scholarly journals Tell me who you hang out with and I will tell you who you are

2021 ◽  
Author(s):  
Valerio Rubino

This report will revolve around a paper published in 2012 by Saygin, which combines diffusion and functionalimaging to prove that the functionally-defined fusiform face area can be identified by a characteristic pattern ofextrinsic connectivity. As the saying goes: “tell me who you hang out with and I will tell who you are”. First, Iwill briefly review some proposals about the relationship between connectivity and function to unravel therelevance of the study at issue. Then, I will touch some issues related to structural connectivity data analysis and how they have been overcome within a probabilistic framework. Next, I will survey experimentswhich built on the latter and to which Saygin’s added. In the following section, I will describe the methods andresults of Saygin’s article, whose limitations and implications will be then explored in the discussion

2021 ◽  
Vol 14 ◽  
Author(s):  
Dongya Wu ◽  
Xin Li ◽  
Jun Feng

Brain connectivity plays an important role in determining the brain region’s function. Previous researchers proposed that the brain region’s function is characterized by that region’s input and output connectivity profiles. Following this proposal, numerous studies have investigated the relationship between connectivity and function. However, this proposal only utilizes direct connectivity profiles and thus is deficient in explaining individual differences in the brain region’s function. To overcome this problem, we proposed that a brain region’s function is characterized by that region’s multi-hops connectivity profile. To test this proposal, we used multi-hops functional connectivity to predict the individual face activation of the right fusiform face area (rFFA) via a multi-layer graph neural network and showed that the prediction performance is essentially improved. Results also indicated that the two-layer graph neural network is the best in characterizing rFFA’s face activation and revealed a hierarchical network for the face processing of rFFA.


2021 ◽  
Vol 18 (183) ◽  
Author(s):  
Venetia Voutsa ◽  
Demian Battaglia ◽  
Louise J. Bracken ◽  
Andrea Brovelli ◽  
Julia Costescu ◽  
...  

The relationship between network structure and dynamics is one of the most extensively investigated problems in the theory of complex systems of recent years. Understanding this relationship is of relevance to a range of disciplines—from neuroscience to geomorphology. A major strategy of investigating this relationship is the quantitative comparison of a representation of network architecture (structural connectivity, SC) with a (network) representation of the dynamics (functional connectivity, FC). Here, we show that one can distinguish two classes of functional connectivity—one based on simultaneous activity (co-activity) of nodes, the other based on sequential activity of nodes. We delineate these two classes in different categories of dynamical processes—excitations, regular and chaotic oscillators—and provide examples for SC/FC correlations of both classes in each of these models. We expand the theoretical view of the SC/FC relationships, with conceptual instances of the SC and the two classes of FC for various application scenarios in geomorphology, ecology, systems biology, neuroscience and socio-ecological systems. Seeing the organisation of dynamical processes in a network either as governed by co-activity or by sequential activity allows us to bring some order in the myriad of observations relating structure and function of complex networks.


2020 ◽  
Author(s):  
Dongya Wu ◽  
Xin Li ◽  
Jun Feng

AbstractBrain connectivity plays an important role in determining the brain region’s function. Previous researchers proposed that the brain region’s function is characterized by that region’s input and output connectivity profiles. Following this proposal, numerous studies have investigated the relationship between connectivity and function. However, based on a preliminary analysis, this proposal is deficient in explaining individual differences in the brain region’s function. To overcome this problem, we proposed that a brain region’s function is characterized by that region’s multi-hops connectivity profile. To test this proposal, we used multi-hops functional connectivity to predict the individual face response of the right fusiform face area (rFFA) via a multi-layers graph neural network and showed that the prediction performance is essentially improved. Results also indicated that the 2-layers graph neural network is the best in characterizing rFFA’s face response and revealed a hierarchical network for the face processing of rFFA.


2020 ◽  
Author(s):  
Katharina Glomb ◽  
Joan Rue Queralt ◽  
David Pascucci ◽  
Michaël Defferrard ◽  
Sebastien Tourbier ◽  
...  

AbstractWe present an approach for tracking fast spatiotemporal cortical dynamics in which we combine white matter connectivity data with source-projected electroencephalographic (EEG) data. We employ the mathematical framework of graph signal processing in order to derive the Fourier modes of the brain structural connectivity graph, or “network harmonics”. These network harmonics are naturally ordered by smoothness. Smoothness in this context can be understood as the amount of variation along the cortex, leading to a multi-scale representation of brain connectivity. We demonstrate that network harmonics provide a sparse representation of the EEG signal, where, at certain times, the smoothest 15 network harmonics capture 90% of the signal power. This suggests that network harmonics are functionally meaningful, which we demonstrate by using them as a basis for the functional EEG data recorded from a face detection task. There, only 13 network harmonics are sufficient to track the large-scale cortical activity during the processing of the stimuli with a 50 ms resolution, reproducing well-known activity in the fusiform face area as well as revealing co-activation patterns in somatosensory/motor and frontal cortices that an unconstrained ROI-by-ROI analysis fails to capture. The proposed approach is simple and fast, provides a means of integration of multimodal datasets, and is tied to a theoretical framework in mathematics and physics. Thus, network harmonics point towards promising research directions both theoretically - for example in exploring the relationship between structure and function in the brain - and practically - for example for network tracking in different tasks and groups of individuals, such as patients.


Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).


Author(s):  
Nurdan Gürkan ◽  
Ahmet Ferda Çakmak

The concept of entrepreneurial orientation, which emerges with the development of strategic management, refers to entrepreneurship orientations of businesses. The businesses need resources in other words organizational slack in order to develop their entrepreneurial trends. The organizational slack consists of three slack type. These slack types are available slack, recoverable slack and potential slack. The purpose of this study is to examine whether organizational slack in the businesses has an effect on entrepreneurial orientation. The relationship between organizational slack and entrepreneurial orientation was investigated through 20 companies that were traded in Borsa Istanbul Corporate Governance Index for 2010-2014 period using panel data analysis method. The results of the study indicate the existence of a statistically significant relationship between and the available slack and the recoverable slack with the entrepreneurial orientation in the businesses. According to findings; there was no statistically significant relationship between potential slack and entrepreneurial orientation.


2019 ◽  
Vol 12 (1) ◽  
pp. 42-51
Author(s):  
Dwi Indah Sulistiani ◽  
Ujang Maman ◽  
Junaidi J

Objective of this research; 1) determine the perception of ranchers against the properties and behavior of the leadership of the companion in the Society of Al-Awwaliyah 2) analyze the relationship between productivity breeder with productivity of livestock in the Society of Al-Awwaliyah 3) identify the relationship perceptions of ranchers against the leadership companion with productivity of livestock in the Society of Al-Awwaliyah , The data used in this study are primary and secondary data. Primary data were obtained from questionnaires which stem from ranchers while secondary data sourced from literature in the form of books and articles. Data processing was performed using Chi-square analysis using SPSS software version 21. One of the factors relating to the productivity of ranchers is the perception of ranchers against the leadership of their companion. Leadership companion views of the nature and behavior of which is owned by a companion. Productivity ranchers indirectly related to the productivity of the cattle business. Characteristics breeder visits of age, years of education, experience ranchers, and businesses in addition to ranchers. The results of data analysis showed that there is a significant relationship between business other than ranchers with ranchers productivity. The relationship between the perception of the nature of the companion breeder with productivity ranchers produce Pearson Chi-Square value is 9.751 and Asymp. Sig. (2-sided) of 0.002. This is due to interest ranchers against leadership qualities possessed by a companion who produce prolific ranchers. Ranchers consider that a companion of his leadership qualities are ideal as a companion.


2019 ◽  
Vol 14 (1) ◽  
pp. 17
Author(s):  
Andi S Tarigan ◽  
Zulkarnaian Siregar

AbstrakPenelitian ini bertujuan untuk mengetahui Pengaruh Harga dan Brand Trust Terhadap Keputusan Pembelian pada Sinergy Celular Medan.Sampel dalam penelitian ini adalah seluruh pengunjung Sinergy Celular Medan sebanyak 77 orang.Teknik pengumpulan data yang digunakan adalah melalui kuesioner (angket) yaitu dengan cara menyebarkan kuesioner kepada sampel (responden) dan mengumpulkannya kembali. Teknik analisis data yang digunakan adalah Regresi Linear Berganda.Sebelum data diregresikan maka terlebih dahulu di uji keterkaitannya antara variabel, datanya diuji menggunakan uji normalitas data, multikolinearitas, dan heterokedastisitas.Serta untuk mengetahui kontribusi faktor Harga dan Brand TrustTerhadap Keputusan Pembelian digunakan rumus Koefisien Determinasi (R2). Hipotesis penelitian diterima apabila t hitung >  t tabel dengan tingkat signifikansi 0,1. Nilai t tabel dalam penelitian ini 1,993. Nilai t hitung variabel X1 sebesar 2,107 t hitung lebih besar dari t tabel maka hipotesis di terima, nilai t hitung variabel X2   sebesar 3,405 t hitung lebih besar dari t tabel maka hipotesis di terima. Kata kunci: Harga, Brand Trust, Keputusan Pembelian AbstractThis study aims to determine the Influence of Price and Brand Trust on Purchasing Decision at Sinergy Celular Medan. The sample in this study is all visitors Sinergy Celular Medan as many as 77 people.Data collection technique used is through questionnaire (questionnaire) that is by distributing questionnaires to the sample (respondent) and collect it back. Data analysis technique used is Multiple Linear Regression. Before the data is diregresikan then first in the test the relationship between variables, the data tested using the test of data normality, multicollinearity, and heterokedastisitas. And to know the contribution of price factors and Brand Trust Against Purchase Decision is used the formula Coefficient of Determination (R2). Research hypothesis accepted if t arithmetic> t table with significance level 0,1. The value of t table in this study is 1,993. Value t arithmetic variable X1 of 2.107 t arithmetic greater than t table then the hypothesis received, the value of t arithmetic variable X2 of 3.405 t arithmetic greater than t table then the hypothesis received. Keywords: Price, Brand Trust, Purchase Decision


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