scholarly journals Origins of Cortical Layer V Surround Receptive Fields in the Rat Barrel Cortex

2010 ◽  
Vol 103 (2) ◽  
pp. 709-724 ◽  
Author(s):  
Nicholas Wright ◽  
Kevin Fox
Keyword(s):  
Barrel Cortex ◽  
Receptive Fields ◽  
Sensory Stimulation ◽  
Cortical Layer ◽  
Sensory Response ◽  
Sources Of Information ◽  
Thalamic Input ◽  
Whisker Pad ◽  
Layer V ◽  
Different Sources

Layer IV of the barrel cortex contains an anatomical map of the contralateral whisker pad, which serves as a useful reference in relating receptive field properties of cells to the cortical columns in which they reside. Recent studies have shown that the degree to which the surround receptive fields of layer IV cells are generated intracortically or subcortically depends on whether they lie in barrel or septal columns. To investigate whether this is true for layer V cells, we blocked intracortical activity in the barrel cortex by infusing muscimol from the cortical surface and measuring spike responses to sensory stimulation in the presence of locally iontophoresed bicuculline. Layer V cells beneath barrels had small subcortically generated single- or double-whisker center receptive fields and larger intracortically generated six to seven whisker surround receptive fields. Conversely, septally located cells received multiwhisker input from both subcortical and cortical sources. Most properties of layer Va and layer Vb cells were very similar. However, layer Vb barrel neurons showed a relative lack of phasic inhibition evoked from sensory input compared with layer Va cells. The direct thalamic input to the layer V cells was not sufficient to evoke a sensory response in the absence of input from superficial layers. These findings suggest that despite the apparent overt similarity of layer V receptive fields, barrel and septal subdivisions process different sources of information within the barrel cortex.

Spatial structure of multiwhisker receptive fields in the barrel cortex is stimulus dependent

2011 ◽  
Vol 106 (2) ◽  
pp. 986-998 ◽  
Author(s):  
Julie Le Cam ◽  
Luc Estebanez ◽  
Vincent Jacob ◽  
Daniel E. Shulz
Keyword(s):  
Spatial Structure ◽  
Barrel Cortex ◽  
Center Of Mass ◽  
Receptive Fields ◽  
Intrinsic Property ◽  
Spatial Separation ◽  
Cortical Layer ◽  
Trigeminal System ◽  
Response Latencies ◽  
Receptive Field Organization

The tactile sensations mediated by the whisker-trigeminal system allow rodents to efficiently detect and discriminate objects. These capabilities rely strongly on the temporal and spatial structure of whisker deflections. Subthreshold but also spiking receptive fields in the barrel cortex encompass a large number of vibrissae, and it seems likely that the functional properties of these multiwhisker receptive fields reflect the multiple-whisker interactions encountered by the animal during exploration of its environment. The aim of this study was to examine the dependence of the spatial structure of cortical receptive fields on stimulus parameters. Using a newly developed 24-whisker stimulation matrix, we applied a forward correlation analysis of spiking activity to randomized whisker deflections (sparse noise) to characterize the receptive fields that result from caudal and rostral directions of whisker deflection. We observed that the functionally determined principal whisker, the whisker eliciting the strongest response with the shortest latency, differed according to the direction of whisker deflection. Thus, for a given neuron, maximal responses to opposite directions of whisker deflections could be spatially separated. This spatial separation resulted in a displacement of the center of mass between the rostral and caudal subfields and was accompanied by differences between response latencies in rostral and caudal directions of whisker deflection. Such direction-dependent receptive field organization was observed in every cortical layer. We conclude that the spatial structure of receptive fields in the barrel cortex is not an intrinsic property of the neuron but depends on the properties of sensory input.

Determinants Considered by Consumers for Brand Selection - with Reference to Laptops in Albania

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Margret Plloçi ◽  
Macit Koc
Keyword(s):  
Primary Data ◽  
Battery Life ◽  
Decision Making Process ◽  
Light Weight ◽  
Sources Of Information ◽  
Technical Features ◽  
The Relationship ◽  
The City ◽  
Different Sources ◽  
Core Features

Abstract Purpose of the article There is relatively a big number of brands in the market of laptops nowadays in Albania. It appears that the number of brands offered in this market could easily be compared to the number of brands in Europe and even broader. The purpose of this study is to help Albanian vendors understand the criteria that consumers take into consideration when they make the decision to purchase a laptop. Methodology/methods The research is based on the collection and the analyses of the primary data collected through interviews to people like managers or employees who work in the sector of trading laptops or in businesses like education where laptops are broadly used recently; then a survey is done through a questionnaire delivered to customers who already own and use a laptop and customers who are potential buyers of laptops. Scientific aim The aim of the research is to identify if there are any relationships between the demographics of the consumers and the criteria of buying a laptop; on the other hand, to find out how is the relationship between the demographics and the features of different brands. Findings The study found out that Albanian consumers have good knowledge of laptops and their brands, and they use different sources of information for making their decisions in buying a laptop; it is found that there are relationships between some demographics like age or gender and the appraisal for some attributes of the laptops like price, design and high graphics card; it is also found that some technical features and other attributes of using laptops are some of the determinants that influence the laptops’ purchases. Conclusions It is realized that one of the most important demographics of the consumers is their age. Some core features like RAM, ROM, battery life, processor quality, light weight or attributes that are connected to the purposes of using the laptop computers like practicality and mobility in using them, work and studying processes, quick access to the internet are determinant factors which influence the decision making process of purchasing a laptop. I would recommend that future researches be focused also on the relationship between the customers’ income and their preferred brand or ranking brands according to the customers’ preferences. Such studies should also extend outside the city of Tirana.

Feature-based multi-criteria recommendation system using a weighted approach with ranking correlation

2021 ◽  
Vol 25 (4) ◽  
pp. 1013-1029
Author(s):  
Zeeshan Zeeshan ◽  
Qurat ul Ain ◽  
Uzair Aslam Bhatti ◽  
Waqar Hussain Memon ◽  
Sajid Ali ◽  
...  
Keyword(s):  
Recommendation System ◽  
Sources Of Information ◽  
Multiple Features ◽  
Recommendation Algorithms ◽  
Label Correlations ◽  
Feature Based ◽  
Multicriteria Model ◽  
Implicit And Explicit ◽  
Hybrid Recommendation ◽  
Different Sources

With the increase of online businesses, recommendation algorithms are being researched a lot to facilitate the process of using the existing information. Such multi-criteria recommendation (MCRS) helps a lot the end-users to attain the required results of interest having different selective criteria – such as combinations of implicit and explicit interest indicators in the form of ranking or rankings on different matched dimensions. Current approaches typically use label correlation, by assuming that the label correlations are shared by all objects. In real-world tasks, however, different sources of information have different features. Recommendation systems are more effective if being used for making a recommendation using multiple criteria of decisions by using the correlation between the features and items content (content-based approach) or finding a similar user rating to get targeted results (Collaborative filtering). To combine these two filterings in the multicriteria model, we proposed a features-based fb-knn multi-criteria hybrid recommendation algorithm approach for getting the recommendation of the items by using multicriteria features of items and integrating those with the correlated items found in similar datasets. Ranks were assigned to each decision and then weights were computed for each decision by using the standard deviation of items to get the nearest result. For evaluation, we tested the proposed algorithm on different datasets having multiple features of information. The results demonstrate that proposed fb-knn is efficient in different types of datasets.

scholarly journals Analysis of corporate political activity strategies of the food industry: evidence from France

2018 ◽  
Vol 21 (18) ◽  
pp. 3407-3421 ◽  
Author(s):  
Melissa Mialon ◽  
Jonathan Mialon
Keyword(s):  
Public Health ◽  
Food Industry ◽  
Evidence Base ◽  
Political Activity ◽  
Health Issues ◽  
Sources Of Information ◽  
Corporate Political Activity ◽  
The Public ◽  
Health Related ◽  
Different Sources

AbstractObjectiveTo identify the corporate political activity (CPA) of major food industry actors in France.DesignWe followed an approach based on information available in the public domain. Different sources of information, freely accessible to the public, were monitored.Setting/SubjectsData were collected and analysed between March and August 2015. Five actors were selected: ANIA (Association Nationale des Industries Agroalimentaires/National Association of Agribusiness Industries); Coca-Cola; McDonald’s; Nestlé; and Carrefour.ResultsOur analysis shows that the main practices used by Coca-Cola and McDonald’s were the framing of diet and public health issues in ways favourable to the company, and their involvement in the community. ANIA primarily used the ‘information and messaging’ strategy (e.g. by promoting deregulation and shaping the evidence base on diet- and public health-related issues), as well as the ‘policy substitution’ strategy. Nestlé framed diet and public health issues, and shaped the evidence base on diet- and public health-related issues. Carrefour particularly sought involvement in the community.ConclusionsWe found that, in 2015, the food industry in France was using CPA practices that were also used by other industries in the past, such as the tobacco and alcohol industries. Because most, if not all, of these practices proved detrimental to public health when used by the tobacco industry, we propose that the precautionary principle should guide decisions when engaging or interacting with the food industry.

Networks with lateral connectivity. III. Plasticity and reorganization of somatosensory cortex

1996 ◽  
Vol 75 (1) ◽  
pp. 217-232 ◽  
Author(s):  
J. Xing ◽  
G. L. Gerstein
Keyword(s):  
Spontaneous Activity ◽  
Network Model ◽  
Training Stimulus ◽  
Receptive Fields ◽  
Cortical Layer ◽  
Cortical Reorganization ◽  
Cortical Lesion ◽  
Behavioral Training ◽  
Dynamic Changes ◽  
Neuronal Groups

1. Mechanisms underlying cortical reorganizations were studied using a three-layered neural network model with neuronal groups already formed in the cortical layer. 2. Dynamic changes induced in cortex by behavioral training or intracortical microstimulation (ICMS) were simulated. Both manipulations resulted in reassembly of neuronal groups and formation of stimulus-dependent assemblies. Receptive fields of neurons and cortical representation of inputs also changed. Many neurons that had been weakly responsive or silent became active. 3. Several types of learning models were examined in simulating behavioral training, ICMS-induced dynamic changes, deafferentation, or cortical lesion. Each learning model most accurately reproduced features of experimental data from different manipulations, suggesting that more than one plasticity mechanism might be able to induce dynamic changes in cortex. 4. After skin or cortical stimulation ceased, as spontaneous activity continued, the stimulus-dependent assemblies gradually reverted into structure-dependent neuronal groups. However, relationships among individual neurons and identities of many neurons did not return to their original states. Thus a different set of neurons would be recruited by the same training stimulus sequence on its next presentation. 5. We also reproduced several typical long-term reorganizations caused by pathological manipulations such as cortical lesions, input loss, and digit fusion. 6. In summary, with Hebbian plasticity rules on lateral connections, the network model is capable of reproducing most characteristics of experiments on cortical reorganization. We propose that an important mechanism underlying cortical plastic changes is formation of temporary assemblies that are related to receipt of strongly synchronized localized input. Such stimulus-dependent assemblies can be dissolved by spontaneous activity after removal of the stimuli.

The yellow-legged gull as a predator of lizards in Balearic Islands

2014 ◽  
Vol 35 (2) ◽  
pp. 207-213 ◽  
Author(s):  
Valentín Pérez-Mellado ◽  
Mario Garrido ◽  
Zaida Ortega ◽  
Ana Pérez-Cembranos ◽  
Abraham Mencía
Keyword(s):  
Balearic Islands ◽  
Predation Pressure ◽  
Vertebrate Species ◽  
Sources Of Information ◽  
Mediterranean Islands ◽  
Lizard Species ◽  
Podarcis Lilfordi ◽  
Larus Michahellis ◽  
Plasticine Models ◽  
Different Sources

Lizards and gulls cohabit in several Mediterranean islands. The yellow-legged gull, Larus michahellis, was found to prey several vertebrate species. However, precise information about the interaction between gulls and other vertebrates, particularly with lizards is still scarce. The Balearic lizard, Podarcis lilfordi, shares several coastal islets with the yellow-legged gull. Using two different sources of information, we studied the interaction of both species in Colom Island (Menorca, Balearic Islands, Spain). We studied the diet of the yellow-legged gull and learnt that the Balearic lizard is not a common prey of the yellow-legged gull. On the other hand, we studied the potential predation pressure of gulls on lizards, using plasticine models of lizards. We did two different experiments from which we can conclude that yellow-legged gulls rarely attack lizards and, consequently, cannot be considered a major threat for this endemic lizard species, at least in the population under study. Finally, we obtained evidence that plasticine models can only be employed with caution to assess predation pressure of opportunistic scavengers, much as gulls are. The majority of marks on models were not the consequence of true attacks by gulls, but the result of ground exploratory behaviour of gulls in search of any edible matter. Therefore, contrary to popular belief, in the case of the yellow-legged gull, the proportion of marked models would be an indication of ground-based wandering activity, rather than a result of its predation pressure on lizards.

scholarly journals ASSESSMENT OF ATTITUDES TOWARDS IMMUNIZATION IN DIFFERENT GROUPS OF POPULATION OF THE RUSSIAN FEDERATION

2017 ◽  
pp. 98-103 ◽  
Author(s):  
N. I. Briko ◽  
A. Ya. Mindlina ◽  
R. V. Polibin ◽  
N. P. Galina ◽  
A. S. Gorokhova ◽  
...  
Keyword(s):  
Medical Students ◽  
Mass Media ◽  
Russian Federation ◽  
Positive Attitude ◽  
The Internet ◽  
Sources Of Information ◽  
Low Level ◽  
Technical Students ◽  
The Russian Federation ◽  
Different Sources

Aim. The study the attitude of population towards the necessity of vaccination. Materials and methods. The survey about the attitude towards vaccination among different groups of population was held. In total there were 1209 respondents: 1031 students of medical, humanitarian and technical universities and 178 parents of children under 2. Results. The most positive attitude towards vaccination was shown by medical students (77%) and parents (71%) and only 33% and 37% of humanitarian and technical students correspondency realize the significance of vaccination. It is worth noting that large number of people could not define their attitude to vaccination. The majority of respondents notices the lack of knowledge about vaccination wherein less than 50% of respondents get the information from doctors. The rest gets it from different sources mostly from the Internet. About 80% of respondents would prefer to get answers to their questions about vaccination in the Internet. Conclusion. The adherence of population of Russia to vaccination has a rather low level. The main reason for it is the lack ofknowledge and availability of true information about vaccination. It is necessary to use diverse sources of information to provide the population with true facts about vaccination, its significance and safety via mass media and the Internet as well.

scholarly journals THE USE OF COMMUNICATIVE APPROACH IN TEACHING READING DESCRIPTIVE TEXT

2020 ◽  
Vol 3 (1) ◽  
pp. 127
Author(s):  
Anna Robiana
Keyword(s):  
Performance Assessment ◽  
Experimental Research ◽  
Learning Process ◽  
Random Sampling ◽  
Reading Skills ◽  
Teaching Reading ◽  
Sources Of Information ◽  
Communicative Approach ◽  
Academic Year ◽  
Different Sources

Reading is central to learning process, by reading people can gain important information in this millennial era. Study reading aims to develop the reading skills that you need to find information quickly, to identify what is important in a text, to compare different sources of information and to read critically. The aim of this experimental research is to investigate the effect of communicative approach on reading competencies of 10th grade students of SMK SEHATI in the academic year of 2018/2019. It is about 60 pupilss were assigned as sample through random sampling. Data of student’s reading competencies were collected by using multiple choice of descriptive text test. The result shows there is significant effect at student’s reading comprehension. Keywords:  Communicative Approach, Performance Assessment, Reading Competency  

scholarly journals Spindle-Shaped Neurons in the Human Posteromedial (Precuneus) Cortex

2022 ◽  
Vol 13 ◽  
Author(s):  
Francisco Javier Fuentealba-Villarroel ◽  
Josué Renner ◽  
Arlete Hilbig ◽  
Oliver J. Bruton ◽  
Alberto A. Rasia-Filho
Keyword(s):  
Brain Area ◽  
Three Dimensional ◽  
Golgi Method ◽  
Cortical Layer ◽  
Von Economo Neurons ◽  
Dendritic Length ◽  
Adult Humans ◽  
Layer V ◽  
Layer Vi

The human posteromedial cortex (PMC), which includes the precuneus (PC), represents a multimodal brain area implicated in emotion, conscious awareness, spatial cognition, and social behavior. Here, we describe the presence of Nissl-stained elongated spindle-shaped neurons (suggestive of von Economo neurons, VENs) in the cortical layer V of the anterior and central PC of adult humans. The adapted “single-section” Golgi method for postmortem tissue was used to study these neurons close to pyramidal ones in layer V until merging with layer VI polymorphic cells. From three-dimensional (3D) reconstructed images, we describe the cell body, two main longitudinally oriented ascending and descending dendrites as well as the occurrence of spines from proximal to distal segments. The primary dendritic shafts give rise to thin collateral branches with a radial orientation, and pleomorphic spines were observed with a sparse to moderate density along the dendritic length. Other spindle-shaped cells were observed with straight dendritic shafts and rare branches or with an axon emerging from the soma. We discuss the morphology of these cells and those considered VENs in cortical areas forming integrated brain networks for higher-order activities. The presence of spindle-shaped neurons and the current discussion on the morphology of putative VENs address the need for an in-depth neurochemical and transcriptomic characterization of the PC cytoarchitecture. These findings would include these spindle-shaped cells in the synaptic and information processing by the default mode network and for general intelligence in healthy individuals and in neuropsychiatric disorders involving the PC in the context of the PMC functioning.

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