bluuebunny/crossref_metadata_2025 huggingface dataset:
Macro-level collision prediction models for evaluating neighbourhood traffic safety
Authors: Lovegrove Gordon R , Sayed Tarek
Published: August 2006

This study describes the development of macro-level (i.e., neighbourhood or traffic zone level) collision prediction models using data from 577 neighbourhoods across the Greater Vancouver Regional District. The objective is to provide a safety planning decision-support tool that facilitates a proactive approach to community planning which addresses road safety before problems emerge. The models are developed using the generalized linear regression modelling (GLM) technique assuming a negative binomial error structure. The resulting models relate traffic collisions to neighbourhood characteristics such as traffic volume, demographics, network shape, and transportation demand management. Several models are presented for total or severe collisions in rural or urban zones using measured and (or) modelled data. It is hoped that quantifying a predictive traffic safety – neighbourhood planning relationship will facilitate improved decisions by community planners and engineers and, ultimately, facilitate improved neighbourhood traffic safety for residents and other road users.Key words: neighbourhood safety, macro-level collision prediction models, road safety, safety planning, transportation demand management, sociodemographic, generalized linear regression modelling.
Testing of light-gauge steel-frame - wood structural panel shear walls
Authors: Branston A E , Chen C Y , Boudreault F A , Rogers C A
Published: August 2006

At present, no Canadian document is available with which engineers can design light-gauge steel-frame – wood structural panel shear walls that are relied upon to resist lateral in-plane loading (earthquake and wind). For this reason, a research project was initiated with the overall goal of developing a shear wall design method that could be used in conjunction with the 2005 National Building Code of Canada. The initial phase of the project was to conduct an experimental study to provide information on the response of single-storey shear walls. An extensive program of tests was completed on walls composed of 1.12 mm thick 230 MPa grade steel framing sheathed with 12.5 mm Douglas-fir plywood, Canadian softwood plywood, or 11 mm oriented strand board wood structural panels. Various wall lengths and connection patterns were incorporated into the program of monotonic and reversed cyclic tests. The scope of testing was selected such that it added to the North American database of information for steel-frame – wood structural panel shear walls. Information on the test program and the general results are provided in this paper.Key words: shear wall, light-gauge steel, wood structural panel, earthquake, wind.
Behaviour of light-gauge steel-frame – wood structural panel shear walls
Authors: Chen C Y , Boudreault F A , Branston A E , Rogers C A
Published: August 2006

The second phase of the research project to develop a shear wall design method that could be used in conjunction with the 2005 National Building Code of Canada involved evaluation of the performance characteristics of the tested steel-frame – wood structural panel shear walls. A nonlinear and pinched resistance versus deflection hysteretic behaviour was exhibited, although in most cases the walls could sustain large inelastic deformation cycles with limited strength degradation. A significant amount of energy could be dissipated under reversed cyclic loading. Walls 1220 mm and 2440 mm in length were able to develop their maximum capacity at similar displacement levels; however, the 610 mm long walls required significantly larger displacements prior to reaching their ultimate shear resistance. The performance of the walls was directly linked to the behaviour of the sheathing-to-framing screw connections, except in one case in which local buckling of the chord studs controlled the ultimate shear resistance. Given the behaviour observed during testing, this type of wall construction can be relied on to resist lateral loading, including earthquake effects in the inelastic range, assuming the designer ensures that failure of the wall is limited to the sheathing-to-framing connections.Key words: shear wall, light-gauge steel, wood structural panel, earthquake, wind.
Investigations on the performance of a liquid column damper (LCD) with different orifice diameter ratios
Authors: Colwell Shane , Basu Biswajit
Published: August 2006

An experimental investigation was carried out of the influence of the orifice in a liquid column damper (LCD) in changing the vibration-suppression characteristics of a structure subjected to earthquake excitations. An analytical solution has been presented for the transfer function of the maximum displacement of the structure, modelled as a single-degree-of-freedom (SDOF) system, with applied harmonic base motion. A standard equivalent linearization technique has been employed to cater for the nonlinear damping of the orifice in the LCD. The experimental results are validated. The performance of the orifice has been evaluated through the experimental testing of various base displacement amplitudes and frequencies. An SDOF system was built on a platform capable of generating sinusoidal excitations of predefined input frequencies and displacements. An LCD was also built with the ability to change its orifice size. Both theoretical and experimental results are plotted to examine and compare the performance of the LCD. It was observed that structural response may increase at off-resonant frequencies due to inappropriate selection of orifice ratios in some cases.Key words: liquid column damper, head loss, orifice, vibration control, earthquake protection.
How do contractors evaluate company competitiveness and market attractiveness? The case of Toronto contractors
Authors: El-Diraby T E , Costa J , Singh S
Published: August 2006

The Canadian construction industry has sustained a healthy growth rate over the last 10 years. This could make the Canadian market attractive to foreign competitors. Moreover, Canadian companies possess enough expertise and resources to be able to effectively compete in the global market. This highlights the increased importance of developing marketing strategies for Canadian companies. This research study provides an understanding of how Toronto construction companies evaluate market attractiveness and company competitiveness. Such evaluation is the first step towards building effective marketing strategies. The research included an analysis of the main indicators of the Toronto market over the last 10 years and one-on-one interviews with 39 experts. The research deployed the analytical hierarchy process to identify the most important factors that can be used for measuring company competitiveness and market attractiveness. The most important factors that influence company competitiveness include customer satisfaction, cost efficiency, and safety record. Factors with the highest impact on market attractiveness are sustainable profitability (return on investment), supply of finance, and overall economic conditions.Key words: construction marketing, company competitiveness, market attractiveness, strategic planning, analytical hierarchy process.
Removal of phenol from aqueous solution by adsorption
Authors: Kaleta Jadwiga
Published: August 2006

The paper presents the results of laboratory tests concerning the possibility of utilizing activated carbon produced in Poland and nonconventional adsorbents, such as modified Clarion clay and clinoptylolite, for removing organic phenol from water. The effect of contact time and pH of the model solution on the adsorption process was assessed during tests conducted under static conditions. A contact time of 30 min was considered as optimum, and the highest efficiency of the adsorption process was achieved using a pH of 7.0. Adsorbent doses affected the course and effectiveness of the adsorption process. The adsorption processes were best described by the Freundlich isotherm. On the basis of the isotherms, the adsorptive capacity of tested adsorbents was calculated. Activated carbon had an adsorptive capacity of 13.22 g/kg, modified Clarion clay 1.24 g/kg, and clinoptylolite 0.23 g/kg. The through-flow conditions were achieved by column filtration. On the basis of breakthrough curves, the adsorptive capacities were higher than those determined through static conditions, namely 61.23, 23.56, and 2.99 g/kg for activated carbon, modified Clarion clay, and clinoptylolite, respectively. Despite their inferior adsorptive characteristics, the modified Clarion clay and clinoptylolite may be applied in filtration systems prior to filters with activated carbon.Key words: phenol, adsorption process, activated carbon, modified clay, clinoptylolite.
Factors regulating lactoferrin gene expressionThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: Teng Christina T.
Published: August 2006

Regulation of gene expression by nuclear receptors and transcription factors involves the concerted action of multiple proteins. The process of transcriptional activation involves chromatin modification, nuclear receptor or transcription factor binding to the response element of the promoter, and coregulator recruitment. Despite advances in knowledge pertaining to the molecular mechanisms of gene regulation overall, there is very limited information available on the molecular mechanism of lactoferrin gene regulation. This review will outline novel information relating to general gene regulation and will discuss the current understanding of the regulation of lactoferrin gene expression by nuclear receptors and transcription factors.
Single nucleotide polymorphisms (SNPs) in human lactoferrin geneThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function and Applications, and has undergone the Journal's usual peer review process.
Authors: Teng Christina T. , Gladwell Wesley
Published: August 2006

The lactoferrin protein possesses antimicrobial and antiviral activities. It is also involved in the modulation of the immune response. In a normal healthy individual, lactoferrin plays a role in the front-line host defense against infection and in immune and inflammatory responses. Whether genomic variations, such as single nucleotide polymorphisms (SNPs), have an effect on the structure and function of lactoferrin protein and whether these variations contribute to the different susceptibility of individuals in response to environmental insults are interesting health-related issues. In this study, the lactoferrin gene was resequenced as part of the Environmental Genome Project of the National Institute of Environmental Health Sciences, which operates within the National Institutes of Health. Ninety-one healthy donors of different ethnicities were used to establish common SNPs in the exons of the lactoferrin gene in the general population. The data will serve as a basis from which study the association of lactoferrin polymorphism and disease.
Lactoferrin downregulates pro-inflammatory cytokines upexpressed in intestinal epithelial cells infected with invasive or noninvasive Escherichia coli strainsThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal’s usual peer review process.
Authors: Berlutti Francesca , Schippa Serena , Morea Clara , Sarli Serena , Perfetto Brunella , Donnarumma Giovanna , Valenti Piera
Published: August 2006

Intestinal epithelial cells are able to differentially interact with commensal or pathogenic microorganisms, triggering a physiological or destructive inflammation, respectively. To mimic commensal–enteroinvasive bacteria–host cell interaction, we infected Caco-2 cells with noninvasive Escherichia coli HB101 and with recombinant invasive E. coli HB101(pRI203). Using DNA microarray mRNA profiling and ELISA assays, we studied the expression of several cytokine and cytokine-related genes in infected Caco-2 cells in the absence or presence of bovine lactoferrin (bLf). Infection of Caco-2 cells with the noninvasive strain induced a slight increase in the expression of interleukin 8 (IL-8), whereas infection with invasive E. coli HB101(pRI203) induced a significant increase in the expression of IL-8 as well as other pro-inflammatory cytokines. The addition of bLf, in native- or holo-form, did not influence expression of cytokine genes by uninfected Caco-2 cells, but it decreased expression of IL-8 by cells infected with E.coli HB101. Moreover, except for IL-8, bLfs dramatically downregulated pro-inflammatory cytokines upexpressed by Caco-2 cells infected with the invasive strain. Although IL-8 was decreased by bLfs, it remained upregulated, suggesting that it could be a signal of persistence of intracellular bacteria. The bLf ability to reduce expression of some pro-inflammatory cytokines, which appears independent of its iron saturation, might represent an important natural mechanism in regulating epithelial cell responses to pathogenic bacteria and in limiting cell damage and the spread of infections.
Lactoferrin promotes collagen gel contractile activity of fibroblasts mediated by lipoprotein receptorsThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: Takayama Yoshiharu , Takezawa Toshiaki
Published: August 2006

Lactoferrin is an iron-binding glycoprotein that belongs to the transferrin family. Recent studies in vitro and in vivo suggest that lactoferrin is a potential therapeutic agent for wound healing. We have shown that both bovine and human lactoferrin enhance the collagen gel contractile activity of WI-38 human fibroblasts. The collagen gel contraction is considered as an in vitro model for reorganization of the collagen matrix during the wound healing process. The elevation of collagen gel contractile activity induced by lactoferrin was accompanied by activation of extracellular-regulated kinase (ERK) 1/2 and myosin light chain kinase (MLCK), and subsequent elevation of myosin light chain (MLC) phosphorylation. The effects of lactoferrin on collagen gel contraction and the activation of the signaling pathway were dependent on the expression of low-density lipoprotein receptor - related protein (LRP) - 1 in the fibroblasts. LRP-1 is known as an endocytosis receptor and is involved in the cellular uptake of diverse ligands, including lactoferrin. In addition, LRP-1 acts as a signaling lactoferrin receptor in mammalian cells by converting the lactoferrin-binding signal into the activation of the intracellular signaling pathway. This property was found to be independent of the endocytic function of LRP-1, as seen in osteoblast-like cells.
Distinct bactericidal activities of bovine lactoferrin peptides LFampin 268–284 and LFampin 265–284: Asp-Leu-Ile makes a differenceThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: van der Kraan Marieke I.A. , Nazmi Kamran , van ’t Hof Wim , Amerongen Arie V. Nieuw , Veerman Enno C.I. , Bolscher Jan G.M.
Published: August 2006

Two lactoferrampin (LFampin) peptides derived from bovine lactoferrin were compared with respect to their bactericidal activities. LFampin 265–284 killed a set of Gram-positive bacteria that were resistant to LFampin 268–284. The presence of265Asp-Leu-267Ile did not simply lead to an overall increased potency, since higher concentrations of LFampin 265–284 than LFampin 268–284 were needed to kill the Gram-negative bacteria that were tested. The Asp-Leu-Ile sequence enhances the propensity of LFampin to adopt an α-helix, as shown by circular dichroism spectroscopy. These results suggest that the helical conformation of the peptide is an important determinant of the susceptibility of Gram-positive bacteria.
Perspectives on interactions between lactoferrin and bacteriaThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: Ling Jessmi M.L. , Schryvers Anthony B.
Published: August 2006

Lactoferrin has long been recognized for its antimicrobial properties, initially attributed primarily to iron sequestration. It has since become apparent that interaction between the host and bacteria is modulated by a complex series of interactions between lactoferrin and bacteria, lactoferrin and bacterial products, and lactoferrin and host cells. The primary focus of this review is the interaction between lactoferrin and bacteria, but interactions with the lactoferrin-derived cationic peptide lactoferricin will also be discussed. We will summarize what is currently known about the interaction between lactoferrin (or lactoferricin) and surface or secreted bacterial components, comment on the potential physiological relevance of the findings, and identify key questions that remain unanswered.
Interactions of lactoferrin with cells involved in immune functionThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: Legrand Dominique , Elass Elisabeth , Carpentier Mathieu , Mazurier Joël
Published: August 2006

The antimicrobial activities of lactoferrin (Lf) depend on its capacity to bind iron and on its direct interaction with the surface of microorganisms. Its protective effect also extends to the regulation of the host response to infections. Depending on the immune status of an individual, Lf can have anti-inflammatory properties that downregulate the immune response and prevent septic shock and damage to tissues. It also acts as a promoter of the activation, differentiation, and (or) proliferation of immune cells. Although most of the anti-inflammatory activities are correlated with the neutralization of proinflammatory molecules by Lf, the promoting activity seems to be related to a direct effect of Lf on immune cells. Although the mechanisms that govern these activities are not clearly defined, and probably differ from cell to cell, several cellular targets and possible mechanisms of action are highlighted. The majority of the molecular targets at the surface of cells are multiligand receptors but, interestingly, most of them have been reported as signaling, endocytosis, and nuclear-targeting molecules. This review focuses on the known and putative mechanisms that allow the immunoregulating effect of Lf in its interactions with immune cells.
Comparison of NMR structures and model-membrane interactions of 15-residue antimicrobial peptides derived from bovine lactoferricinThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: Jing Weiguo , Svendsen John S. , Vogel Hans J.
Published: August 2006

LFB (FKCRRWQWRMKKLGA-HN2) is a 15-residue linear antimicrobial peptide derived from bovine lactoferricin, which has antimicrobial activity similar to that of the intact 25-residue disulfide-cyclized peptide. Previous alanine-scan studies, in which all of the residues in LFB were individually replaced with Ala, showed that the 2 tryptophan (Trp) residues of LFB were crucial to its antimicrobial activity. When either Trp6 or Trp8 was replaced with Ala (LFBA6 and LFBA8, respectively), these 2 peptides were almost devoid of antimicrobial activity. We determined the structures of LFB, LFBA6, and LFBA8 bound to membrane-mimetic SDS micelles using NMR spectroscopy, and studied their interactions with different phospholipid-model membranes. The membrane interactions of LFB exhibited little correlation with its antimicrobial activity, suggesting that the mechanism of action of LFB involves intracellular targets. However, the much higher antimicrobial activity of LFB compared with LFBA6 and LFBA8 might result, in part, from the formation of energetically favorable cation–π interactions observed only in LFB. Information about the importance of Arg and Trp cation–π interactions will provide insight for the future design of potent antimicrobial peptidomimetics.
Effect of lactoferrin on EnteroaggregativeE. coli(EAEC)This paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal’s usual peer review process.
Authors: Ochoa Theresa J. , Brown Eric L. , Guion Chase E. , Chen Jane Z. , McMahon Robert J. , Cleary Thomas G.
Published: August 2006

We previously demonstrated that lactoferrin inhibits adherence of enteropathogenic Escherichia coli to HEp-2 cells and decreases invasiveness of Shigella flexneri in HeLa cells by disruption of the type III secretory system (TTSS) of both enteropathogens. To determine whether these effects were specific to the TTSS, we assessed the activity of bovine lactoferrin on enteroaggregative E. coli (EAEC), enteropathogens whose virulence is not TTSS dependent. Bovine lactoferrin at a concentration of 1.0 and 0.1 mg/mL inhibited EAEC growth. Saturation with iron reversed the bacteriostatic effect. Lactoferrin under nonbacteriostatic conditions decreased EAEC adherence to HEp-2 cells as evaluated by microscopy and CFUs; this effect was not iron dependent. Lactoferrin inhibited EAEC biofilm formation and increased autoagglutination. Lactoferrin blocks EAEC adherence by inducing release and degradation of aggregative adherence fimbria, a key element of EAEC pathogenesis. We hypothesized that lactoferrin binding to lipid A of lipopolysaccharide disrupts the virulence proteins anchored to the bacterial outermembrane. These data suggest that the effect of lactoferrin on surface proteins is not restricted to organisms having a TTSS.
Bovine lactoferrin: benefits and mechanism of action against infectionsThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Functions, and Applications, and has undergone the Journal's usual peer review process.
Authors: Yamauchi Koji , Wakabayashi Hiroyuki , Shin Kouichirou , Takase Mitsunori
Published: August 2006

Ingestion of bovine lactoferrin (bLF) has been reported to show anti-infective, anti-cancer, and anti-inflammatory effects. In particular, it has become evident that oral bLF had a beneficial effect on infections of both digestive and nondigestive tract tissue in various animal models. Furthermore, the effects of bLF have been indicated in clinical studies on patients with Helicobacter pylori infection, chronic hepatitis C, tinea pedis, and other diseases. Immunomodulation in the intestine and systemic sites has been suggested to mediate the protective effects of oral bLF against infection. Recently, we demonstrated the beneficial effects of oral bLF in influenza virus infected mice. BLF administration reduced the lung consolidation score and the number of infiltrating leukocytes in bronchoalveolar lavage fluid. We also investigated the effect of oral bLF on the transcription of genes related to immunity in the small intestine of mice using the quantitative RT-PCR method. We found that intake of bLF increased the expression of IL-12p40, IFN-β, and NOD2. Thus, oral bLF activates the transcription of important immune-related genes in the small intestine, and such transcriptional activation may promote systemic host immunity.
Influences of orally administered lactoferrin on IFN-γ and IL-10 production by intestinal intraepithelial lymphocytes and mesenteric lymph-node cellsThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: Takakura Natsuko , Wakabayashi Hiroyuki , Yamauchi Koji , Takase Mitsunori
Published: August 2006

Intestinal mucosal immunity plays an important role in mucosal and systemic immune responses. We investigated the influences of orally administered bovine lactoferrin (LF) on cytokine production by intestinal intraepithelial lymphocytes (IEL) and mesenteric lymph-node (MLN) cells, especially T cells. Bovine LF or bovine serum albumin (control) was administered to mice once daily for 3 d. After 24 h from the last administration, IEL of the jejunum and ileum and MLN cells were isolated. These cells were cultured with and without the anti-T-cell-receptor antibody, and then the culture supernatants were assayed for cytokines with ELISA. Oral LF did not affect the ratio of T-cell subpopulations in IEL and MLN; however, LF enhanced both interferon (IFN)-γ and interleukin (IL)-10 production by unstimulated IEL and by IEL stimulated with the αβ T-cell receptor but not with the γδ T-cell receptor. LF also enhanced both IFN-γ and IL-10 production by stimulated and unstimulated MLN cells. The production level of IFN-γ by MLN cells was correlated with that of IL-10. These results suggest that oral LF enhances the production of both Th1-type and Th2/Tr-type cytokines in the small intestine of healthy animals.
Lactoferrin and bone; structure–activity relationshipsThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: Cornish J. , Palmano K. , Callon K.E. , Watson M. , Lin J.M. , Valenti P. , Naot D. , Grey A.B. , Reid I.R.
Published: August 2006

The maintenance of the mechanical integrity of the skeleton depends on bone remodeling, the well-coordinated balance between bone formation by osteoblasts and bone resorption by osteoclasts. The coupled action of osteoblasts and osteoclasts is regulated by the action of many local and circulating hormones and factors as well as central regulation by a neurological mechanism. We have previously shown that lactoferrin can promote bone growth. At physiological concentrations, lactoferrin potently stimulates the proliferation and differentiation of primary osteoblasts and acts as a survival factor. Lactoferrin also affects osteoclasts, potently inhibiting their formation. In vivo, local injection of lactoferrin results in substantial increases in bone formation and bone area. In a critical bone-defect model in vivo, lactoferrin was also seen to promote bone growth. The mitogenic effect of lactoferrin in osteoblast-like cells is mediated mainly through low-density lipoprotein-receptor protein-1 (LRP1), a member of the low-density lipoprotein-receptor-related proteins that are primarily known as endocytic receptors; however, LRP1 is not necessary for the anti-apoptotic actions of lactoferrin. Lactoferrin also induces the activation of p42/44 mitogen-activated protein kinase (MAPK) signalling and the PI3-kinase-dependent phosphorylation of Akt in osteoblasts. In this study, we examined other properties of lactoferrin and the way they affect osteogenic activity. The degree of glycosylation, iron-binding, and the structure–activity relationships indicate that lactoferrin maintains osteogenic activity in deglycosylated, holo, and apo forms, and in with various small fragments of the molecule. These data suggest that lactoferrin signals through more than 1 membrane-bound receptor to produce its anabolic skeletal effects, and that it signals through diverse pathways. We conclude that lactoferrin might have a physiological role in bone growth and healing and a potential therapeutic role as an anabolic factor in osteoporosis.
Regulation of physiological and pathological Th1 and Th2 responses by lactoferrinThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: Fischer Romy , Debbabi Hajer , Dubarry Michel , Boyaka Prosper , Tomé Daniel
Published: August 2006

In recent years, Lf has gained increasing interest as a result of its protective effects against a variety of diseases. While iron binding and interactions with mammalian receptors and microbial components are the best described mechanisms of action, recent studies have provided evidence that Lf properties may be related to immunoregulatory effects on Th1/Th2 cell activities. In vitro and in vivo experiments show that Lf is able to stimulate the differentiation of T cells from their immature precursors through the induction of the CD4 antigen. Studies performed under nonpathogenic conditions have shown distinct results with regard to the ability of Lf to support the proliferation and differentiation of Th cells into the Th1 or the Th2 phenotype. In addition, Lf plays different roles in diseases by affecting the Th1/Th2 cytokine balance in a manner dependent on the host’s immune status. Thus, Lf could cause a Th1 polarization in diseases in which the ability to control infection or tumor relies on a strong Th1 response. Lf may also reduce the Th1 component to limit excessive inflammatory responses. Finally, Lf may provide protection against Th1- or Th2-induced diseases, such as autoimmune or allergic diseases, through correction of the Th1/Th2 imbalance.
Ontogenic changes in lactoferrin receptor and DMT1 in mouse small intestine: implications for iron absorption during early lifeThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: Lopez Veronica , Suzuki Yasushi A. , Lönnerdal Bo
Published: August 2006

It has been proposed that lactoferrin receptor (LfR) may be involved in intestinal iron transport during early life. However, it is known that iron homeostasis is regulated by divalent metal transporter 1 (DMT1; Nramp2/DCT1) in the adult small intestine. To address the hypothesis that LfR may play a role as an alternative iron transport pathway during early life, we used immunohistochemistry (IHC) to examine the localization of mouse LfR (mLfR) and DMT1. In addition to studying the localization and abundance of LfR and DMT1 on the apical membrane, intestinal brush-border membrane vesicles (BBMV) were isolated during the first 3 postnatal weeks (postnatal day (PD) 0, 5, 10, and 20). We found that mLfR is expressed in fetal mice as early as gestational days (GD) 13.5, 15.5, and 18.5. A 34 kD band for mLfR was detected at PD 0 through PD 20 in total intestine homogenate. However, mLfR protein did not appear in the BBMV preparations until PD 5 and was highly expressed at PD 10. By IHC, DMT1 protein was minimally observed at PD 0 and PD 5, but by PD 10 DMT1 was predominantly localized in the apical membrane of the maturing intestine. BBMV fractionation revealed 50–120 kD protein bands for DMT1. In these BBMV preparations, the apical-membrane-associated 120 kD band for DMT1 increased in abundance with age. However, in the corresponding total homogenates, only the deglycosylated form of DMT1 (50 kD) was identified. These results indicate that DMT1 is mislocalized during late gestation, minimally expressed during early life, and predominantly expressed in its deglycosylated form until PD 20. The immunolocalization and abundant protein expression of mLfR suggest that accrual of iron from Lf may be the principal iron uptake pathway at this age. In conclusion, our findings support the notion that until the development-dependent expression of DMT1 in the intestine is induced, mLfR may serve as an alternative iron uptake pathway.
Microbicidal action of lactoferrin and lactoferricin and their synergistic effect with metronidazole inEntamoeba histolyticaThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.
Authors: León-Sicairos Nidia , Reyes-López Magda , Ordaz-Pichardo Cynthia , de la Garza Mireya
Published: August 2006

Lactoferrin (Lf), in its iron-free form, has been shown to inhibit the growth of pathogenic microorganisms. In the light of new agents to control amoebiasis, the microbicidal activity of human and bovine Lf and bovine lactoferricin (bLfcin, fragment 4–14), and of each combined with metronidazole, the main drug used in amoebiasis, was evaluated in trophozoites of Entamoeba histolytica. Both lactoferrins and bLfcin were able to kill amoebas in a concentration-dependent manner. This killing effect was modulated according to the culture age, pH, and temperature. Parasites obtained from the stationary phase were more susceptible to Lf than those from the early exponential phase. The effect of Lf and its derived peptide, bLfcin, was prevented by both Fe2+and Fe3+. However, the divalent cations Mg2+and Ca2+prevented the killing effect of Lf but not of bLfcin. A synergistic amoebicidal effect was found between metronidazole and human Lf, bovine Lf, or bLfcin. These data suggest that Lf and bLfcin might be used in amoebiasis if they are administered with a low dose of metronidazole to diminish the toxicity of this drug. Thus, Lf and bLfcin are therapeutically potential candidates for use as antiamoebics in patients.
Nutrient removal from anaerobically digested cattle manure by struvite precipitation
Authors: Zeng Le , Li Xiaomei
Published: August 2006

This paper studied the removal of nutrients including phosphate, ammonium, and potassium from anaerobically digested and centrifuged manure effluents by struvite precipitation. Due to coexistence of high levels of NH4+ and K+ ions in manure effluents, struvite precipitation should include formation of MgNH4PO4·6H2O (struvite) and MgKPO4·6H2O (K-struvite). Nutrient removal experiments with MgCl2 as the magnesium source were conducted with and without phosphate addition to evaluate the influences of the Mg/PO43– ratio, pH, temperature, PO43–/NH4+ ratio, and reaction time. It was found that the required Mg/PO43– molar ratio was more than 5 times higher than the stoichiometric value of 1 when no phosphate was added. Meanwhile, the ammonium removal efficiency increased with the increase of phosphate addition. However, the ammonium removal from digested manure effluents by struvite precipitation is not highly efficient, as the removal efficiency reached only 56% even at a Mg/PO43–/NH4+ molar ratio of 1.5:1.25:1. Furthermore, the potassium removal efficiency was significantly lower than that of ammonium, and the molar percentage of the removed K+ over the total removed NH4+ and K+ was less than 10%. The composition analysis in the precipitated solids indicated that some phosphate in digested manure effluents be removed as magnesium phosphates other than struvite. In addition, different magnesium salts were tested for struvite precipitation. Their superiority for phosphate removal followed an order of MgCl2 > MgSO4 > MgO > Mg(OH)2 > MgCO3. Key words: phosphate removal, ammonia removal, potassium, struvite precipitation, digested cattle manure, magnesium.
Phosphorus uptake by cattail plants in a laboratory-scale experiment related to constructed treatment wetlands
Authors: Weng S , Putz G , Kells J A
Published: August 2006

This paper describes a laboratory-scale study of phosphorus (P) uptake by broad-leaf cattail plants (Typha latifolia) growing in gravel substrate. The cattails were fed synthetic wastewater at P concentrations representative of primary and secondary municipal sewage effluent. Phosphorus uptake to the upper and lower portions of the cattail plants, adsorption to the gravel substrate, and the pore water concentration were measured over a simulated growing season. The objective was to quantify the mass of phosphorus accumulated in each compartment as the growing season progressed. The experimental results show that the partitioning of P between the upper and lower portions of the plants varied throughout the simulated growing season. At the end of the season uptake by cattails had removed about 40% and 45% of the P mass input under the primary and secondary effluent conditions, respectively. Adsorption of P to the gravel substrate and other fine sediments removed about 43% and 56% of the P mass input under the primary and secondary effluent conditions, respectively. The results provide insight into the potential timing and effectiveness of cattail harvesting for removal of P from constructed treatment wetland systems. Key words: constructed treatment wetland, cattail (Typha latifolia), laboratory-scale study, phosphorus removal, phosphorus uptake, phosphorus adsorption, phosphorus mass balance.
Biological treatment of oily wastewater from gas stations by membrane bioreactor
Authors: Tri P T , Visvanathan C , Jegatheesan V
Published: August 2006

In many Asian countries, rapid industrialization and urbanization has led to an increased number of cars, making wastewater from gas stations an important issue of concern in urban environment. This wastewater is characterized by high concentration of oil–water emulsion, which cannot be effectively removed by a conventional gravity separator. An experimental investigation on the treatability of oily wastewater from gas stations using a membrane bioreactor (MBR) system revealed that MBR system could achieve good removal efficiency with stability against shock loading. Optimum operating conditions were found to be at a hydraulic retention time of 4 h and an oil-loading rate of 1.8 kg oil m–3·d–1. It was anticipated that adding powdered activated carbon (PAC) in the MBR could help to adsorb the oils. However, operating the MBR with only microbial flocs has an advantage over adding PAC particles into the MBR, since the former condition could provide a prolonged cycle of filtration with a relatively lesser increase in transmembrane pressure. Key words: activated sludge process, membrane bioreactor, membrane fouling, oily wastewater, powdered activated carbon, transmembrane pressure.
The influence of nitrite and pH (nitrous acid) on aerobic-phase, autotrophic N2O generation in a wastewater treatment bioreactor
Authors: Shiskowski Dean M , Mavinic Donald S
Published: August 2006

Autotrophic ammonia oxidizing bacteria (AOB) are capable of generating nitrous oxide (N2O), via nitrite reduction, in oxygen-limited environments. The recognition of the environmental fate and effects of N2O, as a "greenhouse gas" has prompted researchers to study N2O generation and emission control in wastewater treatment systems. Oxygen, often expressed in terms of the bioreactor liquid dissolved oxygen concentration, is generally viewed as the most important variable with respect to influencing N2O generation. However, some literature data suggest that the nitrite concentration may also influence AOB N2O generation under oxygen-limited conditions, although there are contradictions in the reported information. This paper presents the findings of an investigation that specifically examined the sensitivity of aerobic-phase biomass N2O generation to changes in bioreactor nitrite concentration, via supply of exogenous nitrite, as well as changes in nitrous acid concentration through mixed liquor pH manipulation, in a bench-scale wastewater treatment bioreactor. The data demonstrate the significant influence of nitrite availability on biomass N2O generation in the studied system. Most of the collected data suggest that nitrous acid, as opposed to nitrite proper, was the actual AOB nitrite reductase (NiR) electron acceptor, based on observed N2O generation. In this case, the bioreactor mixed liquor pH, as well as nitrite concentration, would be important with respect to AOB N2O generation and greenhouse gas emissions. Key words: ammonia oxidation, autotrophic denitrification, nitrite reduction, nitrous oxide.
Factors affecting recirculating biofilters (RBFs) for treating municipal wastewater
Authors: Hu Z , Gagnon G A
Published: August 2006

Recirculating biofilters (RBFs) were studied as an option for treating domestic wastewater. In particular, the objective of this investigation was to examine the hydraulic (hydraulic loading rates or HLRs), operational (dosing frequency and recycle ratio), and media characteristics that significantly impact treatment performance. Four types of filter media were examined in this study: sand, crushed glass, peat, and geotextiles. Laboratory controlled experiments demonstrated that dosing frequency impacted treatment performance significantly. A dosing frequency of 96 times per day resulted in significantly higher BOD5 removal than a low dosing frequency of 48 times/d. The average BOD5 concentration in effluent for 96 times/d was 6.2 mg/L, where it was less than half for a dose frequency of 48 times/d (13.3 mg/L). Crushed glass was found to perform similarly as silica sand; which represents an alternative for biofiltration media. Peat filter resulted in the lowest NH4+-N (84.5%) removals and sand filter provided the highest NH4+-N removal (98.0%). Geotextile provided the highest total phosphorus removal (73.8%). Scanning electronic microscope (SEM) images of the biofilm around particles at different depth of filter suggested that filter depth should be considered as a design criterion as well. From a practical perspective this study provides a greater understanding of the critical design factors for RBFs and also demonstrated the feasibility and limitations of possible filter media alternatives (i.e., crushed glass, peat, and geotextile).Key words: recirculating sand filters, sand, crushed glass, peat, geotextiles.
Efficacy of UV irradiation on eight species of Bacillus
Authors: Menetrez M Y , Foarde K K , Webber T D , Dean T R , Betancourt D A
Published: August 2006

Ultraviolet irradiation has commonly been used in the indoor environment to eliminate or control infectious diseases such as tuberculosis in medical care facilities. Heating, ventilating, and air-conditioning (HVAC) system components such as duct-liners, cooling coils, drip-pans, interior insulation, and areas subjected to high levels of moisture can create an environment that is prone to biological contamination. Air supplied to indoor environments can carry biological contaminants that can expose numerous building occupants to pathogenic organisms. Possible terrorist activities could release biological agents into ambient air, or directly into a building environment, or HVAC system may expose multitudes of individuals to dangerous pathogens. The use of germicidal ultraviolet lamps (UVGI) in commercial and residential HVAC systems has increased. A method to determine the antimicrobial efficacy of UVGI irradiation was developed and tested on the surface of agar plates with eight varieties of Bacillus bacteria spores. Bacillus anthracis surrogates were used for their expected similar inactivation responses to UVGI irradiation. The percent kill and k value for each organism was calculated for various periods of exposure.Key words: antimicrobial, germicidal, antimicrobial efficacy, HVAC, biocontaminant.
Impact of blending reuse and lake water on treated water quality
Authors: Comerton Anna M , Andrews Robert C , Bagley David M
Published: August 2006

The impact of supplementing a raw drinking water source with reuse water was examined. Reuse water produced from municipal wastewater by a membrane bioreactor and reverse osmosis (MBR-RO) system was blended with untreated Lake Ontario water, then subjected to conventional water treatment processes, and evaluated in terms of disinfection by-products (DBPs), nitrate, and coliforms. The addition of reuse water to the lake water improved water quality in terms of total organic carbon (TOC) and bromide, which resulted in reduced trihalomethane (THM) formation. This appeared to be entirely due to dilution with no specific impact from the conventional treatment process. Nitrate levels in the reuse water (1.4 mg/L) were higher than the lake water (0.4 mg/L) and, therefore, an increase in the reuse water : lake water blend ratio resulted in a linear increase in nitrate levels. The conventionally treated blend water was shown to meet typical drinking water regulations for THMs, haloacetic acids (HAAs), total coliform, and nitrate. Key words: water reuse, drinking water supplement, reverse osmosis, membrane bioreactor, conventional water treatment, disinfection by-products, nitrate.
Performances d'un biofiltre à garnissage plastique pour le traitement d'effluents fortement contaminés en phénol, cadmium et chrome
Authors: Zidane Fatiha , Berrada Bouchra , Lekhlif Brahim , Lounès Mustapha , Blais Jean-François
Published: August 2006

The presence in domestic wastewater of high concentrations of organic and inorganic contaminants represents a serious problem for the treatment of these effluents. This research aimed to establish the performance of an aerobic biofiltration system with plastic packing for the treatment of effluents having high concentrations of phenol (300–500 mg·L–1), Cd(II) (2.5–10.0 mg·L–1), and Cr(III) (5.0–20.0 mg·L–1). Six biofilter units were first started in batch mode and then operated in continuous mode under similar conditions. High removal yields were measured for chemical oxygen demand (98.3% ± 0.3%), phenol (100% ± 0%), Cr (99.3% ± 0.6%), and Cd (90.4% ± 0.8%) from a synthetic effluent initially containing 300 mg·L–1 phenol, 5.0 mg Cr·L–1, and 2.5 mg Cd·L–1. Thereafter, the six columns were submitted to various operating conditions (hydraulic load, pH, phenol, cadmium, and chromium concentrations). This study showed that this system is efficient for the treatment of effluents having high concentrations of contaminants. To preserve a good efficiency of the system, the affluent must be kept at pH values equal to or higher than 6.0. Key words: biofiltration, phenol, chromium, cadmium, column, effluent, biomass, plastic. [Journal translation]
Décontamination des résidus de contrôle de la pollution de l'air (RCPA) d'incinérateurs de déchets municipaux par lixiviation en milieu basique et adsorption sur tourbe
Authors: Hammy Fatima , Chartier Myriam , Mercier Guy , Blais Jean-François
Published: August 2006

Air pollution control residues (APCR) from municipal waste incinerators are usually considered as hazardous wastes because of their high contents in easily soluble Pb and other toxic metal contaminants. The objective of this research was to compare various techniques using Pb adsorption on Sphagnum peat moss (MT) for the treatment of alkaline leachates produced during the decontamination of various types of APCR including used lime (CU), electrofilter ashes (CE), and boiler ashes (CC). Regeneration tests of saturated MT using hydrochloric and sulphuric acids have revealed that excessive acid consumption (>250 kg acid/metric ton of treated APCR) are necessary for the elution of metals. However, the incineration of the saturated MT and its possible valorization represents an interesting way to explore for the management of the adsorbent. This method allows to reduce by a factor of 3 or 4 the mass of residues and increases in the same proportion the Pb content in the incinerated MT. Finally, the present study has highlighted that ion exchange on the anionic functional groups of MT would be one of the most important mechanisms implied in the Pb fixation on this natural sorbent during the treatment of very alkaline leachates (pH > 11) of APCR.Key words: lead, leaching, incinerator, air pollution control residues (APCR), removal, peat, adsorption, toxicity characteristic leaching procedure (TCLP).[Journal translation]