64 research outputs found

    Realistic Spiking Neuron Statistics in a Population are Described by a Single Parametric Distribution

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    The spiking of activity of neurons throughout the cortex is random and complicated. This complicated activity requires theoretical formulations in order to understand the underlying principles of neural processing. A key aspect of theoretical investigations is characterizing the probability distribution of spiking activity. This study aims to better understand the statistics of the time between spikes, or interspike interval, in both real data and a spiking model with many time scales. Exploration of the interspike intervals of neural network activity can provide a better understanding of neural responses to different stimuli. We consider different parametric distribution fitting techniques to characterize the random spike times of a population of neurons in the visual cortex of a mammal. Five different probability distribution functions were considered, including three mixture models, and their goodness of fit was determined through two criteria: maximum likelihood and Akaike Information Criteria. Despite being largely heterogeneous, both criteria indicated that one distribution, although different for each criteria, was the best fitting for all of the neurons in the data set. The Gamma-Gamma mixture distribution was the best according to maximum likelihood and the Exponential distribution was the best according to AIC. The statistical methodology applied to a burst model yielded the same results, and the AIC formula was further investigated to better understand its consistent selection of the same parametric distribution. We find that complicated neural spiking activity can sometimes be described by a single parametric distribution, which is hopefully comforting for theorists.https://scholarscompass.vcu.edu/uresposters/1194/thumbnail.jp

    Maximizing Soil Carbon Sequestration: Assessing Procedural Barriers to Carbon Management in Cultivated Tropical Perennial Grass Systems

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    The natural capacity of the terrestrial landscape to capture and store carbon from the atmosphere can be used in cultivated systems to maximize the climate change mitigation potential of agricultural regions. A combination of inherent soil carbon storage potential, conservation management, and rhizosphere inputs should be considered when making landscape‐level decisions about agriculture if climate change mitigation is an important goal. However, the ability to accurately predict soil organic carbon accumulation following management change in the tropics is currently limited by the commonly available tools developed in more temperate systems, a gap that must be addressed locally in order to facilitate these types of landscape‐level decisions. Here, we use a case study in Hawaii to demonstrate multiple approaches to measuring and simulating soil carbon changes after the implementation of zero‐tillage cultivation of perennial grasses following more than a century of intensive sugarcane cultivation. We identify advancements needed to overcome the barriers to potential monitoring and projection protocols for soil carbon storage at our site and other similar sites

    Erdafitinib in BCG-treated high risk non-muscle invasive bladder cancer

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    © 2023 The Author(s). Published by Elsevier Ltd on behalf of European Society for Medical Oncology. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Background: Treatment options are limited for patients with high-risk non-muscle-invasive bladder cancer (NMIBC) with disease recurrence after bacillus Calmette–Guérin (BCG) treatment and who are ineligible for/refuse radical cystectomy. FGFR alterations are commonly detected in NMIBC. We evaluated the activity of oral erdafitinib, a selective pan-fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor, versus intravesical chemotherapy in patients with high-risk NMIBC and select FGFR3/2 alterations following recurrence after BCG treatment. Patients and methods: Patients aged ≥18 years with recurrent, BCG-treated, papillary-only high-risk NMIBC (high-grade Ta/T1) and select FGFR alterations refusing or ineligible for radical cystectomy were randomized to 6 mg daily oral erdafitinib or investigator's choice of intravesical chemotherapy (mitomycin C or gemcitabine). The primary endpoint was recurrence-free survival (RFS). The key secondary endpoint was safety. Results: Study enrollment was discontinued due to slow accrual. Seventy-three patients were randomized 2: 1 to erdafitinib (n = 49) and chemotherapy (n = 24). Median follow-up for RFS was 13.4 months for both groups. Median RFS was not reached for erdafitinib [95% confidence interval (CI) 16.9 months-not estimable] and was 11.6 months (95% CI 6.4-20.1 months) for chemotherapy, with an estimated hazard ratio of 0.28 (95% CI 0.1-0.6; nominal P value = 0.0008). In this population, safety results were generally consistent with known profiles for erdafitinib and chemotherapy. Conclusions: Erdafitinib prolonged RFS compared with intravesical chemotherapy in patients with papillary-only, high-risk NMIBC harboring FGFR alterations who had disease recurrence after BCG therapy and refused or were ineligible for radical cystectomy.Peer reviewe

    Utilizing international networks for accelerating research and learning in transformational sustainability science

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    A promising approach for addressing sustainability problems is to recognize the unique conditions of a particular place, such as problem features and solution capabilities, and adopt and adapt solutions developed at other places around the world. Therefore, research and teaching in international networks becomes critical, as it allows for accelerating learning by sharing problem understandings, successful solutions, and important contextual considerations. This article identifies eight distinct types of research and teaching collaborations in international networks that can support such accelerated learning. The four research types are, with increasing intensity of collaboration: (1) solution adoption; (2) solution consultation; (3) joint research on different problems; and (4) joint research on similar problems. The four teaching types are, with increasing intensity of collaboration: (1) adopted course; (2) course with visiting faculty; (3) joint course with traveling faculty; and (4) joint course with traveling students. The typology is illustrated by extending existing research and teaching projects on urban sustainability in the International Network of Programs in Sustainability, with partner universities from Europe, North America, Asia, and Africa. The article concludes with challenges and strategies for extending individual projects into collaborations in international networks.Postprint (author's final draft

    Race/ethnicity, education, and treatment parameters as moderators and predictors of outcome in binge eating disorder.

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    Binge eating disorder (BED) is prevalent among individuals from minority racial/ethnic groups and among individuals with lower levels of education, yet the efficacy of psychosocial treatments for these groups has not been examined in adequately powered analyses. This study investigated the relative variance in treatment retention and post-treatment symptom levels accounted for by demographic, clinical, and treatment variables as moderators and predictors of outcome

    GWAS Meta-Analysis of Suicide Attempt: Identification of 12 Genome-Wide Significant Loci and Implication of Genetic Risks for Specific Health Factors

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    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders

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    Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe
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