Bibliographies thématiques / TAIL EQUIVALENT / Articles de revues

Articles de revues sur le sujet « TAIL EQUIVALENT »

Pour voir les autres types de publications sur ce sujet consultez le lien suivant : TAIL EQUIVALENT.
Auteur : Grafiati
Publié le 11 septembre 2023

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Consultez les 50 meilleurs articles de revues pour votre recherche sur le sujet « TAIL EQUIVALENT ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Parcourez les articles de revues sur diverses disciplines et organisez correctement votre bibliographie.

1

Pakes, Anthony G. « Convolution equivalence and infinite divisibility ». Journal of Applied Probability 41, no 2 (juin 2004) : 407–24. http://dx.doi.org/10.1239/jap/1082999075.

Texte intégral
Résumé :
Known results relating the tail behaviour of a compound Poisson distribution function to that of its Lévy measure when one of them is convolution equivalent are extended to general infinitely divisible distributions. A tail equivalence result is obtained for random sum distributions in which the summands have a two-sided distribution.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Pakes, Anthony G. « Convolution equivalence and infinite divisibility ». Journal of Applied Probability 41, no 02 (juin 2004) : 407–24. http://dx.doi.org/10.1017/s002190020001439x.

Texte intégral
Résumé :
Known results relating the tail behaviour of a compound Poisson distribution function to that of its Lévy measure when one of them is convolution equivalent are extended to general infinitely divisible distributions. A tail equivalence result is obtained for random sum distributions in which the summands have a two-sided distribution.
Styles APA, Harvard, Vancouver, ISO, etc.
3

Fujimura, Kazuya, et Armen Der Kiureghian. « Tail-equivalent linearization method for nonlinear random vibration ». Probabilistic Engineering Mechanics 22, no 1 (janvier 2007) : 63–76. http://dx.doi.org/10.1016/j.probengmech.2006.08.001.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
4

Woodruff, Madeleine Eloise, Rebecca Doyle, Grahame Coleman, Lauren Hemsworth et Carolina Munoz. « Knowledge and attitudes are important factors in farmers’ choice of lamb tail docking length ». Veterinary Record 186, no 10 (20 janvier 2020) : 319. http://dx.doi.org/10.1136/vr.105631.

Texte intégral
Résumé :
BackgroundTail docking is common practice in the sheep industry to prevent soiling of the breech and flystrike. To ensure optimal healing after tail docking and reduce the risk of arthritis, perineal cancers and prolapses, it is recommended to dock tails equivalent to the length of the vulva. However, recent studies have found that some tails are docked too short (24–86 per cent).MethodsTo address this issue, this study aimed to identify key drivers behind tail docking length decisions. Two focus groups, phone (n=30) and online surveys (n=21) were conducted in regional Victoria, Australia to examine farmer knowledge of and attitudes towards appropriate lamb tail length and barriers to best practice. The focus group data were analysed qualitatively, and the surveys were analysed qualitatively and quantitatively.ResultsIn total, 57 per cent of farmers were classed as docking tails short. Short tail docking appeared to be influenced by unawareness of the recommended length and docking at a length that shearers approve of. Other potential factors included lack of knowledge of negative health consequences associated with short tails, importance placed on dag and flystrike prevention, and impracticality of measuring where to dock.ConclusionAddressing these factors in future education and intervention programmes may improve tail docking practice and sheep welfare.
Styles APA, Harvard, Vancouver, ISO, etc.
5

Broccardo, Marco, et Armen Der Kiureghian. « Multicomponent Nonlinear Stochastic Dynamic Analysis by Tail-Equivalent Linearization ». Journal of Engineering Mechanics 142, no 3 (mars 2016) : 04015100. http://dx.doi.org/10.1061/(asce)em.1943-7889.0001026.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
6

Perline, Richard. « Mixed Poisson distributions tail equivalent to their mixing distributions ». Statistics & ; Probability Letters 38, no 3 (juin 1998) : 229–33. http://dx.doi.org/10.1016/s0167-7152(98)00019-4.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Raoufi, Reza, et Mohsen Ghafory-Ashtiany. « Nonlinear random vibration using updated tail equivalent linearization method ». International Journal of Advanced Structural Engineering 6, no 1 (mars 2014) : 1–12. http://dx.doi.org/10.1007/s40091-014-0045-6.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
8

Hager, Emily R., et Hopi E. Hoekstra. « Tail Length Evolution in Deer Mice : Linking Morphology, Behavior, and Function ». Integrative and Comparative Biology 61, no 2 (19 avril 2021) : 385–97. http://dx.doi.org/10.1093/icb/icab030.

Texte intégral
Résumé :
Abstract Determining how variation in morphology affects animal performance (and ultimately fitness) is key to understanding the complete process of evolutionary adaptation. Long tails have evolved many times in arboreal and semi-arboreal rodents; in deer mice, long tails have evolved repeatedly in populations occupying forested habitat even within a single species (Peromyscus maniculatus). Here, we use a combination of functional modeling, laboratory studies, and museum records to test hypotheses about the function of tail-length variation in deer mice. First, we use computational models, informed by museum records documenting natural variation in tail length, to test whether differences in tail morphology between forest and prairie subspecies can influence performance in behavioral contexts relevant for tail use. We find that the deer- mouse tail plays little role in statically adjusting center of mass or in correcting body pitch and yaw, but rather it can affect body roll during arboreal locomotion. In this context, we find that even intraspecific tail-length variation could result in substantial differences in how much body rotation results from equivalent tail motions (i.e., tail effectiveness), but the relationship between commonly-used metrics of tail-length variation and effectiveness is non-linear. We further test whether caudal vertebra length, number, and shape are associated with differences in how much the tail can bend to curve around narrow substrates (i.e., tail curvature) and find that, as predicted, the shape of the caudal vertebrae is associated with intervertebral bending angle across taxa. However, although forest and prairie mice typically differ in both the length and number of caudal vertebrae, we do not find evidence that this pattern is the result of a functional trade-off related to tail curvature. Together, these results highlight how even simple models can both generate and exclude hypotheses about the functional consequences of trait variation for organismal-level performance.
Styles APA, Harvard, Vancouver, ISO, etc.
9

Welcome, D. E., K. Krajnak, M. L. Kashon et R. G. Dong. « An investigation on the biodynamic foundation of a rat tail vibration model ». Proceedings of the Institution of Mechanical Engineers, Part H : Journal of Engineering in Medicine 222, no 7 (1 octobre 2008) : 1127–41. http://dx.doi.org/10.1243/09544119jeim419.

Texte intégral
Résumé :
The objectives of this study are to examine the fundamental characteristics of the biodynamic responses of a rat tail to vibration and to compare them with those of human fingers. Vibration transmission through tails exposed to three vibration magnitudes (1 g, 5 g, and 10 g r.m.s.) at six frequencies (32 Hz, 63 Hz, 125 Hz, 160 Hz, 250 Hz, and 500 Hz) was measured using a laser vibrometer. A mechanical-equivalent model of the tail was established on the basis of the transmissibility data, which was used to estimate the biodynamic deformation and vibration power absorption at several representative locations on the tail. They were compared with those derived from a mechanical-equivalent model of human fingers reported in the literature. This study found that, similar to human fingers, the biodynamic responses of the rat tail depends on the vibration magnitude, frequency, and measurement location. With the restraint method used in this study, the natural frequency of the rat tail is in the range 161–368 Hz, which is mostly within the general range of human finger resonant frequencies (100–350 Hz). However, the damping ratios of the rat tail at the unconstrained locations are from 0.094 to 0.394, which are lower than those of human fingers (0.708–0.725). Whereas the biodynamic responses of human fingers at frequencies lower than 100 Hz could be significantly influenced by the biodynamics of the entire hand—arm system, the rat tail biodynamic responses can be considered independent of the rat body in the frequency range used in this study. Based on these findings it is concluded that, although there are some differences between the frequency dependences of the biodynamic responses of the rat tail and human fingers, the rat tail model can provide a practical and reasonable approach to examine the relationships between the biodynamic and biological responses at midrange to high frequencies, and to understand the mechanisms underlying vibration-induced finger disorders.
Styles APA, Harvard, Vancouver, ISO, etc.
10

Broccardo, Marco, et Armen Der Kiureghian. « Nonlinear stochastic dynamic analysis by evolutionary tail-equivalent linearization method ». Structural Safety 90 (mai 2021) : 102044. http://dx.doi.org/10.1016/j.strusafe.2020.102044.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
11

Lorenzini, Carlo Ambrogi, Corrado Bucherelli, Susanna Falchini, Aldo Giachetti et Giovanna Tassoni. « Equivalent aversiveness of back- and tail-handling in the rat ». Bulletin of the Psychonomic Society 28, no 5 (novembre 1990) : 437–40. http://dx.doi.org/10.3758/bf03334061.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
12

Hill, Jonathan B. « TAIL AND NONTAIL MEMORY WITH APPLICATIONS TO EXTREME VALUE AND ROBUST STATISTICS ». Econometric Theory 27, no 4 (8 mars 2011) : 844–84. http://dx.doi.org/10.1017/s0266466610000514.

Texte intégral
Résumé :
New notions of tail and nontail dependence are used to characterize separately extremal and nonextremal information, including tail log-exceedances and events, and tail-trimmed levels. We prove that near epoch dependence (McLeish, 1975; Gallant and White, 1988) and L0-approximability (Pötscher and Prucha, 1991) are equivalent for tail events and tail-trimmed levels, ensuring a Gaussian central limit theory for important extreme value and robust statistics under general conditions. We apply the theory to characterize the extremal and nonextremal memory properties of possibly very heavy-tailed GARCH processes and distributed lags. This in turn is used to verify Gaussian limits for tail index, tail dependence, and tail-trimmed sums of these data, allowing for Gaussian asymptotics for a new tail-trimmed least squares estimator for heavy-tailed processes.
Styles APA, Harvard, Vancouver, ISO, etc.
13

Stehr, Mads, et Anders Rønn-Nielsen. « Tail asymptotics of an infinitely divisible space-time model with convolution equivalent Lévy measure ». Journal of Applied Probability 58, no 1 (25 février 2021) : 42–67. http://dx.doi.org/10.1017/jpr.2020.73.

Texte intégral
Résumé :
AbstractWe consider a space-time random field on ${{\mathbb{R}^d} \times {\mathbb{R}}}$ given as an integral of a kernel function with respect to a Lévy basis with a convolution equivalent Lévy measure. The field obeys causality in time and is thereby not continuous along the time axis. For a large class of such random fields we study the tail behaviour of certain functionals of the field. It turns out that the tail is asymptotically equivalent to the right tail of the underlying Lévy measure. Particular examples are the asymptotic probability that there is a time point and a rotation of a spatial object with fixed radius, in which the field exceeds the level x, and that there is a time interval and a rotation of a spatial object with fixed radius, in which the average of the field exceeds the level x.
Styles APA, Harvard, Vancouver, ISO, etc.
14

Li, Jin, Zhanglin Li, Shiru Lan et Yong Wu. « The Subexponential Distribution wthin Renewal Model ». Advances in Economics and Management Research 1, no 1 (18 mai 2022) : 9. http://dx.doi.org/10.56028/aemr.1.1.9.

Texte intégral
Résumé :
Here, we investigate asymptotic equivalent formulas for finite-time ruin probabilities in a renewal risk model with a subexponential distribution in this research, in the cases of the negatively dependent and upper tail independent, respectively. First, we extend the related research results of Tao Jiang, and Chengguo Weng et al. to the subexponential case, respectively. Thereafter two precise asymptotic equivalent relations are established, one is the finite-time probability when the random variables of the claims are influenced by the common subexponential distribution in a negative way, and another the finite-time ruin probability when the claimsizes are upper tail independent with the common subexponential distribution.
Styles APA, Harvard, Vancouver, ISO, etc.
15

Garrè, Luca, et Armen Der Kiureghian. « Tail-Equivalent Linearization Method in frequency domain and application to marine structures ». Marine Structures 23, no 3 (juillet 2010) : 322–38. http://dx.doi.org/10.1016/j.marstruc.2010.07.006.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
16

Rivero, Víctor. « Tail asymptotics for exponential functionals of Lévy processes : The convolution equivalent case ». Annales de l'Institut Henri Poincaré, Probabilités et Statistiques 48, no 4 (novembre 2012) : 1081–102. http://dx.doi.org/10.1214/12-aihp477.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
17

Verrey, F., T. Gilbert, T. Mellow, G. Proulx et K. Drickamer. « Endocytosis via coated pits mediated by glycoprotein receptor in which the cytoplasmic tail is replaced by unrelated sequences. » Cell Regulation 1, no 6 (mai 1990) : 471–86. http://dx.doi.org/10.1091/mbc.1.6.471.

Texte intégral
Résumé :
Rat 6 fibroblast cell lines expressing wild-type chicken liver glycoprotein receptor (CHL) or chimeric receptors with alternate cytoplasmic tails were produced to study the role of the cytoplasmic tail in mediating receptor localization in coated pits and endocytosis of ligand. Cells expressing CHL or cells expressing a hybrid receptor that contains the cytoplasmic tail of the asialoglycoprotein receptor display high-efficiency endocytosis of N-acetylglucosamine-conjugated bovine serum albumin in experiments designed to measure an initial internalization step, as well as in studies of continuous uptake and degradation. Substitution of the cytoplasmic tail by the equivalent domain of rat Na,K-ATPase beta subunit or by a stretch of Xenopus laevis globin beta chain does not abolish endocytosis but decreases the endocytosis rate constant from 15%-16%/min to 2.4% and 6.5%/min, respectively. Electron microscopy was used to visualize the glycoprotein binding sites at the surface of Rat 6 cells transfected with the various receptors. The percentage of receptors found in coated areas ranged from 32% for CHL to 9% for the Na,K-ATPase hybrid, indicating that clustering in coated pits correlates with efficiency of endocytosis. We concluded that replacement of the CHL cytoplasmic tail with unrelated sequences does not prevent, but decreases to varying extents, coated-pit localization and endocytosis efficiency. The construct with NH2-terminal globin tail lacks a signal for high-efficiency localization in coated pits but nevertheless is directed to the pits by an alternative mechanism.
Styles APA, Harvard, Vancouver, ISO, etc.
18

Hao, Xuemiao, et Qihe Tang. « Asymptotic Ruin Probabilities of the Lévy Insurance Model under Periodic Taxation ». ASTIN Bulletin 39, no 2 (novembre 2009) : 479–94. http://dx.doi.org/10.2143/ast.39.2.2044644.

Texte intégral
Résumé :
AbstractRecently, Albrecher and his coauthors have published a series of papers on the ruin probability of the Lévy insurance model under the so-called loss-carry-forward taxation, meaning that taxes are paid at a certain fixed rate immediately when the surplus of the company is at a running maximum. In this paper we assume periodic taxation under which the company pays tax at a fixed rate on its net income during each period. We devote ourselves to deriving explicit asymptotic relations for the ruin probability in the most general Lévy insurance model in which the Lévy measure has a subexponential tail, a convolution-equivalent tail, or an exponential-like tail.
Styles APA, Harvard, Vancouver, ISO, etc.
19

Looney, J. E., et J. L. Hamlin. « Isolation of the amplified dihydrofolate reductase domain from methotrexate-resistant Chinese hamster ovary cells ». Molecular and Cellular Biology 7, no 2 (février 1987) : 569–77. http://dx.doi.org/10.1128/mcb.7.2.569-577.1987.

Texte intégral
Résumé :
We isolated overlapping recombinant cosmids that represent the equivalent of two complete dihydrofolate reductase amplicon types from the methotrexate-resistant CHO cell line CHOC400. The type I amplicons are 260 kilobases long, are arranged in head-to-tail fashion, and represent 10 to 15% of the amplicons in the CHOC400 genome. The type II amplicons are 220 kilobases long, are arranged in head-to-head and tail-to-tail configurations, and constituted the majority of the remaining amplicons in CHOC400 cells. The type II amplicon sequences are represented entirely within the type I unit. These are the first complete amplicons to be cloned from a mammalian cell line.
Styles APA, Harvard, Vancouver, ISO, etc.
20

Looney, J. E., et J. L. Hamlin. « Isolation of the amplified dihydrofolate reductase domain from methotrexate-resistant Chinese hamster ovary cells. » Molecular and Cellular Biology 7, no 2 (février 1987) : 569–77. http://dx.doi.org/10.1128/mcb.7.2.569.

Texte intégral
Résumé :
We isolated overlapping recombinant cosmids that represent the equivalent of two complete dihydrofolate reductase amplicon types from the methotrexate-resistant CHO cell line CHOC400. The type I amplicons are 260 kilobases long, are arranged in head-to-tail fashion, and represent 10 to 15% of the amplicons in the CHOC400 genome. The type II amplicons are 220 kilobases long, are arranged in head-to-head and tail-to-tail configurations, and constituted the majority of the remaining amplicons in CHOC400 cells. The type II amplicon sequences are represented entirely within the type I unit. These are the first complete amplicons to be cloned from a mammalian cell line.
Styles APA, Harvard, Vancouver, ISO, etc.
21

Sanaiotti, Tânia, William Magnusson et Zilca Campos. « Maximum size of dwarf caiman, Paleosuchus palpebrosus (Cuvier, 1807), in the Amazon and habitats surrounding the Pantanal, Brazil ». Amphibia-Reptilia 31, no 3 (2010) : 439–42. http://dx.doi.org/10.1163/156853810791769392.

Texte intégral
Résumé :
AbstractThe dwarf caiman, Paleosuchus palpebrosus, is considered one of the smallest crocodilians. However, our surveys indicate that the species regularly reaches larger sizes than usually reported in the literature. Most individuals lose tail tips, and we did not encounter any individual with snout-vent length (SVL) > 70 cm that had an intact tail. P. palpebrosus attains SVL > 112.5 cm (equivalent to a total length with intact tail estimated from SVL of 210 cm) in streams around the Pantanal, 106 cm (198 cm) in flooded forest in central Amazonia, and 100 cm (187 cm) in flooded forest and around the Madeira-Guaporé River.
Styles APA, Harvard, Vancouver, ISO, etc.
22

Yang, Yang, Lirong Wan et Zhengyuan Xin. « Dynamic Response Analysis of the Coal Gangue-like Elastic Rock Sphere Impact on the Massless Tail Beam Based on Contact-Structure Theory and FEM ». Shock and Vibration 2019 (27 octobre 2019) : 1–24. http://dx.doi.org/10.1155/2019/6030542.

Texte intégral
Résumé :
The impact and collision behavior between the coal gangue and the hydraulic support widely exists in the top coal caving. However, due to the complex interactions between the large number of coal gangue particles in the mining surface and the limitations of the coal mining technology and other factors, it becomes a difficult problem to study the collision behavior and the contact response between the coal gangue and the hydraulic support or its main components under the actual caving conditions. In order to accurately grasp the contact response law when the coal gangue impacts the tail beam of the hydraulic support, in combination with the equivalent stiffness of the tail beam jack, the Lankarani–Nikravesh (L-N) nonlinear spring-damping contact model, the structural mechanics model of the tail beam, and the energy conservation law, this paper firstly establishes the system contact-structure dynamic model when the particles impact on the tail beam based on the tail beam equivalent kinematics model. Then, to further study the system contact response, the spring damper module is used in the finite element software for the first time to replace the hydraulic cylinder, and four different types of the rigid-flexible coupling simulations when the impact heights, the impact positions, the rock radii, and the rock materials change are conducted, respectively. Through the combination of the theory and the simulation, the contact response law when the particles impacting the massless tail beam under different working conditions is obtained, and the system contact response differences as well as the coal gangue identifying feasibility on the basis of the response differences after the coal gangue impact are analyzed. The conclusions will provide theoretical reference and simulation method for the study of the impact-contact behavior between the coal gangue and the hydraulic support.
Styles APA, Harvard, Vancouver, ISO, etc.
23

Baier, Fabian, Edith Gruber, Thomas Hein, Elisabeth Bondar-Kunze, Marina Ivanković, Axel Mentler, Carsten A. Brühl, Bernhard Spangl et Johann G. Zaller. « Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia) and associated algae are altered by temperature ». PeerJ 4 (1 novembre 2016) : e2641. http://dx.doi.org/10.7717/peerj.2641.

Texte intégral
Résumé :
BackgroundGlyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known.MethodsWe studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L−1as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L−1) on larval development of Common toads (Bufo bufo, L.; Amphibia: Anura) and associated algae communities under two temperature regimes (15 vs. 20 °C).ResultsHerbicide contamination reduced tail growth (−8%), induced the occurrence of tail deformations (i.e. lacerated or crooked tails) and reduced algae diversity (−6%). Higher water temperature increased tadpole growth (tail and body length (tl/bl) +66%, length-to-width ratio +4%) and decreased algae diversity (−21%). No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C.DiscussionThese herbicide- and temperature-induced changes may have decided effects on ecological interactions in freshwater ecosystems. Although no clear dose-response effect was seen, the presence of glyphosate was decisive for an effect, suggesting that the lowest observed effect concentration (LOEC) in our study was 1.5 mg a.e. glyphosate L−1water. Overall, our findings also question the relevance of pesticide risk assessments conducted at standard temperatures.
Styles APA, Harvard, Vancouver, ISO, etc.
24

Kim, Jinwook, et Yongrae Roh. « Modeling and Design of a Rear-Mounted Underwater Projector Using Equivalent Circuits ». Sensors 20, no 24 (10 décembre 2020) : 7085. http://dx.doi.org/10.3390/s20247085.

Texte intégral
Résumé :
Tonpilz is a popular transducer for underwater projector arrays for sonar systems. For low-frequency transmission, a larger axial dimension of the conventional Tonpilz transducer is required. However, a bulky and heavy Tonpilz element is not suitable due to limitations in terms of the space and payload of the array platform. To address this problem, we developed a rear-mounted Tonpilz transducer to generate a sub-fundamental resonance in addition to the common longitudinal resonance. For this purpose, we developed a new equivalent circuit model that can reflect all the effects of the key design parameters of the transducer, such as suspension thickness (stiffness), tail mass thickness, and head mass thickness. The impedance and transmitting voltage response were evaluated as performance factors at both resonance frequencies. The validity of the circuit was verified by comparing the analysis results with those from the finite element analysis of the same transducer. Based on the results, the transducer structure was designed to have comparable transmitting performance at both resonance frequencies by employing relatively high suspension stiffness, light tail mass, and heavy head mass. The novel design can permit the dual-band operation of the transducer so that the transducer can operate as a wideband projector.
Styles APA, Harvard, Vancouver, ISO, etc.
25

Oesting, Marco. « Equivalent representations of max-stable processes via ℓp-norms ». Journal of Applied Probability 55, no 1 (mars 2018) : 54–68. http://dx.doi.org/10.1017/jpr.2018.5.

Texte intégral
Résumé :
Abstract While max-stable processes are typically written as pointwise maxima over an infinite number of stochastic processes, in this paper, we consider a family of representations based on ℓp-norms. This family includes both the construction of the Reich–Shaby model and the classical spectral representation by de Haan (1984) as special cases. As the representation of a max-stable process is not unique, we present formulae to switch between different equivalent representations. We further provide a necessary and sufficient condition for the existence of an ℓp-norm-based representation in terms of the stable tail dependence function of a max-stable process. Finally, we discuss several properties of the represented processes such as ergodicity or mixing.
Styles APA, Harvard, Vancouver, ISO, etc.
26

Goldie, Charles M., et Sidney Resnick. « Distributions that are both subexponential and in the domain of attraction of an extreme-value distribution ». Advances in Applied Probability 20, no 4 (décembre 1988) : 706–18. http://dx.doi.org/10.2307/1427356.

Texte intégral
Résumé :
When does a distribution F have the property of both being in the domain of attraction of exp {–e–x} and having a second convolution-power tail equivalent to the first: Sufficient conditions and examples are given.
Styles APA, Harvard, Vancouver, ISO, etc.
27

Goldie, Charles M., et Sidney Resnick. « Distributions that are both subexponential and in the domain of attraction of an extreme-value distribution ». Advances in Applied Probability 20, no 04 (décembre 1988) : 706–18. http://dx.doi.org/10.1017/s0001867800018334.

Texte intégral
Résumé :
When does a distribution F have the property of both being in the domain of attraction of exp {–e–x } and having a second convolution-power tail equivalent to the first: Sufficient conditions and examples are given.
Styles APA, Harvard, Vancouver, ISO, etc.
28

Rønn-Nielsen, Anders, et Eva B. Vedel Jensen. « Tail asymptotics for the supremum of an infinitely divisible field with convolution equivalent Lévy measure ». Journal of Applied Probability 53, no 1 (mars 2016) : 244–61. http://dx.doi.org/10.1017/jpr.2015.22.

Texte intégral
Résumé :
Abstract We consider a continuous, infinitely divisible random field in Rd given as an integral of a kernel function with respect to a Lévy basis with convolution equivalent Lévy measure. For a large class of such random fields we compute the asymptotic probability that the supremum of the field exceeds the level x as x → ∞. Our main result is that the asymptotic probability is equivalent to the right tail of the underlying Lévy measure.
Styles APA, Harvard, Vancouver, ISO, etc.
29

Rønn-Nielsen, Anders, et Eva B. Vedel Jensen. « Excursion sets of infinitely divisible random fields with convolution equivalent Lévy measure ». Journal of Applied Probability 54, no 3 (septembre 2017) : 833–51. http://dx.doi.org/10.1017/jpr.2017.37.

Texte intégral
Résumé :
Abstract We consider a continuous, infinitely divisible random field in ℝd, d = 1, 2, 3, given as an integral of a kernel function with respect to a Lévy basis with convolution equivalent Lévy measure. For a large class of such random fields, we compute the asymptotic probability that the excursion set at level x contains some rotation of an object with fixed radius as x → ∞. Our main result is that the asymptotic probability is equivalent to the right tail of the underlying Lévy measure.
Styles APA, Harvard, Vancouver, ISO, etc.
30

Georges, Sara A., W. Lee Kraus, Karolin Luger, Jennifer K. Nyborg et Paul J. Laybourn. « p300-Mediated Tax Transactivation from Recombinant Chromatin : Histone Tail Deletion Mimics Coactivator Function ». Molecular and Cellular Biology 22, no 1 (1 janvier 2002) : 127–37. http://dx.doi.org/10.1128/mcb.22.1.127-137.2002.

Texte intégral
Résumé :
ABSTRACT Efficient transcription of the human T-cell leukemia virus type 1 (HTLV-1) genome requires Tax, a virally encoded oncogenic transcription factor, in complex with the cellular transcription factor CREB and the coactivators p300/CBP. To examine Tax transactivation in vitro, we used a chromatin assembly system that included recombinant core histones. The addition of Tax, CREB, and p300 to the HTLV-1 promoter assembled into chromatin activated transcription several hundredfold. Chromatin templates selectively lacking amino-terminal histone tails demonstrated enhanced transcriptional activation by Tax and CREB, with significantly reduced dependence on p300 and acetyl coenzyme A (acetyl-CoA). Interestingly, Tax/CREB activation from the tailless chromatin templates retained a substantial requirement for acetyl-CoA, indicating a role for acetyl-CoA beyond histone acetylation. These data indicate that during Tax transcriptional activation, the amino-terminal histone tails are the major targets of p300 and that tail deletion and acetylation are functionally equivalent.
Styles APA, Harvard, Vancouver, ISO, etc.
31

Moore, Alex R., Georgia Huang, Sarah Wolf, Patrick J. Walsh, Zahra Fakhraai et Robert A. Riggleman. « Effects of microstructure formation on the stability of vapor-deposited glasses ». Proceedings of the National Academy of Sciences 116, no 13 (13 mars 2019) : 5937–42. http://dx.doi.org/10.1073/pnas.1821761116.

Texte intégral
Résumé :
Glasses formed by physical vapor deposition (PVD) are an interesting new class of materials, exhibiting properties thought to be equivalent to those of glasses aged for thousands of years. Exerting control over the structure and properties of PVD glasses formed with different types of glass-forming molecules is now an emerging challenge. In this work, we study coarse-grained models of organic glass formers containing fluorocarbon tails of increasing length, corresponding to an increased tendency to form microstructures. We use simulated PVD to examine how the presence of the microphase-separated domains in the supercooled liquid influences the ability to form stable glasses. This model suggests that increasing molecule tail length results in decreased thermodynamic stability of the molecules in PVD films. The reduced stability is further linked to the reduced ability of these molecules to equilibrate at the free surface during PVD. We find that, as the tail length is increased, the relaxation times near the surface of the supercooled equilibrium liquid films of these molecules are slowed and become essentially bulk-like, due to the segregation of the fluorocarbon tails to the free surface. Surface diffusion is also markedly reduced due to clustering of the molecules at the surface. Based on these results, we propose a trapping mechanism where tails are unable to move between local phase-separated domains on the relevant deposition time scales.
Styles APA, Harvard, Vancouver, ISO, etc.
32

Büttner, Carina R., Yingzhou Wu, Karen L. Maxwell et Alan R. Davidson. « Baseplate assembly of phage Mu : Defining the conserved core components of contractile-tailed phages and related bacterial systems ». Proceedings of the National Academy of Sciences 113, no 36 (23 août 2016) : 10174–79. http://dx.doi.org/10.1073/pnas.1607966113.

Texte intégral
Résumé :
Contractile phage tails are powerful cell puncturing nanomachines that have been co-opted by bacteria for self-defense against both bacteria and eukaryotic cells. The tail of phage T4 has long served as the paradigm for understanding contractile tail-like systems despite its greater complexity compared with other contractile-tailed phages. Here, we present a detailed investigation of the assembly of a “simple” contractile-tailed phage baseplate, that of Escherichia coli phage Mu. By coexpressing various combinations of putative Mu baseplate proteins, we defined the required components of this baseplate and delineated its assembly pathway. We show that the Mu baseplate is constructed through the independent assembly of wedges that are organized around a central hub complex. The Mu wedges are comprised of only three protein subunits rather than the seven found in the equivalent structure in T4. Through extensive bioinformatic analyses, we found that homologs of the essential components of the Mu baseplate can be identified in the majority of contractile-tailed phages and prophages. No T4-like prophages were identified. The conserved simple baseplate components were also found in contractile tail-derived bacterial apparatuses, such as type VI secretion systems, Photorhabdus virulence cassettes, and R-type tailocins. Our work highlights the evolutionary connections and similarities in the biochemical behavior of phage Mu wedge components and the TssF and TssG proteins of the type VI secretion system. In addition, we demonstrate the importance of the Mu baseplate as a model system for understanding bacterial phage tail-derived systems.
Styles APA, Harvard, Vancouver, ISO, etc.
33

De Robertis, E. M., A. Fainsod, L. K. Gont et H. Steinbeisser. « The evolution of vertebrate gastrulation ». Development 1994, Supplement (1 janvier 1994) : 117–24. http://dx.doi.org/10.1242/dev.1994.supplement.117.

Texte intégral
Résumé :
The availability of molecular markers now permits the analysis of the common elements of vertebrate gastrulation. While gastrulation appears to be very diverse in the vertebrates, by analyzing a head-organizer marker, goosecoid, and a marker common to all forming mesoderm, Brachyury, we attempt to identify homologous structures and equivalent stages in Xenopus, zebrafish, chick and mouse gastrulation. Using a tail-organizer marker, Xnot-2, we also discuss how the late stages of gastrulation lead to the formation of the postanal tail, a structure characteristic of the chordates.
Styles APA, Harvard, Vancouver, ISO, etc.
34

Cheng, Xing Hua, Tao Yang et Zhong Dong Chang. « Thermoelastic Analysis of an Heterogeneous Orthotropic Nose Cap for a Hypersonic Vehicle ». Advanced Materials Research 338 (septembre 2011) : 325–34. http://dx.doi.org/10.4028/www.scientific.net/amr.338.325.

Texte intégral
Résumé :
Considering xz plane heterogeneous mechanical properties and thermal-pressure loads, thermoelastic analysis is applied on orthotropic nose cap of a hypersonic vehicle in the flight trajectory. The results show that the thermal-stress of sphere section presents annular, the Mises equivalent stress is of periodicity of 90° in tail so obviously that a reasonable connection is important. Finally, two connections, bolted and plug connection, are considered to relax the overnice tail constrains, and the results show that the plug connection is reasonable for the hypersonic heterogeneous orthotropic nose cap
Styles APA, Harvard, Vancouver, ISO, etc.
35

Hult, Henrik, et Filip Lindskog. « On regular variation for infinitely divisible random vectors and additive processes ». Advances in Applied Probability 38, no 1 (mars 2006) : 134–48. http://dx.doi.org/10.1239/aap/1143936144.

Texte intégral
Résumé :
We study the tail behavior of regularly varying infinitely divisible random vectors and additive processes, i.e. stochastic processes with independent but not necessarily stationary increments. We show that the distribution of an infinitely divisible random vector is tail equivalent to its Lévy measure and we study the asymptotic decay of the probability for an additive process to hit sets far away from the origin. The results are extensions of known univariate results to the multivariate setting; we exemplify some of the difficulties that arise in the multivariate case.
Styles APA, Harvard, Vancouver, ISO, etc.
36

Hult, Henrik, et Filip Lindskog. « On regular variation for infinitely divisible random vectors and additive processes ». Advances in Applied Probability 38, no 01 (mars 2006) : 134–48. http://dx.doi.org/10.1017/s0001867800000847.

Texte intégral
Résumé :
We study the tail behavior of regularly varying infinitely divisible random vectors and additive processes, i.e. stochastic processes with independent but not necessarily stationary increments. We show that the distribution of an infinitely divisible random vector is tail equivalent to its Lévy measure and we study the asymptotic decay of the probability for an additive process to hit sets far away from the origin. The results are extensions of known univariate results to the multivariate setting; we exemplify some of the difficulties that arise in the multivariate case.
Styles APA, Harvard, Vancouver, ISO, etc.
37

Wang, Ziqi, et Armen Der Kiureghian. « Tail-Equivalent Linearization of Inelastic Multisupport Structures Subjected to Spatially Varying Stochastic Ground Motion ». Journal of Engineering Mechanics 142, no 8 (août 2016) : 04016053. http://dx.doi.org/10.1061/(asce)em.1943-7889.0001106.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
38

Dila Keswara, Yane, et Sri Rejeki Handayani. « Uji Aktivitas Analgetik Ekstrak Etanol Daun Inggu (Ruta angustifolia [l.] Pers) Pada Tikus Putih Jantan ». Journal Syifa Sciences and Clinical Research 1, no 2 (12 septembre 2019) : 57–69. http://dx.doi.org/10.37311/jsscr.v1i2.2662.

Texte intégral
Résumé :
Pain is an uncomfortable feeling caused by strong or destructive stimulation, if unchecked can affect daily routine. This study aims to determine the analgesic effect and dosage of the leaf extract ethanol, as well as to determine the effectiveness of the leaf extract ethanol as a narcotic analgesic by the Tail Flick method or as a non-narcotic analgesic by the Paw Pressure Test Randall Selitto method. Extraction was done by maceration of leaf powder with a solvent 96% ethanol. 25 male Wistar white rats were divided into 5 groups, positive group mefenamic acid 9 mg /200 g BW for the Paw Pressure Test Randall Selitto Method and tramadol 0.9 mg /200 g BW for the Tail Flick Method, negative control CMC Na 0,5%, ethanol extract leaves inggu leaves a dose of 10 mg /200 g BW, 20 mg /200 g BW and 40 mg /200 g BW. The data obtained were analyzed by ANOVA test, then LSD test was used to determine differences between groups. The results showed extract dosage of 10 mg /200 g BW, 20 mg /200 g BW, 40 mg /200 g BW had analgesic effect. Extract dosage of 20 mg /200 g BW and 40 mg /200 g BW in the Randall selitto Paw Pressure Test method is equivalent to mefenamic acid, extract dose 10 mg /200 g BW, 20 mg /200 g BW, and 40 mg /200 g BW the Tail Flick method is equivalent to Tramadol. Ethanol leaf extract is more effective as a narcotic analgesic by the Tail Flick method.
Styles APA, Harvard, Vancouver, ISO, etc.
39

ALKAN, EMRE. « RAMANUJAN SUMS AND THE BURGESS ZETA FUNCTION ». International Journal of Number Theory 08, no 08 (19 septembre 2012) : 2069–92. http://dx.doi.org/10.1142/s1793042112501187.

Texte intégral
Résumé :
The Mellin transform of a summatory function involving weighted averages of Ramanujan sums is obtained in terms of Bernoulli numbers and values of the Burgess zeta function. The possible singularity of the Burgess zeta function at s = 1 is then shown to be equivalent to the evaluation of a certain infinite series involving such weighted averages. Bounds on the size of the tail of these series are given and specific bounds are shown to be equivalent to the Riemann hypothesis.
Styles APA, Harvard, Vancouver, ISO, etc.
40

Liang, Jiaxin, Xiaowu Tang, Tianqi Wang, Weikang Lin, Jing Yan et Chunqing Fu. « Analysis for Ground Deformation Induced by Undercrossed Shield Tunnels at a Small Proximity Based on Equivalent Layer Method ». Sustainability 14, no 16 (12 août 2022) : 9972. http://dx.doi.org/10.3390/su14169972.

Texte intégral
Résumé :
Shield excavation and tail grouting are the main causes of ground deformation in tunnel construction, especially in the case of new tunnels undercrossing existing tunnels, which have stricter requirements for settlement control. This paper investigates the equivalent layer method, which is used to simulate ground deformation induced by shield construction and tail grouting via numerical analysis. The research is based on a case study of Beijing’s newly built Metro Line 12 undercrossing the existing Metro Line 10, which is constructed in soft soil. Three-dimensional finite simulation via Plaxis 3D is performed, incorporating the equivalent layer method. Parametric analysis is carried out to explore the influence of the thickness (δ) and elastic modulus (E) of the equivalent layer on surface settlement. It is shown that the surface settlement increases almost linearly with the increase in δ, and it is insensitive to changes in E. The δ is the dominating factor affecting the surface settlement. Based on the Beijing Metro Lines project, the predicted surface settlement is analyzed and compared with monitoring data. Based on a case study of Beijing Metro, the applicability of the equivalent layer method is verified, and the empirical values for δ and E are summarized. δ = 1.8 Gp and E = 2 MPa are suitable values for analysis, which could be references for other shield tunnel constructions in soft soil. With the obtained empirical values of the equivalent layer method, the deformation caused by grouting and undercrossing tunnels could be accurately predicted, which is benefit for reducing budget and environmental protection.
Styles APA, Harvard, Vancouver, ISO, etc.
41

Duncan, Tyrone E., Yi Yan et Peng Yan. « Exact asymptotics for a queue with fractional Brownian input and applications in ATM networks ». Journal of Applied Probability 38, no 4 (décembre 2001) : 932–45. http://dx.doi.org/10.1239/jap/1011994183.

Texte intégral
Résumé :
In this paper, a single channel FIFO fluid queue with an infinite buffer space and a long-range dependent input is studied. The input traffic is modeled by an average input rate plus a standard fractional Brownian motion as the fluctuation. Lower and upper bounds are derived for the tail distribution of the transient queue length at time T, which result in a logarithmic characterization of the asymptotic behavior of the tail distribution. Furthermore, the exact asymptotic is also obtained. It is observed that the transient queue length under fractional Brownian input does not suffer from the heavy-tail property as does the steady-state queue length. The results are used to compute the equivalent bandwidth requirement for ATM broadband connections with fractional Brownian traffic feed and finite connection holding time.
Styles APA, Harvard, Vancouver, ISO, etc.
42

Sysoev, Vasiliy O., Masato Kato, Lillian Sutherland, Rong Hu, Steven L. McKnight et Dylan T. Murray. « Dynamic structural order of a low-complexity domain facilitates assembly of intermediate filaments ». Proceedings of the National Academy of Sciences 117, no 38 (9 septembre 2020) : 23510–18. http://dx.doi.org/10.1073/pnas.2010000117.

Texte intégral
Résumé :
The coiled-coil domains of intermediate filament (IF) proteins are flanked by regions of low sequence complexity. Whereas IF coiled-coil domains assume dimeric and tetrameric conformations on their own, maturation of eight tetramers into cylindrical IFs is dependent on either “head” or “tail” domains of low sequence complexity. Here we confirm that the tail domain required for assembly ofDrosophilaTm1-I/C IFs functions by forming labile cross-β interactions. These interactions are seen in polymers made from the tail domain alone, as well as in assembled IFs formed by the intact Tm1-I/C protein. The ability to visualize such interactions in situ within the context of a discrete cellular assembly lends support to the concept that equivalent interactions may be used in organizing other dynamic aspects of cell morphology.
Styles APA, Harvard, Vancouver, ISO, etc.
43

Duncan, Tyrone E., Yi Yan et Peng Yan. « Exact asymptotics for a queue with fractional Brownian input and applications in ATM networks ». Journal of Applied Probability 38, no 04 (décembre 2001) : 932–45. http://dx.doi.org/10.1017/s0021900200019148.

Texte intégral
Résumé :
In this paper, a single channel FIFO fluid queue with an infinite buffer space and a long-range dependent input is studied. The input traffic is modeled by an average input rate plus a standard fractional Brownian motion as the fluctuation. Lower and upper bounds are derived for the tail distribution of the transient queue length at time T, which result in a logarithmic characterization of the asymptotic behavior of the tail distribution. Furthermore, the exact asymptotic is also obtained. It is observed that the transient queue length under fractional Brownian input does not suffer from the heavy-tail property as does the steady-state queue length. The results are used to compute the equivalent bandwidth requirement for ATM broadband connections with fractional Brownian traffic feed and finite connection holding time.
Styles APA, Harvard, Vancouver, ISO, etc.
44

Zhang, Yan, Xiuxiang An, JoAnne Stubbe et Mingxia Huang. « Investigation of in Vivo Roles of the C-terminal Tails of the Small Subunit (ββ′) of Saccharomyces cerevisiae Ribonucleotide Reductase ». Journal of Biological Chemistry 288, no 20 (25 mars 2013) : 13951–59. http://dx.doi.org/10.1074/jbc.m113.467001.

Texte intégral
Résumé :
The small subunit (β2) of class Ia ribonucleotide reductase (RNR) houses a diferric tyrosyl cofactor (Fe2III-Y•) that initiates nucleotide reduction in the large subunit (α2) via a long range radical transfer (RT) pathway in the holo-(α2)m(β2)n complex. The C-terminal tails of β2 are predominantly responsible for interaction with α2, with a conserved tyrosine residue in the tail (Tyr356 in Escherichia coli NrdB) proposed to participate in cofactor assembly/maintenance and in RT. In the absence of structure of any holo-RNR, the role of the β tail in cluster assembly/maintenance and its predisposition within the holo-complex have remained unknown. In this study, we have taken advantage of the unusual heterodimeric nature of the Saccharomyces cerevisiae RNR small subunit (ββ′), of which only β contains a cofactor, to address both of these issues. We demonstrate that neither β-Tyr376 nor β′-Tyr323 (Tyr356 equivalent in NrdB) is required for cofactor assembly in vivo, in contrast to the previously proposed mechanism for E. coli cofactor maintenance and assembly in vitro. Furthermore, studies with reconstituted-ββ′ and an in vivo viability assay show that β-Tyr376 is essential for RT, whereas Tyr323 in β′ is not. Although the C-terminal tail of β′ is dispensable for cofactor formation and RT, it is essential for interactions with β and α to form the active holo-RNR. Together the results provide the first evidence of a directed orientation of the β and β′ C-terminal tails relative to α within the holoenzyme consistent with a docking model of the two subunits and argue against RT across the β β′ interface.
Styles APA, Harvard, Vancouver, ISO, etc.
45

Finkelshtein, Dmitri, et Pasha Tkachov. « Kesten's bound for subexponential densities on the real line and its multi-dimensional analogues ». Advances in Applied Probability 50, no 2 (juin 2018) : 373–95. http://dx.doi.org/10.1017/apr.2018.18.

Texte intégral
Résumé :
Abstract We study the tail asymptotic of subexponential probability densities on the real line. Namely, we show that the n-fold convolution of a subexponential probability density on the real line is asymptotically equivalent to this density multiplied by n. We prove Kesten's bound, which gives a uniform in n estimate of the n-fold convolution by the tail of the density. We also introduce a class of regular subexponential functions and use it to find an analogue of Kesten's bound for functions on ℝd. The results are applied to the study of the fundamental solution to a nonlocal heat equation.
Styles APA, Harvard, Vancouver, ISO, etc.
46

FENG, JAMES Q. « Buoyancy-driven motion of a gas bubble through viscous liquid in a round tube ». Journal of Fluid Mechanics 609 (31 juillet 2008) : 377–410. http://dx.doi.org/10.1017/s0022112008002516.

Texte intégral
Résumé :
The steady axisymmetric flow of viscous liquid relative to a gas bubble due to its buoyancy-driven motion in a round tube is computed by solving the nonlinear Navier–Stokes equations using a Galerkin finite-element method with a boundary-fitted mesh. When the bubble is relatively small compared with the tube size (e.g. the volume-equivalent radius of the bubble is less than a quarter of the tube radius R), the bubble exhibits similar behaviour to one moving in an extended liquid, developing a spherical-cap shape with increasing Reynolds number (Re) if the capillary number is not too small. The long-bubble (also known as a Taylor bubble) characteristics can be observed with bubbles of volume-equivalent radius greater than the tube radius, especially when the surface tension effect is relatively weak (e.g. for Weber number We greater than unity). The computed values of Froude number Fr for most cases agree well with the correlation formulae derived from experimental data for long bubbles, and even with (short) bubbles of volume-equivalent radius three-quarters of the tube radius. All of the computed surface profiles of long bubbles exhibit a prolate-like nose shape, yet various tail shapes can be obtained by adjusting the parameter values of Re and We. At large Weber number (e.g. We=10), the bubble tail forms a concave profile with a gas ‘cup’ developed at small Re and a ‘skirt’ at large Re with sharply curved rims. For We≤1, the bubble tail profile appears rounded without large local curvatures, although a slightly concave tail may develop at large Re. non-uniform annular film adjacent to the tube wall is commonly observed when Weber number is small, especially for bubbles of volume <3πR3, suggesting that the surface tension effect can play a complicated role. Nonetheless the computed value of Fr is found to be generally independent of the bubble length for bubbles of volume-equivalent radius greater than the tube radius. If the bubble length reaches about 2.5 tube radii, the value of its frontal radius becomes basically the same as that for long bubbles of much larger volume. An examination of the distribution of the z-component of traction along the bubble surface reveals the basic mechanism for long bubbles rising at a terminal velocity that is independent of bubble volume.
Styles APA, Harvard, Vancouver, ISO, etc.
47

Shida, Claudio S., et Vera B. Henriques. « Monte Carlo Comparative Study of Model Detergent and Lipid Aggregation on a Lattice ». International Journal of Modern Physics C 09, no 06 (septembre 1998) : 801–7. http://dx.doi.org/10.1142/s0129183198000728.

Texte intégral
Résumé :
We have studied the aggregation of model amphiphilic molecules on a square lattice through Monte Carlo simulations via Metropolis. Amphiphilic molecules are modeled with a hydrophilic head represented by a small set of "water-loving" sites whereas the hydrophobic double-tail is represented by a second set of oil-loving sites. We have compared aggregation properties of single-stail (detergents) and double-tail (phospholipids) amphiphiles with equivalent hydrophobicity ratios. Equilibrium quantities such as average particle energy, specific heat, free amphiphile density show similar behavior for both model systems. The transition region associated with aggregation occurs at high temperatures for phospholipids as compared to detergents.
Styles APA, Harvard, Vancouver, ISO, etc.
48

Ward, Brian M., Andrea S. Weisberg et Bernard Moss. « Mapping and Functional Analysis of Interaction Sites within the Cytoplasmic Domains of the Vaccinia Virus A33R and A36R Envelope Proteins ». Journal of Virology 77, no 7 (1 avril 2003) : 4113–26. http://dx.doi.org/10.1128/jvi.77.7.4113-4126.2003.

Texte intégral
Résumé :
ABSTRACT Incorporation of the vaccinia virus A36R protein into the outer membrane of intracellular enveloped virions (IEV) is dependent on expression of the A33R protein. Possible interactions of the 200-amino-acid cytoplasmic domain of the A36R protein with itself or with the cytoplasmic domain of the A33R, A34R, B5R, or F12L IEV membrane protein was investigated by using the yeast two-hybrid system. A strong interaction was detected only between the cytoplasmic domains of the A36R and A33R proteins. Upon further analyses, the interaction site was mapped to residues 91 to 111 of the A36R protein. To investigate the role of the A36R:A33R interaction during viral infection, five recombinant vaccinia viruses containing B5R-GFP as a marker were constructed. Four had the full-length A36R gene replaced with various-length C-terminal truncations of A36R, of which two contained residues 91 to 111 and two were missing this region. The fifth recombinant virus had an A33R gene with most of the 40-amino-acid cytoplasmic tail deleted. Residues 91 to 111 of A36R and the cytoplasmic tail of A33R were required for a strong interaction between the two proteins during viral infection and for maximal amounts of A36R protein on IEV. Mutants lacking these regions of A33R or A36R formed IEV that exhibited only short sporadic intracellular movement, displayed no actin tails, and formed small plaques on cell monolayers equivalent to those of an A36R deletion mutant and smaller than those formed by point mutations that specifically abrogate actin tail formation. The A33R interaction site of the A36R protein is highly conserved among orthopoxviruses and may overlap binding sites for cellular proteins needed for microtubular movement and actin tail formation.
Styles APA, Harvard, Vancouver, ISO, etc.
49

Armstrong, David A., Mohsen Farahani et Parminder S. Surdhar. « Oxidation of tetrahydropterins by azide radical and the spectra of trihydropterin radicals ». Canadian Journal of Chemistry 68, no 11 (1 novembre 1990) : 1974–78. http://dx.doi.org/10.1139/v90-303.

Texte intégral
Résumé :
Spectrophotometric titration of tetrahydropterins with incremental amounts of •N3 showed that 6,7-dimethyl-7,8-dihydropterin was an intermediate in the oxidation of 6,7-dimethyltetrahydropterin at the two electron-equivalent oxidation point. The eventual end product at four electron equivalents was 6,7-dimethylpterin. In the case of unsubstituted tetrahydropterin, the dihydro form was clearly not an exclusive product at the two electron equivalent point, and this was attributed to the disproportionation of different forms of dihydropterin to tetrahydropterin and pterin.The azide radical oxidized tetrahydropterins to trihydropterin radicals, •PnH3, with overall second-order rate constants at pH 7 of 4.1, 3.8, and 2.9 × 109 M−1 s−1 for tetrahydropterin, 6,7-dimethyltetrahydropterin, and 6-carboxylated tetrahydropterin, respectively. At pH 10 the rate constants are slightly larger due to the presence of the deprotonated enolate forms of tetrahydropterins. Spectra vary somewhat with substitution in the pterin molecule, but all species have a strong peak (ε ~9000 M−1 cm−1) near 320 nm and lower absorption above this, with a tail extending to 580 nm. Keywords: tetrahydropterin oxidation, tetrahydropterin, trihydropterin radical, azide radical, trihydropterin spectrum.
Styles APA, Harvard, Vancouver, ISO, etc.
50

Amos, L. A. « Brain dynein crossbridges microtubules into bundles ». Journal of Cell Science 93, no 1 (1 mai 1989) : 19–28. http://dx.doi.org/10.1242/jcs.93.1.19.

Texte intégral
Résumé :
Cytoplasmic dynein was purified from pig brain, using a modified version of published procedures, in order to study its interaction with microtubules. Since the preparation produces ATP-dependent sliding of taxol-stabilized purified microtubules over glass and runs on SDS-containing gels as a major band exceeding 300,000 Mr plus a medium chain band at about 75,000 Mr, it is assumed to be identical to the mammalian brain dynein (MAP 1C) purified by Vallee and colleagues. When viewed by electron microscopy in negative stain, individual particles show two distinct configurations. Some are clearly similar to the two-headed bouquet structure already shown for MAP 1C. A larger number of molecules in the present preparation appear to have two heads fused together, forming a dimeric globular particle with two separate tails. They are referred to as phiparticles, because of their resemblance to the greek letter phi. A model for the structural relationship between the two molecular forms is presented. The stems of two associated dynein subunits may separate beyond the base, to form a bouquet, or they may remain fused to form the larger tail of a phi-particle. The smaller tail probably represents a combined pair of features equivalent to the ‘stalks’ shown to emanate from axonemal dynein heads by Goodenough and colleagues. Both tails of a phi-particle can bind to microtubules, even in the presence of ATP, and cause microtubule bundling. These results suggest a complete structural homology between axonemal and cytoplasmic dynein.
Styles APA, Harvard, Vancouver, ISO, etc.
Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!

Vers la bibliographie