scholarly journals P2P4GS : une spécification de grille pair-à-pair de services auto-gérés

2014 ◽  
Vol Volume 17 - 2014 - Special... ◽  
Author(s):  
Bassirou Gueye ◽  
Olivier Flauzac ◽  
Ibrahima Niang ◽  
Cyril Rabat
Keyword(s):  
Peer To Peer ◽  
The Other ◽  
Grid Services ◽  
End User ◽  
Management Protocol ◽  
Management Of Resources ◽  
International Audience ◽  
Adaptive Solution ◽  
High Degree ◽  
Grid Based

International audience The grid-based peer-to-peer architectures were used either for storage and data sharing or computing. So far, the proposed solutions with respect to grid services are based on hierarchical topologies, which present a high degree of centralization. The main issue of this centralization is the unified management of resources and the difficult to react rapidly against failure and faults that can affect grid users. In this paper, we propose a original specification, called P2P4GS, that enables selfmanaged service of peer-to- peer grid. Therefore, we design a self-adaptive solution for services deployment and invocation which take account the paradigm of peer-to-peer services. Furthermore, the deployment, and invocation are completely delegated to the platform and are done a transparent manner with respect to the end user. We propose a generic specification that is not related to a particular peer-to-peer architecture or a management protocol services defined in advance. On the other hand, we propose a study of algorithmic complexities of deployment and service localization primitives in P2P4GS by immersing them on the classical topologies of P2P stack ie the ring and tree. The obtained performances are satisfactory for these different topologies.

scholarly journals Simply generated trees, conditioned Galton―Watson trees, random allocations and condensation: Extended abstract

2012 ◽  
Vol DMTCS Proceedings vol. AQ,... (Proceedings) ◽  
Author(s):  
Svante Janson
Keyword(s):  
Random Trees ◽  
The Other ◽  
Random Allocation ◽  
Allocation Model ◽  
Standard Case ◽  
Infinite Degree ◽  
International Audience ◽  
Watson Process ◽  
Simply Generated Trees ◽  
High Degree

International audience We give a unified treatment of the limit, as the size tends to infinity, of random simply generated trees, including both the well-known result in the standard case of critical Galton-Watson trees and similar but less well-known results in the other cases (i.e., when no equivalent critical Galton-Watson tree exists). There is a well-defined limit in the form of an infinite random tree in all cases; for critical Galton-Watson trees this tree is locally finite but for the other cases the random limit has exactly one node of infinite degree. The random infinite limit tree can in all cases be constructed by a modified Galton-Watson process. In the standard case of a critical Galton-Watson tree, the limit tree has an infinite "spine", where the offspring distribution is size-biased. In the other cases, the spine has finite length and ends with a vertex with infinite degree. A node of infinite degree in the limit corresponds to the existence of one node with very high degree in the finite random trees; in physics terminology, this is a type of condensation. In simple cases, there is one node with a degree that is roughly a constant times the number of nodes, while all other degrees are much smaller; however, more complicated behaviour is also possible. The proofs use a well-known connection to a random allocation model that we call balls-in-boxes, and we prove corresponding results for this model.

ADAPTING A PURE DECENTRALIZED PEER-TO-PEER PROTOCOL FOR GRID SERVICES INVOCATION

2005 ◽  
Vol 15 (01n02) ◽  
pp. 67-84 ◽  
Author(s):  
DOMENICO TALIA ◽  
PAOLO TRUNFIO
Keyword(s):  
Peer To Peer ◽  
The Other ◽  
Grid Services ◽  
Other Hand ◽  
Merging Techniques ◽  
Grid Resources ◽  
Load Conditions

Several aspects of today's Grids are based on centralized or hierarchical services. However, as Grids increase their size from tens to thousands of hosts, functionalities should be decentralized to avoid bottlenecks and guarantee scalability. A way to ensure Grid scalability is to adopt Peer-to-Peer (P2P) models and techniques to implement non-hierarchical decentralized Grid services and systems. Pure decentralized P2P protocols based on a pervasive exchange of messages, such as Gnutella, appear to be inadequate for OGSA Grids, where peers communicate among them through Grid Services mechanisms. On the other hand, this class of protocols offers useful properties in dealing with Grid resources heterogeneity and dynamicity. This paper proposes a modified Gnutella discovery protocol, named Gridnut, which makes it suitable for OGSA Grids. In particular, Gridnut uses appropriate message buffering and merging techniques to make Grid Services effective as a way to exchange messages in a P2P fashion. We present the design of Gridnut and compare Gnutella and Gridnut performances under different network and load conditions.

C-Terminal amino acid sequence of chicken pepsinogen and its homology with sequences of other acid proteases

1980 ◽  
Vol 45 (4) ◽  
pp. 1144-1154 ◽  
Author(s):  
Miroslav Baudyš ◽  
Helena Keilová ◽  
Vladimír Kostka
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
The Other ◽  
Terminal Sequence ◽  
Terminal Part ◽  
Terminal Amino Acid ◽  
Tryptic Peptides ◽  
Terminal Amino ◽  
High Degree ◽  
Terminal Amino Acid Sequence

To determine the primary structure of the C-terminal part of the molecule of chicken pepsinogen the tryptic, chymotryptic and thermolytic digest of the protein were investigated and peptides derived from this region were sought. These peptides permitted the following 21-residue C-terminal sequence to be determined: ...Ile-Arg-Glu-Tyr-Tyr-Val-Ile-Phe-Asp-Arg-Ala-Asn-Asn-Lys-Val-Gly-Leu-Ser-Pro-Leu-Ser.COOH. A comparison of this structure with the C-terminal sequential regions of the other acid proteases shows a high degree of homology between chicken pepsinogen and these proteases (e.g., the degree of homology with respect to hog pepsinogen and calf prochymosin is about 66%). Additional tryptic peptides, derived from the N-terminal part of the zymogen molecule whose amino acid sequence has been reported before, were also obtained in this study. This sequence was extended by two residues using an overlapping peptide. An ancillary result of this study was the isolation of tryptic peptides derived from other regions of the zymogen molecule.

scholarly journals Involvement of loop 5 lysine residues and the N-terminal β-hairpin of the ribotoxin hirsutellin A on its insecticidal activity

2016 ◽  
Vol 397 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Miriam Olombrada ◽  
Lucía García-Ortega ◽  
Javier Lacadena ◽  
Mercedes Oñaderra ◽  
José G. Gavilanes ◽  
...  
Keyword(s):  
Active Sites ◽  
Structural Changes ◽  
The Other ◽  
Spatial Proximity ◽  
Ribonucleolytic Activity ◽  
The Family ◽  
Lysine Residues ◽  
Hirsutella Thompsonii ◽  
Close Spatial Proximity ◽  
High Degree

Abstract Ribotoxins are cytotoxic members of the family of fungal extracellular ribonucleases best represented by RNase T1. They share a high degree of sequence identity and a common structural fold, including the geometric arrangement of their active sites. However, ribotoxins are larger, with a well-defined N-terminal β-hairpin, and display longer and positively charged unstructured loops. These structural differences account for their cytotoxic properties. Unexpectedly, the discovery of hirsutellin A (HtA), a ribotoxin produced by the invertebrate pathogen Hirsutella thompsonii, showed how it was possible to accommodate these features into a shorter amino acid sequence. Examination of HtA N-terminal β-hairpin reveals differences in terms of length, charge, and spatial distribution. Consequently, four different HtA mutants were prepared and characterized. One of them was the result of deleting this hairpin [Δ(8-15)] while the other three affected single Lys residues in its close spatial proximity (K115E, K118E, and K123E). The results obtained support the general conclusion that HtA active site would show a high degree of plasticity, being able to accommodate electrostatic and structural changes not suitable for the other previously known larger ribotoxins, as the variants described here only presented small differences in terms of ribonucleolytic activity and cytotoxicity against cultured insect cells.

Methylene. III. Gas phase reactions with 1-chloropropane

1969 ◽  
Vol 312 (1509) ◽  
pp. 141-161 ◽  
Keyword(s):  
Gas Phase ◽  
Rate Constants ◽  
Hydrogen Abstraction ◽  
The Other ◽  
Gas Phase Reactions ◽  
Other Hand ◽  
Chlorine Substituent ◽  
High Degree ◽  
Singlet Methylene

The work described in this and the following paper is a continuation of that in parts I and II, devoted to elucidation of the mechanism of the reactions of methylene with chloroalkanes, with particular reference to the reactivities of singlet and triplet methylene in abstraction and insertion processes. The products of the reaction between methylene, prepared by the photolysis of ketene, and 1-chloropropane have been identified and estimated and their dependence on reactant pressures, photolysing wavelength and presence of foreign gases (oxygen and carbon mon­oxide) has been investigated. Both insertion and abstraction mechanisms contribute significantly to the over-all reaction, insertion being relatively much more important than with chloroethane. This type of process appears to be confined to singlet methylene. If, as seems likely, there is no insertion into C—Cl bonds under our conditions (see part IV), insertion into C2—H and C3—H bonds occurs in statistical ratio, approximately. On the other hand, the chlorine substituent reduces the probability of insertion into C—H bonds in its vicinity. As in the chloroethane system, both species of methylene show a high degree of selectivity in their abstraction reactions. We find that k S Cl / k S H >7.7, k T Cl / k T H < 0.14, where the k ’s are rate constants for abstraction, and the super- and subscripts indicate the species of methylene and the type of atom abstracted, respectively. Triplet methylene is discriminating in hydrogen abstraction from 1-C 3 H 7 Cl, the overall rates for atoms attached to C1, C2, C3 being in the ratios 2.63:1:0.

The In Vitro Sensitivities of 70 Strains of Shigella

PEDIATRICS ◽  
1964 ◽  
Vol 34 (5) ◽  
pp. 705-707
Author(s):  
WILLIAM D. DONALD
Keyword(s):  
Clinical Trials ◽  
Gastrointestinal Tract ◽  
Tetracycline Resistance ◽  
The Other ◽  
Drug Of Choice ◽  
High Degree ◽  
As Toxicity ◽  
Selection Of

In vitro sensitivities of 70 shigella strains isolated over a recent 18-month period are reported. The high degree of sulfadiazine resistance casts some doubt on the selection of this agent as the drug of choice in the treatment of shigellosis, at least in this community. Some of the other agents, although inhibiting the growth of the organisms in vitro, have disadvantages such as toxicity or failure of absorption from the gastrointestinal tract. Tetracycline resistance was found in only 7% of the organisms tested, but from this and other reports we may anticipate the occurrence of more organisms resistant to this agent. The results of the sensitivities to ampicillin are encouraging and further studies including clinical trials of this agent are in order.

Photoreceptor coupling in turtle retina

1998 ◽  
Vol 15 (4) ◽  
pp. 755-764 ◽  
Author(s):  
M.L. FIRSOV ◽  
D.G. GREEN
Keyword(s):  
Receptive Field ◽  
Gap Junctions ◽  
Direct Evidence ◽  
Physiological Responses ◽  
The Other ◽  
Morphological Data ◽  
Chelydra Serpentina ◽  
Intracellular Injection ◽  
Coupled Cells ◽  
High Degree

Photoreceptors in the isolated turtle retina of two species of turtle, Chelydra serpentina and Pseudemus scripta elegans, were penetrated with double-barrel electrodes. Physiological responses were recorded through one barrel and Neurobiotin tracer was injected from the other. Intracellular injection of Neurobiotin revealed patterns of tracer-coupled photoreceptors. Both the patterns of tracer coupling and the electrophysiology suggest a high degree of specificity of connections. Rods seem to be coupled only to rods and green and red cones seem to be coupled to cones of the same spectral type. Receptive-field profiles, measured with a thin, sharply focused slit of light, often had well-defined peaks and troughs in sensitivity. We have taken advantage of this observation and used the position of a peak in sensitivity to locate the position on the retina of a coupled cell. In one rod, it was possible to correlate physiological and morphological data and to show that the peaks in the physiological receptive field occurred at positions on the retina where there were dye-coupled cells. This provides direct evidence that gap junctions produce the physiological coupling between rods.

scholarly journals Żywiołowe rozprzestrzenianie się Poznania: profil morfologiczny i mikroekonomiczny

2020 ◽  
pp. 81-99
Author(s):  
Piotr Lityński
Keyword(s):  
Spatial Structure ◽  
Urban Sprawl ◽  
The Other ◽  
Moderate Degree ◽  
Financial Situation ◽  
Housing Preferences ◽  
Household Budget ◽  
High Degree ◽  
Financial Losses ◽  
Morphological Assessment

The aim of the article is to assess Poznań’s urban sprawl from the perspective of the morphology of space and financial situation of suburban households. The morphological assessment uses a method based on two grids of squares with a side: 1 km, 500 m; and data on the location of buildings from CCGCD. On the other hand, the assessment of households was carried out on the basis of the CSO Household Budget database. The results of the research indicate that the analyzed communes in the Poznań area are characterized by a moderate degree of disorder in the spatial structure. There are no communes with a completely compact specificity, there are also no communes with an absolutely high degree of spatial disorder. Households causing urban sprawl in Poznań are entities that incur moderate financial losses in order to maximize their housing preferences.

scholarly journals Formación y cultura escrita: los libros del agrimensor Francisco Falcón (1764)

2020 ◽  
pp. 611
Author(s):  
Amparo García Cuadrado
Keyword(s):  
Eighteenth Century ◽  
Quantitative Analysis ◽  
The Other ◽  
Interesting Part ◽  
The Subject ◽  
Scientific Nature ◽  
High Degree ◽  
The Relationship ◽  
Private Collections ◽  
Bibliographic Collection

This article approaches the study of the private library of the Murcian land surveyor Francisco Falcón de los Reyes, from the first half of the eighteenth century, which constitutes a clear example of the relationship between education and written culture. From the data extracted from a postmortem inventory and the subsequent appraisal and partition of goods among the heirs, we carried out a quantitative and qualitative analysis of said library. First, the text provides a biographical profile of this geometer, a descendant of slaves (new Christians), and describes the formative precariousness of these professionals in their time. The quantitative analysis of the bibliographic collection and its comparison with other private collections from similar socioeconomic fields indicate the importance of this particular collection. The qualitative study of authors and titles shows, on one hand, the high degree of mathematical training of the subject, who is shown to be a recipient of the fundamentally Valencian pre-illustrated reformist scientific mainstream, and, on the other hand, the purpose with which those books were incorporated into the funds of the collection. Together with the library, which we could call professional, due to its scientific nature, the inventoried religious matter in the form of printed documents makes up another interesting part of the collection, one of a catechetical nature in its various formative levels

scholarly journals AgFact: Linking farmers with facts

1997 ◽  
pp. 145-147
Author(s):  
G.I. Ogle ◽  
A.L. Craigie ◽  
M.J. Baker
Keyword(s):  
Service Sector ◽  
The Other ◽  
Information Need ◽  
End User ◽  
Information Base ◽  
The Public ◽  
High Profile ◽  
Key Issues ◽  
Distribution Chain

The AgLINK bulletin series dominated all agricultural and horticultural information publications from the late 1960s to the late 1980s, when it was discontinued. The collapse of such a high profile series raises questions about the viability of such a mechanism for linking farmers with facts. This failure highlights three key issues: the need to define and allocate the costs based on who benefits; the appropriate positioning of parties within the distribution chain; and a quality specification to which bulletins must adhere. We consider that AgFACT, the AgResearch pastoral agriculture information base which superseded AgLINK in 1997, should largely be cost neutral to science groups in AgResearch. However, the resources for providing information need to be met by science programmes, a cost which is outweighed by the opportunity to communicate with science stakeholders. The costs of distribution and retail need to fall with the other parties who benefit from the dissemination of this information - the retailer and the end user. We also consider that the role of AgResearch is in manufacture rather than sales to the public, which is best done by the agricultural service sector. AgFACT must maintain tight specifications, to ensure that it is relevant to farmers and other users, accurate and unbiased, and up to date. The penalty for not doing so is a loss of value and, moreover, a risk of it becoming a public liability. Keywords: AgFACT, AgLINK, agricultural information, information base, technology transfer

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