1,857 research outputs found

    Modification of the Erosion Productivity Index Calculator to Incorporate Subsurface Drainage Systems.

    Get PDF
    The main purpose of this research is to enable EPIC to simulate the effect of subsurface drainage systems on water budget components, sediment loss and the crop yield. To accomplish the stated purpose, four steps were taken: (1) the accuracy of the original EPIC in simulating sediment loss, crop yield and surface runoff volume for a non-subsurface drained plot was determined, (2) the hydrology section time step simulation was changed from daily to hourly and a subsurface drainage subprogram was incorporated into the model, (3) the accuracy of the modified model in simulating surface runoff volume, sediment loss, crop yield and water table fluctuations for a non-subsurface drained plot was determined, and (4) the accuracy of the model in predicting surface runoff volume, subsurface drained volume, water table fluctuations, sediment loss and crop yield for a subsurface drained plot was determined. Evaluating the performance of the original EPIC and the modified EPIC (EPIC-WT) on a non-subsurface drained plot showed that the accuracy of the EPIC-WT in simulating surface runoff volume, sediment loss and crop yield was good and comparable to the accuracy of the original EPIC. Also, EPIC-WT was tested on subsurface drained plot, and the values of surface runoff volume, subsurface drained volume, sediment loss and water table fluctuations predicted by the model were quite satisfactory

    The future of AD clinical trials with the advent of anti-amyloid therapies: An CTAD Task Force report

    Get PDF
    BACKGROUND: Aducanumab (ADUHELMTM) was approved for the treatment of Alzheimer\u27s disease (AD) in the US. This approval was supported by an effect on the cerebral amyloid plaque load and evidence of cognitive efficacy to be confirmed in post-marketing trials. Other anti-amyloid antibodies are under investigation in phase III (donanemab, lecanemab, gantenerumab) and have shown preliminary evidence of a cognitive benefit in phase II trials. Although these agents target a small segment of patients with mild cognitive impairment due to AD or mild AD dementia, their advent will change the design of future clinical trials both for anti-amyloid and non-amyloid drugs. These changes will promote the selection of patients in clinical trials by amyloid and tau biomarkers that identify patients with appropriate biology and may follow the treatment response to approved amyloid antibodies. The use of these agents creates the opportunity to test combined drug therapies and to conduct comparative assessments with innovative therapies and newly approved drugs available in clinical practice. Blood-based AD biomarkers should be implemented in research and could facilitate the recruitment into clinical trials. Anti-amyloid antibodies will have positive (e.g., more early diagnosis) and negative impacts (some subjects will be reluctant to participate in trials and risk assignment to placebo) on AD trials in the immediate future. We present the results of the CTAD Task Force on this topic, in Boston, November 6, 2021

    Strongly bounded groups and infinite powers of finite groups

    Full text link
    We define a group as strongly bounded if every isometric action on a metric space has bounded orbits. This latter property is equivalent to the so-called uncountable strong cofinality, recently introduced by G. Bergman. Our main result is that G^I is strongly bounded when G is a finite, perfect group and I is any set. This strengthens a result of Koppelberg and Tits. We also prove that omega_1-existentially closed groups are strongly bounded.Comment: 10 pages, no figure. Versions 1-3 were entitled "Uncountable groups with Property (FH)". To appear in Comm. Algebr

    Physics-guided machine learning approaches to predict the ideal stability properties of fusion plasmas

    Get PDF
    One of the biggest challenges to achieve the goal of producing fusion energy in tokamak devices is the necessity of avoiding disruptions of the plasma current due to instabilities. The disruption event characterization and forecasting (DECAF) framework has been developed in this purpose, integrating physics models of many causal events that can lead to a disruption. Two different machine learning approaches are proposed to improve the ideal magnetohydrodynamic (MHD) no-wall limit component of the kinetic stability model included in DECAF. First, a random forest regressor (RFR), was adopted to reproduce the DCON computed change in plasma potential energy without wall effects, , for a large database of equilibria from the national spherical torus experiment (NSTX). This tree-based method provides an analysis of the importance of each input feature, giving an insight into the underlying physics phenomena. Secondly, a fully-connected neural network has been trained on sets of calculations with the DCON code, to get an improved closed form equation of the no-wall limit as a function of the relevant plasma parameters indicated by the RFR. The neural network has been guided by physics theory of ideal MHD in its extension outside the domain of the NSTX experimental data. The estimated value of has been incorporated into the DECAF kinetic stability model and tested against a set of experimentally stable and unstable discharges. Moreover, the neural network results were used to simulate a real-time stability assessment using only quantities available in real-time. Finally, the portability of the model was investigated, showing encouraging results by testing the NSTX-trained algorithm on the mega ampere spherical tokamak (MAST)

    Potential Peripheral Biomarkers for the Diagnosis of Alzheimer's Disease

    Get PDF
    Advances in the discovery of a peripheral biomarker for the diagnosis of Alzheimer's would provide a way to better detect the onset of this debilitating disease in a manner that is both noninvasive and universally available. This paper examines the current approaches that are being used to discover potential biomarker candidates available in the periphery. The search for a peripheral biomarker that could be utilized diagnostically has resulted in an extensive amount of studies that employ several biological approaches, including the assessment of tissues, genomics, proteomics, epigenetics, and metabolomics. Although a definitive biomarker has yet to be confirmed, advances in the understanding of the mechanisms of the disease and major susceptibility factors have been uncovered and reveal promising possibilities for the future discovery of a useful biomarker

    Donepezil and galanin interactions in an animal model of Alzheimer’s disease

    Full text link
    Alzheimer\u27s disease (AD) is a neurodegenerative disorder marked by a progressive loss of cognitive function. One of the neurobiological hallmarks of AD is a progressive loss of cholinergic neurons and a decrease in the amount of acetylcholine in the brain. Pharmacological therapies have targeted the cholinergic system, specifically first-line, palliative treatment using acetylcholinesterase (AChE) inhibitors, such as donepezil. Donepezil has been shown to increase cholinergic tone and ameliorate some of the cognitive deficits in AD patients. Galanin, a neuropeptide that inhibits the evoked release of several neurotransmitters including acetylcholine as well as modulates seveal intracellular cascades, is overexpressed in AD resulting in an as yet unidentified modulation of neurobiological function. Galanin also impairs learning and memory when administered centrally to rodents, suggesting it may contribute to the cognitive impairments observed in AD. While the mechanism by which galanin impairs learning has yet to be determined, studies suggest it is through cholinergic mechanisms. We investigated the ability of donepezil to rescue learning and memory deficits induced by galanin administration, and by extension isolated whether the learning impairments produced by galanin were ameliorated by increasing cholinergic tone. We also investigated the effects of donepezil and galanin in an animal model of AD, i.e. their effects on learning and memory following a slight lesion of cholinergic neurons analogous to the cholinergic loss seen in AD. This study provides vital information about the relationship between galanin-induced deficits and acetylcholine, and helps to clarify the roles of donepezil and galanin in AD

    Antithrombotic Treatment for Acute Extracranial Carotid Artery Dissections: A Meta-Analysis

    Get PDF
    IntroductionCarotid artery dissection is a leading cause of stroke in younger patients, with an associated prevalence of 2.6–3.0 per 100,000 population. This meta-analysis aims to determine whether in patients managed medically, treatment with anticoagulants or antiplatelet agents was associated with a better outcome with respect to mortality, ischaemic stroke, and major bleeding episodes.Patients and methodsA comprehensive search strategy was employed of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (January 1966 to March 2015), and EMBASE (January 1980 to March 2015) databases. Primary outcomes were death (all causes) or disability. Secondary outcomes were ischaemic stroke, symptomatic intracranial haemorrhage, and major extracranial haemorrhage during the reported follow-up period.ResultsNo completed randomized trials were found. Comparing antiplatelets with anticoagulants across 38 studies (1,398 patients), there were no significant differences in the odds of death (effects size, ES, −0.007, p = .871), nor in the death and disability comparison or across any secondary outcomes.ConclusionThere were no randomised trials comparing either anticoagulants or antiplatelets with control, thus there is no level 1 evidence to support their routine use for the treatment of carotid artery dissection. Also, there were no randomised trials that directly compared anticoagulants with antiplatelet drugs, and the reported non-randomised studies did not show any evidence of a significant difference between the two
    corecore