bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processing Technology Comparison of Physicochemical and Functional Properties of Cassava Starch Extracted from Fresh Root and Dry Chips
Authors: Abera Solomon , Rakshit Sudip Kumar 
Published: July 2003

AbstractStarch was extracted from dry chips of three varieties of cassava using wet milling and dry milling methods. The physicochemical and functional properties were compared with those from fresh root. The starch obtained exhibited lower peak viscosities, breakdowns and setbacks, and higher pasting and peak temperatures than that from fresh root. Most thermal properties (onset and peak temperatures of gelatinization and retrogradation; conclusion temperatures, enthalpies and peak height indices of retrogradation; and degree of retrogradation) were found to be higher than those of fresh‐root starch. Moreover, swelling power, paste clarity and freeze‐thaw stability of the former were inferior to those of the latter. Both types of starches exhibited increased rate of syneresis with increase in freeze‐thaw cycles. Differences observed in properties of starches derived from dry chips by wet and dry millings were very minimal. No indication of major change in granule structure was noted for dry‐chip starch that would alter the properties relative to fresh root starch. Higher fiber content and annealing due to exposure to heat and moisture of the former accounted for most of the variations of properties as compared to the latter. With the advanced technology used in starch manufacturing industry today it would be possible to obtain starch from dry chips with similar quality from fresh root. This would enable the industry to overcome the cycle of glut and low season, and allow them to remain open for longer period of time in a year.
Power‐aware broadcasting and activity scheduling in ad hoc wireless networks using connected dominating sets
Authors: Wu Jie , Wu Bing , Stojmenovic Ivan 
Published: June 2003

AbstractIn ad hoc mobile wireless networks, owing to host mobility, broadcasting is expected to be more frequently used to find a route to a particular host, to page a host, and to alarm all hosts. A straightforward broadcasting by flooding is usually very costly and will result in substantial redundancy and more energy consumption. Power consumption is an important issue since most mobile hosts operate on battery. Broadcasting based on a connected dominating set is a promising approach, where only nodes in the dominating set need to relay the broadcast packet. A set is dominating if all the nodes in the system are either in the set or are neighbors of nodes in the set. Wu and Li proposed a simple and efficient distributed algorithm for calculating connected dominating set in ad hoc wireless networks, where connections of nodes are determined by their geographical distances. In general, nodes in the connected dominating set consume more energy to handle various bypass traffic than nodes outside the set. To prolong the life span of each node and, hence, the network by balancing the energy consumption in the system, nodes should be alternately chosen to form a connected dominating set. Activity scheduling deals with the way of rotating the role of each node among a set of given operation modes (e.g. dominating nodes versus dominated nodes). In this paper, we propose to apply the notion of power‐aware connected dominating set to broadcasting and activity scheduling. The effectiveness of the proposed method in prolonging the life span of the network is confirmed through simulation. Copyright © 2003 John Wiley & Sons, Ltd.
SpatialAgents: integrating user mobility and program mobility in ubiquitous computing environments
Authors: Satoh Ichiro 
Published: June 2003

AbstractThis paper presents a framework for the building of context‐aware applications in ubiquitous and mobile computing settings. The framework provides people, places, and things with computational functionalities to support and annotate them. It is unique among existing systems because the functionalities are implemented by mobile agents. Using location‐tracking systems, this framework can navigate mobile agents to stationary or mobile computers near the locations of the entities and places to which the agents are attached, even when the locations change. The framework provides a way for mobile agents to follow their users as they move about and to adhere to places as virtual Post‐its. A prototype implementation of the framework has been built on a Java‐based mobile agent system and tested with several practical applications, including follow‐me applications and a user navigational assistance system. Copyright © 2003 John Wiley & Sons, Ltd.
Average case analysis‐based protocols to initialize packet radio networks
Authors: Myoupo Jean‐Fréderic , Thimonier Loys , Ravelomanana Vlady 
Published: June 2003

AbstractWe propose two randomized protocols by which n (n not known) initially identical stations of a Packet Radio Network (PRN) are assigned ID numbers from 1 to n to distinguish them. They run regardless of the number of stations per channel. The first one is a naive protocol and is derived from recursive probabilistic divide‐and‐conquer techniques. It requires n/lnk broadcast rounds, where k is the number of communication channels. The second solution needs the well‐known prefix sums algorithm and we show that in this scenario the described protocol terminates in O(n/k) broadcast rounds on the average case whenever k ≤ n/lnn. These results are obtained by means of the average case analysis of algorithms, using probabilistic generating functions and formal methods. Surprisingly, our last protocol performs as well as the efficiency‐oriented protocol of Hayashi et al. in1, 2, which depends on the number of stations per channel. And moreover, it can handle the case where k∈[n/3lnn, n/lnn]. Copyright © 2003 John Wiley & Sons, Ltd.
A resource‐efficient QoS routing protocol for mobile ad hoc networks
Authors: De Swades , Qiao Chunming , Das Sajal K. 
Published: June 2003

AbstractThe performance of existing QoS routing protocols is often constrained with high control traffic and database maintenance overhead. We observe that by proper coupling of nodal mobility and location information, better QoS support can be achieved with reduced control traffic and database requirements. In this paper, we investigate the performance of a location‐aware QoS routing protocol, calledtrigger‐based distributed routing(TDR), for mobile ad hoc networks. In this protocol, the nodal database size is reduced by maintaining only local neighborhood information, and route maintenance control overhead is kept low by maintaining only one route at a time for a session. Distributed rerouting control and directed alternate route discovery help reduce the rerouting control overhead and perform quicker route repair. Moreover, rerouting based on signal degradation history makes it possible to minimize the in‐session route failure. Our evaluation shows that the TDR protocol has significantly better QoS support and reduced overhead requirements compared to the existing QoS routing protocols in ad hoc networks. Copyright © 2003 John Wiley & Sons, Ltd.
Reliable MAC layer multicast in IEEE 802.11 wireless networks
Authors: Sun Min‐te , Huang Lifei , Wang Shaoyong , Arora Anish , Lai Ten‐Hwang 
Published: June 2003

AbstractMulticast/broadcast is an important service primitive in networks. It is supported by all IEEE 802.x standards, including 802.11. The IEEE 802.11 multicast/broadcast protocol is based on the basic access procedure of Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA). This protocol does not provide any media access control (MAC) layer recovery on multicast/broadcast frames. As a result, the reliability of the multicast/broadcast service is reduced owing to the increased probability of lost frames resulting from interference or collisions. Recently, a few MAC protocols have been proposed to enhance the reliability and the efficiency of the 802.11 multicast/broadcast protocol. In this paper, we observe that these protocols are still unreliable or inefficient. To redress the problems of reliability and efficiency, we propose a reliable Batch Mode Multicast MAC protocol (BMMM), which in most cases reduces the number of contention phases fromnto 1, wherenis the number of intended receivers in the multicast/broadcast. This considerably reduces the time required for a multicast/broadcast. We then propose a Location Aware Multicast MAC protocol (LAMM), which uses station location information to further improve upon BMMM. Extensive analysis and simulation results validate the reliability and efficiency of our multicast MAC protocols. Copyright © 2003 John Wiley & Sons, Ltd.
A new BlueRing scatternet topology for Bluetooth with its formation, routing, and maintenance protocols
Authors: Lin Ting‐Yu , Tseng Yu‐Chee , Chang Keng‐Ming 
Published: June 2003

AbstractThe basic networking unit in Bluetooth is piconet, and a larger‐area Bluetooth network can be formed by multiple piconets, called scatternet. However, the structure of scatternets is not defined in the Bluetooth specification and remains as an open issue at the designers' choice. It is desirable to have simple yet efficient scatternet topologies with good supports of routing protocols, considering that Bluetooths are to be used for personal area networks with design goals of simplicity and compactness. In the literature, although many routing protocols have been proposed for mobile ad hoc networks, directly applying them poses a problem due to Bluetooth's special baseband and MAC‐layer features. In this work, we propose an attractive scatternet topology called BlueRing, which connects piconets as a ring interleaved by bridges between piconets, and address its formation, routing, and topology‐maintenance protocols. The BlueRing architecture enjoys the following fine features. First, routing on BlueRing is stateless in the sense that no routing information needs to be kept by any host once the ring is formed. This would be favorable for environments such as Smart Homes where computing capability is limited. Second, the architecture is scalable to median‐size scatternets easily (e.g. around 50 ∼ 70 Bluetooth units). In comparison, most star‐ or treelike scatternet topologies can easily form a communication bottleneck at the root of the tree as the network enlarges. Third, maintaining a BlueRing is an easy job even as some Bluetooth units join or leave the network. To tolerate single‐point failure, we propose a protocol‐level remedy mechanism. To tolerate multipoint failure, we propose a recovery mechanism to reconnect the BlueRing. Graceful failure is tolerable as long as no two or more critical points fail at the same time. As far as we know, the fault‐tolerant issue has not been properly addressed by existing scatternet protocols yet. In addition, we also evaluate the ideal network throughput at different BlueRing sizes and configurations by mathematical analysis. Simulation results are presented, which demonstrate that BlueRing outperforms other scatternet structures with higher network throughput and moderate packet delay. Copyright © 2003 John Wiley & Sons, Ltd.
A cell‐based location‐sensing method for wireless networks
Authors: Chu Hung‐Chi , Jan Rong‐Hong 
Published: June 2003

AbstractOne of the most important applications for mobile commerce is location‐based application and the core technology of location‐based applications is the location‐determination technology. In this paper, we present a location‐sensing method, calledcell‐based location‐sensing methodand its positioning accuracy for the wireless networks with hexagonal structure and mesh structure. In addition, the accuracy of the method is optimized by tuning the transmitting power of base stations. In the optimal transmitting power, an accuracy of within 9.1667% (7.2182%) cell area for hexagonal structure (mesh structure) can be achieved by the cell‐based location‐sensing method. We believe that the results are useful for deploying wireless networks for location‐based applications. Copyright © 2003 John Wiley & Sons, Ltd.
A stability aware cluster routing protocol for mobile ad hoc networks
Authors: Chiu Chun‐Yuah , Chen Gen‐Huey , Wu Eric Hsiao‐Kuang 
Published: June 2003

AbstractAn ad hoc network is formed by a collection of mobile nodes without any centralized access point or existing infrastructure. Communications between mobile nodes require routing over multiple‐hop wireless paths. Since mobile nodes could be of high mobility, an effective and adaptive routing protocol must have ongoing details of the topology information. However, it wastes limited bandwidth to keep routing information up‐to‐date and reliable. Thus, one of the crucial design objectives to achieve routing responsiveness and updating efficiency is the minimization of reaction to mobility. Specifically, a scalable and QoS‐guaranteed routing protocol is desired for novel multimedia applications in mobile ad hoc networks.In this paper, we propose an efficiently repairable routing protocol, called Gravitational Cluster Routing (GCR) Protocol. It contains a stable cluster structure to cover dense areas and avoid articulation nodes. The reaction to mobility can be reduced significantly by unicast. Active routing paths can be maintained locally in each cluster. Besides, repairable levels of active routing paths, which rank their stabilities, are evaluated. By their aid, the proposed GCR can find routing paths that satisfy different parameters of QoS. These mechanisms can improve the stability of active connections. Copyright © 2003 John Wiley & Sons, Ltd.
SIR‐dependent repression of non‐telomeric genes in Saccharomyces cerevisiae?
Authors: Marchfelder Uta , Rateitschak Katja , Ehrenhofer‐Murray Ann E. 
Published: July 2003

AbstractThe proteins Sir2, Sir3 and Sir4 repress transcription of the silent mating‐type loci HML and HMR and of reporter genes inserted at telomeres. Previous microarray analyses suggested that additional non‐telomeric genes exist which are repressed by the Sir proteins. In this study, we tested the expression of 12 such genes by Northern analysis and RT–PCR. However, we were unable to verify their SIR‐dependent regulation, which suggests that SIR‐mediated repression may be restricted to the known repressed regions. Copyright © 2003 John Wiley & Sons, Ltd.
ALG2, the Hansenula polymorpha isocitrate lyase gene
Authors: Berardi Enrico , Gambini Annalisa , Bellu Anna Rita 
Published: July 2003

AbstractTo set the basis for molecular and cellular studies of the glyoxylate cycle in methylotrophic yeasts, we isolated and characterized ALG2, the Hansenula polymorpha isocitrate lyase gene. Complementation work and sequence analysis revealed an ORF of 1458 nucleotides, encoding a 486 amino acid protein with a predicted molecular mass of 54.9 kDa. This protein is shorter than the Saccharomyces cerevisiae and Candida tropicalis ICLs, lacks a PST1 signal and possesses a PTS2‐like signal. The transcriptional regulation of ALG2 mRNA levels by carbon source is mainly achieved by glucose repression–derepression, whereas ethanol induction plays only a minor role. We present evidence indicating that, in H. polymorpha, neither isocitrate lyase activity nor the ALG2 gene product are necessary for C1‐peroxisome degradation triggered by ethanol. Therefore, the involvement of glyoxylate in degradation, as described by Kulachkovsky et al. (1997) for Pichia methanolica, does not necessarily apply to all methylotrophic yeasts. The relevant nucleotide sequence has been deposited at GenBank (Accession No. AF373067.1). Copyright © 2003 John Wiley & Sons, Ltd.
Assembly interdependence among the S. cerevisiae bud neck ring proteins Elm1p, Hsl1p and Cdc12p
Authors: Thomas Courtney L. , Blacketer Melissa J. , Edgington Nicholas P. , Myers Alan M. 
Published: July 2003

AbstractIn Saccharomyces cerevisiae, a complex comprising more than 20 different polypeptides assembles in a ring at the neck between the mother cell and the bud. This complex functions to coordinate cell morphology with cell division. Relatively little is known about this control system, including the physical relationships between the components of the neck ring. This study addressed the assembly interactions of three components of the ring, specifically the protein kinases Elm1p and Hsl1p and the septin Cdc12p. Specific amino acid substitutions in each of these three proteins were identified that either cause or suppress a characteristic phenotype of abnormally elongated cells and delay in the G2–M transition. Each protein was fused to green fluorescent protein, and its ability to localize at the neck was monitored in vivo in cells of various genotypes. Localization of Hsl1p to the neck requires Elm1p function. Elm1p localized normally in the absence of Hsl1p, although a specific point mutation in Hsl1p clearly affected Elm1p localization. The cdc12‐122 mutation prevented assembly of Elm1p or Hsl1p into the neck ring. Normal assembly of Cdc12p at the neck was dependent upon Elm1p and also, to a smaller extent, on Hsl1p. Ectopic localization of Cdc12p at the bud tip was observed frequently in elm1 mutants and also, to a lesser extent, in hsl1 mutants. Thus, Elm1p is a key factor in the assembly and/or maintenance of Hsl1p, as well as at least one septin, into the bud neck ring. Copyright © 2003 John Wiley & Sons, Ltd.
Distribution and sequence analysis of a novel Ty3‐like element in natural Saccharomyces paradoxus isolates
Authors: Fingerman Ethan G. , Dombrowski Peter G. , Francis Chantal A. , Sniegowski Paul D. 
Published: July 2003

AbstractLittle is known about the transposable elements of species closely related to Saccharomyces cerevisiae. We present a novel transposable element in Saccharomyces paradoxus, a close congener of S. cerevisiae. Sequence analysis of this element, designated Ty3‐1p, indicates that it is a homologue of the S. cerevisiae Ty3 element. Ty3‐1p shares 82% nucleotide identity with an S. cerevisiae Ty3 element and appears to be structured identically to Ty3, containing two overlapping open reading frames, six retroviral‐like domains, a J domain, and flanking sigma‐like elements. A sigma element from Ty3‐1p is 75% identical to a Ty3 sigma element. There is no evidence of horizontal transfer of Ty3 in Saccharomyces sensu stricto. We assess the distributions of Ty3p and Ty3 element insertions in natural population samples of S. paradoxus and S. cerevisiae. The S. paradoxus population sample exhibits Ty3p insertions present at a variety of sites at low frequency; this suggests that Ty3p elements are active in the sampled population. The S. cerevisiae population sample exhibits a uniform Ty3 hybridization profile in which all element insertions appear to be fixed. We comment on the possible causes of these contrasting observed distributions (GenBank Accession Nos AY198186 and AY198187). Copyright © 2003 John Wiley & Sons, Ltd.
The effect of under‐ and overexpressed CoEXG1‐encoded exoglucanase secreted by Candida oleophila on the biocontrol of Penicillium digitatum
Authors: Yehuda Hila , Droby Samir , Bar‐Shimon Meirav , Wisniewski Michael , Goldway Martin 
Published: July 2003

AbstractThe yeast, Candida oleophila, is acknowledged for its biocontrol activity against postharvest moulds. However, the mechanism of this activity is not fully understood. One of the conjectured modes of action is associated with extracellular lytic enzymes, such as β‐exoglucanase. The relationship of β‐exoglucanase in the biocontrol activity of C. oleophila was investigated by generating C. oleophila CoEXG1‐knockouts and double‐CoEXG1 transformants. The knockout transformants secreted 0–13% of the exoglucanase activity detected in the medium of the untransformed yeast (depending on the medium), indicating that CoEXG1 is the main gene responsible for the production of the secreted exoglucanase. Correspondingly, the double‐CoEXG1 transformants secreted approximately twice as much 1,3‐β‐exoglucanase as the untransformed C. oleophila. The biocontrol activity of the CoEXG1‐knockout and the double‐CoEXG1 transformants against Penicillium digitatum did not differ from that of the untransformed C. oleophila on kumquats. These results imply that the 1,3‐β‐exoglucanase encoded by the gene CoEXG1 is not involved in the biocontrol activity of C. oleophila against P. digitatum under these experimental terms. However, these findings do not rule out the possibilities, that the participation of CoEXG1 in biocontrol is dependent on the activity of other gene products, or that its effect may be manifested under altered environmental conditions. Copyright © 2003 John Wiley & Sons, Ltd.
Genome‐wide identification of fungal GPI proteins
Authors: de Groot Piet W. J. , Hellingwerf Klaas J. , Klis Frans M. 
Published: July 2003

AbstractGlycosylphosphatidylinositol‐modified (GPI) proteins share structural features that allow their identification using a genomic approach. From the known S. cerevisiae and C. albicans GPI proteins, the following consensus sequence for the GPI attachment site and its downstream region was derived: [NSGDAC]–[GASVIETKDLF]–[GASV]–X(4,19)–[FILMVAGPSTCYWN](10)>, where > indicates the C‐terminal end of the protein. This consensus sequence, which recognized known GPI proteins from various fungi, was used to screen the genomes of the yeasts S. cerevisiae, C. albicans, Sz. pombe and the filamentous fungus N. crassa for putative GPI proteins. The subsets of proteins so obtained were further screened for the presence of an N‐terminal signal sequence for the secretion and absence of internal transmembrane domains. In this way, we identified 66 putative GPI proteins in S. cerevisiae. Some of these are known GPI proteins that were not identified by earlier genomic analyses, indicating that this selection procedure renders a more complete image of the S. cerevisiae GPI proteome. Using the same approach, 104 putative GPI proteins were identified in the human pathogen C. albicans. Among these were the proteins Gas/Phr, Ecm33, Crh and Plb, all members of GPI protein families that are also present in S. cerevisiae. In addition, several proteins and protein families with no significant homology to S. cerevisiae proteins were identified, including the cell wall‐associated Als, Csa1/Rbt5, Hwp1/Rbt1 and Hyr1 protein families. In Sz. pombe, which has a low level of (galacto)mannan in the cell wall compared to C. albicans and S. cerevisiae, only 33 GPI candidates were identified and in N. crassa 97. BLAST searches revealed that about half of the putative GPI proteins that were identified in Sz. pombe and N. crassa are homologous to known or putative GPI proteins from other fungi. We conclude that our algorithm is selective and can also be used for GPI protein identification in other fungi. Copyright © 2003 John Wiley & Sons, Ltd.
Saccharomyces cerevisiae Set1p is a methyltransferase specific for lysine 4 of histone H3 and is required for efficient gene expression
Authors: Boa Simon , Coert Claudette , Patterton Hugh‐G. 
Published: July 2003

AbstractSeveral homologues of the Drosophila Su(var)3‐9 protein were recently reported to methylate lysine 9 of histone H3. Whereas this methylation signal served to recruit heterochromatin‐associated proteins to transcriptionally silenced regions, histone H3 methylated at lysine 4 was associated with transcriptionally active areas of the genome. These findings suggested that the interplay between lysine 4 and 9 methylation is crucial in eukaryotic gene regulation. Here we provide evidence that Saccharomyces cerevisiae Set1p is a methyltransferase specific for lysine 4 of histone H3. In addition, we show that the absence of Set1p and lysine 4 methylation result in decreased transcription of approximately 80% of the genes in S. cerevisiae. Hierarchical clustering analysis of the set1− expression profile revealed a correspondence to that of a mad2− strain, suggesting that the transcriptional defect in the set1− strain may be due to changes in chromatin structure. These findings establish a central role for methylation of histone H3 lysine 4 in transcriptional regulation. Copyright © 2003 John Wiley & Sons, Ltd.