arXiv: Biological Physics最新文献_第7页

Dale's Principle is necessary for an optimal neuronal network's dynamics 戴尔原理是最优神经网络动力学的必要条件

arXiv: Biological Physics Pub Date : 2013-07-02 DOI: 10.4236/am.2013.410A2002

E. Catsigeras

{"title":"Dale's Principle is necessary for an optimal neuronal network's dynamics","authors":"E. Catsigeras","doi":"10.4236/am.2013.410A2002","DOIUrl":"https://doi.org/10.4236/am.2013.410A2002","url":null,"abstract":"We study a mathematical model of biological neuronal networks composed by any finite number $N geq 2$ of non necessarily identical cells. The model is a deterministic dynamical system governed by finite-dimensional impulsive differential equations. The statical structure of the network is described by a directed and weighted graph whose nodes are certain subsets of neurons, and whose edges are the groups of synaptical connections among those subsets. First, we prove that among all the possible networks such that their respective graphs are mutually isomorphic, there exists a dynamical optimum. This optimal network exhibits the richest dynamics: namely, it is capable to show the most diverse set of responses (i.e. orbits in the future) under external stimulus or signals. Second, we prove that all the neurons of a dynamically optimal neuronal network necessarily satisfy Dale's Principle, i.e. each neuron must be either excitatory or inhibitory, but not mixed. So, Dale's Principle is a mathematical necessary consequence of a theoretic optimization process of the dynamics of the network. Finally, we prove that Dale's Principle is not sufficient for the dynamical optimization of the network.","PeriodicalId":360136,"journal":{"name":"arXiv: Biological Physics","volume":"286 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131680876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Modeling of blood vessel constriction in 2-D case using molecular dynamics method 用分子动力学方法建立二维病例血管收缩模型

arXiv: Biological Physics Pub Date : 2013-06-25 DOI: 10.1063/1.4868829

M. Rendi, Suprijadi, S. Viridi

引用次数: 2

Non-Thermal Mechanism of Weak Microwave Fields Influence on Nerve Fiber 弱微波场对神经纤维影响的非热机制

arXiv: Biological Physics Pub Date : 2013-05-09 DOI: 10.1063/1.4821027

M. Shneider, M. Pekker

引用次数: 19

Coherent Diffraction and Holographic Imaging of Individual Biomolecules Using Low-Energy Electrons 利用低能电子对单个生物分子进行相干衍射和全息成像

arXiv: Biological Physics Pub Date : 2013-05-07 DOI: 10.1007/978-94-007-6232-9_29

T. Latychevskaia, J. Longchamp, C. Escher, H. Fink

引用次数: 7

Measuring leaf chlorophyll concentration from its color: A way in monitoring environment change to plantations 从叶片颜色测量叶绿素浓度:监测人工林环境变化的一种方法

arXiv: Biological Physics Pub Date : 2013-05-06 DOI: 10.1063/1.4820322

Muhammad Abdul Hakim Shibghatallah, S. Khotimah, S. Suhandono, S. Viridi, T. Kesuma

引用次数: 73

Penetration Deep into Tissues of Reactive Oxygen Species Generated in Floating-Electrode Dielectric Barrier Discharge (FE-DBD): in Vitro Agarose Gel Model Mimicking an Open Wound 漂浮电极介质阻挡放电(FE-DBD)中产生的活性氧深入组织:模拟开放性伤口的琼脂糖凝胶模型

arXiv: Biological Physics Pub Date : 2013-03-14 DOI: 10.1615/PLASMAMED.2013006218

D. Dobrynin, G. Fridman, G. Friedman, A. Fridman

引用次数: 33

Effects of anchored flexible polymers on mechanical properties of model biomembranes 锚定柔性聚合物对生物膜模型力学性能的影响

arXiv: Biological Physics Pub Date : 2013-02-25 DOI: 10.1063/1.4794653

Hao Wu, H. Noguchi

引用次数: 1

Comparative Molecular Mechanics and Quantum Mechanics Study of Microhydration of Nucleic Acid Bases 核酸碱基微水化的分子力学与量子力学比较研究

arXiv: Biological Physics Pub Date : 2013-02-11 DOI: 10.4236/JBPC.2016.72005

J. Lino, E. Gonz'alez, A. Deriabina, M. Velasco, V. Poltev

{"title":"Comparative Molecular Mechanics and Quantum Mechanics Study of Microhydration of Nucleic Acid Bases","authors":"J. Lino, E. Gonz'alez, A. Deriabina, M. Velasco, V. Poltev","doi":"10.4236/JBPC.2016.72005","DOIUrl":"https://doi.org/10.4236/JBPC.2016.72005","url":null,"abstract":"DNA is the most important biological molecule, and its hydration contributes essentially to the structure and functions of the double helix. We analyze the microhydration of the individual bases of nucleic acids and their methyl derivatives using methods of molecular mechanics (MM) with the Poltev-Malenkov (PM), AMBER and OPLS force fields, as well as ab initio Quantum Mechanics (QM) calculations at MP2/6-31G(d,p) level of theory. A comparison is made between the calculated interaction energies and the experimental enthalpies of microhydration of bases, obtained from mass spectrometry at low temperatures. Each local water-base interaction energy minimum obtained with MM corresponds to the minimum obtained with QM. General qualitative agreement was observed in the geometrical characteristics of the local minima obtained via the two groups of methods. MM minima correspond to slightly more coplanar structures than those obtained via QM methods, and the absolute MM energy values overestimate corresponding values obtained with QM. For Adenine and Thymine the QM local minima energy values are closer to those obtained by the PM potential (average of 0.72 kcal/mol) than by the AMBER force field (1.86 kcal/mol). The differences in energy between MM and QM results are more pronounced for Guanine and Cytosine, especially for minima with the water molecule forming H-bonds with two proton-acceptor centers of the base. Such minima are the deepest ones obtained via MM methods while QM calculations result in the global minima corresponding to water molecule H-bonded to one acceptor and one donor site of the base. Calculations for trimethylated bases with a water molecule corroborate the MM results. The energy profiles were obtained with some degrees of freedom of the water molecule being frozen. This data will contribute to the improvement of the molecular mechanics force fields.","PeriodicalId":360136,"journal":{"name":"arXiv: Biological Physics","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127616322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structure-property-function relationships in triple helical collagen hydrogels 三螺旋胶原水凝胶的结构-性能-功能关系

arXiv: Biological Physics Pub Date : 2012-12-09 DOI: 10.1557/opl.2012.1653

Giuseppe Tronci, A. Doyle, S. Russell, D. Wood

{"title":"Structure-property-function relationships in triple helical collagen hydrogels","authors":"Giuseppe Tronci, A. Doyle, S. Russell, D. Wood","doi":"10.1557/opl.2012.1653","DOIUrl":"https://doi.org/10.1557/opl.2012.1653","url":null,"abstract":"In order to establish defined biomimetic systems, type I collagen was functionalised with 1,3-Phenylenediacetic acid (Ph) as aromatic, bifunctional segment. Following investigation on molecular organization and macroscopic properties, material functionalities, i.e. degradability and bioactivity, were addressed, aiming at elucidating the potential of this collagen system as mineralization template. Functionalised collagen hydrogels demonstrated a preserved triple helix conformation. Decreased swelling ratio and increased thermo-mechanical properties were observed in comparison to state-of-the-art carbodiimide (EDC)-crosslinked collagen controls. Ph-crosslinked samples displayed no optical damage and only a slight mass decrease (~ 4 wt.-%) following 1-week incubation in simulated body fluid (SBF), while nearly 50 wt.-% degradation was observed in EDC-crosslinked collagen. SEM/EDS revealed amorphous mineral deposition, whereby increased calcium phosphate ratio was suggested in hydrogels with increased Ph content. This investigation provides valuable insights for the synthesis of triple helical collagen materials with enhanced macroscopic properties and controlled degradation. In light of these features, this system will be applied for the design of tissue-like scaffolds for mineralized tissue formation.","PeriodicalId":360136,"journal":{"name":"arXiv: Biological Physics","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124418148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

Chemo-mechanical instabilities in polarizable active layers 极化活性层的化学-机械不稳定性

arXiv: Biological Physics Pub Date : 2012-07-25 DOI: 10.14288/1.0042953

M. Koepf

引用次数: 0