bluuebunny/crossref_metadata_2025 huggingface dataset:
IT competency and firm performance: is organizational learning a missing link?
Authors: Tippins Michael J. , Sohi Ravipreet S.
Published: June 2003

Many companies have developed strategies that include investing heavily in information technology (IT) in order to enhance their performance. Yet, this investment pays off for some companies but not others. This study proposes that organization learning plays a significant role in determining the outcomes of IT. Drawing from resource theory and IT literature, the authors develop the concept of IT competency. Using structural equations modeling with data collected from managers in 271 manufacturing firms, they show that organizational learning plays a significant role in mediating the effects of IT competency on firm performance. Copyright © 2003 John Wiley & Sons, Ltd.
Self‐guided/conscious evolution
Authors: Banathy Bela H.
Published: June 2003

I start out by mapping the evolutionary journey of our species. I focus on the cultural evolution of the last 50,000 years of our seven million year journey. Studying the journey I have learned how evolution has worked in the evolutionary design space and what its principles and rules are. This led me to attain evolutionary consciousness. Evolutionary consciousness became the springboard to leap into conscious evolution and propose ways and means by which to engage in self‐guided evolution. In closing, I introduce an evolutionary design process, metaphorically called the Agora Project: building new agoras in the 21st century. Copyright © 2002 John Wiley & Sons, Ltd.
The self‐guiding evolution of civilizations
Authors: Elgin Duane
Published: June 2003

The universe is creating self‐organizing and self‐referencing systems at every scale. In accord with this dynamic, the human family is working to become consciously self‐organizing at progressively larger scales. We have evolved from awakening hunter‐gatherers to a species that has created a wired world whose actions are changing the face of the planet. Because the impact of humanity is now global, that is the scale at which we are challenged to become reflective if we are to be choiceful about our common future. We are challenged to no longer ‘run on automatic’, but to pay attention to how we pay attention as entire civilizations. The vehicle of collective attention at a civilizational scale is the mass media—particularly broadcast television. If civilizations are to realize their potential for full reflective consciousness and become self‐guiding in their evolution, then it is vital for the public to mobilize the public's airwaves on behalf of the public interest. Copyright © 2002 John Wiley & Sons, Ltd.
Boundary‐spanning dialogue for the 21st‐century agoras
Authors: Christakis Alexander N. , Brahms Sabrina
Published: June 2003

The paper identifies the critical role dialogue must play in constructing and sustaining the 21st‐century agoras in the context of the Global Village. Recognizing that the trends towards globalization are irreversible, it describes a boundary‐spanning dialogue approach (BDA) as the necessary, but not sufficient, foundation for enabling human beings to conceptualize and materialize the idealization of ‘conscious evolution of humanity’. The approach to BDA described in the paper is based on over 30 years of research, development and testing in the social systems design arena. Many stories from the design arena are available and documented. A major challenge for the agoras of the 21st century will be their capacity to engage multilingual, multicultural and geographically dispersed stakeholders in a boundary‐spanning dialogue among civilizations in the context of the Global Village. Two stories from past applications of BDA in the social systems design arena are presented in this paper. The first story discusses a project in Washington, DC involving Native American leaders and Federal Government executives, in the late 1980s. The second story focuses on a peace‐building workshop between Israelis and Palestinians that was facilitated by members of the bi‐communal Cypriot community. Copyright © 2002 John Wiley & Sons, Ltd.
Conscious evolution: the next stage of human development
Authors: Marx Hubbard Barbara
Published: June 2003

Conscious evolution is emerging in our generation because humanity has gained the powers of co‐destruction of our world, or the co‐creation of immeasurable futures. The purpose of conscious evolution is to learn how to be responsible for the ethical guidance of evolution. This new world view arises out of three new conditions: the new cosmology, the new crises and our new capacities, leading toward a macroshift. The Foundation for Conscious Evolution is formed to discover and offer a new developmental path to the next stage of human evolution. It offers three projects to serve this purpose: Gateway to our Conscious Evolution, a six‐month online educational program; the development of a conscious evolution community in Santa Barbara and the formation of a ‘Peace Room’ on the web and in localities to scan for, map, connect and communicate what is working to heal and evolve our world. Copyright © 2002 John Wiley & Sons, Ltd.
Cationisation of Glycerol Plasticised Wheat Starch under Microhydric Molten Conditions
Authors: Ayoub Ali , Bliard Christophe
Published: July 2003

Cationisation of glycerol plasticised wheat starch was performed in a molten mixture under the action of thermo‐mechanical energy using two reagents: 3‐chloro‐2‐hydroxypropyltrimethylammonium chloride and 2‐epoxypropyltrimethylammonium chloride. The reaction was catalysed with sodium hydroxide under microhydric conditions. The results showed that under these conditions the reaction proceeds rapidly and reaches completion within a few minutes. The reaction efficiencies were higher for lower degrees of substitution (DS). The epoxide showed a higher reactivity than the chloro derivative. Both destructurisation of starch granules and increased sodium hydroxide concentration enhanced the reaction, but an increase in plasticiser concentration had a negative effect. Measurements of intrinsic viscosity showed a decrease of the average molecular weight of the product, which was attributed to the thermo‐mechanical melting process. An increase in water affinity with DS was seen in the water sorption properties of the chemically modified starch.
Chemical and Physical Characterisation of Grain Tef [Eragrostis tef (Zucc.) Trotter] Starch Granule Composition
Authors: Bultosa Geremew , Taylor John R. N.
Published: July 2003

Chemical and physical properties of starch granules isolated from five grain tef (Eragrostis tef) varieties were characterised and compared with those of maize starch. Endogenous starch lipids extracted with hot water‐saturated n‐butanol and total starch lipids extracted with n‐hexane after HCl hydrolysis were 7.8 mg/g (mean) and 8.9 mg/g (mean), respectively, slightly lower than in the maize starch granules. The starch phosphorus content (0.65 mg/g) was higher than that of maize starch but virtually the same as reported for rice starch. The starch granule‐swelling factor was lower than that of maize starch and extent of amylose leaching was higher. The starch X‐ray diffraction pattern was characteristic of A type starch with a mean crystallinity of 37%, apparently lower than the crystallinity of maize starch and more similar to that reported for rice and sorghum starches. The starch DSC gelatinisation temperature was high, like for other tropical cereals; To, Tp, Tc and ΔH were in the range 63.8—65.4, 70.2—71.3, 81.3—81.5 °C and 2.28—7.22 J/g, respectively. The lower swelling, apparently lower percentage crystallinity and lower DSC gelatinisation endotherms than maize starch suggest that the proportion of long amylopectin A chains in tef starch is smaller than in maize starch.
Characteristics of Modified β‐Cyclodextrin Bound to Cellulose Powder
Authors: Rehmann Lars , Yoshii Hidefumi , Furuta Takeshi
Published: July 2003

Monochlorotriazinyl‐β‐cyclodextrin (MCT‐β‐CD) was covalently bonded to cellulose powder. The amount of MCT‐β‐CD bonded to cellulose could be determined by infrared spectroscopy. The coupling reaction was characterized as a physical adsorption of the MCT‐β‐CD on the cellulose powder followed by an apparently zero order chemical reaction. The reaction rate constant was found to be k = 6.43 · 10‐4 ± 0.11 · 10‐4 g g‐1 s‐1. The immobilized cyclodextrin was able to include and release d‐limonene as a model flavor compound. The maximum molar inclusion ratio was 0.85, which is the same inclusion ratio as for d‐limonene in native β‐cyclodextrin. The release rates of dlimonene included in the fixed MCT‐β‐CD were monitored at various relative humidities and 50 °C. The release kinetics could be modeled using the Avrami equation. These results demonstrate that flavors as well as other hydrophobic compounds can be included and released from MCT‐β‐CD immobilized on cellulose.
Extraction, Physicochemical and Compaction Properties of Tacca Starch — a Potential Pharmaceutical Excipient
Authors: Kunle Olobayo O. , Ibrahim Yakubu E. , Emeje Martins O. , Shaba Sam , Kunle Yemisi
Published: July 2003

Some physicochemical properties of tacca starch (Tacca leontopetaloides, Taccaceae) have been examined and the results compared to those of maize and potato starches. Tacca starch was found to have a higher amylose content than maize starch but a lower content than potato starch. The starch granules were small (average particle size 3.5 μm) relative to maize and potato starches and were predominantly polyhedral with edges. The gelatinisation characteristics except from the temperature were similar to those of maize starch but much higher than those of potato starch. Tacca starch had relatively higher swelling power and solubility than the other starches. Its features in the formation of compacts (tablets) were comparable to those of maize starch with tacca starch being more resistant to deformation.
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

Starch 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.
Passion for Learning, Passion for Life
Authors: Misangyi Watts Margit
Published: June 2003

By discussing service learning and describing an online course as an example, this chapter focuses on service learning as a method for taking the distance out of the educational experience.
The Shallow End of Cyberspace
Authors: Bertsch Michael
Published: June 2003

Text immersion is a way to get at information literacy because students learn to use the tools of knowledge management—computers, networks, software, and critical thinking, which they have contextualized through their ordering of raw data into information.
Cyberphilosophy, Learning Cells, and Distance Education
Authors: Cooper Wesley
Published: June 2003

This chapter discusses the use of learning cells in classrooms.
Experiential Knowledge
Authors: Wolsk David
Published: June 2003

Experience should come before book learning. Let's turn educational practice upside down and see if we can do a better job of teaching and learning.
Taking the Distance out of Education
Authors: Misangyi Watts Margit
Published: June 2003

This concluding chapter articulates the philosophical dilemmas we face as a culture and how these must be dealt with in light of our educational models.
Introduction: Technology as Catalyst
Authors: Misangyi Watts Margit
Published: June 2003

This volume addresses some of the implications of technologies for teaching and learning. Technology is viewed as a catalyst to improving educational practice.
Internet Metaphors Matter
Authors: Taniguchi Megumi I.
Published: June 2003

Computer metaphors are taken for granted and thus powerfully guide the way in which teachers work with students. Redefinition of our guiding metaphor is vital in taking the distance out of education.
Technology as Environment: From Collections to Connections
Authors: Hensley Randy Burke
Published: June 2003

When technology is used as an environment for learning rather than as an instrument of learning, it begins to look, feel, smell, and act like a pretechnology library.
A MOOcentric Perspective on Education and Information Technology
Authors: Cooper Wesley
Published: June 2003

This chapter is a personal account of the transformative nature of technology on the teaching and learning of one faculty member.
A Case Study: Linking Students Across Geographical and Cultural Distances
Authors: Romanoff Stephen J.
Published: June 2003

A case study of creating community through distance learning is examined, focusing on the use of low‐cost technology to link students across six time zones, the interdisciplinary approaches used, and the implications for national and global community building.
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

In 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

This 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

We 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

The 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

Multicast/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

The 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

One 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

An 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

The 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

To 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

In 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

Little 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

The 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

Glycosylphosphatidylinositol‐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

Several 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.
Nested cooperativity and salt dependence of the ATPase activity of the archaeal chaperonin Mm‐cpn
Authors: Kusmierczyk Andrew R , Martin Jörg
Published: July 2003

The properties of the ATPase activity of the type II chaperonin from Methanococcus maripaludis (Mm‐cpn) were examined. Mm‐cpn can hydrolyze not only ATP, but also CTP, UTP, and GTP, albeit with different effectiveness. The ATPase activity is dependent on magnesium and potassium ions, and is effectively inhibited by sodium ions. Maximal rates of ATP hydrolysis are achieved at 600 mM potassium. Initial rates of ATP hydrolysis by Mm‐cpn were determined at various ATP concentrations, revealing for the first time the presence of both positive intra‐ring and negative inter‐ring cooperativity in the archaeal chaperonin.
An Anatomical Database of Carpal Bone Measurements for Intercarpal Arthrodesis
Authors: MIDDLETON A. , MACGREGOR D. , COMPSON J. P.
Published: July 2003

During limited intercarpal fusion it is sometimes difficult to determine correct screw length and staple size. This is because of overlap, and the shape and orientation of the carpal bones on radiography. One hundred complete sets of dry cadaver carpal bones were measured to provide an anatomical database of carpal bone measurements. This should help prevent inadvertent overpenetration of fixation devices during surgery.
Early Parental Experiences of Obstetric Brachial Plexus Palsy
Authors: BELLEW M. , KAY S. P.
Published: July 2003

Early parental experiences of having a child with obstetric brachial plexus palsy were examined to determine whether there were any areas of dissatisfaction and, if so, whether these resulted from their distress and a need to blame someone, or from problems in the communication of bad news. A high level of dissatisfaction was reported with similar levels of dissatisfaction found in a mildly injured group that did not require surgery, and a severely injured group that did. This suggests either that degree of dissatisfaction is not related to degree of disability, or that dissatisfaction was due to factors other than a reaction to their child having a problem. Support was found for the latter as the parents reported details of problems in communication, particularly the giving of inaccurate and misleading information.
A method for the identification and characterization of clusters of schools along the transect lines of fisheries-acoustic surveys
Authors: Petitgas Pierre
Published: July 2003

The school-aggregation pattern (schools and clusters of schools) is presumed to play a significant role in determining pelagic fish-stock catchability. However, its analysis has seldom been undertaken because it requires field-behavioural data that is seldom available. Such information can now be obtained by analysing school-based data of fisheries-acoustic surveys. This paper proposes a method for doing so. The method allows for the identification of clusters of schools and the estimation of their parameters along one-dimensional, acoustic-survey transect lines. It is based on a spatial point-process approach that considers schools as point events occurring along the track sailed by a ship. More precisely, it is based on defining a maximum distance between schools in a cluster. This distance is chosen to optimize various criteria and in particular that of homogeneity concerning school location inside the clusters and school number per km. The algorithm is described and applied to a series of acoustic surveys carried out in the Bay of Biscay. The pertinence of the clusters obtained by the algorithm is evaluated by analysing which component of the spatial distribution of the schools corresponds to those clusters. This involves considering all the distances between school events and performing simulations of cluster point processes. The school clusters obtained by the proposed algorithm represent a small-range structure of a few kilometres when a longer-range structure of tens of kilometres was also present in the data.
Burrow density and stock size fluctuations of Nephrops norvegicus in a semi-enclosed bay
Authors: Smith C.J , Papadopoulou K.-N
Published: July 2003

An underwater television technique was used to investigate burrow density of Nephrops norvegicus in a large semi-enclosed bay in the west central Aegean. Pagasitikos Bay has the shallowest occurrence of Nephrops in high densities in Greek waters with an estimated population area of 376 km2. As trawling is by law prohibited in the bay, Nephrops is fished only by bottom nets. Burrow densities were estimated seasonally (May, August and November 1998 and February 1999) by video sled transects at nine stations around the bay. Bottom trawls were undertaken to estimate animal abundance, mean individual carapace length and mean weight. Total stock estimate (number and weight) was undertaken for 100 and 75% burrow occupancy with the ground delimited by the 60 m contour. Annual removal by fishermen was estimated to be 1.5–2% of the stock. Densities were found to be higher than in other Greek Nephrops grounds. Variations in burrow density were found both between stations and within stations over time, with an overall decrease in density in 1999. The decrease in density during 1999, in conjunction with an increase in mean carapace length from the trawl catches was attributed to an eutrophication event evidenced by a flock layer settling onto the seabed and causing, in the worst cases, patches of anoxic surface sediments. The event was most probably the result of high nutrient run-off into the bay.
The diel-vertical distribution and characteristics of pre-spawning aggregations of pollock (Pollachius virens) as inferred from hydroacoustic observations: the implications for survey design
Authors: Neilson John D , Clark Donald , Melvin Gary D , Perley Peter , Stevens Chris
Published: July 2003

The characteristics of pollock (the synonymous European common name is saithe) pre-spawning aggregations were described at two locations with contrasting bathymetric features on the Scotian Shelf, off the Canadian Maritimes. The data were collected using a split-beam echosounder onboard a research vessel, augmented with periodic, bottom-trawl samples. Pollock form aggregations each fall that persist at the same location over time. Such aggregations appeared to be associated with spawning. Hydroacoustic information indicates that pollock become more densely aggregated at night. This could reflect movement away from the study area during the day, or changes in the proportion of pollock in the acoustic dead zone over the 24-h period. The hydroacoustic information indicates that while pollock can occur up to 30 m off bottom, the greatest proportion remains within 1–5 m off bottom during both day and night. The length composition of the pollock aggregations differed between the two sites, with larger fish found at the site further offshore. Within an aggregation, there was spatial heterogeneity with respect to fish size, with larger fish found primarily within the core area of aggregation as shown by the hydroacoustics. An appropriate survey design for obtaining an index of abundance for pollock would reflect both the contagious (patchy) distribution as they prepare to spawn, and the diel differences in the availability of the fish to the hydroacoustic-sampling gear.
Modelling stochastic fish stock dynamics using Markov Chain Monte Carlo
Authors: Lewy P. , Nielsen A.
Published: July 2003

A new age-structured stock dynamics approach including stochastic survival and recruitment processes is developed and implemented. The model is able to analyse detailed sources of information used in standard age-based fish stock assessment such as catch-at-age and effort data from commercial fleets and research surveys. The stock numbers are treated as unobserved variables subject to process errors while the catches are observed variables subject to both sampling and process errors. Results obtained for North Sea plaice using Markov Chain Monte Carlo methods indicate that the process error by far accounts for most of the variation compared to sampling error. Comparison with results from a simpler separable model indicates that the new model provides more precise estimates with fewer parameters.
Demersal assemblages and depth distribution of elasmobranchs from the continental shelf and slope off the Balearic Islands (western Mediterranean)
Authors: Massutí Enric , Moranta Joan
Published: July 2003

The analysis of 131 hauls from four bottom trawl fishing surveys carried out between depths of 46 and 1713 m in two different areas off the Balearic Islands yielded a total of 23 elasmobranch species belonging to eight families. Cluster analysis and multidimensional scaling (MDS) ordination were applied to detect zonation patterns and some ecological parameters (e.g. species richness, abundance and biomass, mean weight, diversity and evenness) were calculated for each assemblage. For each area, analysis of similitude (ANOSIM) and similarity percentage analysis (SIMPER) were also applied to detect differences between seasons and depths. For the most important species (Galeus melastomus, Scyliorhinus canicula, Centroscymnus coelolepis, Etmopterus spinax, Squalus blainvillei, Raja naevus, Raja asterias, Raja clavata, Raja miraletus and Raja oxyrhinchus), abundance and size distributions were analysed by depth.
Spatial dynamics of a nearshore, micronekton sound-scattering layer
Authors: Benoit-Bird Kelly J , Au Whitlow W.L
Published: July 2003

In the Hawaiian Islands, there is a distinct resident community of micronekton, distributed along a narrow band where the upper underwater slopes of the islands meet the oceanic, mesopelagic environment. This mesopelagic boundary community serves as an important food resource to many animals. The goal of this work was to examine spatial heterogeneity of the Hawaiian mesopelagic boundary biomass at a range of scales, in the context of its diel vertical and horizontal migrations. A modified echosounder was used to sample the coasts of three Hawaiian Islands, permitting a range of scales from several meters to several kilometers to be assessed rapidly. The Hawaiian mesopelagic boundary community fits the hierarchical model of patch structure with patches within patches that are part of a larger-scale matrix of patches. Large differences in the overall distribution patterns of the mesopelagic boundary community exist along with a wide range of overall mesopelagic-animal densities. High animal-density locations have boundary-community layers with a large (kilometers) horizontal extent, and low animal-density locations have small (tens of meters), discrete patches. Higher animal-density locations are also more complex than low-density sites, with more levels of patchiness within the same range of spatial scales. Both time of day and distance from shore significantly affected the geometric and density characteristics as well as the distribution of aggregations within the boundary layer. Horizontal and vertical structures of the mesopelagic boundary community are also coupled. In high-density sites, there is strong vertical layering in acoustic-scattering strength while in low-density sites vertical acoustic structure is absent. The differences observed in the distribution of the mesopelagic boundary community at different levels of overall mesopelagic-animal density suggest biological forcing as the dominant mechanism. A description of heterogeneity in the mesopelagic boundary community in Hawaii is the first step in understanding its importance to both neritic and oceanic ecosystems and its potential for linking these two systems.