explicitly representing patient history as a time series.
OBJECTIVE
The aim of this study is to examine whether by explicitly modelling the temporal dimension of patient history event prediction may be improved.
METHODS
This study investigates methods for multivariate sequential modelling with a particular emphasis on long short-term memory (LSTM) recurrent neural networks. Data from a CVD decision support tool is linked to routinely collected national datasets including pharmaceutical dispensing, hospitalization, laboratory test results, and deaths. The study uses a 2-year observation and a 5-year prediction window. Selected methods are applied to the linked dataset. The experiments performed focus on CVD event prediction. CVD death or hospitalization in a 5-year interval was predicted for patients with history of lipid-lowering therapy.
RESULTS
The results of the experiments showed temporal models are valuable for CVD event prediction over a 5-year interval. This is especially the case for LSTM, which produced the best predictive performance among all models compared achieving AUROC of 0.801 and average precision of 0.425. The non-temporal model comparator ridge classifier (RC) trained using all quarterly data or by aggregating quarterly data (averaging time-varying features) was highly competitive achieving AUROC of 0.799 and average precision of 0.420 and AUROC of 0.800 and average precision of 0.421, respectively.
CONCLUSION
This study provides evidence that the use of deep temporal models particularly LSTM in clinical decision support for chronic disease would be advantageous with LSTM significantly improving on commonly used regression models such as logistic regression and Cox proportional hazards on the task of CVD event prediction.
Topics: Humans; Cardiovascular Diseases; Risk Factors; Risk Assessment; Neural Networks, Computer; Multivariate Analysis
PubMed: 36564011
DOI: 10.1055/s-0042-1758687