Showing papers by "University of Windsor published in 2005"

Flexible and reconfigurable manufacturing systems paradigms

Abstract: Reconfigurable Manufacturing System (RMS) is a new manufacturing systems paradigm that aims at achieving cost-effective and rapid system changes, as needed and when needed, by incorporating principles of modularity, integrability, flexibility, scalability, convertibility, and diagnosability. RMS promises customized flexibility on demand in a short time, while Flexible Manufacturing Systems (FMSs) provides generalized flexibility designed for the anticipated variations and built-in a priori. The characteristics of the two paradigms are outlined and compared. The concept of manufacturing system life cycle is presented. The main types of flexibility in manufacturing systems are discussed and contrasted with the various reconfiguration aspects including hard (physical) and soft (logical) reconfiguration. The types of changeability and transformability of manufacturing systems, their components as well as factories, are presented along with their enablers and compared with flexibility and reconfigurability. The importance of having harmonized human-machine manufacturing systems is highlighted and the role of people in the various manufacturing paradigms and how this varies in pursuit of productivity are illustrated. Finally, the industrial and research challenges presented by these manufacturing paradigms are discussed.

Critical science gaps impede use of no-take fishery reserves

Abstract: As well as serving valuable biodiversity conservation roles, functioning no-take fishery reserves protect a portion of the fishery stock as insurance against future overfishing. So long as there is adequate compliance by the fishing community, it is likely that they will also sustain and even enhance fishery yields in the surrounding area. However, there are significant gaps in scientific knowledge that must be filled if no-take reserves are to be used effectively as fishery management tools. Unfortunately, these gaps are being glossed over by some uncritical advocacy. Here, we review the science, identify the most crucial gaps, and suggest ways to fill them, so that a promising management tool can help meet the growing challenges faced by coastal marine fisheries.

Handling missing data in self‐report measures

Abstract: Self-report measures are extensively used in nursing research. Data derived from such reports can be compromised by the problem of missing data. To help ensure accurate parameter estimates and valid research results, the problem of missing data needs to be appropriately addressed. However, a review of nursing research literature revealed that issues such as the extent and pattern of missingness, and the approach used to handle missing data are seldom reported. The purpose of this article is to provide researchers with a conceptual overview of the issues associated with missing data, procedures used in determining the pattern of missingness, and techniques for handling missing data. The article also highlights the advantages and disadvantages of these techniques, and makes distinctions between data that are missing at the item versus variable levels. Missing data handling techniques addressed in this article include deletion approaches, mean substitution, regression-based imputation, hot-deck imputation, multiple imputation, and maximum likelihood imputation.

Geochemistry of Neoarchean (ca. 2.55–2.50 Ga) volcanic and ophiolitic rocks in the Wutaishan greenstone belt, central orogenic belt, North China craton: Implications for geodynamic setting and continental growth

Abstract: Geological investigation of the Neoarchean (2.55–2.50 Ga) Wutaishan greenstone belt in the central orogenic belt of the North China craton has provided new information on the geodynamic origin of this belt and its mineral deposits. Structural, geochronological, and geochemical characteristics of the Wutaishan greenstone belt suggest that it formed in a forearc tectonic environment at ca. 2.55 Ga and accreted to the Eastern continental block at ca. 2.50 Ga. A ridge subduction model is proposed to explain several unique geological features of the Wutaishan greenstone belt, such as the generation of dunites and chromitite-hosting harzburgites with U-shaped rare earth element (REE) patterns, formation of volcanogenic massive sulphides (VMS) and banded iron formations (BIF), extrusion of mafic to felsic volcanic rocks, and intrusion of tonalite-trondhjemite-granodiorite plutons (TTG). Anomalously high geothermal gradients in the subarc mantle-wedge beneath the Wutaishan forearc may have increased its buoyancy, resulting in its accretion to the continental crust. We propose that ridge subduction also played an important role in the growth of Archean continental crust. In this model, the origin of Archean TTG is genetically linked to eclogites through partial melting of accreted and/or underplated oceanic plateaus and normal oceanic crust under amphibolite to eclogite metamorphic conditions by upwelling of an anomalously hot asthenospheric mantle window resulting from ridge subduction. TTG suites intruding Archean accretionary complexes formed the nuclei of intra-oceanic island arcs; subsequent juxtaposition of these arcs resulted in the lateral growth of Archean continental crust.

Actinyl Peroxide Nanospheres

Abstract: [*] Prof. P. C. Burns, K.-A. Kubatko, G. SigmonDepartment of Civil Engineering and Geological SciencesUniversity of Notre Dame156 Fitzpatrick Hall, Notre Dame, IN 46556 (USA)Fax: ( +1)574-631-9236E-mail: pburns@nd.eduProf.Dr. B. J. Fryer, J. E. GagnonGreat Lakes Institute for Environmental ResearchUniversity of WindsorWindsor, Ontario N9B 3P4 (Canada)Dr. M. R. Antonio, Dr. L. SoderholmChemistry DivisionArgonne National LaboratoryArgonne, IL 60439 (USA)[**] Thisresearch was supportedat the Universityof Notre Dameby theEnvironmental Management Science Program of the Office ofScience, US Department of Energy (DE-FG07-97ER14820), and theNational Science Foundation Environmental Molecular ScienceInstitute at the University of Notre Dame (EAR02-21966). Thisresearch was supported at Argonne National Laboratory by the USDepartmentofEnergyOfficeofBasicEnergySciences(DOE/BES)–Chemical Sciences Division and by the Material Sciences Divisionfor the Advanced Photon Source studies under contract number W-31-109-ENG-38.

Invasion risks posed by the aquarium trade and live fish markets on the Laurentian Great Lakes

Abstract: International trade is an important mechanism for global non-indigenous species introductions, which have had profound impacts on the biodiversity of aquatic ecosystems including the Laurentian Great Lakes. The best-documented vector by which non-indigenous species have entered the Great Lakes is ballast water discharged by transoceanic ships. A variety of potential alternative vectors exist, including the intentional release of aquarium or food organisms. To assess whether these vectors pose a significant invasion risk for the Great Lakes, we surveyed fish sold live in markets and fish, mollusks and macrophytes sold in pet and aquarium stores within the Great Lakes watershed. We evaluated invasion risk using information on species’ thermal tolerance, history of invasion elsewhere, and potential propagule loads as indicated by frequency of occurrence in shops. Our research suggests that both the aquarium industry and live fish markets represent potential sources of future invaders to the Great Lakes, including several aquarium fishes and macrophytes, as well as Asian carp species sold in fish markets. Currently, few regulatory mechanisms exist to control these potential vectors.

Plk4 haploinsufficiency causes mitotic infidelity and carcinogenesis.

Abstract: The polo-like kinase Plk4 (also called Sak) is required for late mitotic progression, cell survival and postgastrulation embryonic development. Here we identified a phenotype resulting from Plk4 haploinsufficiency in Plk4 heterozygous cells and mice. Plk4+/- embryonic fibroblasts had increased centrosomal amplification, multipolar spindle formation and aneuploidy compared with wild-type cells. The incidence of spontaneous liver and lung cancers was approximately 15 times high in elderly Plk4+/- mice than in Plk4+/+ littermates. Using the in vivo model of partial hepatectomy to induce synchronous cell cycle entry, we determined that the precise regulation of cyclins D1, E and B1 and of Cdk1 was impaired in Plk4+/- regenerating liver, and p53 activation and p21 and BubR1 expression were suppressed. These defects were associated with progressive cell cycle delays, increased spindle irregularities and accelerated hepatocellular carcinogenesis in Plk4+/- mice. Loss of heterozygosity occurs frequently (approximately 60%) at polymorphic markers adjacent to the PLK4 locus in human hepatoma. Reduced Plk4 gene dosage increases the probability of mitotic errors and cancer development.

Polybrominated Diphenyl Ethers and Hydroxylated and Methoxylated Brominated and Chlorinated Analogues in the Plasma of Fish from the Detroit River

Abstract: Novel classes and congeners of contaminant residues that are structurally analogous to polybrominated diphenyl ether (PBDE) flame retardants were assessed in the plasma of seven benthic- and six pelagic-feeding fish species from the highly contaminated Detroit River corridor, namely, hydroxylated-PBDEs (OH-PBDEs), methoxylated-PBDEs (MeO-PBDEs), and the antimicrobial OH-trichlorodiphenyl ether, triclosan, and its methylated (MeO) triclosan analogue. In all samples sigmaPBDE concentrations were comprised mainly of BDE47, BDE99, and BDE100 (>85%) and ranged from 155 pg/g wet weight (ww) to 21 069 pg/g ww. Of the 14 OH-PBDE congeners assessed, as many as 10 congeners were identified, although profiles were generally dominated by 6-OH-BDE47 with lesser amounts of 2'-OH-BDE68, 4'-OH-BDE49, and 4-OH-BDE42. sigmaOH-PBDE concentrations ranged from 2.7 to 198 pg/g ww, with sigmaPBDE to sigmaOH-PBDE concentration ratios ranging from 0.0005 to 0.02. OH-PBDEs are likely derived in these freshwater species as metabolites of precursor PBDEs and are subsequently retained in the blood, for example, 6-OH-BDE47, 4'-OH-BDE49, and 4-OH-BDE42 could be derived from BDE47. Portions of concentrations of the OH-PBDEs may also be of alternate origins and are accumulated and retained in these fish. In all samples, the 14 MeO-PBDEs monitored were below detection ( 10 000 pg/g ww and is clearly a bioaccumulative halogenated phenolic compound in these fish. MeO-triclosan concentrations were considerably lower. In addition to emerging classes of brominated contaminant such as PBDEs, whether of metabolic or anthropogenic origin, fish collected from the Detroit River are exposed to a complex profile of PBDE-like organohalogens.

The effect of music listening on work performance

Abstract: This study measured the effect of music listening on state positive affect, work quality and time-on-task of computer information systems developers. Effects of music on work performance, in this c...

Diversity in the olfactory epithelium of bony fishes : Development, lamellar arrangement, sensory neuron cell types and transduction components

Abstract: In this study we use a taxon-based approach to examine previous, as well as new findings on several topics pertaining to the peripheral olfactory components in teleost fishes. These topics comprise (1) the gross anatomy of the peripheral olfactory organ, including olfactory sensory neuron subtypes and their functional parameters, (2) the ultrastructure of the olfactory epithelium, and (3) recent findings regarding the development of the nasal cavity and the olfactory epithelium. The teleosts are living ray-finned fish, and include descendants of early-diverging orders (e.g., salmon), specialized descendants (e.g., goldfish and zebrafish), as well as the Acanthopterygii, numerous species with sharp bony rays, including perch, stickleback, bass and tuna. Our survey reveals that the olfactory epithelium lines a multi-lamellar olfactory rosette in many teleosts. In Acanthopterygii, there are also examples of flat, single, double or triple folded olfactory epithelia. Diverse species ventilate the olfactory chamber with a single accessory nasal sac, whereas the presence of two sacs is confined to species within the Acanthopterygii. Recent studies in salmonids and cyprinids have shown that both ciliated olfactory sensory neurons (OSNs) and microvillous OSNs respond to amino acid odorants. Bile acids stimulate ciliated OSNs, and nucleotides activate microvillous OSNs. G-protein coupled odorant receptor molecules (OR-, V1R-, and V2R-types) have been identified in several teleost species. Ciliated OSNs express the G-protein subunit Gαolf/s, which activates cyclic AMP during transduction. Localization of G protein subunits Gα0 and Gαq/11 to microvillous or crypt OSNs, varies among different species. All teleost species appear to have microvillous and ciliated OSNs. The recently discovered crypt OSN is likewise found broadly. There is surprising diversity during ontogeny. In some species, OSNs and supporting cells derive from placodal cells; in others, supporting cells develop from epithelial (skin) cells. In some, epithelial cells covering the developing olfactory epithelium degenerate, in others, these retract. Likewise, there are different mechanisms for nostril formation. We conclude that there is considerable diversity in gross anatomy and development of the peripheral olfactory organ in teleosts, yet conservation of olfactory sensory neuron morphology. There is not sufficient information to draw conclusions regarding the diversity of teleost olfactory receptors or transduction cascades.

Constructing the neoliberal sexual actor: Responsibility and care of the self in the discourse of barebackers

Abstract: This paper analyses on the discourses employed by a subset of gay and bisexual men who no longer practise protected sex more than twenty years into the HIV epidemic. In‐depth interviews with 102 men in Toronto are used to examine the moral reasoning of those for whom the language of barebacking provides a shared set of accounts and tacit understandings for unprotected sex. Barebacking raises some of the central issues of contemporary theory around risk, responsibility, and ethics, and poses new challenges to HIV prevention policy as barebacking discourses adapt some of the major tenets of neoliberal ideology by combining notions of informed consent, contractual interaction, free market choice, and responsibility in new ways. At the same time, interviews with barebackers reveal competing and contradictory discourses that suggest new avenues of engagement for HIV prevention initiatives.

Critical swimming speeds of late-stage coral reef fish larvae: variation within species, among species and between locations

Abstract: The swimming abilities of larval fishes are important for their survival, potentially affecting their ability to avoid predators, obtain food and control dispersal patterns. Near settlement swimming abilities may also influence spatial and temporal patterns of recruitment. We examined Critical speed (U-crit) swimming ability in late stage larvae of 89 species of coral reef fishes from the Great Barrier Reef and the Caribbean. Coefficients of variation in U-crit calculated at the individual level were high (28.4%), and this was not explained by differences in size or condition factor of these same larvae. Among species U-crit ranged from 5.5 cm s−1 to 100.8 cm s−1 (mean=37.3 cm s−1), with 95% of species able to swim faster than the average current speed around Lizard Island, suggesting that most species should be capable of influencing their spatial and temporal patterns of settlement. Inter-specific differences in swimming ability (at both the family and species levels) were significantly correlated with size and larval morphology. Correlations were found between swimming performance and propulsive area, fineness ratio and aspect ratio, and these morphological parameters may prove useful for predicting swimming ability in other taxa. Overall, the swimming speeds of larvae from the same families at the two locations were relatively similar, although the Lutjanidae and Acanthuridae from the Caribbean were significantly slower than those from the great barrier reef. Differences in swimming speed and body form among late stage larvae suggests that they will respond differently to factors influencing survival and transport during their pelagic phase, as well as habitat use following settlement.

AIDS optimism, condom fatigue, or self-esteem? Explaining unsafe sex among gay and bisexual men.

Abstract: This study examines leading explanations for unsafe sex in light of in‐depth interviews with 102 high‐risk gay and bisexual men in Toronto to see how well they engage with the social circumstances and reasoning processes of men in their sexual relationships. We argue that there is an inadequate fit between some of the leading explanations and the discursive accounts provided by high risk men themselves. Their accounts focus on unsafe sex occurring as a resolution to condom and erectile difficulties, through momentary lapses and trade offs, out of personal turmoil and depression, and as a byproduct of strategies of disclosure and intuiting safety. This study examines, in particular, the circumstances and rationales associated with men who identify their practices as “barebacking.” We conclude with recommendations for communicating prevention messages to those most at risk based on the self‐understandings of gay and bisexual men who most frequently practice unprotected sex.

The Barbarian's Beverage: A History of Beer in Ancient Europe

Abstract: Comprehensive and detailed, this is the first ever study of ancient beer and its distilling, consumption and characteristics Examining evidence from Greek and Latin authors from 700 BC to AD 900, the book demonstrates the important technological as well as ideological contributions the Europeans made to beer throughout the ages. The study is supported by textual and archaeological evidence and gives a fresh and fascinating insight into an aspect of ancient life that has fed through to modern society and which stands today as one of the world’s most popular beverages. Students of ancient history, classical studies and the history of food and drink will find this an useful and enjoyable read.

Pancratistatin: A natural anti-cancer compound that targets mitochondria specifically in cancer cells to induce apoptosis

Abstract: The major hurdle in the fight against cancer is the non-specific nature of current treatments. The search for specific drugs that are non-cytotoxic to normal cells and can effectively target cancer cells has lead some researchers to investigate the potential anti-cancer activity of natural compounds. Some natural compounds, such as Taxol, have been shown to possess some anti-cancer potential. Pancratistatin (PST) is a natural compound that was isolated from the spider lily Pancratium littorale and shown to exhibit antineoplastic activity. The specificity of PST to cancer cells and the mechanism of PST's action remain unknown. This study provides a detailed look at the effect of PST treatment on cancerous and normal cells. Our results indicate that PST induced apoptosis selectively in cancer cells and that the mitochondria may be the site of action of PST in cancer cells. A biochemical target available specifically in cancer cells may lead to the development of new and more effective cancer fighting agents.

Mining Web Log Sequential Patterns with Position Coded Pre-Order Linked WAP-Tree

Abstract: Sequential mining is the process of applying data mining techniques to a sequential database for the purposes of discovering the correlation relationships that exist among an ordered list of events. An important application of sequential mining techniques is web usage mining, for mining web log accesses, where the sequences of web page accesses made by different web users over a period of time, through a server, are recorded. Web access pattern tree (WAP-tree) mining is a sequential pattern mining technique for web log access sequences, which first stores the original web access sequence database on a prefix tree, similar to the frequent pattern tree (FP-tree) for storing non-sequential data. WAP-tree algorithm then, mines the frequent sequences from the WAP-tree by recursively re-constructing intermediate trees, starting with suffix sequences and ending with prefix sequences. This paper proposes a more efficient approach for using the WAP-tree to mine frequent sequences, which totally eliminates the need to engage in numerous re-construction of intermediate WAP-trees during mining. The proposed algorithm builds the frequent header node links of the original WAP-tree in a pre-order fashion and uses the position code of each node to identify the ancestor/descendant relationships between nodes of the tree. It then, finds each frequent sequential pattern, through progressive prefix sequence search, starting with its first prefix subsequence event. Experiments show huge performance gain over the WAP-tree technique.