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Nevin Manimala Statistics

Stabilization of reaction-diffusion fractional-order memristive neural networks

Neural Netw. 2023 May 27;165:290-297. doi: 10.1016/j.neunet.2023.05.042. Online ahead of print.

ABSTRACT

This paper investigates the stabilization control of fractional-order memristive neural networks with reaction-diffusion terms. With regard to the reaction-diffusion model, a novel processing method based on Hardy-Poincarè inequality is introduced, as a result, the diffusion terms are estimated associated with the information of the reaction-diffusion coefficients and the regional feature, which may be beneficial to obtain conditions with less conservatism. Then, based on Kakutani’s fixed point theorem of set-valued maps, new testable algebraic conclusion for ensuring the existence of the system’s equilibrium point is obtained. Subsequently, by means of Lyapunov stability theory, it is concluded that the resulting stabilization error system is global asymptotic/Mittag-Leffler stable with a prescribed controller. Finally, an illustrative example about is provided to show the effectiveness of the established results.

PMID:37307670 | DOI:10.1016/j.neunet.2023.05.042

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Nevin Manimala Statistics

Epicasting: An Ensemble Wavelet Neural Network for forecasting epidemics

Neural Netw. 2023 Jun 1;165:185-212. doi: 10.1016/j.neunet.2023.05.049. Online ahead of print.

ABSTRACT

Infectious diseases remain among the top contributors to human illness and death worldwide, among which many diseases produce epidemic waves of infection. The lack of specific drugs and ready-to-use vaccines to prevent most of these epidemics worsens the situation. These force public health officials and policymakers to rely on early warning systems generated by accurate and reliable epidemic forecasters. Accurate forecasts of epidemics can assist stakeholders in tailoring countermeasures, such as vaccination campaigns, staff scheduling, and resource allocation, to the situation at hand, which could translate to reductions in the impact of a disease. Unfortunately, most of these past epidemics exhibit nonlinear and non-stationary characteristics due to their spreading fluctuations based on seasonal-dependent variability and the nature of these epidemics. We analyze various epidemic time series datasets using a maximal overlap discrete wavelet transform (MODWT) based autoregressive neural network and call it Ensemble Wavelet Neural Network (EWNet) model. MODWT techniques effectively characterize non-stationary behavior and seasonal dependencies in the epidemic time series and improve the nonlinear forecasting scheme of the autoregressive neural network in the proposed ensemble wavelet network framework. From a nonlinear time series viewpoint, we explore the asymptotic stationarity of the proposed EWNet model to show the asymptotic behavior of the associated Markov Chain. We also theoretically investigate the effect of learning stability and the choice of hidden neurons in the proposal. From a practical perspective, we compare our proposed EWNet framework with twenty-two statistical, machine learning, and deep learning models for fifteen real-world epidemic datasets with three test horizons using four key performance indicators. Experimental results show that the proposed EWNet is highly competitive compared to the state-of-the-art epidemic forecasting methods.

PMID:37307664 | DOI:10.1016/j.neunet.2023.05.049

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Nevin Manimala Statistics

Reinforced mixture learning

Neural Netw. 2023 May 25;165:175-184. doi: 10.1016/j.neunet.2023.05.018. Online ahead of print.

ABSTRACT

In this article, we formulate the standard mixture learning problem as a Markov Decision Process (MDP). We theoretically show that the objective value of the MDP is equivalent to the log-likelihood of the observed data with a slightly different parameter space constrained by the policy. Different from some classic mixture learning methods such as Expectation-Maximization (EM) algorithm, the proposed reinforced algorithm requires no distribution assumptions and can handle the non-convex clustered data by constructing a model-free reward to evaluate the mixture assignment based on the spectral graph theory and Linear Discriminant Analysis (LDA). Extensive experiments on both synthetic and real examples demonstrate that the proposed method is comparable with the EM algorithm when the Gaussian mixture assumption is satisfied, and significantly outperforms it and other clustering methods in most scenarios when the model is misspecified. A Python implementation of our proposed method is available at https://github.com/leyuanheart/Reinforced-Mixture-Learning.

PMID:37307663 | DOI:10.1016/j.neunet.2023.05.018

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Nevin Manimala Statistics

Evaluation of evolving sepsis screening criteria in discriminating suspected sepsis and mortality among adult patients admitted to the intensive care unit

Int J Nurs Stud. 2023 May 19;145:104529. doi: 10.1016/j.ijnurstu.2023.104529. Online ahead of print.

ABSTRACT

BACKGROUND: Institutions struggle with successful use of sepsis alerts within electronic health records.

OBJECTIVE: Test the association of sepsis screening measurement criteria in discrimination of mortality and detection of sepsis in a large dataset.

DESIGN: Retrospective, cohort study using a large United States (U.S.) intensive care database. The Institutional Review Board exempt status was obtained from Kansas University Medical Center Human Research Protection Program (10-1-2015).

SETTING: 334 U.S. hospitals participating in the eICU Research Institute.

PARTICIPANTS: Nine hundred twelve thousand five hundred and nine adult intensive care admissions from 183 hospitals.

METHODS: Exposures included: systemic inflammatory response syndrome criteria ≥ 2 (Sepsis-1); systemic inflammatory response syndrome criteria with organ failure criteria ≥ 3.5 points (Sepsis-2); and sepsis-related organ failure assessment score ≥ 2 and quick score ≥ 2 (Sepsis-3). Discrimination of outcomes was determined with/without (adjusted/unadjusted) baseline risk exposure to a model. The receiver operating characteristic curve (AUROC) and odds ratios (ORs) for each decile of baseline risk of sepsis or death were assessed.

RESULTS: Within the eligible cohort of 912,509, a total of 86,219 (9.4 %) patients did not survive their hospital stay and 186,870 (20.5 %) met the definition of suspected sepsis. For suspected sepsis discrimination, Sepsis-2 (unadjusted AUROC 0.67, 99 % CI: 0.66-0.67 and adjusted AUROC 0.77, 99 % CI: 0.77-0.77) outperformed Sepsis-3 (SOFA unadjusted AUROC 0.61, 99 % CI: 0.61-0.61 and adjusted AUROC 0.74, 99 % CI: 0.74-0.74) (qSOFA unadjusted AUROC 0.59, 99 % CI: 0.59-0.60 and adjusted AUROC 0.73, 99 % CI: 0.73-0.73). Sepsis-2 also outperformed Sepsis-1 (unadjusted AUROC 0.58, 99 % CI: 0.58-0.58 and adjusted AUROC 0.73, 99 % CI: 0.73-0.73). In between differences of AUROCs were statistically significantly different. Sepsis-2 ORs were higher for the outcome of suspected sepsis when considering deciles of risk than the other measurement systems.

CONCLUSIONS AND RELEVANCE: Sepsis-2 outperformed other systems in suspected sepsis detection and was comparable to SOFA in prognostic accuracy of mortality in adult intensive care patients.

PMID:37307638 | DOI:10.1016/j.ijnurstu.2023.104529

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Nevin Manimala Statistics

Mood and anxiety spectrum disorders detected by neuropsychiatric interviews in young adults born preterm: A prospective cohort study

Eur J Paediatr Neurol. 2023 Jun 8;45:57-60. doi: 10.1016/j.ejpn.2023.06.002. Online ahead of print.

ABSTRACT

BACKGROUND: Psychopathology has not yet been studied beyond pediatric age for all degrees of prematurity, including late-preterm, particularly in those who grew up with no apparent neurodevelopmental sequelae. This study aimed to examine psychopathological outcome following preterm birth and admission to neonatal intensive care in young adults without major neurodevelopmental and psychopathological problems that emerged during childhood.

METHODS: An Italian single-center prospective cohort study. Eighty-nine young adults (40 admitted to neonatal intensive care unit with less than 37 weeks of gestation and no medical history of other neurological or psychiatric conditions in childhood and 49 healthy peers born at term, matched by age, sex, and education) underwent neuropsychiatric interviews at the age of 20 ± 1 years; MINI International Neuropsychiatric Interview, Beck Depression Inventory and Barratt Impulsive Scale, results were correlated to individual neonatal data and cognitive measures.

RESULTS: We found a significantly higher prevalence of psychopathology at MINI score (22.5% vs. 4.2%; χ2 = 6.7; p = 0,010) and prevalence of previous stressful life events in the preterm compared to at-term group. B.D.I. (testing depression) and BIS-11(testing impulsivity) did not highlight a statistically significant difference between the groups. All patients had average I.Q., a statistically significant difference (p < 0.001) was observed between groups with a better performance in controls than cases.

CONCLUSIONS: Preterm infants attaining young adult age with otherwise typical development during childhood are at risk of psychopathology and lower resilience to stressful life events. The MINI interview could be a useful tool to highlight the psychopathology of preterm infants attaining adult age.

PMID:37307630 | DOI:10.1016/j.ejpn.2023.06.002

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Nevin Manimala Statistics

Effect of artemisinin combined with allicin on improving cardiac function, fibrosis and NF-κB signaling pathway in rats with diabetic cardiomyopathy

Acta Biochim Pol. 2023 Jun 12. doi: 10.18388/abp.2020_6692. Online ahead of print.

ABSTRACT

Myocardial fibrosis and inflammation cause cardiac hypertrophy, arrhythmias, and heart failure in diabetics, a leading cause of mortality. Since it’s complicated, no drug treats diabetic cardiomyopathy. This research examined the effects of artemisinin and allicin on heart function, myocardial fibrosis, and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway in diabetic cardiomyopathy rats. A total of 50 rats were separated into 5 groups, 10 of which were the control group. 40 rats received 65 μg/g streptozotocin intraperitoneally. 37 of 40 animals fit the investigation. The artemisinin, allicin, and artemisinin/allicin groups each included nine animals. The artemisinin group received 75 mg/kg of artemisinin, the allicin group received 40 mg/kg of allicin, and the combination group received equal dosages of artemisinin and allicin gavage for four weeks. After the intervention, in each group cardiac functions, myocardial fibrosis, and NF-κB signaling pathway protein expression were assessed. All of the examined groups had greater levels of LVEDD, LVESD, LVEF, FS, E/A, and the NF-κB pathway proteins: NF-κB p65 and p-NF-κB p65 than the normal group, except for the combination group. Artemisinin and allicin did not vary statistically. Compared to the model group, the artemisinin, allicin, and combined groups showed various degrees of improvement from the pathological pattern, with more intact muscle fibers, neater arrangement, more normal cell morphology, artemisinin and allicin alleviated cardiac dysfunction and decreased myocardium fibrosis in diabetic cardiomyopathy rats by inactivating the NF-κB signaling cascade.

PMID:37307593 | DOI:10.18388/abp.2020_6692

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Nevin Manimala Statistics

Sodium evolution in hyponatraemia: a mixed effects model analysis of the hyponatraemia registry

Eur J Endocrinol. 2023 Jun 12:lvad062. doi: 10.1093/ejendo/lvad062. Online ahead of print.

ABSTRACT

OBJECTIVE: Achieving recommended targets of sodium correction is challenging to physicians treating hyponatraemia. Plasma sodium has to be increased effectively, yet overcorrection must be prevented. This is often hampered by a high variability of responses to treatment. Here, we sought to delineate factors influencing sodium evolution.

DESIGN: We retrospectively analysed 3,460 patients from the multinational Hyponatraemia Registry comprising a wide range of hyponatraemia aetiologies and treatment strategies.

METHODS: Multivariable linear mixed effects models were applied to identify predictors of plasma sodium evolution within the first 24 hours of treatment.

RESULTS: Evolution of sodium levels over time showed a curvilinear pattern with steeper rise at earlier timepoints. Baseline sodium showed the most pronounced impact with an additional increment of 3.12 mEq/L for every 10 mEq/L initial sodium reduction. With sodium increments of 1.9 mEq/L and 1.4 mEq/L per 24 hours, respectively, the entities hypovolaemic and thiazide-associated hyponatraemia were independent factors for sodium evolution. Therapeutic regimens using hypertonic saline (4.6 mEq/L/24 h), tolvaptan (3.4 mEq/L/24 h), or combination therapy (2.6 mEq/L/24 h) were also associated with a significantly larger sodium rise when compared with no active treatment.

CONCLUSIONS: Choice and dosing of active hyponatraemia therapy should be adjusted not only according to aetiology but most importantly to pre-treatment sodium. Although counterintuitive, less aggressive therapy in more profound hyponatraemia might be safer but yet effective at least in less severe cases.

PMID:37307578 | DOI:10.1093/ejendo/lvad062

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Nevin Manimala Statistics

A quantitative theory for genomic offset statistics

Mol Biol Evol. 2023 Jun 12:msad140. doi: 10.1093/molbev/msad140. Online ahead of print.

ABSTRACT

Genomic offset statistics predict the maladaptation of populations to rapid habitat alteration based on association of genotypes with environmental variation. Despite substantial evidence for empirical validity, genomic offset statistics have well-identified limitations, and lack a theory that would facilitate interpretations of predicted values. Here, we clarified the theoretical relationships between genomic offset statistics and unobserved fitness traits controlled by environmentally selected loci, and proposed a geometric measure to predict fitness after rapid change in local environment. The predictions of our theory were verified in computer simulations and in empirical data on African pearl millet (Cenchrus americanus) obtained from a common garden experiment. Our results proposed a unified perspective on genomic offset statistics, and provided a theoretical foundation necessary when considering their potential application in conservation management in the face of environmental change.

PMID:37307566 | DOI:10.1093/molbev/msad140

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Nevin Manimala Statistics

Versatile detection of diverse selective sweeps with Flex-sweep

Mol Biol Evol. 2023 Jun 12:msad139. doi: 10.1093/molbev/msad139. Online ahead of print.

ABSTRACT

Understanding the impacts of selection pressures influencing modern-day genomic diversity is a major goal of evolutionary genomics. In particular, the contribution of selective sweeps to adaptation remains an open question, with persistent statistical limitations on the power and specificity of sweep detection methods. Sweeps with subtle genomic signals have been particularly challenging to detect. While many existing methods powerfully detect specific types of sweeps and/or those with strong signals, their power comes at the expense of versatility. We present Flex-sweep, a machine learning-based tool designed to detect sweeps with a variety of subtle signals, including those thousands of generations old. It is especially valuable for non-model organisms, for which we have neither expectations about the overall characteristics of sweeps nor outgroups with population-level sequencing to otherwise facilitate detecting very old sweeps. We show that Flex-sweep has the power to detect sweeps with subtle signals, even in the face of demographic model misspecification, recombination rate heterogeneity, and background selection. Flex-sweep detects sweeps up to 0.125 * 4Ne generations old, including those that are weak, soft, and/or incomplete; it can also detect strong, complete sweeps up to 0.25 * 4Ne generations old. We apply Flex-sweep to the 1000 Genomes Yoruba data set and, in addition to recovering previously identified sweeps, show that sweeps disproportionately occur within genic regions and close to regulatory regions. In addition, we show that virus-interacting proteins (VIPs) are strongly enriched for selective sweeps, recapitulating previous results that demonstrate the importance of viruses as a driver of adaptive evolution in humans.

PMID:37307561 | DOI:10.1093/molbev/msad139

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Nevin Manimala Statistics

Utility of Regional Maxillary Nerve Blocks in Improving Cleft Palate Postoperative Outcomes

J Craniofac Surg. 2023 Jun 12. doi: 10.1097/SCS.0000000000009464. Online ahead of print.

ABSTRACT

BACKGROUND: Palatoplasty procedures used to repair cleft palates are commonly associated with limiting postoperative pain. Regional anesthetic blocks have been utilized to improve pain outcomes and decrease opioid intake, yet additional data is needed to fully explore its utility in this setting.

OBJECTIVE: To explore whether ultrasound-guided suprazygomatic maxillary blocks (SMB) improve postoperative pain, postoperative opioid use, time to oral feeding, and length of stay compared with a palatal field block in cleft palate repair.

METHODS: In this retrospective chart review, 47 patients aged 9 to 25 months who underwent cleft palate repair between 2013 and 2020 were allocated into 2 groups: a control group where patients received only palatal local anesthetic in a field block fashion (N=29), and Maxillary block group who received ultrasound-guided SMB (N=18). Patients were matched by age and cleft Veau type. The primary outcomes were total postoperative morphine equivalent consumption, average pain scores, length of stay, and time to first oral feed.

RESULTS: Comparing field block versus SMB groups, there was not a statistical difference in the overall dose of postoperative morphine equivalent opioid administration (11.71 vs. 13.36 mg; P=0.483), average pain scores (5.78 vs. 5.27; P=0.194), time to first oral feed [17.21 vs. 14.48 h; P=0.407, 95% CI: (-3.85, 9.32)] or length of stay (P=0.292).

CONCLUSION: The use of SMBs did not demonstrate a difference in the postoperative outcomes evaluated by this study. Further study is needed to define its utility in cleft palate repair.

PMID:37307540 | DOI:10.1097/SCS.0000000000009464