A Signature of Passivity? An Explorative Study of the N3 Event-Related Potential Component in Passive Oddball Tasks

AbstractBackgroundMany passive oddball experiments show a sharp negative deflection N3 after P3b, peaking between 400 and 500 ms, but this wave has never been analyzed properly. We conducted five passive oddball experiments, in which the number of deviants (i.e., one or two), their alleged meaning, and their distinctiveness varied.ResultsMastoid- or common-referenced waveforms showed a fronto-central N3 in all experiments. The data were CSD (Current Source Density) transformed and underwent a Principal Component Analysis (PCA). The PCA revealed N3 containing two subcomponents with very stable peak latencies of about 415 and 455 ms, respectively. Both topography of the subcomponents and their variation with experimental conditions were very similar, indicating a midfrontal sink and a posterior temporal source. An analysis of P3a and P3b components replicated previously known effects.ConclusionsWe discuss the similarities and differences between the passive N3 and other components including the MMN, N1, late positive Slow Wave, and reorienting negativity. We also make general hypotheses about a possible functional meaning of N3; on this basis, specific hypotheses are formulated and further experiments are suggested to test these hypotheses.

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Effect of the chain length on near-infrared spectra of 1-alcohols from methanol to 1-decanol

NIR news ◽

10.1177/0960336019836861 ◽

2019 ◽

Vol 30 (3) ◽

pp. 6-8

Author(s):

Mirosław Antoni Czarnecki ◽

Michał Kwaśniewicz

Keyword(s):

Principal Component Analysis ◽

Chain Length ◽

Infrared Spectra ◽

Near Infrared ◽

Principal Component ◽

Pure Liquid ◽

Chemometric Methods ◽

Near Infrared Spectra ◽

Similarities And Differences ◽

Self Association

This work shows the effect of the chain length on near-infrared spectra of 1-alcohols and is based on a recent paper by Kwaśniewicz and Czarnecki ( Appl Spectrosc 2018, 72: 288). Near-infrared spectra of 1-alcohols from methanol to 1-decanol in the pure liquid phase were recorded from 5200 to 9000 cm−1. The similarities and differences between the spectra were analyzed by the classical and chemometric methods (principal component analysis). The obtained results reveal that the near-infrared spectra of methanol, ethanol, and 1-propanol are appreciably different from the spectra of higher 1-alcohols. As shown, the degree of self-association of 1-alcohols decreases with the increase in the chain length.

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Reply to “Current source density approaches improve spatial resolution in event related potential analysis in people with Parkinson’s disease”

Clinical Neurophysiology ◽

10.1016/j.clinph.2019.07.009 ◽

2019 ◽

Vol 130 (10) ◽

pp. 2000

Author(s):

Inbal Maidan

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Spatial Resolution ◽

Current Source ◽

Event Related Potential ◽

Current Source Density ◽

Potential Analysis ◽

Source Density

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Principal component analysis of coronaviruses reveals their diversity and seasonal and pandemic potential

PLoS ONE ◽

10.1371/journal.pone.0242954 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0242954

Author(s):

Tomokazu Konishi

Keyword(s):

Principal Component Analysis ◽

Genome Sequencing ◽

Principal Component ◽

Component Analysis ◽

Influenza Viruses ◽

Sequencing Data ◽

Similarities And Differences ◽

Annual Changes

Coronaviruses and influenza viruses have similarities and differences. In order to comprehensively compare them, their genome sequencing data were examined by principal component analysis. Coronaviruses had fewer variations than a subclass of influenza viruses. In addition, differences among coronaviruses that infect a variety of hosts were also small. These characteristics may have facilitated the infection of different hosts. Although many of the coronaviruses were conservative, those repeatedly found among humans showed annual changes. If SARS-CoV-2 changes its genome like the Influenza H type, it will repeatedly spread every few years. In addition, the coronavirus family has many other candidates for new pandemics.

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Application of principal component analysis to the indicators of water exchange of triticale shoots under NaCl stress

Butlerov Communications ◽

10.37952/roi-jbc-01/20-62-4-129 ◽

2020 ◽

Vol 62 (4) ◽

pp. 129-134

Author(s):

Viktor V. Ivanishchev ◽

Keyword(s):

Oxidative Stress ◽

Hydrogen Peroxide ◽

Principal Component Analysis ◽

Water Content ◽

Osmotic Potential ◽

Water Regime ◽

Principal Component ◽

Nacl Stress ◽

Experimental Conditions ◽

Salt Ions

The results of the study of the water regime characteristics (without and taking into account the indicators of oxidative stress) of triticale shoots under conditions of short-term NaCl stress were analyzed with the principal component analysis (PCA). It is shown that the water content is the most stable indicator of triticale shoots under experimental conditions. The results of the analysis led to the conclusion that its value is not determined by the value of stomatal conductivity and/or transpiration. Determination of the correlation coefficients between the studied characteristics yielded negative values between the water content and other indicators of the water regime, as well as oxidative stress, except for the value of lipid peroxidation (LPO) (0.67). Despite the closest relationship between the water content and the osmotic potential according to the results of cluster analysis, the correlation between them was negative (-0.76). This can be explained by different physiological and biochemical mechanisms that support each of these indicators. It is also shown that manifestations of oxidative stress are closely related to the osmotic potential and water content. In this case, the formation of a first-order cluster was observed between the content of water and hydrogen peroxide. This is not unexpected, but the correlation coefficient between them was only 0.018. This value can be interpreted in such a way that water is needed for the formation of hydrogen peroxide, but their quantitative ratio (water : hydrogen peroxide) in the shoots of triticale is significantly different. The inclusion in the analysis of the results of the accumulation of salt ions showed a closer relationship between the increase in the content of salt ions and the change in transpiration, stomatal conductivity and the content of proline than with the water content in the shoots of triticale under experimental conditions.

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EEG Bands During Wakefulness, Slow-Wave, and Paradoxical Sleep As a Result of Principal Component Analysis in the Rat

SLEEP ◽

10.1093/sleep/24.4.374 ◽

2001 ◽

Vol 24 (4) ◽

pp. 374-380 ◽

Cited By ~ 35

Author(s):

María Corsi-Cabrera ◽

Enrique Pérez-Garci ◽

Yolanda Del Río-Portilla ◽

Enrique Ugalde ◽

Miguel Angel Guevara

Keyword(s):

Principal Component Analysis ◽

Slow Wave ◽

Paradoxical Sleep ◽

Principal Component ◽

Component Analysis

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EEG Bands During Wakefulness, Slow-Wave and Paradoxical Sleep as a Result Of Principal Component Analysis in Man

SLEEP ◽

10.1093/sleep/23.6.1a ◽

2000 ◽

Vol 23 (6) ◽

pp. 1-7 ◽

Cited By ~ 39

Author(s):

María Corsi-Cabrera ◽

Miguel Angel Guevara ◽

Yolanda Del Río-Portilla ◽

Consuelo Arce ◽

Yolanda Villanueva-Hernández

Keyword(s):

Principal Component Analysis ◽

Slow Wave ◽

Paradoxical Sleep ◽

Principal Component ◽

Component Analysis

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PENGELOLAAN PERIKANAN KARANG DI TAMAN NASIONAL WAKATOBI: PERSPEKTIF AKTOR DAN AGEN

Marine Fisheries Journal of Marine Fisheries Technology and Management ◽

10.29244/jmf.9.1.89-96 ◽

2018 ◽

Vol 9 (1) ◽

pp. 89

Author(s):

Mercy - Patanda ◽

Sugeng Hari Wisudo ◽

Daniel Rudolf Monintja ◽

Budy - Wiryawan

Keyword(s):

Principal Component Analysis ◽

Coral Reef ◽

Marine Protected Areas ◽

National Park ◽

Principal Component ◽

Component Analysis ◽

Conservation Areas ◽

Similarities And Differences ◽

The Government ◽

Fishing Area

Stakeholders, who are agents and actors in this matter play an important role in the management of reef fisheries in Wakatobi National Park. This study aims to identify the agents and actors in Wakatobi Regency and to identify similarities and differences of the perception between agents and actors in the management of conservation areas. The method used is Principal Component Analysis (PCA). The result showed that there was a similar perception between agent and actor in which that the conservation gives benefit for the society in Wakatobi and the lack of regulation in Wakatobi Regency. Different perceptions between actors and agents occurred due to fishermen intention to fully utilize the resources for their welfare while the government intents to limit the fishing area in order to preserve the natural resources and the environment. Therefore, management related to the regulation on legal-size of fish and the effectiveness of marine protected areas are needed. Keywords: Stakeholders, Coral Reef, Conservation, Wakatobi ABSTRAKPemangku kepentingan sangat berperan penting dalam pengelolaan perikanan karang di Taman Nasional Kabupaten Wakatobi. Tujuan penelitian adalah mengidentifikasi agen dan aktor yang berada di Kabupaten Wakatobi serta melihat persamaan dan perbedaan persepsi antara agen dengan aktor dalam pengelolaan kawasan konservasi. Penelitian ini menggunakan analisis Principal Component Analysis (PCA). Hasil kajian menunjukkan adanya persamaan persepsi antara agen dan aktor yaitu konservasi memberikan manfaat bagi masyarakat yang ada di Wakatobi dan masih kurangnya peraturan di Kabupaten Wakatobi. Perbedaan persepsi pada aktor dan agen karena nelayan ingin memanfaatkan perairan Taman nasional Wakatobi semaksimal mungkin untuk kesejahteraan nelayan sedangkan pemerintah membatasi wilayah penangkapan dalam rangka menjaga sumber daya alam dan lingkungannya sehingga perlu tindakan pengelolaan yaitu penentuan ukuran ikan yang tertangkap dan pengefektifan daerah perlindungan laut.Kata kunci: Pemangku Kepentingan, Perikanan Karang, Konservasi, Wakatobi

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Analysis of synaptic events in the opossum piriform cortex with improved current source-density techniques

Journal of Neurophysiology ◽

10.1152/jn.1989.61.4.702 ◽

1989 ◽

Vol 61 (4) ◽

pp. 702-718 ◽

Cited By ~ 55

Author(s):

R. Rodriguez ◽

L. B. Haberly

Keyword(s):

Piriform Cortex ◽

Current Source ◽

Field Potential ◽

Pyramidal Cells ◽

Superficial Layer ◽

Current Source Density ◽

Membrane Currents ◽

Source Density ◽

Potential Component ◽

Association Fibers

1. The piriform cortex of the opossum was studied by current source-density (CSD) analysis of field potentials to determine the laminar and temporal distribution of synaptic currents evoked by lateral olfactory tract (LOT) stimulation. 2. Extracellular conductivity was measured as a function of depth at high resolution and incorporated into CSD computations. Inclusion of the conductivity term resulted in relatively subtle changes in the shapes of CSD profiles. Resolution and accuracy of CSD computations was further improved by use of a new smoothing approach and averaging of multiple potential profiles obtained at the same site. 3. The CSD depth profile resulting from LOT stimulation revealed six major synaptic events that were consistently present at anterior, middle, and posterior sites: one during the first (A1) peak of the initial surface negative dichrotic field potential component, three during the second (B1) peak, one during the surface positive field potential component (period 2), and one during the second surface negative component (period 3). In addition, CSD profiles were computed for the population spike generated by synchronous discharge of action potentials. Depths of the net inward and outward membrane currents underlying these events were correlated with the cortical lamination as determined histologically by placement of small dye marks. 4. In agreement with previous reports it is concluded that the large inward membrane current in layer Ia during the A1 wave underlies a monosynaptic EPSP evoked in distal apical dendritic segments of pyramidal cells by afferent fibers. This EPSP displays a marked paired shock facilitation. 5. Based on anatomic and physiological considerations it is concluded that the three spatially and temporally distinct inward membrane currents (sinks) that were observed in layers III, superficial Ib, and mid- to deep-Ib during the B1 wave, underlie disynaptic EPSPs resulting from direct synaptic interactions between pyramidal cells. It is postulated that the layer III sink is generated in basal dendrites largely via local axon collaterals, the superficial layer Ib sink in intermediate apical dendritic segments by association fibers originating in the anterior piriform cortex, and the deep Ib sink in proximal apical segments by association fibers originating largely in the posterior piriform cortex. 6. The latencies of the layer Ia and superficial layer Ib sinks (presumed mono- and large disynaptic EPSPs, respectively) increased from anterior to posterior. Amplitude of the superficial Ib sink relative to the Ia sink increased from anterior to posterior.(ABSTRACT TRUNCATED AT 400 WORDS)

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Converging Inputs to the Entorhinal Cortex From the Piriform Cortex and Medial Septum: Facilitation and Current Source Density Analysis

Journal of Neurophysiology ◽

10.1152/jn.1997.78.5.2602 ◽

1997 ◽

Vol 78 (5) ◽

pp. 2602-2615 ◽

Cited By ~ 19

Author(s):

C. Andrew Chapman ◽

Ronald J. Racine

Keyword(s):

Entorhinal Cortex ◽

Piriform Cortex ◽

Current Source ◽

Field Potential ◽

Medial Septum ◽

Current Source Density ◽

Short Term ◽

Source Density ◽

Potential Component ◽

Stimulation Of

Chapman, C. Andrew and Ronald J. Racine. Converging inputs to the entorhinal cortex from the piriform cortex and medial septum: facilitation and current source density analysis. J. Neurophysiol. 78: 2602–2615, 1997. The entorhinal cortex receives sensory inputs from the piriform cortex and modulatory inputs from the medial septum. To examine short-term synaptic facilitation effects in these pathways, current source density (CSD) analysis was used first to localize the entorhinal cortex membrane currents, which generate field potentials evoked by stimulation of these afferents. Field potentials were recorded at 50-μm intervals through the medial entorhinal cortex in urethan-anesthetized rats and the one-dimensional CSD was calculated. Piriform cortex stimulation evoked a surface-negative, deep-positive field potential component in the entorhinal cortex with mean onset and peak latencies of 10.4 and 18.4 ms. The component followed brief 100-Hz stimulation, consistent with a monosynaptic response. CSD analysis linked the component to a current sink, which often began in layer I before peaking in layer II. A later, surface-positive field potential component peaked at latencies near 45 ms and was associated with a current source in layer II. Medial septal stimulation evoked positive and negative field potential components which peaked at latencies near 7 and 16 ms, respectively. A weaker and more prolonged surface-negative, deep-positive component peaked at latencies near 25 ms. The early components were generated by currents in the hippocampal formation, and the late surface-negative component was generated by currents in layers II to IV of the entorhinal cortex. Short-term facilitation effects in conscious animals were examined using electrodes chronically implanted near layer II of the entorhinal cortex. Paired-pulse stimulation of the piriform cortex at interpulse intervals of 30 and 40 ms caused the largest facilitation (248%) of responses evoked by the second pulse. Responses evoked by medial septal stimulation also were facilitated maximally (59%) by a piriform cortex conditioning pulse delivered 30–40 ms earlier. Paired pulse stimulation of the medial septum caused the largest facilitation (149%) at intervals of 70 ms, but piriform cortex evoked responses were facilitated maximally (46%) by a septal conditioning pulse 100–200 ms earlier. Frequency potentiation effects were maximal during 12- to 18-Hz stimulation of either the piriform cortex or medial septum. Occlusion tests suggested that piriform cortex and medial septal efferents activate the same neurons. The CSD analysis results show that evoked field potential methods can be used effectively in chronically prepared animals to examine synaptic responses in the converging inputs from the piriform cortex and medial septum to the entorhinal cortex. The short-term potentiation phenomena observed here suggest that low-frequency activity in these pathways during endogenous oscillatory states may enhance entorhinal cortex responsivity to olfactory inputs.

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AVALIAÇÃO DO PERFIL SENSORIAL DE AMÊNDOAS DE CUPUAÇU E CACAU TORRADAS UTILIZANDO ANÁLISE DESCRITIVA QUANTITATIVA

Boletim do Centro de Pesquisa de Processamento de Alimentos ◽

10.5380/cep.v18i2.1214 ◽

2000 ◽

Vol 18 (2) ◽

Author(s):

MARISE BONIFÁCIO QUEIROZ ◽

NELSON HORÁCIO PEZOA GARCIA

Keyword(s):

Principal Component Analysis ◽

Descriptive Analysis ◽

Principal Component ◽

The Other ◽

Sensory Characteristics ◽

Sensory Profile ◽

Discriminative Ability ◽

Tukey Test ◽

Similarities And Differences ◽

Sensory Descriptive Analysis

Utilizou-se a análise descritiva quantitativa (ADQ) para desenvolver terminologia descritiva e perfil sensorial de amêndoas de cupuaçu e cacau torradas. Quatro amostras de cupuaçu torradas em forno elétrico rotativo a 150 ºC por 38, 40, 42 e 44 minutos e uma amostra de cacau torrada por 38 minutos foram avaliadas sensorialmente e comparadas entre si. Foram gerados 12 termos que melhor descreveram as similaridades e diferenças entre as amostras, sendo apontados 8 com maior predominância segundo a análise de componente principal (ACP). Equipe de 9 julgadores foi selecionada com base no poder de discriminação (F amostra significativo para p≤0,50), repetibilidade (F repetição não significativo para p>0,05) e concordância de cada um com a equipe. A intensidade de cada descritor ou atributo foi fixada em escala não estruturada de 10 cm, ancorada por extremos que variavam de fraco para forte, baixa para alta, etc. Os dados obtidos foram avaliados estatisticamente (ANOVA, Teste de Tukey e ACP). Observou-se que o cacau torrado apresentou características sensoriais diferentes do cupuaçu, sendo bem mais ácido e amargo, com coloração mais escura e acentuado sabor de chocolate. Já o cupuaçu apresentou sabor de chocolate mais suave e mais doce que o cacau. Abstract Descriptive terminology and sensory profile of cupuasu and cocoa roasted bean were developed by sensory descriptive analysis (QDA). Four cupuasu samples roasted in an electrical rotating oven at 150 ºC and time of 38, 40, 42 and 44 minutes and one cocoa sample roasted for 38 minutes were sensory evaluated and compared. Twelve terms which best described similarities and differences among the samples were generated, being noted eight terms with greater predominance, according to the Principal Component Analysis (PCA). Nine panelists were selected on the basis of their discriminative ability (F sample significant for p≤0.50), reproducibility of judgments (F reproducibility significant for >0.05) and panel agreement. The intensity of each descriptor or attribute were fixed in an 10 cm unstructured scale, anchored in the ends on the terms weak and strong, low and high, etc. Data were analyzed by ANOVA, Tukey test and PCA, presenting results in tables and charts. It was observed that roasted cocoa presented different sensory characteristics, being sourer, bitter, darker and with accentuated chocolate taste than cupuasu. In the other hand the cupuasu presented smoother chocolate taste and sweeter than cocoa.

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