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1.
Entropy (Basel) ; 25(4)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37190377

RESUMO

Cortical neurons receive mixed information from the collective spiking activities of primary sensory neurons in response to a sensory stimulus. A recent study demonstrated an abrupt increase or decrease in stimulus intensity and the stimulus intensity itself can be respectively represented by the synchronous and asynchronous spikes of S1 neurons in rats. This evidence capitalized on the ability of an ensemble of homogeneous neurons to multiplex, a coding strategy that was referred to as synchrony-division multiplexing (SDM). Although neural multiplexing can be conceived by distinct functions of individual neurons in a heterogeneous neural ensemble, the extent to which nearly identical neurons in a homogeneous neural ensemble encode multiple features of a mixed stimulus remains unknown. Here, we present a computational framework to provide a system-level understanding on how an ensemble of homogeneous neurons enable SDM. First, we simulate SDM with an ensemble of homogeneous conductance-based model neurons receiving a mixed stimulus comprising slow and fast features. Using feature-estimation techniques, we show that both features of the stimulus can be inferred from the generated spikes. Second, we utilize linear nonlinear (LNL) cascade models and calculate temporal filters and static nonlinearities of differentially synchronized spikes. We demonstrate that these filters and nonlinearities are distinct for synchronous and asynchronous spikes. Finally, we develop an augmented LNL cascade model as an encoding model for the SDM by combining individual LNLs calculated for each type of spike. The augmented LNL model reveals that a homogeneous neural ensemble model can perform two different functions, namely, temporal- and rate-coding, simultaneously.

2.
Sensors (Basel) ; 22(12)2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35746198

RESUMO

Although the application of a wide range of sensors has been generalized through the development of technology, the processing of massive alerts generated through data analysis and monitoring remains a challenge. This problem is also found in cyber security because the intrusion detection system (IDS) produces a tremendous number of alerts. Massive alerts not only significantly increase resources for analysis, but also make it difficult to analyze the overall situation of the system. In order to handle massive alerts, we propose using an indicator as a frequency-based representation. The proposed indicator is generated from categorical parameters of alerts that occur within a unit time utilizing frequency and is used for situational awareness with machine learning to detect whether there is a threat or not. The advantage of using indicators is that they can determine the situation for a period without analyzing individual alerts, which helps security experts to recognize the situation in the system and focus on targets that require in-depth analysis. In addition, the conversion from the categorical parameters which is highly related to analysis to numeric parameter allows for applying machine learning. For performance evaluation, we collect data from an HAI testbed similar to real critical infrastructure and conduct experiments using indicators and XGBoost, a classification machine learning algorithm against five famous vulnerability attacks. Consequently, we show that the proposed method can detect attacks with more than 90 percent accuracy, and the performance is enhanced using heterogeneous intrusion detection systems.


Assuntos
Algoritmos , Segurança Computacional , Aprendizado de Máquina
3.
BMC Bioinformatics ; 22(1): 507, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34663215

RESUMO

BACKGROUND: Ubiquitylation is an important post-translational modification of proteins that not only plays a central role in cellular coding, but is also closely associated with the development of a variety of diseases. The specific selection of substrate by ligase E3 is the key in ubiquitylation. As various high-throughput analytical techniques continue to be applied to the study of ubiquitylation, a large amount of ubiquitylation site data, and records of E3-substrate interactions continue to be generated. Biomedical literature is an important vehicle for information on E3-substrate interactions in ubiquitylation and related new discoveries, as well as an important channel for researchers to obtain such up to date data. The continuous explosion of ubiquitylation related literature poses a great challenge to researchers in acquiring and analyzing the information. Therefore, automatic annotation of these E3-substrate interaction sentences from the available literature is urgently needed. RESULTS: In this research, we proposed a model based on representation and attention mechanism based deep learning methods, to automatic annotate E3-substrate interaction sentences in biomedical literature. Focusing on the sentences with E3 protein inside, we applied several natural language processing methods and a Long Short-Term Memory (LSTM)-based deep learning classifier to train the model. Experimental results had proved the effectiveness of our proposed model. And also, the proposed attention mechanism deep learning method outperforms other statistical machine learning methods. We also created a manual corpus of E3-substrate interaction sentences, in which the E3 proteins and substrate proteins are also labeled, in order to construct our model. The corpus and model proposed by our research are definitely able to be very useful and valuable resource for advancement of ubiquitylation-related research. CONCLUSION: Having the entire manual corpus of E3-substrate interaction sentences readily available in electronic form will greatly facilitate subsequent text mining and machine learning analyses. Automatic annotating ubiquitylation sentences stating E3 ligase-substrate interaction is significantly benefited from semantic representation and deep learning. The model enables rapid information accessing and can assist in further screening of key ubiquitylation ligase substrates for in-depth studies.


Assuntos
Aprendizado Profundo , Ubiquitina-Proteína Ligases , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
4.
J Neurosci ; 35(48): 15827-36, 2015 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-26631465

RESUMO

The feedback-related negativity (FRN) is a commonly observed potential in scalp electroencephalography (EEG) studies related to the valence of feedback about a subject's performance. This potential classically manifests as a negative deflection in medial frontocentral EEG contacts following negative feedback. Recent work has shown prominence of theta power in the spectral composition of the FRN, placing it within the larger class of "frontal midline theta" cognitive control signals. Although the dorsal anterior cingulate cortex (dACC) is thought to be the cortical generator of the FRN, conclusive data regarding its origin and propagation are lacking. Here we examine intracranial electrophysiology from the human medial and lateral prefrontal cortex (PFC) to better understand the anatomical localization and communication patterns of the FRN. We show that the FRN is evident in both low- and high-frequency local field potentials (LFPs) recorded on electrocorticography. The FRN is larger in medial compared with lateral PFC, and coupling between theta band phase and high-frequency LFP power is also greater in medial PFC. Using Granger causality and conditional mutual information analyses, we provide evidence that feedback-related information propagates from medial to lateral PFC, and that this information transfer oscillates with theta-range periodicity. These results provide evidence for the dACC as the cortical source of the FRN, provide insight into the local computation of frontal midline theta, and have implications for reinforcement learning models of cognitive control.


Assuntos
Mapeamento Encefálico , Epilepsia/patologia , Lateralidade Funcional/fisiologia , Neurorretroalimentação/métodos , Córtex Pré-Frontal/fisiopatologia , Reforço Psicológico , Algoritmos , Eletroencefalografia , Epilepsia/reabilitação , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Tempo de Reação , Estatísticas não Paramétricas , Tomógrafos Computadorizados
5.
J Biomed Inform ; 62: 125-35, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27349858

RESUMO

BACKGROUND: A complex disease is caused by heterogeneous biological interactions between genes and their products along with the influence of environmental factors. There have been many attempts for understanding the cause of these diseases using experimental, statistical and computational methods. In the present work the objective is to address the challenge of representation and integration of information from heterogeneous biomedical aspects of a complex disease using semantics based approach. METHODS: Semantic web technology is used to design Disease Association Ontology (DAO-db) for representation and integration of disease associated information with diabetes as the case study. The functional associations of disease genes are integrated using RDF graphs of DAO-db. Three semantic web based scoring algorithms (PageRank, HITS (Hyperlink Induced Topic Search) and HITS with semantic weights) are used to score the gene nodes on the basis of their functional interactions in the graph. RESULTS: Disease Association Ontology for Diabetes (DAO-db) provides a standard ontology-driven platform for describing genes, proteins, pathways involved in diabetes and for integrating functional associations from various interaction levels (gene-disease, gene-pathway, gene-function, gene-cellular component and protein-protein interactions). An automatic instance loader module is also developed in present work that helps in adding instances to DAO-db on a large scale. CONCLUSIONS: Our ontology provides a framework for querying and analyzing the disease associated information in the form of RDF graphs. The above developed methodology is used to predict novel potential targets involved in diabetes disease from the long list of loose (statistically associated) gene-disease associations.


Assuntos
Algoritmos , Biologia Computacional , Doença/genética , Web Semântica , Genes , Humanos , Proteínas
6.
Data Brief ; 52: 110003, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38293574

RESUMO

Diabetes has emerged as a prevalent disease, affecting millions of individuals annually according to statistics. Numerous studies have delved into identifying key genes implicated in the causal mechanisms of diabetes. This paper specifically concentrates on 20 functional genes identified in various studies contributing to the complexities associated with Type 2 diabetes (T2D), encompassing complications such as nephropathy, retinopathy, cardiovascular disorders, and foot ulcers. These functional genes serve as a foundation for identifying regulatory genes, their regulators, and protein-protein interactions. The current study introduces a multi-layer Knowledge Graph (DbKB based on MSNMD: Multi-Scale Network Model for Diabetes), encompassing biological networks such as gene regulatory networks and protein-protein interaction networks. This Knowledge Graph facilitates the visualization and querying of inherent relationships between biological networks associated with diabetes, enabling the retrieval of regulatory genes, functional genes, interacting proteins, and their relationships. Through the integration of biologically relevant genetic, molecular, and regulatory information, we can scrutinize interactions among T2D candidate genes [1] and ascertain diseased genes [2]. The first layer of regulators comprises direct regulators to the functional genes, sourced from the TRRUST database in the human transcription factors dataset, thereby forming a multi-layered directed graph. A comprehensive exploration of these direct regulators reveals a total of 875 regulatory transcription factors, constituting the initial layer of regulating transcription factors. Moving to the second layer, we identify 550 regulatory genes. These functional genes engage with other proteins to form complexes, exhibiting specific functions. Leveraging these layers, we construct a Knowledge Graph aimed at identifying interaction-driven sub-networks involving (i) regulating functional genes, (ii) functional genes, and (iii) protein-protein interactions.

7.
Neurosci Res ; 195: 1-8, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37236268

RESUMO

Sensory information about the environment constantly changes or varies depending on circumstances. However, once we repeatedly experience objects, our brain can perceive and recognize them as identical, even if they are slightly altered or include some diversity. We can stably perceive things without interference from minor external changes or variety. Our recent study focusing on visual perception showed that repeatedly viewing the same oriented grating stimuli enables information representation for low-contrast (or weak-intensity) orientations in the primary visual cortex. We observed low contrast-preferring neurons, whose firing rates increased by reducing the luminance contrast. The number of such neurons increased after the experience, and the neuronal population, including such neurons, can represent even low-contrast orientations. This study indicated that experience leads to flexible information representations that continuously respond to inputs of various strengths at the neuronal population level in the primary sensory cortex. In this perspective article, in addition to the above mechanism, I would discuss alternative mechanisms for perceptual stabilization. The primary sensory cortex represents external information faithfully without alterations, as well as in a state distorted by experience. Both sensory representations may cooperatively and dynamically affect hierarchical downstream, resulting in stable perception.


Assuntos
Córtex Visual , Percepção Visual , Humanos , Percepção Visual/fisiologia , Encéfalo , Córtex Visual/fisiologia , Neurônios/fisiologia , Estimulação Luminosa/métodos
8.
Stud Health Technol Inform ; 290: 414-418, 2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35673047

RESUMO

Patient safety event (PSE) reports are an important source of information for analyzing risks in healthcare processes. However, the reports' quality is often low due to missing or imprecise information. We work towards an automatic analysis of reports and quality evaluation. To leverage a suitable data representation of health IT-induced medication error reports, we apply the Shapes Constraint Language (SHACL). We define an ontology representing these reports and construct a corresponding SHACL graph. Three authors manually annotate and transform 20 textual reports to the SHACL representation. Furthermore, we use this representation to compute a quality score for each report. The results indicate the suitability of SHACL as a representation of health IT-induced medication error reports, which paves a path of automatically extracting information from PSE reports using text mining and transform them to SHACL for quality evaluation.


Assuntos
Idioma , Erros de Medicação , Tecnologia Biomédica , Mineração de Dados , Humanos , Erros de Medicação/prevenção & controle , Relatório de Pesquisa
9.
Artigo em Inglês | MEDLINE | ID: mdl-33748331

RESUMO

Conventional and current wisdom assumes that the brain represents probability as a continuous number to many decimal places. This assumption seems implausible given finite and scarce resources in the brain. Quantization is an information encoding process whereby a continuous quantity is systematically divided into a finite number of possible categories. Rounding is a simple example of quantization. We apply this information theoretic concept to develop a novel quantized (i.e., discrete) probability distortion function. We develop three conjunction probability gambling tasks to look for evidence of quantized probability representations in the brain. We hypothesize that certain ranges of probability will be lumped together in the same indifferent category if a quantized representation exists. For example, two distinct probabilities such as 0.57 and 0.585 may be treated indifferently. Our extensive data analysis has found strong evidence to support such a quantized representation: 59/76 participants (i.e., 78%) demonstrated a best fit to 4-bit quantized models instead of continuous models. This observation is the major development and novelty of the present work. The brain is very likely to be employing a quantized representation of probability. This discovery demonstrates a major precision limitation of the brain's representational and decision-making ability.

10.
E-Cienc. inf ; 7(2)dic. 2017.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1506115

RESUMO

n este ensayo se analizan los Sistemas para la Organización del Conocimiento (SOC) con el objetivo de establecer su definición y la forma en que evolucionó históricamente. Se propone que los SOC son fundamentales en la bibliotecología, en tanto que estandarizan los procesos ordenadores y posibilitan el efectivo rescate de la información. Se determina que: (1) en la parte conceptual confluyen diversos conceptos de SOC, (2) su evolución histórica está asociada a visiones interdisciplinarias (epistemología, ciencias cognitivas, bibliotecología, ciencias computacionales), (3) históricamente, han pasado por diversas etapas, asociadas a los paradigmas organizadores imperantes y, (4) actualmente, están en un proceso de ajuste a contextos digitales asociados a la Web 2.0, la Web Semántica y el Linked Data. Finalmente, puede concluirse que el estudio teórico de los SOC es importante, ya que contribuye a una mejor planeación de las aplicaciones prácticas que éstos pueden tener en la organización de recursos de información.


his essay analyzes Knowledge Organization Systems (KOS) with the aim to establish its concept and historical evolution. It proposes that KOS are essential in library science because standardizes the ordering process and enable an effective information retrieval. It determines that: (1) in the conceptual facet converges many concepts of KOS, (2) their historical evolution is associated with interdisciplinary visions (epistemology, cognitive sciences, library science, computer science), (3) along the time, have gone through various stages, associated with prevailing organizers paradigms and, (4) currently, KOS are in a process of adjustment to digital contexts: associated with the Web 2.0, Semantic Web and Linked Data. Finally, it concludes that the theoretical study about the KOS is important because it contributes to a better planning of the practical applications that it may have in the organization of information resources.

11.
Rev. cuba. farm ; 48(4)oct.-dic. 2014. ilus
Artigo em Espanhol | LILACS, CUMED | ID: lil-748778

RESUMO

INTRODUCCIÓN: el Centro de Estudios, Documentación e Información de Medicamentos se ha propuesto el desarrollo e implementación de un sistema de gestión de la calidad total, que le permita la evaluación y certificación de la calidad de sus servicios. Se hace entonces imperativo para esta organización el diagnóstico de su desempeño, identificar fortalezas y debilidades, así como implementar acciones en aquellos procesos susceptibles a mejoras. OBJETIVO: evaluar los procesos de organización, representación y almacenamiento de la información en el Centro de Estudio, Documentación e Información de Medicamentos (CEDIMED). MÉTODOS: se analizó la variable organización, representación y almacenamiento de la información, incluida en el Modelo Integral para Auditar Organizaciones de Información en Cuba; para lo cual se evaluó el comportamiento de ocho indicadores. RESULTADOS: dos indicadores fueron evaluados de excelente, uno de regular y cinco recibieron evaluación de mal. Estos últimos fueron: normalización de la descripción bibliográfica, sistemas de lenguajes para la descripción de contenidos, tiempo para el procesamiento de los documentos, utilización de software para la ejecución de los procesos técnicos y representación de la información a través de catálogos. En general, la variable estudiada fue evaluada de mal. CONCLUCIONES: la falta de capacitación de los recursos humanos de la organización en las actividades propias de la representación y organización de la información, resulta ser el factor determinante en los resultados alcanzados por el CEDIMED en esta variable(AU)


INTRODUCTION: the Center for Study, Documentation and Information of Drugs has set out to develop and implement an overall quality management system that allows the evaluation and certification of the quality of its services. It was then imperative for this organization to make a diagnosis of its performance, to identify strengths and weaknesses and to carry out actions in those processes that may be upgraded. OBJECTIVE: to evaluate the processes of information organization, representation and storage in the Center of Study, Documentation and Information of Drugs (CEDIMED). METHODS: the variable called information organization, representation and storage included in the Integrated Model for Auditing Information Organizations in Cuba was analyzed on the basis of the behavior of eight indicators. RESULTS: two indicators were rated as excellent, one as regular and five as unsatisfactory. The latter were standardization of bibliographic description, language systems for content descriptions, time elapsed for document processing, use of software for technical processes and representation of information through the catalogues. The general evaluation of this variable was unsatisfactory. CONCLUSIONS: the lack of training of human resources in the center in terms of information representation and organization activities was the key factor for the results achieved in this specific variable by CEDIMED(AU)


Assuntos
Humanos , Armazenamento e Recuperação da Informação , Ciência da Informação , Auditoria Administrativa , Cuba
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