scholarly journals Poisson balanced spiking networks

2020 ◽  
Vol 16 (11) ◽  
pp. e1008261
Author(s):  
Camille E. Rullán Buxó ◽  
Jonathan W. Pillow
Keyword(s):  
Linear Models ◽  
Nonlinear Function ◽  
Threshold Function ◽  
Future Research ◽  
Linear Dynamical Systems ◽  
Integrate And Fire ◽  
Network Output ◽  
Spiking Networks ◽  
Different Populations ◽  
Positive Correlations

An important problem in computational neuroscience is to understand how networks of spiking neurons can carry out various computations underlying behavior. Balanced spiking networks (BSNs) provide a powerful framework for implementing arbitrary linear dynamical systems in networks of integrate-and-fire neurons. However, the classic BSN model requires near-instantaneous transmission of spikes between neurons, which is biologically implausible. Introducing realistic synaptic delays leads to an pathological regime known as “ping-ponging”, in which different populations spike maximally in alternating time bins, causing network output to overshoot the target solution. Here we document this phenomenon and provide a novel solution: we show that a network can have realistic synaptic delays while maintaining accuracy and stability if neurons are endowed with conditionally Poisson firing. Formally, we propose two alternate formulations of Poisson balanced spiking networks: (1) a “local” framework, which replaces the hard integrate-and-fire spiking rule within each neuron by a “soft” threshold function, such that firing probability grows as a smooth nonlinear function of membrane potential; and (2) a “population” framework, which reformulates the BSN objective function in terms of expected spike counts over the entire population. We show that both approaches offer improved robustness, allowing for accurate implementation of network dynamics with realistic synaptic delays between neurons. Both Poisson frameworks preserve the coding accuracy and robustness to neuron loss of the original model and, moreover, produce positive correlations between similarly tuned neurons, a feature of real neural populations that is not found in the deterministic BSN. This work unifies balanced spiking networks with Poisson generalized linear models and suggests several promising avenues for future research.

scholarly journals Poisson balanced spiking networks

2019 ◽  
Author(s):  
Camille E. Rullán Buxó ◽  
Jonathan W. Pillow
Keyword(s):  
Linear Models ◽  
Nonlinear Function ◽  
Threshold Function ◽  
Future Research ◽  
Linear Dynamical Systems ◽  
Integrate And Fire ◽  
Network Output ◽  
Spiking Networks ◽  
Different Populations ◽  
Positive Correlations

AbstractAn important problem in computational neuroscience is to understand how networks of spiking neurons can carry out various computations underlying behavior. Balanced spiking networks (BSNs) provide a powerful framework for implementing arbitrary linear dynamical systems in networks of integrate-and-fire neurons (Boerlin et al. [1]). However, the classic BSN model requires near-instantaneous transmission of spikes between neurons, which is biologically implausible. Introducing realistic synaptic delays leads to an pathological regime known as “ping-ponging”, in which different populations spike maximally in alternating time bins, causing network output to overshoot the target solution. Here we document this phenomenon and provide a novel solution: we show that a network can have realistic synaptic delays while maintaining accuracy and stability if neurons are endowed with conditionally Poisson firing. Formally, we propose two alternate formulations of Poisson balanced spiking networks: (1) a “local” framework, which replaces the hard integrate-and-fire spiking rule within each neuron by a “soft” threshold function, such that firing probability grows as a smooth nonlinear function of membrane potential; and (2) a “population” framework, which reformulates the BSN objective function in terms of expected spike counts over the entire population. We show that both approaches offer improved robustness, allowing for accurate implementation of network dynamics with realistic synaptic delays between neurons. Moreover, both models produce positive correlations between similarly tuned neurons, a feature of real neural populations that is not found in the original BSN. This work unifies balanced spiking networks with Poisson generalized linear models and suggests several promising avenues for future research.

338 Nitrogen Use Efficiency Is Proportionally More Improved When Young Bulls Are Ranked on Residual Body Gain Rather Than on Residual Feed Intake

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 187-188
Author(s):  
Pablo Guarnido Lopez ◽  
Isabelle Ortigues Marty ◽  
Cantalapiedra-Hijar Gonzalo
Keyword(s):  
Nitrogen Use Efficiency ◽  
Feed Intake ◽  
Linear Models ◽  
Residual Feed Intake ◽  
Residual Body ◽  
Nitrogen Use ◽  
N Metabolism ◽  
Use Efficiency ◽  
Δ 15N ◽  
Positive Correlations

Abstract Animals with superior feed efficiency (FE) may also have an improved nitrogen use efficiency (NUE), which would be beneficial to economic profitability while reducing environmental impacts. When genetically selecting animals on FE, it is preferable to use residual traits [e.g. residual feed intake (RFI) or residual body gain (RG)] rather than ratios because of their predictable genetic outcomes. We studied the relationship of RFI and RG with NUE, estimated from the validated 15N abundance in plasma, across two contrasted diets based on corn or grass silages. We evaluated FE of 588 (half by diet) Charolais bulls (545 ± 57 kg BW) from 12 experimental cohorts (different farms and periods) over 200 days. Before the end of the FE test, plasma was sampled and analyzed for δ 15N. NUE was related to FE through simple-linear models with variables previously corrected for the cohort and diet effects. The models’ slopes were standardized according to FE deviation in order to compare the response of NUE to FE between indices. Higher NUE was related to higher FE (P < 0.001), showing positive correlations with RG (r=-0.40) and negative with RFI (r=0.29). However, the standardized slope of NUE to RG was significantly higher (+28%; P < 0.05) than that of NUE to RFI. This stronger NUE relation to RG compared to RFI could reflect a higher potential of RG animals to deposit N as compared to a more conservational N metabolism in RFI individuals. Regarding diets, and despite the correction of NUE and FE for this effect, the slopes of NUE to FE were numerically (P > 0.05) higher (-16% and +36%; for RG and RFI) in corn-based diets, which agrees with superior NUE observed in corn-vs-grass diets. Results suggested that superior RG animals may present proportionally higher NUE than superior RFI animals, with even better results in corn-vs-grass diets.

scholarly journals Dysphonia in adults with developmental stuttering: A descriptive study

2017 ◽  
Vol 64 (1) ◽  
Author(s):  
Anél Botha ◽  
Elizbé Ras ◽  
Shabnam Abdoola ◽  
Jeannie Van der Linde
Keyword(s):  
Voice Quality ◽  
Severity Index ◽  
Health Condition ◽  
World Health ◽  
International Classification Of Functioning ◽  
Future Research ◽  
Positive Correlations ◽  
Developmental Stuttering ◽  
Moderate Positive Correlation

Background: Persons with stuttering (PWS) often present with other co-occurring conditions. The World Health Organization’s (WHO) International Classification of Functioning, Disability and Health (ICF) proposes that it is important to understand the full burden of a health condition. A few studies have explored voice problems among PWS, and the characteristics of voices of PWS are relatively unknown. The importance of conducting future research has been emphasised.Objectives: This study aimed to describe the vocal characteristics of PWS.Method: Acoustic and perceptual data were collected during a comprehensive voice assessment. The severity of stuttering was also determined. Correlations between the stuttering severity instrument (SSI) and the acoustic measurements were evaluated to determine the significance. Twenty participants were tested for this study.Result: Only two participants (10%) obtained a positive Dysphonia Severity Index (DSI) score of 1.6 or higher, indicating that no dysphonia was present, while 90% of participants (n = 18) scored lower than 1.6, indicating that those participants presented with dysphonia. Some participants presented with weakness (asthenia) of voice (35%), while 65% presented with a slightly strained voice quality. Moderately positive correlations between breathiness and SSI (r = 0.40, p = 0.08) have been reported. In addition, participants with high SSI scores also scored a poor DSI of below 1.6, as observed by a moderate positive correlation between SSI and DSI (r = 0.41).Conclusion: The majority of PWS presented with dysphonia, evident in the perceptual or acoustic parameters of their voices. These results can be used for further investigation to create awareness and to establish intervention strategies for voice disorders among PWS.

Control of flexible manipulators: A survey

Robotica ◽  
2004 ◽  
Vol 22 (5) ◽  
pp. 533-545 ◽  
Author(s):  
M. Benosman ◽  
G. Le Vey
Keyword(s):  
Linear Models ◽  
Control Strategies ◽  
Research Area ◽  
Future Research ◽  
Complex Nature ◽  
Open Problems ◽  
Complex Models ◽  
The Many ◽  
The One ◽  
Flexible Arms

A survey of the field of control for flexible multi-link robots is presented. This research area has drawn great attention during the last two decades, and seems to be somewhat less “attractive” now, due to the many satisfactory results already obtained, but also because of the complex nature of the remaining open problems. Thus it seems that the time has come to try to deliver a sort of “state of the art” on this subject, although an exhaustive one is out of scope here, because of the great amount of publications. Instead, we survey the most salient progresses – in our opinion – approximately during the last decade, that are representative of the essential different ideas in the field. We proceed along with the exposition of material coming from about 119 included references. We do not pretend to deeply present each of the methods quoted hereafter; however, our goal is to briefly introduce most of the existing methods and to refer the interested reader to more detailed presentations for each scheme. To begin with, a now well-established classification of the flexible arms control goals is given. It is followed by a presentation of different control strategies, indicating in each case whether the approach deals with the one-link case, which can be successfully treated via linear models, or with the multi-link case which necessitates nonlinear, more complex, models. Some possible issues for future research are given in conclusion.

scholarly journals CA1 pyramidal cells have diverse biophysical properties, affected by development, experience, and aging

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3836 ◽  
Author(s):  
Erin C. McKiernan ◽  
Diano F. Marrone
Keyword(s):  
Pyramidal Cells ◽  
Ionic Currents ◽  
Review Literature ◽  
Cellular Heterogeneity ◽  
Future Research ◽  
Biophysical Properties ◽  
Rich Diversity ◽  
Development Experience ◽  
Network Output ◽  
The Rich

Neuron types (e.g., pyramidal cells) within one area of the brain are often considered homogeneous, despite variability in their biophysical properties. Here we review literature demonstrating variability in the electrical activity of CA1 hippocampal pyramidal cells (PCs), including responses to somatic current injection, synaptic stimulation, and spontaneous network-related activity. In addition, we describe how responses of CA1 PCs vary with development, experience, and aging, and some of the underlying ionic currents responsible. Finally, we suggest directions that may be the most impactful in expanding this knowledge, including the use of text and data mining to systematically study cellular heterogeneity in more depth; dynamical systems theory to understand and potentially classify neuron firing patterns; and mathematical modeling to study the interaction between cellular properties and network output. Our goals are to provide a synthesis of the literature for experimentalists studying CA1 PCs, to give theorists an idea of the rich diversity of behaviors models may need to reproduce to accurately represent these cells, and to provide suggestions for future research.

scholarly journals The Evolution of Data Sharing Practices in the Psychological Literature

2021 ◽  
Author(s):  
Judith Neve ◽  
Guillaume A Rousselet
Keyword(s):  
Data Sharing ◽  
Linear Models ◽  
Generalized Additive Models ◽  
Additive Models ◽  
Future Research ◽  
Science Data ◽  
Editorial Policies ◽  
Psychological Science ◽  
The Impact

Sharing data has many benefits. However, data sharing rates remain low, for the most part well below 50%. A variety of interventions encouraging data sharing have been proposed. We focus here on editorial policies. Kidwell et al. (2016) assessed the impact of the introduction of badges in Psychological Science; Hardwicke et al. (2018) assessed the impact of Cognition’s mandatory data sharing policy. Both studies found policies to improve data sharing practices, but only assessed the impact of the policy for up to 25 months after its implementation. We examined the effect of these policies over a longer term by reusing their data and collecting a follow-up sample including articles published up until December 31st, 2019. We fit generalized additive models as these allow for a flexible assessment of the effect of time, in particular to identify non-linear changes in the trend. These models were compared to generalized linear models to examine whether the non-linearity is needed. Descriptive results and the outputs from generalized additive and linear models were coherent with previous findings: following the policies in Cognition and Psychological Science, data sharing statement rates increased immediately and continued to increase beyond the timeframes examined previously, until reaching close to 100%. In Clinical Psychological Science, data sharing statement rates started to increase only two years following the implementation of badges. Reusability rates jumped from close to 0% to around 50% but did not show changes within the pre-policy nor the post-policy timeframes. Journals that did not implement a policy showed no change in data sharing rates or reusability over time. There was variability across journals in the levels of increase, so we suggest future research should examine a larger number of policies to draw conclusions about their efficacy. We also encourage future research to investigate the barriers to data sharing specific to psychology subfields to identify the best interventions to tackle them.

scholarly journals Predicting the Electrical Energy Consumption of Electric Arc Furnaces Using Statistical Modeling

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 959 ◽  
Author(s):  
Leo S. Carlsson ◽  
Peter B. Samuelsson ◽  
Pär G. Jönsson
Keyword(s):  
Statistical Modeling ◽  
Statistical Models ◽  
Linear Models ◽  
Nonlinear Models ◽  
Electrical Energy ◽  
Electric Arc ◽  
Future Research ◽  
Published Data ◽  
Industrial Setting ◽  
Input Variables

Statistical modeling, also known as machine learning, has gained increased attention in part due to the Industry 4.0 development. However, a review of the statistical models within the scope of steel processes has not previously been conducted. This paper reviews available statistical models in the literature predicting the Electrical Energy (EE) consumption of the Electric Arc Furnace (EAF). The aim was to structure published data and to bring clarity to the subject in light of challenges and considerations that are imposed by statistical models. These include data complexity and data treatment, model validation and error reporting, choice of input variables, and model transparency with respect to process metallurgy. A majority of the models are never tested on future heats, which essentially renders the models useless in a practical industrial setting. In addition, nonlinear models outperform linear models but lack transparency with regards to which input variables are influencing the EE consumption prediction. Some input variables that heavily influence the EE consumption are rarely used in the models. The scrap composition and additive materials are two such examples. These observed shortcomings have to be correctly addressed in future research applying statistical modeling on steel processes. Lastly, the paper provides three key recommendations for future research applying statistical modeling on steel processes.

scholarly journals P030: Acute pain resolution after an emergency department visit: a 14-day trajectory analysis

CJEM ◽  
2019 ◽  
Vol 21 (S1) ◽  
pp. S73-S74
Author(s):  
R. Daoust ◽  
J. Paquet ◽  
A. Cournoyer ◽  
E. Piette ◽  
J. Morris ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Acute Pain ◽  
Linear Models ◽  
Rating Scale ◽  
Numeric Rating Scale ◽  
The Other ◽  
Future Research ◽  
Intensity Level ◽  
Opioid Prescription ◽  
Mild Pain

Introduction: The objective of the study was to evaluate the acute pain intensity evolution in ED discharged patients using Group-based trajectory modeling (GBTM). This method identified patient groups with similar profiles of change over time without assuming the existence of a particular pattern or number of groups. Methods: This was a prospective cohort study of ED patients aged ≥18 years with an acute pain condition (≤ 2 weeks) and discharged with an opioid prescription. Patients completed a 14-day diary assessing daily pain intensity level (0-10 numeric rating scale) and pain medication use. Results: Among the 372 included patients, six distinct post-ED pain intensity trajectories were identified: two started with severe levels of pain, one remained with severe pain intensity (12.6% of the sample) and the other ended with moderate pain intensity level (26.3%). Two other trajectories had severe initial pain, one decreased to mild pain (21.7%) and the other to no-pain (13.8%). Another trajectory had moderate initial pain which decreased to a mild level (15.9%) and the last one started with mild pain intensity and had no pain at the end of the 14-day (9.7%). The pain trajectory patterns were significantly associated with age, type of painful conditions, pain intensity at ED discharge, and with opioid consumption. Conclusion: Acute pain resolution following an ED visit seems to progress through six different trajectory patterns that are more informative than simple linear models and could be useful to adapt acute pain management in future research.

scholarly journals Early childhood teachers’ socialization of children’s emotional competence

2019 ◽  
Vol 12 (2) ◽  
pp. 133-150 ◽  
Author(s):  
Susanne Ayers Denham ◽  
Hideko Hamada Bassett
Keyword(s):  
Linear Models ◽  
Emotional Competence ◽  
Early Childhood Teachers ◽  
Future Research ◽  
Emotion Knowledge ◽  
Content Type ◽  
Children's Emotion ◽  
Teacher Professional ◽  
Socioeconomic Risk ◽  
Crucial Set

Purpose Emotional competence supports preschoolers’ social relationships and school success. Parents’ emotions and reactions to preschoolers’ emotions can help them become emotionally competent, but scant research corroborates this role for preschool teachers. Expected outcomes included: teachers’ emotion socialization behaviors functioning most often like parents’ in contributing to emotional competence, with potential moderation by socioeconomic risk. This paper aims to discuss this issue. Design/methodology/approach Participants included 80 teachers and 312 preschoolers experiencing either little economic difficulty or socioeconomic risk. Children’s emotionally negative/dysregulated, emotionally regulated/productive and emotionally positive/prosocial behaviors were observed, and their emotion knowledge was assessed in Fall and Spring. Teachers’ emotions and supportive, nonsupportive and positively emotionally responsive reactions to children’s emotions were observed during Winter. Hierarchical linear models used teacher emotions or teacher reactions, risk and their interactions as predictors, controlling for child age, gender and premeasures. Findings Some results resembled those parents’: positive emotional environments supported children’s emotion knowledge; lack of nonsupportive reactions facilitated positivity/prosociality. Others were unique to preschool classroom environments (e.g. teachers’ anger contributed to children’s emotion regulation/productive involvement; nonsupportiveness predicted less emotional negativity/dysregulation). Finally, several were specific to children experiencing socioeconomic risk: supportive and nonsupportive reactions, as well as tender emotions, had unique, but culturally/contextually explainable, meanings in their classrooms. Research limitations/implications Applications to teacher professional development, and both limitations and suggestions for future research are considered. Originality/value This study is among the first to examine how teachers contribute to the development of preschoolers’ emotional competence, a crucial set of skills for life success.

Sino-Russian negotiation styles: A cross-cultural analysis of situated patterns

2019 ◽  
pp. 205789111988781 ◽  
Author(s):  
Tariq H Malik
Keyword(s):  
Cultural Analysis ◽  
Strategic Partnership ◽  
Future Research ◽  
Economic Sectors ◽  
Two Cultures ◽  
Mixed Markets ◽  
The Two Cultures ◽  
Negotiation Style ◽  
Belt And Road ◽  
Positive Correlations

China and Russia have transitioned from centralised economies to mixed markets, they have developed institutions and economic sectors and they joined hands in the strategic partnership in economic and political paths through the Belt and Road Initiative (BRI). Most writers compare or contrast their political and economic powers and preferences vis-a-vis Western cultures and countries; none assess the cultural and contextual styles between the two partners. We build on this question to assess whether and how the two neighbours differ in negotiation style rather than how their institutions shape their behaviour. Based on the behavioural negotiation framework proposed in the early 1990s, we gathered evidence through two surveys: one in Russia and the other in China. We received 988 responses from China and 708 responses from Russia, which we analysed in correlational statistics. The statistical analysis shows negative correlations for four styles of negotiation and positive correlations for six styles of negotiation. We interpreted the negative correlation as divergence between the two cultures and positive correlation as convergence between the two cultures on those styles. The magnitude of the correlation further supports the competing positions of the two cultures on the semantic spectrums. We offer theoretical and policy suggestions at the end of the article. In concluding remarks, we draw attention to multiple gaps which can be filled in future research.

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