arXiv - PHYS - Biological Physics最新文献_第8页

In-silico model of the pregnant uterus as a network of oscillators under sparse adaptive control 作为稀疏自适应控制下振荡器网络的妊娠子宫内模拟模型

arXiv - PHYS - Biological Physics Pub Date : 2024-08-01 DOI: arxiv-2408.00956

Giuseppe Maria Ferro, Andrea Somazzi, Didier Sornette

{"title":"In-silico model of the pregnant uterus as a network of oscillators under sparse adaptive control","authors":"Giuseppe Maria Ferro, Andrea Somazzi, Didier Sornette","doi":"arxiv-2408.00956","DOIUrl":"https://doi.org/arxiv-2408.00956","url":null,"abstract":"To ensure optimal survival of the neonate, the biological timing of\u0000parturition must be tightly controlled. Medical studies show that a variety of\u0000endocrine systems play the role of a control system, establishing a dynamic\u0000balance between the forces that cause uterine quiescence during pregnancy and\u0000the forces that produce coordinated uterine contractility at parturition. These\u0000control mechanism, and the factors that affect their performance, are still\u0000poorly understood. To help fill this gap, we propose a model of the pregnant\u0000uterus as a network of FitzHugh-Nagumo oscillators, with each cell symbolizing\u0000the electrical activity of a myocyte. The model is augmented with sparse\u0000adaptive control mechanisms representing the regulating endocrine functions.\u0000The control system is characterized by the fraction of controlled sites, and\u0000strength of control. We quantitatively find the conditions for which the\u0000control system exhibit a balance between robustness (resilience against\u0000perturbations) and flexibility (ability to switch function with minimal cost)\u0000crucial for optimal neonatal survival. Specifically, we show that Braxton-Hicks\u0000and Alvarez contractions, which are observed sporadic contractions of the\u0000uterine muscle, serve as a safety valve against over-controlling, strategically\u0000suppressed yet retained to optimize the control system's efficiency. Preterm\u0000birth is suggested to be understood as a mis-identification of the control\u0000boundaries. These insights contribute to advancing our understanding of\u0000maternal-fetal health.","PeriodicalId":501040,"journal":{"name":"arXiv - PHYS - Biological Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939928","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

Microscopic model for aging of biocondensates 生物凝结物老化的微观模型

arXiv - PHYS - Biological Physics Pub Date : 2024-07-31 DOI: arxiv-2407.21710

Hugo Le Roy, Paolo De Los Rios

{"title":"Microscopic model for aging of biocondensates","authors":"Hugo Le Roy, Paolo De Los Rios","doi":"arxiv-2407.21710","DOIUrl":"https://doi.org/arxiv-2407.21710","url":null,"abstract":"Biomolecular condensates are membraneless compartments in the cell that are\u0000involved in a wide diversity of biological processes. These phase-separated\u0000droplets usually exhibit a viscoelastic mechanical response. A behavior\u0000rationalized by modeling the complex molecules that make up a condensate as\u0000stickers and spacers, which assemble into a network-like structure. The proper\u0000functioning of biocondensates requires precise control over their composition,\u0000size, and mechanical response. For example, several neurodegenerative diseases\u0000are associated with dysfunctional condensates that solidify over a long period\u0000of time (days) until they become solid. A phenomenon usually described as\u0000aging. The emergence of such a long timescale of evolution from microscopic\u0000events, as well as the associated microscopic reorganization leading to aging,\u0000remains mostly an open question. In this article, we explore the connection\u0000between the mechanical properties of the condensates and their microscopic\u0000structure. We propose a minimal model for the dynamic of stickers and spacers,\u0000and show that entropy minimization of spacers leads to an attractive force\u0000between stickers. Our system displays a surprisingly slow relaxation toward\u0000equilibrium, reminiscent of glassy systems and consistent with the\u0000liquid-to-solid transition observed. To explain this behavior, we study the\u0000clustering dynamic of stickers and successfully explain the origin of glassy\u0000relaxation.","PeriodicalId":501040,"journal":{"name":"arXiv - PHYS - Biological Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867117","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

SSPACE Astrobiology Payload-1 (SAP-1) SSPACE 天体生物学有效载荷-1（SAP-1）

arXiv - PHYS - Biological Physics Pub Date : 2024-07-30 DOI: arxiv-2407.21183

A Lokaveer, Thomas Anjana, Maliyekkal Yasir, S Yogahariharan, Akash Dewangan, Saurabh Kishor Mahajan, Sakshi Aravind Tembhurne, Gunja Subhash Gupta, Devashish Bhalla, Anantha Datta Dhruva, Aloke Kumar, Koushik Viswanathan, Vikram Khaire, Anand Narayanan, Priyadarshnam Hari

{"title":"SSPACE Astrobiology Payload-1 (SAP-1)","authors":"A Lokaveer, Thomas Anjana, Maliyekkal Yasir, S Yogahariharan, Akash Dewangan, Saurabh Kishor Mahajan, Sakshi Aravind Tembhurne, Gunja Subhash Gupta, Devashish Bhalla, Anantha Datta Dhruva, Aloke Kumar, Koushik Viswanathan, Vikram Khaire, Anand Narayanan, Priyadarshnam Hari","doi":"arxiv-2407.21183","DOIUrl":"https://doi.org/arxiv-2407.21183","url":null,"abstract":"The SSPACE Astrobiology Payload (SAP) series, starting with the SAP-1 project\u0000is designed to conduct in-situ microbiology experiments in low earth orbit.\u0000This payload series aims to understand the behaviour of microbial organisms in\u0000space, particularly those critical for human health, and the corresponding\u0000effects due to microgravity and solar/galactic radiation. SAP-1 focuses on\u0000studying Bacillus clausii and Bacillus coagulans, bacteria beneficial to\u0000humans. It aims to provide a space laboratory for astrobiology experiments\u0000under microgravity conditions. The hardware developed for these experiments is\u0000indigenous and tailored to meet the unique requirements of autonomous\u0000microbiology experiments by controlling pressure, temperature, and nutrition\u0000flow to bacteria. A rotating platform, which forms the core design, is\u0000innovatively utilised to regulate the flow and mixing of nutrients with dormant\u0000bacteria. The technology demonstration models developed at SSPACE have yielded\u0000promising results, with ongoing efforts to refine, adapt for space conditions,\u0000and prepare for integration with nanosatellites or space modules. The\u0000anticipated payload will be compact, approximately 1U in size (10cm x 10cm x\u000010cm), consume less than 5W power, and offer flexibility for various\u0000microbiological studies.","PeriodicalId":501040,"journal":{"name":"arXiv - PHYS - Biological Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867118","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

Fragmentation and aggregation of cyanobacterial colonies 蓝藻菌落的破碎和聚集

arXiv - PHYS - Biological Physics Pub Date : 2024-07-30 DOI: arxiv-2407.21115

Yuri Z. Sinzato, Robert Uittenbogaard, Petra M. Visser, Jef Huisman, Maziyar Jalaal

{"title":"Fragmentation and aggregation of cyanobacterial colonies","authors":"Yuri Z. Sinzato, Robert Uittenbogaard, Petra M. Visser, Jef Huisman, Maziyar Jalaal","doi":"arxiv-2407.21115","DOIUrl":"https://doi.org/arxiv-2407.21115","url":null,"abstract":"Fluid flow has a major effect on the aggregation and fragmentation of\u0000bacterial colonies. Yet, a generic framework to understand and predict how\u0000hydrodynamics affects colony size remains elusive. This study investigates how\u0000fluid flow affects the formation and maintenance of large colonial structures\u0000in cyanobacteria. We performed experiments on laboratory cultures and lake\u0000samples of the cyanobacterium Microcystis, while their colony size distribution\u0000was measured simultaneously by direct microscopic imaging. We demonstrate that\u0000EPS-embedded cells formed by cell division exhibit significant mechanical\u0000resistance to shear forces. However, at elevated hydrodynamic stress levels\u0000(exceeding those typically generated by surface wind mixing) these colonies\u0000experience fragmentation through an erosion process. We also show that single\u0000cells can aggregate into small colonies due to fluid flow. However, the\u0000structural integrity of these flow-induced colonies is weaker than that of\u0000colonies formed by cell division. We provide a mathematical analysis to support\u0000the experiments and demonstrate that a population model with two categories of\u0000colonies describes the measured size distributions. Our results shed light on\u0000the specific conditions wherein flow-induced fragmentation and aggregation of\u0000cyanobacteria are decisive and indicate that colony formation under natural\u0000conditions is mainly driven by cell division, although flow-induced aggregation\u0000could play a role in dense bloom events. These findings can be used to improve\u0000prediction models and mitigation strategies for toxic cyanobacterial blooms and\u0000also offer potential applications in other areas such as algal biotechnology or\u0000medical settings where the dynamics of biological aggregates play a significant\u0000role.","PeriodicalId":501040,"journal":{"name":"arXiv - PHYS - Biological Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867064","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

Non-linear inhibitory responses enhance performance in collective decision-making 非线性抑制反应可提高集体决策的绩效

arXiv - PHYS - Biological Physics Pub Date : 2024-07-30 DOI: arxiv-2407.20927

David March-Pons, Romualdo Pastor-Satorras, M. Carmen Miguel

引用次数: 0

Constrained motion of self-propelling eccentric disks linked by a spring 由弹簧连接的自推进偏心盘的受约束运动

arXiv - PHYS - Biological Physics Pub Date : 2024-07-30 DOI: arxiv-2407.20610

Tian-liang Xu, Chao-ran Qin, Bin Tang, Jin-cheng Gao, Jiankang Zhou, Kang Chen, Tian Hui Zhang, Wen-de Tian

{"title":"Constrained motion of self-propelling eccentric disks linked by a spring","authors":"Tian-liang Xu, Chao-ran Qin, Bin Tang, Jin-cheng Gao, Jiankang Zhou, Kang Chen, Tian Hui Zhang, Wen-de Tian","doi":"arxiv-2407.20610","DOIUrl":"https://doi.org/arxiv-2407.20610","url":null,"abstract":"It has been supposed that the interplay of elasticity and activity plays a\u0000key role in triggering the non-equilibrium behaviors in biological systems.\u0000However, the experimental model system is missing to investigate the\u0000spatiotemporally dynamical phenomena. Here, a model system of an active chain,\u0000where active eccentric-disks are linked by a spring, is designed to study the\u0000interplay of activity, elasticity, and friction. Individual active chain\u0000exhibits longitudinal and transverse motion, however, it starts to self-rotate\u0000when pinning one end, and self-beats when clamping one end. Additionally, our\u0000eccentric-disk model can qualitatively reproduce such behaviors and explain the\u0000unusual self-rotation of the first disk around its geometric center. Further,\u0000the structure and dynamics of long chains were studied via simulations without\u0000steric interactions. It was found that hairpin conformation emerges in free\u0000motion, while in the constrained motions, the rotational and beating\u0000frequencies scale with the flexure number (the ratio of self-propelling force\u0000to bending rigidity), ~4/3. Scaling analysis suggests that it results from the\u0000balance between activity and energy dissipation. Our findings show that\u0000topological constraints play a vital role in non-equilibrium synergy behavior.","PeriodicalId":501040,"journal":{"name":"arXiv - PHYS - Biological Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867142","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

Design of a System for Analyzing Cell Mechanics 设计细胞力学分析系统

arXiv - PHYS - Biological Physics Pub Date : 2024-07-30 DOI: arxiv-2407.21182

Hasan Berkay Abdioglu, Yagmur Isik, Merve Sevgi, Ufuk Gorkem Kirabali, Yunus Emre Mert, Gulnihal Guldogan, Selin Serdarli, Tarik Taha Gulen, Huseyin Uvet

引用次数: 0

Laser patterned diamond electrodes for adhesion and proliferation of human mesenchymal stem cells 用于人类间充质干细胞粘附和增殖的激光图案金刚石电极

arXiv - PHYS - Biological Physics Pub Date : 2024-07-28 DOI: arxiv-2407.19582

Hassan N. Al Hashem, Amanda N. Abraham, Deepak Sharma, Andre Chambers, Mehrnoosh Moghaddar, Chayla L. Reeves, Sanjay K. Srivastava, Amy Gelmi, Arman Ahnood

{"title":"Laser patterned diamond electrodes for adhesion and proliferation of human mesenchymal stem cells","authors":"Hassan N. Al Hashem, Amanda N. Abraham, Deepak Sharma, Andre Chambers, Mehrnoosh Moghaddar, Chayla L. Reeves, Sanjay K. Srivastava, Amy Gelmi, Arman Ahnood","doi":"arxiv-2407.19582","DOIUrl":"https://doi.org/arxiv-2407.19582","url":null,"abstract":"The ability to form diamond electrodes on insulating polycrystalline diamond\u0000substrates using single-step laser patterning, and the use of the electrodes as\u0000a substrate that supports the adhesion and proliferation of human mesenchymal\u0000stem cells (hMSCs) is demonstrated. Laser induced graphitisation results in a\u0000conductive amorphous carbon surface, rich in oxygen and nitrogen terminations.\u0000This results in an electrode with a high specific capacitance of 182 uF/cm2, a\u0000wide water window of 3.25 V, and a low electrochemical impedance of 129\u0000Ohms/cm2 at 1 kHz. The electrodes surface exhibited a good level of\u0000biocompatibility with hMSCs, supporting cell adhesion and proliferation. The\u0000cells cultured on the electrode displayed significant elongation and alignment\u0000along the direction of the laser patterned microgrooves. Because of its\u0000favourable electrochemical performance and biocompatibility, the\u0000laser-patterned diamond electrodes create a potential for a versatile platform\u0000in stem cell therapeutics.","PeriodicalId":501040,"journal":{"name":"arXiv - PHYS - Biological Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867120","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

Cell Sorting in an Active Nematic Vertex Model 活跃向列顶点模型中的细胞排序

arXiv - PHYS - Biological Physics Pub Date : 2024-07-28 DOI: arxiv-2407.19591

Jan Rozman, Julia M. Yeomans

引用次数: 0

Criticality enhances the reinforcement of disordered networks by rigid inclusions 临界性增强了刚性夹杂物对无序网络的强化作用

arXiv - PHYS - Biological Physics Pub Date : 2024-07-28 DOI: arxiv-2407.19563

Jordan L. Shivers, Jingchen Feng, Fred C. MacKintosh

{"title":"Criticality enhances the reinforcement of disordered networks by rigid inclusions","authors":"Jordan L. Shivers, Jingchen Feng, Fred C. MacKintosh","doi":"arxiv-2407.19563","DOIUrl":"https://doi.org/arxiv-2407.19563","url":null,"abstract":"The mechanical properties of biological materials are spatially\u0000heterogeneous. Typical tissues are made up of a spanning fibrous extracellular\u0000matrix in which various inclusions, such as living cells, are embedded. While\u0000the influence of inclusions on the stiffness of common elastic materials such\u0000as rubber has been studied for decades and can be understood in terms of the\u0000volume fraction and shape of inclusions, the same is not true for disordered\u0000filamentous and fibrous networks. Recent work has shown that, in isolation,\u0000such networks exhibit unusual viscoelastic behavior indicative of an underlying\u0000mechanical phase transition controlled by network connectivity and strain. How\u0000this behavior is modified when inclusions are present is unclear. Here, we\u0000present a theoretical and computational study of the influence of rigid\u0000inclusions on the mechanics of disordered elastic networks near the\u0000connectivity-controlled central force rigidity transition. Combining scaling\u0000theory and coarse-grained simulations, we predict and confirm an anomalously\u0000strong dependence of the composite stiffness on inclusion volume fraction,\u0000beyond that seen in ordinary composites. This stiffening exceeds the\u0000well-established volume fraction-dependent stiffening expected in conventional\u0000composites, e.g., as an elastic analogue of the classic volume fraction\u0000dependent increase in the viscosity of liquids first identified by Einstein. We\u0000show that this enhancement is a consequence of the interplay between\u0000inter-particle spacing and an emergent correlation length, leading to an\u0000effective finite-size scaling imposed by the presence of inclusions. We outline\u0000the expected scaling of the shear modulus and strain fluctuations with the\u0000inclusion volume fraction and network connectivity, confirm these predictions\u0000in simulations, and discuss potential experimental tests and implications for\u0000our predictions in real systems.","PeriodicalId":501040,"journal":{"name":"arXiv - PHYS - Biological Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867143","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