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Literatura académica sobre el tema "Backbone dynamic"

Autor: Grafiati

Publicado: 11 de marzo de 2023

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Artículos de revistas sobre el tema "Backbone dynamic"

Kharchenko, Vladlena, Michal Nowakowski, Mariusz Jaremko, Andrzej Ejchart y Łukasz Jaremko. "Dynamic 15N{1H} NOE measurements: a tool for studying protein dynamics". Journal of Biomolecular NMR 74, n.º 12 (12 de septiembre de 2020): 707–16. http://dx.doi.org/10.1007/s10858-020-00346-6.

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AbstractIntramolecular motions in proteins are one of the important factors that determine their biological activity and interactions with molecules of biological importance. Magnetic relaxation of 15N amide nuclei allows one to monitor motions of protein backbone over a wide range of time scales. 15N{1H} nuclear Overhauser effect is essential for the identification of fast backbone motions in proteins. Therefore, exact measurements of NOE values and their accuracies are critical for determining the picosecond time scale of protein backbone. Measurement of dynamic NOE allows for the determination of NOE values and their probable errors defined by any sound criterion of nonlinear regression methods. The dynamic NOE measurements can be readily applied for non-deuterated or deuterated proteins in both HSQC and TROSY-type experiments. Comparison of the dynamic NOE method with commonly implied steady-state NOE is presented in measurements performed at three magnetic field strengths. It is also shown that improperly set NOE measurement cannot be restored with correction factors reported in the literature.

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YE, JIEPING, RAVI JANARDAN y SONGTAO LIU. "PAIRWISE PROTEIN STRUCTURE ALIGNMENT BASED ON AN ORIENTATION-INDEPENDENT BACKBONE REPRESENTATION". Journal of Bioinformatics and Computational Biology 02, n.º 04 (diciembre de 2004): 699–717. http://dx.doi.org/10.1142/s021972000400082x.

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Determining structural similarities between proteins is an important problem since it can help identify functional and evolutionary relationships. In this paper, an algorithm is proposed to align two protein structures. Given the protein backbones, the algorithm finds a rigid motion of one backbone onto the other such that large substructures are matched. The algorithm uses a representation of the backbones that is independent of their relative orientations in space and applies dynamic programming to this representation to compute an initial alignment, which is then refined iteratively. Experiments indicate that the algorithm is competitive with two well-known algorithms, namely DALI and LOCK.

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Walker, Ian D. "Continuous Backbone “Continuum” Robot Manipulators". ISRN Robotics 2013 (16 de julio de 2013): 1–19. http://dx.doi.org/10.5402/2013/726506.

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This paper describes and discusses the history and state of the art of continuous backbone robot manipulators. Also known as continuum manipulators, these robots, which resemble biological trunks and tentacles, offer capabilities beyond the scope of traditional rigid-link manipulators. They are able to adapt their shape to navigate through complex environments and grasp a wide variety of payloads using their compliant backbones. In this paper, we review the current state of knowledge in the field, focusing particularly on kinematic and dynamic models for continuum robots. We discuss the relationships of these robots and their models to their counterparts in conventional rigid-link robots. Ongoing research and future developments in the field are discussed.

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Dent, Erik W., Elliott B. Merriam y Xindao Hu. "The dynamic cytoskeleton: backbone of dendritic spine plasticity". Current Opinion in Neurobiology 21, n.º 1 (febrero de 2011): 175–81. http://dx.doi.org/10.1016/j.conb.2010.08.013.

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Bertini, Ivano, Donald A. Bryant, Stefano Ciurli, Alexander Dikiy, Claudio O. Fernández, Claudio Luchinat, Niyaz Safarov, Alejandro J. Vila y Jindong Zhao. "Backbone Dynamics of Plastocyanin in Both Oxidation States". Journal of Biological Chemistry 276, n.º 50 (16 de agosto de 2001): 47217–26. http://dx.doi.org/10.1074/jbc.m100304200.

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A model-free analysis based on15NR1,15NR2, and15N-1H nuclear Overhauser effects was performed on reduced (diamagnetic) and oxidized (paramagnetic) forms of plastocyanin fromSynechocystissp. PCC6803. The protein backbone is rigid, displaying a small degree of mobility in the sub-nanosecond time scale. The loops surrounding the copper ion, involved in physiological electron transfer, feature a higher extent of flexibility in the longer time scale in both redox states, as measured from D2O exchange of amide protons and from NH-H2O saturation transfer experiments. In contrast to the situation for other electron transfer proteins, no significant difference in the dynamic properties is found between the two redox forms. A solution structure was also determined for the reduced plastocyanin and compared with the solution structure of the oxidized form in order to assess possible structural changes related to the copper ion redox state. Within the attained resolution, the structure of the reduced plastocyanin is indistinguishable from that of the oxidized form, even though small chemical shift differences are observed. The present characterization provides information on both the structural and dynamic behavior of blue copper proteins in solution that is useful to understand further the role(s) of protein dynamics in electron transfer processes.

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Kim, Yeon Su, Kyeong Ho Moon, Se Ky Chang y Jai Kyun Mok. "Strength Analysis of Chassis Structure for Medium-Sized Low-Floor Vehicle under Dynamic Load Cases". Key Engineering Materials 452-453 (noviembre de 2010): 709–12. http://dx.doi.org/10.4028/www.scientific.net/kem.452-453.709.

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For the medium-sized low-floor bus, backbone structure of chassis was designed to have light-weight structure with SAPH (Steel Automobile Press Hot rolled) 440. Strength for the designed backbone structure was also analyzed by finite element method under various dynamic load cases considered in this paper. On the basis of the analysis results, the structural safety for the designed backbone structure was evaluated and discussed in this paper.

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Saeedvand, Saeed, Hadi S. Aghdasi y Leili Mohammad Khanli. "Novel Distributed Dynamic Backbone-based Flooding in Unstructured Networks". Peer-to-Peer Networking and Applications 13, n.º 3 (18 de noviembre de 2019): 872–89. http://dx.doi.org/10.1007/s12083-019-00817-0.

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BONONI, LUCIANO, MARCO DI FELICE y SARA PIZZI. "DBA-MAC: DYNAMIC BACKBONE-ASSISTED MEDIUM ACCESS CONTROL PROTOCOL FOR EFFICIENT BROADCAST IN VANETS". Journal of Interconnection Networks 10, n.º 04 (diciembre de 2009): 321–44. http://dx.doi.org/10.1142/s0219265909002601.

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Active safety systems based on dissemination of alert messages are one of the most important applications of Vehicular ad Hoc Networks (VANETs). These systems typically require to provide efficient and reliable delivery of safety information to all the vehicles travelling over a geographical area. Reducing the delivery delay is also a crucial issue due to the real-time nature of the communication. To meet these requirements, in this paper we design a cross-layered MAC and clustering solution for the fast propagation of broadcast messages in a VANET. A distributed dynamic clustering algorithm is proposed in order to create a dynamic virtual backbone inside the vehicular network. The vehicle-members of the backbone are responsible for implementing an efficient message propagation. The backbone creation and maintenance are proactively performed aiming to balance the stability of backbone connections as well as cost/efficiency trade-off and hops-reduction when forwarding the broadcast messages. A fast multi-hop MAC forwarding scheme is defined to exploit the role of backbone vehicles, under a cross-layered approach. Simulation results show that our cross-layer scheme guarantees high message delivery ratio, reduces the delivery delay and provides efficient channel utilization when compared with other dissemination schemes for VANETs.

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Rong, Xiao Yang, Tian Hong Yang, Pei Tao Wang, Hong Wang y Yang Li. "Dynamic Triaxial Test Research of Stage Change of Cohesive Soil". Applied Mechanics and Materials 353-356 (agosto de 2013): 937–40. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.937.

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With the STX-50 pneumatic-typed dynamic triaxial system, the undrained dynamic triaxial tests on the saturated cohesive soil are performed to study the dynamic strength properties. The changing process of the dynamic strength, backbone curve and the soil deformation of the cohesive soil under dynamic load are zoom analysis by stages to get their regularity. It is found that the stage change of the dynamic strength, backbone curve and the soil deformation all exist, which the stage I of the soil deformation has little damage, the stage III is not allowed, the stage II is determined by the importance of the concrete and the sensitive degree to the deformation. In order to analysis the deformation stability and stress stability of the formation in the effect of the dynamic load, provide qualitative and quantitative basis for the soil dynamic study.

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Wu, Celimuge, Xianfu Chen, Yusheng Ji, Satoshi Ohzahata y Toshihiko Kato. "Efficient Broadcasting in VANETs Using Dynamic Backbone and Network Coding". IEEE Transactions on Wireless Communications 14, n.º 11 (noviembre de 2015): 6057–71. http://dx.doi.org/10.1109/twc.2015.2447812.

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Tesis sobre el tema "Backbone dynamic"

Olwal, Thomas. "Dynamic power control in backbone wireless mesh networks : a decentralized approach". Phd thesis, Université Paris-Est, 2010. http://tel.archives-ouvertes.fr/tel-00598277.

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The remarkable evolution of wireless networks into the next generation to provide ubiquitous and seamless broadband applications has recently triggered the emergence of Wireless Mesh Networks (WMNs). The WMNs comprise stationary Wireless Mesh Routers (WMRs) forming Wireless Backbone Mesh Networks (WBMNs) and mobile Wireless Mesh Clients (WMCs) forming the WMN access. While WMCs are limited in function and radio resources, the WMRs are expected to support heavy duty applications : that is, WMRs have gateway and bridge functions to integrate WMNs with other networks such as the Internet, cellular, IEEE 802.11, IEEE 802.15, IEEE 802.16, sensor networks, et cetera. Consequently, WMRs are constructed from fast switching radios or multiple radio devices operating on multiple frequency channels. WMRs are expected to be self-organized, self-configured and constitute a reliable and robust WBMN which needs to sustain high traffic volumes and long "online" time. However, meeting such stringent service expectations requires the development of decentralized dynamic transmission power control (DTPC) approaches. This thesis addresses the DTPC problem for both single and multiple channel WBMNs. For single channel networks, the problem is formulated as the minimization of both the link-centric and network-centric convex cost function. In order to solve this issue, multiple access transmission aware (MATA) models and algorithms are proposed. For multi-radio multi-channel (MRMC) WBMNs, the network is modelled as sets of unified channel graphs (UCGs), each consisting of interconnected active network users communicating on the same frequency channel. For each UCG set, the minimization of stochastic quadratic cost functions are developed subject to the dynamic Link State Information (LSI) equations from all UCGs. An energy-efficient multi-radio unification protocol (PMMUP) is then suggested at the Link-Layer (LL). Predictive estimation algorithms based on this protocol are proposed to solve such objective functions. To address transmission energy and packet instabilities, and interference across multiple channels, singularly-perturbed weakly-coupled (SPWC) control problems are formulated. In order to solve the SPWC transmission power control problem, a generalized higher-order recursive algorithm (HORA) that obtains the Riccati Stabilizing Solutions to the control problem is developed. The performance behaviours of the proposed models and algorithms are evaluated both analytically and through computer simulations. Several simulations are performed on a large number of randomly generated topologies. Simulation and analytical results confirm the efficacy of the proposed algorithms compared to the most recently studied techniques

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Huang, He. "Large-Amplitude Vibration of Imperfect Rectangular, Circular and Laminated Plate with Viscous Damping". ScholarWorks@UNO, 2014. http://scholarworks.uno.edu/td/1924.

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Large-amplitude vibration of thin plates and shells has been critical design issues for many engineering structures. The increasingly more stringent safety requirements and the discovery of new materials with amazingly superior properties have further focused the attention of research on this area. This thesis deals with the vibration problem of rectangular, circular and angle-ply composite plates. This vibration can be triggered by an initial vibration amplitude, or an initial velocity, or both. Four types of boundary conditions including simply supported and clamped combined with in-plane movable/immovable are considered. To solve the differential equation generated from the vibration problem, Lindstedt's perturbation technique and Runge-Kutta method are applied. In previous works, this problem was solved by Lindstedt's Perturbation Technique. This technique can lead to a quick approximate solution. Yet based on mathematical assumptions, the solution will no longer be accurate for large amplitude vibration, especially when a significant amount of imperfection is considered. Thus Runge-Kutta method is introduced to solve this problem numerically. The comparison between both methods has shown the validity of the Lindstedt's Perturbation Technique is generally within half plate thickness. For a structure with a sufficiently large geometric imperfection, the vibration can be represented as a well-known backbone curve transforming from soften-spring to harden-spring. By parameter variation, the effects of imperfection, damping ratio, boundary conditions, wave numbers, young's modulus and a dozen more related properties are studied. Other interesting research results such as the dynamic failure caused by out-of-bound vibration and the change of vibration mode due to damping are also revealed.

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COGLIATI, CLELIA. "NMR study of chicken Liver Bile Acid Binding Protein: interaction and dynamics". Doctoral thesis, Università degli Studi di Verona, 2010. http://hdl.handle.net/11562/343942.

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Il principale obiettivo di questo lavoro di tesi è lo studio del ruolo giocato da un ponte disolfuro sulle proprietà di legame di una proteina citosolica, la Liver Bile Acid Binding Protein (L-BABP), nella quale è naturalmente presente. In particolare si vuole far luce sulle capacità della proteina di legare Acidi Biliari (BA) e sulle sue proprietà funzionali. Gli acidi biliari circolano tra il fegato e l’intestino attraverso un meccanismo definito “circolazione enteroepatica”, il quale è fortemente regolato dagli stessi acidi biliari. Gli acidi biliari sono infatti in grado di influenzare l’espressione di numerosi geni coinvolti nella loro sintesi e nel loro trasporto, mediante un legame con recettori di acidi biliari intracellulari primari, quali il recettore farnesoide X (FXR). La comprensione del meccanismo che regola l’interazione di trasportatori intracellulari con acidi biliari è un passaggio chiave per la costruzione di un modello rappresentativo del trasferimento di BAs dal citoplasma al nucleo e potrebbe essere utilizzato per lo studio di agenti terapeutici applicabili nel trattamento di disordini metabolici, quali l’obesità, il diabete di tipo 2, l’iperlipidemia e l’aterosclerosi. Per raggiungere una dettagliata descrizione dal punto di vista molecolare e della dinamica coinvolta nella formazione di un complesso ternario, tra L-BABP e due molecole di acidi biliari, è stata utilizzata la spettroscopia NMR (Nuclear Magnetic Resonance), parallelamente ad un’analisi cinetica e termodinamica, specificatamente implementata per questi studi. Nello specifico, mediante la Risonanza Magnetica Nucleare, sono state studiate le proprietà strutturali, di interazione e di dinamica di due forme di L-BABP di pollo, diverse tra loro per la presenza/assenza di un ponte disolfuro. Le interazioni proteina/ligando caratteristiche del complesso sono state studiate arricchendo alternativamente la proteina ed il ligando, con isotopi NMR attivi. La proteina è stata titolata aggiungendo concentrazioni sempre crescenti dell’acido glico-colico (GCA) e glico-chenodeossicolico (GCDA), arricchiti in 15N, in modo da poter seguire la variazione delle loro risonanze attraverso l’acquisizione e l’analisi di numerosi spettri NMR (HSQC, DOSY). I dati ottenuti hanno permesso di determinare la stechiometria di legame e i fenomeni di scambio, ma non sono risultati sufficienti per ricavare informazioni dettagliate sull’affinità, la cooperatività e i meccanismi di legame. Si è quindi deciso di analizzare la variazione dei segnali NMR in funzione della concentrazione di ligando per fare maggiore chiarezza sul meccanismo di interazione tra L-BABP e gli acidi biliari. A questo scopo, sono stati recentemente riportati, nuovi approcci NMR per lo studio delle interazioni proteina/ligandi che avvengono nella scala dei tempi dei micro- e millisecondi, che sfruttano l’analisi delle larghezze di riga ed esperimenti di “relaxation dispersion”. In particolare la combinazione di questi due approcci di indagine si sono rivelati utili per la comprensione della relazione esistente tra dinamica e funzione della proteina. Studi di rilassamento 15N, effettuati sulla proteina apo, hanno rivelato la presenza di moti lenti, nella scala dei tempi de micro- millisecondi. La principale domanda a cui si vuole rispondere è se tali moti sono essenziali per il legame con gli acidi biliari, se portano a conformazioni competenti all’inserimento dei ligandi e se sono influenzati dalla presenza del ponte disolfuro. L’analisi delle larghezze di riga, estratte dagli esperimenti di titolazione, effettuati sulla proteina arricchita isotopicamente in 15N, con successive aggiunte di GCDA, e gli esperimenti di “relaxation dispersion” hanno permesso di individuare un meccanismo di legame a più stadi e di ricavare alcune delle costanti cinetiche coinvolte.
The aim of this thesis is to understand the role played by a naturally occurring disulphide bridge on the bile acid (BA) binding and functional properties of cytosolic Liver Bile Acid Binding Protein (L-BABP). Bile acids circulate between liver and intestine through a mechanism defined as “enterohepatic circulation”, which is a tightly regulated process, particularly by BAs themselves. Indeed BAs are able to influence the expression of numerous genes involved in their synthesis and transport by binding to the primary intracellular nuclear bile acid receptor, farnesoid X receptor (FXR). Understanding the mechanism regulating the interactions of intracellular carriers with bile acid is a key step to provide a model for the transfer of BAs from cytoplasm to the nucleus and can be used to inspire design of therapeutic agents in the treatment of metabolic disorders, such as obesity, type 2 diabetes, hyperlipidaemia and atherosclerosis. To achieve a detailed molecular and dynamical description of the binding mechanism driving to the formation of the ternary complex of L-BABPs with two BA molecules, spectroscopic methods together with kinetic and thermodynamic analysis have been applied and implemented. In particular structural, dynamical and interaction properties of two forms of chicken L-BABP (cL-BABP), differing by the presence/absence of a naturally occurring disulphide bridge, have been investigated through nuclear magnetic resonance (NMR) approaches. The study of protein-ligand interactions by NMR was performed analysing complexes where, alternatively, either the protein or the ligand were isotopically labelled. 15N enriched glycocholic (GCA) and glycochenodeoxycholic acid (GCDA), two of the most important members of bile salts pool, were employed for protein titrations and their resonances followed through the acquisition and analysis of several NMR experiments (HSQC, DOSY). The obtained results shed light on binding stoichiometry and ligand exchange phenomena but were not sufficient to derive detailed information on affinity, cooperativity and binding mechanism. Thus NMR lineshape analysis as a function of ligand concentration was chosen as an appropriate tool to investigate the complex interaction mechanism within the cL-BABP/BA system. In this line, new NMR approaches have been recently described which allow a reliable and sensitive investigation of ligand binding events occurring on microsecond to millisecond (μs-ms) time scales using lineshape and relaxation dispersion experiments[1]. Particularly, the combination of these NMR methods can be useful in the study of complex multi-step mechanisms, allowing the correlation between protein dynamics and function[2]. 15N relaxation studies, performed on the apo-protein, revealed the presence of slow motions occurring on the microseconds-milliseconds timescale. The central question to be addressed is here whether these motions are essential for ligand uptake, how they can eventually lead to conformations competent for binding and how they are influenced by the presence of the disulfide bridge. The analysis of titration experiments of 15N labelled protein with unlabelled GCDA through lineshape analysis and relaxation dispersion allowed to define a multi-step binding mechanism for bile salt binding to liver BABPs and to provide an estimate of the kinetics involved.

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Vivona, Sandro. "VAMP7: a model system to study the Longin Domain-SNARE motif". Doctoral thesis, Università degli studi di Padova, 2009. http://hdl.handle.net/11577/3421900.

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Eukaryotic cells rely on a complex system of membrane-enclosed compartments that are maintained by the trafficking of shuttling vesicles. The fusion of these vesicles with the target compartment relies on multiprotein complexes that have been conserved throughout eukaryotic evolution. SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins are considered the engine of membrane fusion in all trafficking pathways of the cell. Upon specific protein-protein interactions, SNARE proteins that are localized in opposing membranes form a four helix bundle that releases free energy and induces membrane fusion. The SNARE motif is the elementary unit of this bundle and defines all SNARE proteins. SNARE proteins possess other regulatory domains that contribute in modulating the specificity of the fusion event. One of these accessory elements is the Longin Domain (LD). Other than being well conserved among all eukaryotes, the LD is not limited to SNAREs only and is present in many molecular processes related to the life cycle of vesicles. LD-containing SNAREs are called Longins and are divided in three main subfamilies: Ykt6p, Sec22b, VAMP7. The Longin Domain (LD) is usually composed of about 120 amino acids arranged in a globular structural fold that consists of five ? strands (?1- ?5) sandwiched by one ? helix (?1) on one side and two helices (?2 and ?3) on the other side. The LD can fold back onto the SNARE motif in Ykt6p and Sec22b but not in Nyv1p – a fourth minor longin subfamily. This intramolecular interaction involves a surface-exposed hydrophobic pocket contributed by the ?1-?3 structural elements, which is bound by the SNARE motif. This mechanism eventually inhibits and prevents unspecific formation of the SNARE complex, thus regulating the vesicle fusion process. However, very little is known about the dynamic properties of such mechanism. The present study uses VAMP7 as a model system to reveal these characteristics. Our interest in VAMP7 relies on the fact that not only VAMP7 lacks any direct evidence of the LD-SNARE interaction, but it also offers a system of natural variations to the usual LD-SNARE domain arrangement that can prove extremely useful in our study. The present work reveals unknown dynamic properties of the LD-SNARE interaction supporting a dominantly “closed conformation” for Longins, with heterogeneous characteristics. The results shown in this research complement well with what we already know about a similar auto-inhibitory mechanism observed in the Syntaxin subfamily of SNAREs. Therefore, we provide here new bases for a better understanding of the regulatory mechanisms involved in vesicle fusion.
Le cellule eucariote sono caratterizzate da un complesso sistema di membrane, che offre svariate compartimentazioni con diverse condizioni chimico-fisiche. Se da una parte tale sistema permette la realizzazione di un’ampia gamma di processi biochimici, dall’altra richiede un altrettanto complesso sistema di interscambio atto al suo mantenimento. Tale interscambio è assicurato dal trafficking di vescicole che originano da un compartimento donatore e riversano il loro contenuto in un compartimento accettore attraverso un processo che richiede la fusione delle membrane lipidiche. Tale processo si fonda sull’organizzazione di complessi macromolecolari a cui contribuiscono varie famiglie proteiche ben conservate attraverso l’evoluzione eucariotica. La famiglia delle SNARE è una di queste. Le SNAREs sono considerate i motori della fusione di membrane. La loro capacità di formare complessi specifici in trans tra le due memrane su cui risiedono fornisce il contributo energetico necessario a indurre la fusione degli strati lipidici. Tali complessi consistono in un intreccio di quattro eliche chiamate SNARE motifs, domini di circa 60-70 amino acidi che definiscono tutte le SNAREs. Oltre allo SNARE motif, le SNAREs contengono spesso domini accessori a funzione regolativa. Uno di questi è il Longin Domain (LD). Il LD non è limitato alle sole SNAREs e anzi si ritrova in altre famiglie proteiche tutte coinvolte in processi molecolari riguardanti il ciclo vitale di una vescicola. Nelle SNAREs, il LD definisce una famiglia chiamata Longins, suddivisa a sua volta nelle proteine Ykt6, Sec22b e VAMP7. Il LD consiste di circa 120 aminoacidi organizzati in una struttura spaziale globulare che comprende un piano di cinque foglietti ? (?1- ?5), complessati da un’alfa elica (?1) su un lato e da altre due eliche (?2-?3) sull’altro. In Ykt6 e Sec22b si è dimostrata la possibilità che il LD si ripieghi sullo SNARE motif e lo coordini su una sua superficie idrofobica compresa tra ?1 e ?3. Questo meccanismo si è dimostrato in grado di prevenire la formazione di complessi SNARE non specifici. Tuttavia ben poco si conosce ad oggi sulla natura di questa interazione in termini dinamici, a differenza di quanto invece si sa per un analogo meccanismo osservato nella famiglia SNARE delle Sintaxine. In altri temrini non è dato sapere se nelle Longine questo meccanismo implica una conformazione stabilmente “chiusa” di LD e SNARE, o se piuttosto esso si realizza come un equilibrio dinamico tra conformazioni aperte e chiuse. Una serie di motivi, tra cui l’assenza di dati diretti per questo fenomeno in VAMP7 e la possibilità di usufruire di sue varianti naturali, ci hanno spinto a scegliere VAMP7 come sistema modello per fornire le risposte ai suddetti interrogativi. I nostri dati suggeriscono per le Longine una conformazione stabilmente chiusa, ma non omogenea e capace di cambi conformazionali molto rapidi. Questo lavoro complementa bene quanto già noto per le sintaxine e fornisce dunque la possibilità di comprendere meglio i meccanismi regolativi gneralmente adottati nella fusione vescicolare.

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Wong, Kam-Bo. "Structure and backbone dynamics of native proteins and their denatured states". Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627135.

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Wood, Matthew James. "Solution structure and backbone dynamics of the thrombomodulin fragments TMEGF45 and TMEGF45ox /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9988316.

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Babur, Tamoor [Verfasser]. "Structure and relaxation dynamics of comb-like polymers with rigid backbone / Tamoor Babur". Halle, 2017. http://d-nb.info/1139253743/34.

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Ibrahim, Moustafa Ismaiel Omar. "Biophysical studies of the structure and backbone dynamics of gsPGK using NMR relaxation methods". Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543234.

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Guan, Xiao y 关晓. "NMR approaches to protein conformation and backbone dynamics: studies on hyperthermophilicacylphosphatase and neuropeptide secretoneurin". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44079230.

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Guan, Xiao. "NMR approaches to protein conformation and backbone dynamics studies on hyperthermophilic acylphosphatase and neuropeptide secretoneurin /". Click to view the E-thesis via HKUTO, 2010. http://sunzi.lib.hku.hk/hkuto/record/B44079230.

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Libros sobre el tema "Backbone dynamic"

Wendling, Fabrice y Fernando H. Lopes da Silva. Dynamics of EEGs as Signals of Neuronal Populations. Editado por Donald L. Schomer y Fernando H. Lopes da Silva. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228484.003.0003.

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This chapter gives an overview of approaches used to understand the generation of electroencephalographic (EEG) signals using computational models. The basic concept is that appropriate modeling of neuronal networks, based on relevant anatomical and physiological data, allows researchers to test hypotheses about the nature of EEG signals. Here these models are considered at different levels of complexity. The first level is based on single cell biophysical properties anchored in classic Hodgkin-Huxley theory. The second level emphasizes on detailed neuronal networks and their role in generating different kinds of EEG oscillations. At the third level are models derived from the Wilson-Cowan approach, which constitutes the backbone of neural mass models. Another part of the chapter is dedicated to models of epileptiform activities. Finally, the themes of nonlinear dynamic systems and topological models in EEG generation are discussed.

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Watts, Michael J. Thinking the African Food Crisis. Editado por Ronald J. Herring. Oxford University Press, 2013. http://dx.doi.org/10.1093/oxfordhb/9780195397772.013.016.

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This chapter reviews food security in the West African Sahel, exploring the question of why, since the great drought-famines, of the late 1960s and early 1970s, food security and vulnerability to both climatic and market perturbations have not substantially improved and in some respects has deteriorated. Using my book Silent Violence, which was published in 1983, I revisit and review theories of famine and food security as they have been developed in and around African development. Using a village study in northern Nigeria, I argue that the precariousness of rural life can be explained by the shifting political economy of Nigeria and the forms of rural differentiation and inequality associated with, in the Nigerian case, the emergence of oil as the economic backbone of the country. While Nigeria as a petrostate is a special case, the dynamics at work point to general conditions prevailing across the West African Sahel. Since the 1970s there have been important shifts in policy regarding food and famine, and the ruling orthodoxy is now building resilience through the combination of traditional adaptability and decentralized forms of market integration. I investigate the origins and consequences of this approach and whether it can address the looming problems of global climate change.

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Radivojević, Ana y Linda Hildebrand. SUSTAINABLE AND RESILIENT BUILDING DESIGN: approaches, methods and tools. Editado por Saja Kosanović, Tillmann Klein y Thaleia Konstantinou. TU Delft Bouwkunde, 2018. http://dx.doi.org/10.47982/bookrxiv.26.

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The challenges to which contemporary building design needs to respond grow steadily. They originate from the influence of changing environmental conditions on buildings, as well as from the need to reduce the impact of buildings on the environment. The increasing complexity requires the continual revision of design principles and their harmonisation with current scientific findings, technological development, and environmental, social, and economic factors. It is precisely these issues that form the backbone of the thematic book, Sustainable and Resilient Building Design: Approaches, Methods, and Tools. The purpose of this book is to present ongoing research from the universities involved in the project Creating the Network of Knowledge Labs for Sustainable and Resilient Environments (KLABS). The book starts with the exploration of the origin, development, and the state-of-the-art notions of environmental design and resource efficiency. Subsequently, climate change complexity and dynamics are studied, and the design strategy for climate-proof buildings is articulated. The investigation into the resilience of buildings is further deepened by examining a case study of fire protection. The book then investigates interrelations between sustainable and resilient building design, compares their key postulates and objectives, and searches for the possibilities of their integration into an outreaching approach. The fifth article in the book deals with potentials and constraints in relation to the assessment of the sustainability (and resilience) of buildings. It critically analyses different existing building certification models, their development paths, systems, and processes, and compares them with the general objectives of building ratings. The subsequent paper outlines the basis and the meaning of the risk and its management system, and provides an overview of different visual, auxiliary, and statistical risk assessment methods and tools. Following the studies of the meanings of sustainable and resilient buildings, the book focuses on the aspects of building components and materials. Here, the life cycle assessment (LCA) method for quantifying the environmental impact of building products is introduced and analysed in detail, followed by a comprehensive comparative overview of the LCA-based software and databases that enable both individual assessment and the comparison of different design alternatives. The impact of climate and pollution on the resilience of building materials is analysed using the examples of stone, wood, concrete, and ceramic materials. Accordingly, the contribution of traditional and alternative building materials to the reduction of negative environmental impact is discussed and depicted through different examples. The book subsequently addresses existing building stock, in which environmental, social, and economic benefits of building refurbishment are outlined by different case studies. Further on, a method for the upgrade of existing buildings, described as ‘integrated rehabilitation’, is deliberated and supported by best practice examples of exoskeleton architectural prosthesis. The final paper reflects on the principles of regenerative design, reveals the significance of biological entities, and recognises the need to assign to buildings and their elements a more advanced role towards natural systems in human environments.

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Capítulos de libros sobre el tema "Backbone dynamic"

Rhee, Seung H., Jaewoo Yoon, Heonjun Choi y Insoo Choi. "Dynamic Capacity Resizing of Virtual Backbone Networks". En Networking — ICN 2001, 698–707. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/3-540-47728-4_68.

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Menéndez, C., S. Accordino, J. Rodriguez, D. Gerbino y G. Appignanesi. "Dynamic Analysis of Backbone-Hydrogen-Bond Propensity for Protein Binding and Drug Design". En Biopolymers for Medical Applications, 317–38. Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742: CRC Press, 2016. http://dx.doi.org/10.1201/9781315368863-14.

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Wielemborek, Radosław, Dariusz Laskowski y Piotr Łubkowski. "Effectiveness of Providing Data Confidentiality in Backbone Networks Based on Scalable and Dynamic Environment Technologies". En Advances in Intelligent Systems and Computing, 523–31. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-19216-1_50.

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Singh, Harsimran y Laura S. Busenlehner. "Probing Backbone Dynamics with Hydrogen/Deuterium Exchange Mass Spectrometry". En Protein Dynamics, 81–99. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-658-0_5.

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Gronenborn, Angela M. y G. Marius Clore. "Analysis of Backbone Dynamics of Interleukin-1β". En Computational Aspects of the Study of Biological Macromolecules by Nuclear Magnetic Resonance Spectroscopy, 227–31. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4757-9794-7_17.

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Clore, G. Marius y Angela M. Gronenborn. "Analysis of backbone dynamics of interleukin-1β". En Proteins, 53–56. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-010-9063-6_6.

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Cammarano, A., P. L. Green, T. L. Hill y S. A. Neild. "Nonlinear System Identification Through Backbone Curves and Bayesian Inference". En Nonlinear Dynamics, Volume 1, 255–62. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-15221-9_23.

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Londono, Julian M., Simon A. Neild y Jonathan E. Cooper. "Systems with Bilinear Stiffness: Extraction of Backbone Curves and Identification". En Nonlinear Dynamics, Volume 1, 307–13. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-15221-9_27.

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Hill, T. L., A. Cammarano, S. A. Neild y D. J. Wagg. "Relating Backbone Curves to the Forced Responses of Nonlinear Systems". En Nonlinear Dynamics, Volume 1, 113–22. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-15221-9_9.

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Peter, Simon, Robin Riethmüller y Remco I. Leine. "Tracking of Backbone Curves of Nonlinear Systems Using Phase-Locked-Loops". En Nonlinear Dynamics, Volume 1, 107–20. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-29739-2_11.

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Actas de conferencias sobre el tema "Backbone dynamic"

Bettig, B., C. Sandu, A. Joshi y K. Birru. "Dynamic solver selection for an Internet simulation backbone". En the 2003 ACM symposium. New York, New York, USA: ACM Press, 2003. http://dx.doi.org/10.1145/952532.952566.

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Liu, Kai, Tianyi Wu, Cong Liu y Guodong Guo. "Dynamic Group Transformer: A General Vision Transformer Backbone with Dynamic Group Attention". En Thirty-First International Joint Conference on Artificial Intelligence {IJCAI-22}. California: International Joint Conferences on Artificial Intelligence Organization, 2022. http://dx.doi.org/10.24963/ijcai.2022/166.

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Recently, Transformers have shown promising performance in various vision tasks. To reduce the quadratic computation complexity caused by each query attending to all keys/values, various methods have constrained the range of attention within local regions, where each query only attends to keys/values within a hand-crafted window. However, these hand-crafted window partition mechanisms are data-agnostic and ignore their input content, so it is likely that one query maybe attend to irrelevant keys/values. To address this issue, we propose a Dynamic Group Attention (DG-Attention), which dynamically divides all queries into multiple groups and selects the most relevant keys/values for each group. Our DG-Attention can flexibly model more relevant dependencies without any spatial constraint that is used in hand-crafted window based attention. Built on the DG-Attention, we develop a general vision transformer backbone named Dynamic Group Transformer (DGT). Extensive experiments show that our models can outperform the state-of-the-art methods on multiple common vision tasks, including image classification, semantic segmentation, object detection, and instance segmentation.

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Melidis, P., P. Nicopolitidis, G. Papadimitriou y E. Varvarigos. "Energy efficient optical backbone networks: A dynamic threshold approach". En 2014 IEEE 21st Symposium on Communications and Vehicular Technology in the Benelux (SCVT). IEEE, 2014. http://dx.doi.org/10.1109/scvt.2014.7046708.

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Devi, Monisha, Nityananda Sarma y Sanjib Kumar Deka. "Dynamic virtual backbone based routing in cognitive radio networks". En 2015 IEEE International Conference on Advanced Networks and Telecommuncations Systems (ANTS). IEEE, 2015. http://dx.doi.org/10.1109/ants.2015.7413663.

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Tanaka, Hirokazu. "A Case Study of the Backbone System Based on the Dynamic Equilibrium View : A dynamic equilibrium approach to backbone system design and implementation". En 2020 6th International Conference on Information Management (ICIM). IEEE, 2020. http://dx.doi.org/10.1109/icim49319.2020.244684.

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Di Felice, Marco, Luca Bedogni y Luciano Bononi. "Dynamic backbone for fast information delivery invehicular ad hoc networks". En the 8th ACM Symposium. New York, New York, USA: ACM Press, 2011. http://dx.doi.org/10.1145/2069063.2069065.

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Fajjari, Ilhem, Nadjib Aitsaadi, Guy Pujolle y Hubert Zimmermann. "An optimised dynamic resource allocation algorithm for Cloud's backbone network". En 2012 IEEE 37th Conference on Local Computer Networks (LCN 2012). IEEE, 2012. http://dx.doi.org/10.1109/lcn.2012.6423621.

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Krebs, Martin. "Dynamic Virtual Backbone Management for Service Discovery in Wireless Mesh Networks". En 2009 IEEE Wireless Communications and Networking Conference. IEEE, 2009. http://dx.doi.org/10.1109/wcnc.2009.4917691.

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Clad, Francois, Antoine Gallais y Pascal Merindol. "Energy-efficient data collection in WSN: A sink-oriented dynamic backbone". En ICC 2012 - 2012 IEEE International Conference on Communications. IEEE, 2012. http://dx.doi.org/10.1109/icc.2012.6363937.

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Yamamoto, Hiroshi, Shohei Kamamura, Rie Hayashi, Takafumi Hamano y Koichi Genda. "Effectiveness of dynamic reconfiguration of path protection for Carrier's backbone network". En 2015 10th Asia-Pacific Symposium on Information and Telecommunication Technologies (APSITT). IEEE, 2015. http://dx.doi.org/10.1109/apsitt.2015.7217081.

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Informes sobre el tema "Backbone dynamic"

Perdigão, Rui A. P. Beyond Quantum Security with Emerging Pathways in Information Physics and Complexity. Synergistic Manifolds, junio de 2022. http://dx.doi.org/10.46337/220602.

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Information security and associated vulnerabilities have long been a pressing challenge, from the fundamental scientific backstage to the frontline across the most diverse sectors of society. At the tip of the iceberg of this problem, the citizens immediately feel that the reservation of privacy and the degradation of the quality and security of the information and communication on which they depend for the day-to-day activities, already of crucial relevance, are at stake. Naturally though, the challenges do not end there. There is a whole infrastructure for storing information, processing and communication, whose security and reliability depend on key sectors gearing modern society – such as emergency communication systems (medical, civil and environmental protection, among others), transportation and geographic information, the financial communications systems at the backbone of day-to-day transactions, the information and telecommunications systems in general. And crucially the entire defence ecosystem that in essence is a stalwart in preventing our civilisation to self-annihilate in full fulfilment of the second principle of thermodynamics. The relevance of the problem further encompasses the preservation of crucial values such as the right to information, security and integrity of democratic processes, internal administration, justice, defence and sovereignty, ranging from the well-being of the citizen to the security of the nation and beyond. In the present communication, we take a look at how to scientifically and technically empower society to address these challenges, with the hope and pragmatism enabled by our emerging pathways in information physics and complexity. Edging beyond classical and quantum frontiers and their vulnerabilities to unveil new principles, methodologies and technologies at the core of the next generation system dynamic intelligence and security. To illustrate the concepts and tools, rather than going down the road of engineered systems that we can ultimately control, we take aim at the bewildering complexity of nature, deciphering new secrets in the mathematical codex underlying its complex coevolutionary phenomena that so heavily impact our lives, and ultimately bringing out novel insights, methods and technologies that propel information physics and security beyond quantum frontiers.

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Teye, Joseph Kofi y Ebenezer Nikoi. The Political Economy of the Cocoa Value Chain in Ghana. Institute of Development Studies (IDS), marzo de 2021. http://dx.doi.org/10.19088/apra.2021.007.

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The cocoa sector has, historically, been the backbone of the Ghanaian economy. Many households depend directly on the cocoa sector for livelihoods, and aspects of the cocoa industry, such as input supplies to farmers and cocoa pricing, have historically featured prominently in national and local politics. This paper examines the basic underlying political economy dynamics of the cocoa value chain, with particular focus on how the interests, powers and interactions of various actors along the value chain have contributed to agricultural commercialisation in Ghana. The paper also explores the challenges affecting the cocoa value chain, social difference within the chain, and how various segments of the cocoa value chain have been affected by the COVID-19 pandemic in Ghana since March 2020.

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Yu, Haichao, Haoxiang Li, Honghui Shi, Thomas S. Huang y Gang Hua. Any-Precision Deep Neural Networks. Web of Open Science, diciembre de 2020. http://dx.doi.org/10.37686/ejai.v1i1.82.

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We present Any-Precision Deep Neural Networks (Any- Precision DNNs), which are trained with a new method that empowers learned DNNs to be flexible in any numerical precision during inference. The same model in runtime can be flexibly and directly set to different bit-width, by trun- cating the least significant bits, to support dynamic speed and accuracy trade-off. When all layers are set to low- bits, we show that the model achieved accuracy compara- ble to dedicated models trained at the same precision. This nice property facilitates flexible deployment of deep learn- ing models in real-world applications, where in practice trade-offs between model accuracy and runtime efficiency are often sought. Previous literature presents solutions to train models at each individual fixed efficiency/accuracy trade-off point. But how to produce a model flexible in runtime precision is largely unexplored. When the demand of efficiency/accuracy trade-off varies from time to time or even dynamically changes in runtime, it is infeasible to re-train models accordingly, and the storage budget may forbid keeping multiple models. Our proposed framework achieves this flexibility without performance degradation. More importantly, we demonstrate that this achievement is agnostic to model architectures. We experimentally validated our method with different deep network backbones (AlexNet-small, Resnet-20, Resnet-50) on different datasets (SVHN, Cifar-10, ImageNet) and observed consistent results.

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Carpita, Nicholas C., Ruth Ben-Arie y Amnon Lers. Pectin Cross-Linking Dynamics and Wall Softening during Fruit Ripening. United States Department of Agriculture, julio de 2002. http://dx.doi.org/10.32747/2002.7585197.bard.

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Our study was designed to elucidate the chemical determinants of pectin cross-linking in developing fruits of apple and peach and to evaluate the role of breakage cross-linkages in swelling, softening, and cell separation during the ripening. Peaches cell walls soften and swell considerably during the ripening, whereas apples fruit cells maintain wall firmness but cells separate during late stages of ripening. We used a "double-reduction" technique to show that levels of non-methyl esters of polyuronic acid molecules were constant during the development and ripening and decreased only in overripe fruit. In peach, methyl and non-methyl esters increased during the development and decreased markedly during the ripening. Non-methyl ester linkages in both fruit decreased accompanied fruit softening. The identity of the second component of the linkage and its definitive role in the fruit softening remain elusive. In preliminary examination of isolated apples cell walls, we found that phenolic compounds accumulate early in wall development but decrease markedly during ripening. Quantitative texture analysis was used to correlate with changes to wall chemistry from the fresh-picked ripe stage to the stage during storage when the cell separation occurs. Cell wall composition is similar in all cultivars, with arabinose as the principal neutral sugar. Extensive de-branching of these highly branched arabinans pre-stages softening and cell-cell separation during over-ripening of apple. The longer 5-arabinans remain attached to the major pectic polymer rhamnogalacturonan I (RG I) backbone. The degree of RG I branching, as judged from the ratios of 2-Rha:2,4-Rha, also decreases, specially after an extensive arabinan de-branching. Loss of the 4-Rham linkages correlated strongly with the softening of the fruit. Loss of the monomer or polymer linked to the RG I produce directly or indirectly the softening of the fruit. This result will help to understand the fruit softening and to have better control of the textural changes in fruit during the ripening and especially during the storage. 'Wooliness', an undesirable mealy texture that is induced during chilling of some peach cultivars, greatly reduces the fruit storage possibilities. In order to examine the hypothesis that the basis for this disorder is related to abnormality in the cell wall softening process we have carried out a comparative analysis using the resistant cultivar, Sunsnow, and a sensitive one, Hermosa. We investigated the activity of several pectin- and glycan-modifying enzymes and the expression of their genes during ripening, chilling, and subsequent shelf-life. The changes in carbohydrate status and in methyl vs. non-methyl uronate ester levels in the walls of these cultivars were examined as well to provide a basis for comparison of the relevant gene expression that may impact appearance of the wooly character. The activities of the specific polygalacturonase (PGase) and a CMC-cellulase activities are significantly elevated in walls of peaches that have become wooly. Cellulase activities correlated well with increased level of the transcript, but differential expression of PGase did not correspond with the observed pattern of mRNA accumulation. When expression of ethylene biosynthesis related genes was followed no significant differences in ACC synthase gene expression was observed in the wooly fruit while the normal activation of the ACC oxidase was partially repressed in the Hermosa wooly fruits. Normal ripening-related loss of the uronic acid-rich polymers was stalled in the wooly Hermosa inconsistent with the observed elevation in a specific PGase activity but consistent with PG gene expression. In general, analysis of the level of total esterification, degree of methyl esterification and level of non-methyl esters did not reveal any major alterations between the different fruit varieties or between normal and abnormal ripening. Some decrease in the level of uronic acids methyl esterification was observed for both Hermosa and Sunsnow undergoing ripening following storage at low temperature but not in fruits ripening after harvest. Our results support a role for imbalanced cell wall degradation as a basis for the chilling disorder. While these results do not support a role for the imbalance between PG and pectin methyl esterase (PME) activities as the basis for the disorder they suggest a possible role for imbalance between cellulose and other cell wall polymer degradation during the softening process.

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