The tasks of neural computation are remarkably diverse. To function optimally, neuronal networks have been hypothesized to operate near a nonequilibrium critical point. However, experimental evidence for critical dynamics has been inconclusive. Here, we show that the dynamics of cultured cortical networks are critical. We analyze neuronal network data collected at the individual neuron level using the framework of nonequilibrium phase transitions. Among the most striking predictions confirmed is that the mean temporal profiles of avalanches of widely varying durations are quantitatively described by a single universal scaling function. We also show that the data have three additional features predicted by critical phenomena: approximate power law distributions of avalanche sizes and durations, samples in subcritical and supercritical phases, and scaling laws between anomalous exponents.
We show that slowly sheared metallic nanocrystals deform via discrete strain bursts (slips), whose size distributions follow power laws with stress-dependent cutoffs. We show for the first time that plasticity reflects tuned criticality, by collapsing the stress-dependent slip-size distributions onto a predicted scaling function. Both power-law exponents and scaling function agree with mean-field theory predictions. Our study of 7 materials and 2 crystal structures, at various deformation rates, stresses, and crystal sizes down to 75 nm, attests to the universal characteristics of plasticity.
Treatment satisfaction is lower among diabetic patients who have a lower educational level, who are insulin treated or have a diabetic complication and is related to difficulties in taking medications and coming to follow-up visits. Addressing the specific needs of these patients might be effective in improving their satisfaction, thus having a positive influence on other clinical outcomes.
Slowly-compressed single crystals, bulk metallic glasses (BMGs), rocks, granular materials, and the earth all deform via intermittent slips or “quakes”. We find that although these systems span 12 decades in length scale, they all show the same scaling behavior for their slip size distributions and other statistical properties. Remarkably, the size distributions follow the same power law multiplied with the same exponential cutoff. The cutoff grows with applied force for materials spanning length scales from nanometers to kilometers. The tuneability of the cutoff with stress reflects “tuned critical” behavior, rather than self-organized criticality (SOC), which would imply stress-independence. A simple mean field model for avalanches of slipping weak spots explains the agreement across scales. It predicts the observed slip-size distributions and the observed stress-dependent cutoff function. The results enable extrapolations from one scale to another, and from one force to another, across different materials and structures, from nanocrystals to earthquakes.
BackgroundThe efficacy of disease management programs in improving the outcome of heart failure patients remains uncertain and may vary across health systems. This study explores whether a countrywide disease management program is superior to usual care in reducing adverse health outcomes and improving well-being among community-dwelling adult patients with moderate-to-severe chronic heart failure who have universal access to advanced health-care services and technologies.MethodsIn this multicenter open-label trial, 1,360 patients recruited after hospitalization for heart failure exacerbation (38%) or from the community (62%) were randomly assigned to either disease management or usual care. Disease management, delivered by multi-disciplinary teams, included coordination of care, patient education, monitoring disease symptoms and patient adherence to medication regimen, titration of drug therapy, and home tele-monitoring of body weight, blood pressure and heart rate. Patients assigned to usual care were treated by primary care practitioners and consultant cardiologists.The primary composite endpoint was the time elapsed till first hospital admission for heart failure exacerbation or death from any cause. Secondary endpoints included the number of all hospital admissions, health-related quality of life and depression during follow-up. Intention-to-treat comparisons between treatments were adjusted for baseline patient data and study center.ResultsDuring the follow-up, 388 (56.9%) patients assigned to disease management and 387 (57.1%) assigned to usual care had a primary endpoint event. The median (range) time elapsed until the primary endpoint event or end of study was 2.0 (0–5.0) years among patients assigned to disease management, and 1.8 (0–5.0) years among patients assigned to usual care (adjusted hazard ratio, 0.908; 95% confidence interval, 0.788 to 1.047). Hospital admissions were mostly (70%) unrelated to heart failure.Patients assigned to disease management had a better health-related quality of life and a lower depression score during follow-up.ConclusionsThis comprehensive disease management intervention was not superior to usual care with respect to the primary composite endpoint, but it improved health-related quality of life and depression. A disease-centered approach may not suffice to make a significant impact on hospital admissions and mortality in patients with chronic heart failure who have universal access to health care.Clinical trial registrationClinicaltrials.gov identifier: NCT00533013. Trial registration date: 9 August 2007. Initial protocol release date: 20 September 2007.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-017-0855-z) contains supplementary material, which is available to authorized users.
The consumer model is able to explain only to a modest extent the variation in satisfaction, but dissatisfaction is a good predictor of the intention to change doctors.
Dietary changes are known to affect gut community structure, but questions remain about the mechanisms by which diet induces shifts in microbiome membership. Here, we addressed these questions in the rumen microbiome ecosystem - a complex microbial community that resides in the upper digestive tract of ruminant animals and is responsible for the degradation of the ingested plant material. Our dietary intervention experiments revealed that diet affects the most abundant taxa within the microbiome and that a specific group of methanogenic archaea of the order Methanomicrobiales is highly sensitive to its changes. Using metabolomic analyses together with in vitro microbiology approaches and whole-genome sequencing of Methanomicrobium mobile, a key species within this group, we identified that redox potential changes with diet and is the main factor that causes these dietary induced alternations in this taxa's abundance. Our genomic analysis suggests that the redox potential effect stems from a reduced number of anti-reactive oxygen species proteins coded in this taxon's genome. Our study highlights redox potential as a pivotal factor that could serve as a sculpturing force of community assembly within anaerobic gut microbial communities.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.