bluuebunny/crossref_metadata_2025 huggingface dataset:
Location Determines Degradation
Authors: Wong Wei
Published: March 2009

Subcellular location and cell cycle status determine whether a scaffold protein is degraded by the proteasome.
Retinal Protection
Authors: Ray L. Bryan
Published: March 2009

An enzyme that deacetylates histones in the nucleus also functions in the cytoplasm to promote the survival of retinal neurons in mice.
Science Signaling
Podcast: 13 January 2009
Authors: Scott John D. , Wong Wei , VanHook Annalisa M.
Published: March 2009

The scaffold protein mAKAP localizes factors important for the cellular response to hypoxia.
Growth and Patterning in the Limb: Signaling Gradients Make the Decision
Authors: Yang Yingzi
Published: March 2009

Signaling gradients coordinately regulate proliferation and cell fate determination in the developing limb.
Integrins Are More Engaging in 3D
Authors: Wong Wei
Published: March 2009

Culture environment and presence of extracellular matrix attachments synergize to regulate the angiogenic signals that tumor cells release.
Draxin and Axon Guidance
Authors: Hines Pamela J.
Published: March 2009

A protein cue guides the formation of bundles of nerve fibers that connect the cerebral hemispheres.
Nematodes Behaving Badly
Authors: Pickersgill Helen
Published: March 2009

Mutations in neuropeptide receptors prevent nematode worms from swimming away to avoid bacterial pathogens.
How to Evolve into a Parasite
Authors: Wong Wei
Published: March 2009

A steroid hormone and its nuclear receptor regulate dauer formation and infectivity in larvae from different nematode species.
Switching Numbers
Authors: Foley John F.
Published: March 2009

Under the right conditions, TGF-β activates Smad1 and Smad5 to stimulate cell migration.
Separating Immune Cell Fate
Authors: Pickersgill Helen
Published: March 2009

T cells that respond quickly to infection and later to reinfection arise from a single precursor cell type.
Grappling with Membrane Fusion
Authors: Hurtley Stella M.
Published: March 2009

The protein complexin may act as a force-transferring switch during membrane fusion.
Science Signaling
Podcast: 27 January 2009
Authors: Foley John F. , VanHook Annalisa M.
Published: March 2009

Leptin secreted by adipose tissue decreases insulin production through both direct and indirect mechanisms.
Doing the Glutamine Two-Step
Authors: Adler Elizabeth M.
Published: March 2009

The ability of essential amino acids to enter cells and activate mTORC1 signaling depends on their exchange for glutamine.
Water in the Brain
Authors: Ray L. Bryan
Published: March 2009

The growth factor erythropoietin can prevent swelling associated with brain injury.
The Timing Is in the Genes
Authors: Wong Wei
Published: March 2009

mRNA stability determines when genes are expressed in response to tumor necrosis factor.
Positive and Negative Modulation of Angiogenesis by VEGFR1 Ligands
Authors: Cao Yihai
Published: March 2009

PlGF and VEGF-B exhibit dual effects on angiogenesis mediated by VEGF-A.
Does a Leaky Store Lead to a Long Life?
Authors: Adler Elizabeth M.
Published: March 2009

TRPP2 channels decrease endoplasmic reticulum Ca
2+
concentration and thereby sensitivity to apoptosis involving Ca
2+
release from this store.
AMPA Receptor Modulator
Authors: Stern Peter
Published: March 2009

A distinctive family of proteins involved in the assembly of the most common excitatory brain receptor has been discovered.
Divisive Tension
Authors: Hurtley Stella M.
Published: March 2009

The mechanism for sensing tension across chromosome pairs before mitotic separation relies on the distance between enzyme and substrate.
When the Endogenous Hallucinogenic Trace AmineN,N-Dimethyltryptamine Meets the Sigma-1 Receptor
Authors: Su Tsung-Ping , Hayashi Teruo , Vaupel D. Bruce
Published: March 2009

An endogenous hallucinogenic compound binds to a ligand-gated chaperone.
Bacterial FIC Proteins AMP Up Infection
Authors: Roy Craig R. , Mukherjee Shaeri
Published: March 2009

A bacterial protein posttranslationally modifies and inactivates Rho family GTPases in host cells.
Antifungal Combinations against Simulated
Candida albicans
Endocardial Vegetations
Authors: Pai Manjunath P.
Published: March 2009

The in vitro effects of flucytosine (5FC), liposomal amphotericin B (L-AmB), and micafungin (Mica) combinations against two
Candida albicans
strains that simulated 24-hour-old endocardial vegetations were studied. Mica was superior to 5FC or L-AmB, and the 5FC-L-AmB-Mica combination was superior to all other treatments for one strain but no different from the dual combination of L-AmB-Mica for the other strain.
Tetracycline Susceptibility Testing and Resistance Genes in Isolates of
Acinetobacter baumannii
-
Acinetobacter calcoaceticus
Complex from a U.S. Military Hospital
Authors: Akers Kevin S. , Mende Katrin , Yun Heather C. , Hospenthal Duane R. , Beckius Miriam L. , Yu Xin , Murray Clinton K.
Published: March 2009

Infections with multidrug-resistant
Acinetobacter baumannii
-
Acinetobacter calcoaceticus
complex bacteria complicate the care of U.S. military personnel and civilians worldwide. One hundred thirty-three isolates from 89 patients at our facility during 2006 and 2007 were tested by disk diffusion, Etest, and broth microdilution for susceptibility to tetracycline, doxycycline, minocycline, and tigecycline. Minocycline was the most active in vitro, with 90% of the isolates tested susceptible. Susceptibilities varied significantly with the testing method. The acquired tetracycline resistance genes
tetA, tetB
, and
tetA
(39) were present in the isolates.
Identification of the Efflux Transporter of the Fluoroquinolone Antibiotic Ciprofloxacin in Murine Macrophages: Studies with Ciprofloxacin-Resistant Cells
Authors: Marquez Béatrice , Caceres Nancy E. , Mingeot-Leclercq Marie-Paule , Tulkens Paul M. , Van Bambeke Françoise
Published: March 2009

Ciprofloxacin, the most widely used totally synthetic antibiotic, is subject to active efflux mediated by a MRP-like transporter in wild-type murine J774 macrophages. To identify the transporter among the seven potential Mrps, we used cells made resistant to ciprofloxacin obtained by long-term exposure to increasing drug concentrations (these cells show less ciprofloxacin accumulation and provide a protected niche for ciprofloxacin-sensitive intracellularListeria monocytogenes). In the present paper, we first show that ciprofloxacin-resistant cells display a faster efflux of ciprofloxacin which is inhibited by gemfibrozil (an unspecific MRP inhibitor). Elacridar, at a concentration known to inhibit P-glycoprotein and breast cancer resistance protein (BCRP), only slightly increased ciprofloxacin accumulation, with no difference between resistant and wild-type cells. Analysis at the mRNA (real-time PCR) and protein (Western blotting) levels revealed an overexpression of Mrp2 and Mrp4.Mrp4transcripts, however, were overwhelmingly predominant (45% [wild-type cells] to 95% [ciprofloxacin-resistant cells] of allMrptranscripts tested [Mrp1toMrp7]). Silencing ofMrp2andMrp4with specific small interfering RNAs showed that only Mrp4 is involved in ciprofloxacin transport in both ciprofloxacin-resistant and wild-type cells. The study therefore identifies Mrp4 as the most likely transporter of ciprofloxacin in murine macrophages but leaves open a possible common upregulation mechanism for both Mrp4 and Mrp2 upon chronic exposure of eukaryotic cells to this widely used antibiotic.
Long-Term Follow-Up Trial of Oral Rifampin-Cotrimoxazole Combination versus Intravenous Cloxacillin in Treatment of Chronic Staphylococcal Osteomyelitis
Authors: Euba G. , Murillo O. , Fernández-Sabé N. , Mascaró J. , Cabo J. , Pérez A. , Tubau F. , Verdaguer R. , Gudiol F. , Ariza J.
Published: March 2009

Oral therapies alternative to fluoroquinolones against staphylococcal chronic osteomyelitis have not been evaluated in comparative studies. Consecutive nonaxial
Staphylococcus aureus
chronic osteomyelitis cases were included in a comparative trial after debridement. Fifty patients were randomized: group A (
n
= 22) was treated with cloxacillin for 6 weeks intravenously plus 2 weeks orally (p.o.), and group B (
n
= 28) was treated with rifampin-cotrimoxazole for 8 weeks p.o. During follow-up (10 years), five relapses occurred: two (10%) in group A and three (11%) in group B. Foreign-body maintenance was associated with relapse (
P
= 0.016). Oral rifampin-cotrimoxazole treatment showed outcomes comparable to those for intravenous cloxacillin treatment.
Genital Tract, Cord Blood, and Amniotic Fluid Exposures of Seven Antiretroviral Drugs during and after Pregnancy in Human Immunodeficiency Virus Type 1-Infected Women
Authors: Yeh Rosa F. , Rezk Naser L. , Kashuba Angela D. M. , Dumond Julie B. , Tappouni Hiba L. , Tien Hsiao-Chuan , Chen Ya-Chi , Vourvahis Manoli , Horton Amanda L. , Fiscus Susan A. , Patterson Kristine B.
Published: March 2009

The objective of the study was to measure antiretroviral exposures in four physiological compartments during pregnancy, delivery, and postpartum. This prospective, open-label, longitudinal study collected paired blood plasma (BP) and genital tract (GT) aspirates antepartum, at delivery, and up to 12 weeks postpartum. Antiretroviral cord BP and amniotic fluid concentrations were also measured. Drug concentrations were analyzed by validated high-performance liquid chromatography/UV and liquid chromatography/tandem mass spectrometry methods, with secondary compartment concentrations presented as the percentage of BP. Fourteen women taking lamivudine plus zidovudine and either lopinavir-ritonavir (
n
= 7), nelfinavir (
n
= 6), or nevirapine (
n
= 1) were enrolled; four also received tenofovir. GT penetration relative to BP was highest for the nucleoside reverse transcriptase inhibitors compared to the protease inhibitors and nevirapine. Only antepartum nelfinavir GT penetration was significantly higher than in the second trimester (geometric mean ratio [GMR], 179.3) or third trimester (GMR, 41.9). Compared to nonpregnant historical controls, antepartum GT penetration was significantly lower (
P
< 0.05) for zidovudine (GMR, 0.25) and lopinavir (GMR, 0.03); postpartum lopinavir GT penetration continued to be significantly lower (GMR, 0.27). Cord BP exposures were highest for lamivudine and tenofovir (≥100%), with cord BP levels of the remaining drugs ranging from 49 to 86% of that of the respective BP level. Amniotic exposures for lamivudine, zidovudine, tenofovir, and nelfinavir were ≥100%, nevirapine exposure was 53%, and lopinavir and ritonavir exposures were ≤6% that of BP. We conclude that GT, cord BP, and amniotic fluid exposures vary within and between antiretroviral drug classes and biologic sites. Measurement of antiretroviral exposure in maternal genital secretions, cord BP, and amniotic fluid may be needed to identify signals of subtherapeutic or supratherapeutic drug exposure.
Comparative Antipneumococcal Activities of Sulopenem and Other Drugs
Authors: Kosowska-Shick Klaudia , Ednie Lois M. , McGhee Pamela , Appelbaum Peter C.
Published: March 2009

For 297 penicillin-susceptible, -intermediate, and -resistant pneumococcal strains, the sulopenem MIC
50
s were 0.008, 0.06, and 0.25, respectively, and the sulopenem MIC
90
s were 0.016, 0.25, and 0.5 μg/ml, respectively. The MIC
50
s of amoxicillin for the corresponding strains were 0.03, 0.25, and 2.0 μg/ml, respectively, and the MIC
90
s were 0.03, 1.0, and 8.0 μg/ml, respectively. The combination of amoxicillin and clavulanate gave MICs similar to those obtained with amoxicillin alone. The sulopenem MICs were similar to those of imipenem and meropenem. The MICs of ß-lactams increased with those of penicillin G, and among the quinolones tested, moxifloxacin had the lowest MICs. Additionally, 45 strains of drug-resistant type 19A pneumococci were tested by agar dilution and gave sulopenem MIC
50
s and MIC
90
s of 1.0 and 2.0 μg/ml, respectively. Both sulopenem and amoxicillin (with and without clavulanate) were bactericidal against all 12 strains tested at 2× MIC after 24 h. Thirty-one strains from 10 countries with various penicillin, amoxicillin, and carbapenems MICs, including those with the highest sulopenem MICs, were selected for sequencing analysis of the
pbp1a
,
pbp2x
, and
pbp2b
regions encoding the transpeptidase active site and MurM. We did not find any correlations between specific penicillin-binding protein-MurM patterns and changes in the MICs.
Antifungal Activities of Natural and Synthetic Iron Chelators Alone and in Combination with Azole and Polyene Antibiotics against
Aspergillus fumigatus
Authors: Zarember Kol A. , Cruz Anna R. , Huang Chiung-Yu , Gallin John I.
Published: March 2009

Antifungal effects of iron chelators (lactoferrin, deferoxamine, deferiprone, and ciclopirox) were tested alone and in combination with antifungal drugs against
Aspergillus fumigatus
B5233 conidia. Lactoferrin, ciclopirox, and deferiprone inhibited whereas deferoxamine enhanced fungal growth. Antifungal synergy against conidia was observed for combinations of ketoconazole with ciclopirox or deferiprone, lactoferrin with amphotericin B, and fluconazole with deferiprone. Iron chelation alone or combined with antifungal drugs may be useful for prevention and treatment of mycosis.
In Vitro Activity of Micafungin against Planktonic and Sessile
Candida albicans
Isolates
Authors: Jacobson Melissa J. , Steckelberg Kathryn E. , Piper Kerryl E. , Steckelberg James M. , Patel Robin
Published: March 2009

Planktonic and sessile susceptibilities to micafungin were determined for 30 clinical isolates of
Candida albicans
obtained from blood or other sterile sites. Planktonic and sessile MIC
90
s for micafungin were 0.125 and 1.0 μg/ml, respectively.
Cryptococcus neoformansDirectly Stimulates Perforin Production and Rearms NK Cells for Enhanced Anticryptococcal Microbicidal Activity
Authors: Marr Kaleb J. , Jones Gareth J. , Zheng Chunfu , Huston Shaunna M. , Timm-McCann Martina , Islam Anowara , Berenger Byron M. , Ma Ling Ling , Wiseman Jeremy C. D. , Mody Christopher H.
Published: March 2009

NK cells, in addition to possessing antitumor and antiviral activity, exhibit perforin-dependent microbicidal activity against the opportunistic pathogenCryptococcus neoformans. However, the factors controlling this response, particularly whether the pathogen itself provides an activation or rearming signal, are largely unknown. The current studies were performed to determine whether exposure to this fungus alters subsequent NK cell anticryptococcal activity. NK cells lost perforin and mobilized lysosome-associated membrane protein 1 to the cell surface following incubation with the fungus, indicating that degranulation had occurred. Despite a reduced perforin content during killing, NK cells acquired an enhanced ability to killC. neoformans, as demonstrated using auxotrophs that allowed independent assessment of the killing of two strains. De novo protein synthesis was required for optimal killing; however, there was no evidence that a soluble factor contributed to the enhanced anticryptococcal activity. Exposure of NK cells toC. neoformanscaused the cells to rearm, as demonstrated by increased perforin mRNA levels and enhanced loss of perforin when transcription was blocked. Degranulation alone was insufficient to provide the activation signal as NK cells lost anticryptococcal activity following treatment with strontium chloride. However, NK cells regained the activity upon prolonged exposure toC. neoformans, which is consistent with activation by the microbe. The enhanced cytotoxicity did not extend to tumor killing since NK cells exposed toC. neoformansfailed to kill NK-sensitive tumor targets (K562 cells). These studies demonstrate that there is contact-mediated microbe-specific rearming and activation of microbicidal activity that are necessary for optimal killing ofC. neoformans.
Iron-Regulated Surface Determinant Protein A Mediates Adhesion ofStaphylococcus aureusto Human Corneocyte Envelope Proteins
Authors: Clarke Simon R. , Andre Guillaume , Walsh Evelyn J. , Dufrêne Yves F. , Foster Timothy J. , Foster Simon J.
Published: March 2009

The ability ofStaphylococcus aureusto colonize the human nares is a crucial prerequisite for disease. IsdA is a majorS. aureussurface protein that is expressed during human infection and required for nasal colonization and survival on human skin. In this work, we show that IsdA binds to involucrin, loricrin, and cytokeratin K10, proteins that are present in the cornified envelope of human desquamated epithelial cells. To measure the forces and dynamics of the interaction between IsdA and loricrin (the most abundant protein of the cornified envelope), single-molecule force spectroscopy was used, demonstrating high-specificity binding. IsdA acts as a cellular adhesin to the human ligands, promoting whole-cell binding to immobilized proteins, even in the absence of otherS. aureuscomponents (as shown by heterologous expression inLactococcus lactis). Inhibition experiments revealed the binding of the human ligands to the same IsdA region. This region was mapped to the NEAT domain of IsdA. The NEAT domain also was found to be required forS. aureuswhole-cell binding to the ligands as well as to human nasal cells. Thus, IsdA is an important adhesin to human ligands, which predominate in its primary ecological niche.
The Plasmid of
Escherichia coli
Strain S88 (O45:K1:H7) That Causes Neonatal Meningitis Is Closely Related to Avian Pathogenic
E. coli
Plasmids and Is Associated with High-Level Bacteremia in a Neonatal Rat Meningitis Model
Authors: Peigne Chantal , Bidet Philippe , Mahjoub-Messai Farah , Plainvert Céline , Barbe Valérie , Médigue Claudine , Frapy Eric , Nassif Xavier , Denamur Erick , Bingen Edouard , Bonacorsi Stéphane
Published: March 2009

A new
Escherichia coli
virulent clonal group, O45:K1, belonging to the highly virulent subgroup B2
1
was recently identified in France, where it accounts for one-third of
E. coli
neonatal meningitis cases. Here we describe the sequence, epidemiology and function of the large plasmid harbored by strain S88, which is representative of the O45:K1 clonal group. Plasmid pS88 is 133,853 bp long and contains 144 protein-coding genes. It harbors three different iron uptake systems (aerobactin, salmochelin, and the
sitABCD
genes) and other putative virulence genes (
iss
,
etsABC
,
ompT
P
, and
hlyF
). The pS88 sequence is composed of several gene blocks homologous to avian pathogenic
E. coli
plasmids pAPEC-O2-ColV and pAPEC-O1-ColBM. PCR amplification of 11 open reading frames scattered throughout the plasmid was used to investigate the distribution of pS88 and showed that a pS88-like plasmid is present in other meningitis clonal groups such as O18:K1, O1:K1, and O83:K1. A pS88-like plasmid was also found in avian pathogenic strains and human urosepsis strains belonging to subgroup B2
1
. A variant of S88 cured of its plasmid displayed a marked loss of virulence relative to the wild-type strain in a neonatal rat model, with bacteremia more than 2 log CFU/ml lower. The salmochelin siderophore, a known meningovirulence factor, could not alone explain the plasmid's contribution to virulence, as a salmochelin mutant displayed only a minor fall in bacteremia (0.9 log CFU/ml). Thus, pS88 is a major virulence determinant related to avian pathogenic plasmids that has spread not only through meningitis clonal groups but also human urosepsis and avian pathogenic strains.
Reproducible Community Dynamics of the Gastrointestinal Microbiota following Antibiotic Perturbation
Authors: Antonopoulos Dionysios A. , Huse Susan M. , Morrison Hilary G. , Schmidt Thomas M. , Sogin Mitchell L. , Young Vincent B.
Published: March 2009

Shifts in microbial communities are implicated in the pathogenesis of a number of gastrointestinal diseases, but we have limited understanding of the mechanisms that lead to altered community structures. One difficulty with studying these mechanisms in human subjects is the inherent baseline variability of the microbiota in different individuals. In an effort to overcome this baseline variability, we employed a mouse model to control the host genotype, diet, and other possible influences on the microbiota. This allowed us to determine whether the indigenous microbiota in such mice had a stable baseline community structure and whether this community exhibited a consistent response following antibiotic administration. We employed a tag-sequencing strategy targeting the V6 hypervariable region of the bacterial small-subunit (16S) rRNA combined with massively parallel sequencing to determine the community structure of the gut microbiota. Inbred mice in a controlled environment harbored a reproducible baseline community that was significantly impacted by antibiotic administration. The ability of the gut microbial community to recover to baseline following the cessation of antibiotic administration differed according to the antibiotic regimen administered. Severe antibiotic pressure resulted in reproducible, long-lasting alterations in the gut microbial community, including a decrease in overall diversity. The finding of stereotypic responses of the indigenous microbiota to ecologic stress suggests that a better understanding of the factors that govern community structure could lead to strategies for the intentional manipulation of this ecosystem so as to preserve or restore a healthy microbiota.
Modelling aquatic vegetation and dissolved oxygen after a flood event in the Bow River, Alberta, Canada
Authors: Robinson K. L. , Valeo C. , Ryan M. C. , Chu A. , Iwanyshyn M.
Published: March 2009

Traditionally, macrophyte density has been considered the primary factor affecting the large dissolved oxygen fluctuations in the Bow River. After a major flood event scoured macrophytes in 2005, and subsequently changed river dynamics, the City of Calgary needed to update their predictive computer model for water quality to reflect the new conditions, which led to this study. A 2006 aquatic vegetation survey was also completed to assess post-flood conditions. The survey found that the average macrophyte dry weight was much lower (28 g/m2 ± 100 (p = 0.05)) than the historic average of 241 g/m2 ± 29, while the average periphyton chlorophyll-a concentration was higher (343 mg/m2 ± 71) than the historic average (158 mg/m2 ± 17)). Dissolved oxygen (DO) fluctuations were similar to pre-flood levels despite changes in the dominant vegetation. Using the results of this survey, the significant and previously unrecognized effects of periphyton diurnal processes on DO concentrations in the Bow River were identified and the Bow River water quality model (BRWQM) was recalibrated to reflect these findings. Adjustments were made to the BRWQM’s periphyton submodel to account for the more dominant role played by these organisms in river processes, and a competitive shading factor between macrophytes and periphyton was also introduced to more accurately model the species' competition for available sunlight. This newly calibrated and validated version of BRWQM was tested and found capable of predicting the occurrence of low DO concentrations in the Bow River and can provide a useful tool for forecasting the water quality effects of the city's planned wastewater infrastructure expansion.
River flow abstraction due to hydraulic storage at freezeup
Authors: Beltaos Spyros
Published: March 2009

A hydrologic extreme that can be partly generated by ice effects is low winter flow, which is known for potential impacts on water quality and quantity of rivers receiving effluent discharges or industrial withdrawals. Flow abstraction caused by hydraulic storage during the upstream propagation of an ice cover is quantified using the equations of continuity for ice and water. The flow abstraction is shown to increase with increasing ice concentration, but to decrease with increasing ice cover thickness. Numerical values are consistent with winter abstractions indicated by flow data from Canadian hydrometric stations. The present results further suggest that low-flow conditions in winter should generally improve, or at least not deteriorate, under a warmer climate.
Investigation of shear resistance of steel bridge girders by load testing and monitoring of load response data under highway traffic conditions
Authors: Au Alexander , Lam Clifford , Tharmabala Bala
Published: March 2009

A recent strength evaluation of the Hogg’s Hollow Bridge on Highway 401 in Ontario revealed a significant deficiency in the shear resistance of the existing girders at support locations. This was attributed to the absence of transverse stiffeners at the extreme ends of the girders. However, none of the bridge girders showed any signs of distress. The Ontario Ministry of Transportation recently conducted a field study to investigate this shear issue in greater detail. To that end, a test program was devised to (a) monitor the real stresses in the end panels of two selected girders in the Hogg’s Hollow Bridge when subjected to (i) a test truck with known axle loads and (ii) normal highway traffic loading, and (b) calibrate the observed stresses against theoretically expected responses in the girders and calculate the live load capacity factor using the shear data derived from the field measurements.
Robust global and local search approach to resource-constrained project scheduling
Authors: Kim Jin-Lee , Ellis Ralph D.
Published: March 2009

The resource-constrained project scheduling problem (RCPSP) is one of the most challenging problems in construction scheduling applications, in which optimal solutions are of great value to project planners. This paper presents a new adaptive hybrid genetic algorithm search simulator (AHGASS) for finding an optimal solution to the problem, and provides the strategies and practical procedures to develop the algorithm. Elitist genetic algorithm (EGA) developed is used for the global search, while random walk algorithm for the local search is incorporated into the EGA to overcome the drawbacks of general genetic algorithms, which are computationally intensive and premature convergence to a local solution. Computational experiments are presented to demonstrate the performance and accuracy of AHGASS. The proposed algorithm provides a comparable and competitive performance compared with the existing genetic algorithm (GA) hybrid heuristic methods. The findings demonstrate that AHGASS has significant promise for solving a large-sized RCPSP.
Implementation of project change management best practice in different project environments
Authors: Zou Yi , Lee Sang-Hoon
Published: March 2009

Change orders are ubiquitous in construction projects, and effective and efficient control of changes is critical to project success. There have been many empirical suggestions as to how to manage changes for best project outcomes, but this research is specifically aimed at exploring the relationship between project characteristics and the implementation of project change management best practices (PCMBP). Construction project data for this research are derived from the Construction Industry Institute (CII) benchmarking and metrics (BM&M) database. Binary logistic regressions and factorial analysis of variance (ANOVA) are performed to find out the differences among diverse types of projects in terms of the extents to which the PCMBP elements have been implemented. The findings can assist construction industry practitioners with using PCMBP more purposefully in accordance with specific project characteristics so that they will be better able to develop and administer their project execution plans.
Étude des conséquences de la détérioration de l’uni des chaussées sur le comportement des véhicules et la sécurité des usagers de la route
Authors: Richard Marc J. , Doré Guy , Vassev Vladislav , Fradette Nicolas
Published: March 2009

Le véhicule routier est devenu le moyen de transport le plus utilisé au monde. Ainsi, les artères routières sont devenues beaucoup plus chargées et exploitées, ce qui a entraîné une détérioration accélérée des surfaces des chaussées. Cette détérioration est d’autant plus importante dans les régions nordiques, comme le Québec, où les conditions hivernales sont également une cause importante de dégradation des chaussées. L’avancement de la technologie informatique nous permet, aujourd’hui, de procéder à des simulations dynamiques tenant compte des conditions routières ainsi que des caractéristiques de différents véhicules. En conséquence, nous pouvons simuler avec une grande fiabilité le comportement dynamique de différents types de voitures, et ceci nous permet d’analyser les influences de plusieurs caractéristiques routières, en particulier la forte influence de l’indice de rugosité international (IRI) sur le confort et la sécurité.
Integration of four-dimensional computer-aided design modeling and three-dimensional animation of operations simulation for visualizing construction of the main stadium for the Beijing 2008 Olympic games
Authors: Lu Ming , Zhang Yang , Zhang Jianping , Hu Zhenzhong , Li Jiulin
Published: March 2009

In this paper, we give a state review of modeling methodologies for four-dimensional computer-aided design (4D CAD) and three-dimensional (3D) animation of operations simulation. We then present our efforts of integrating 4D CAD and 3D animation of operations simulation to facilitate the construction planning of the main stadium for the Beijing 2008 Olympic Games (nicknamed the “Bird’s Nest”). We propose a “zoom” interface between 4D CAD and 3D animation of operations simulation to enable a natural synergy of two separate, but organically linked research streams. For concept proving and application demonstration, we seamlessly integrated two computer systems resulting from previous in-house research to plan and visualize the construction of the “Bird’s Nest” in close collaboration with the main contractor. The integrated construction planning methodology is found instrumental in visually and intuitively conveying the master project schedule and detailed operations plan for construction of the “Bird’s Nest”.
Electrochemical removal of organics and oil from sawmill and ship effluentsA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Drogui Patrick , Asselin Mélanie , Brar Satinder K. , Benmoussa Hamel , Blais Jean-François
Published: March 2009

The present study investigates the electrocoagulation treatment of two different wastewaters, namely sawmill wastewater and ship waste effluent, charged with organic matter. Monopolar electrode configuration was studied for both types of effluents at current intensity of 2.0 A for a total treatment time of 90 min. Soluble chemical oxygen demand (CODs) removal was very low (12.5% to 13.6%) for sawmill effluent in comparison to 74.7% to 75.4% obtained for ship effluents. Thus, ship effluent was further examined in details for its treatment efficacy in terms of electrode configuration and type, current intensity, treatment time, and pH. It was observed that bipolar electrode configuration using the Al electrode at 0.3 A gave the highest CODsremoval of 77%. Effluent pH increased rapidly in the initial 20 min with a concomitant decrease in CODsconcentration. Electrocoagulated-flocculated ship effluent improved performance relative to simple flocculation with respective removals of 86% of turbidity, 56% of CODs; 69% of total COD (CODt), 90% of oil and grease, 94% of C10-C50hydrocarbons and 89% of biochemical oxygen demand (BOD5). Residual Al3+concentration in the solution followed a linear trend with treatment time. Meanwhile, the sludge production increased progressively during 60 min of treatment time. Total cost for treatment of ship effluent, including energy, electrodes, and sludge disposal fee is estimated between CAN$1.34 and CAN$2.40m–3.
Behavior of slab–column connections with partially debonded reinforcement under lateral loading
Authors: Choi Jung-Wook , Ali Malika , Alexander Scott D.B.
Published: March 2009

In a flat plate structure, slab–column connections must possess sufficient drift capacity to survive the lateral deformation resulting from wind or earthquake. Partial debonding of the flexural reinforcement may be a means of increasing drift capacity of a slab–column structure. This article summarizes cyclic loading tests conducted on two full-scale interior slab–column connections, one with and one without partially debonded reinforcement. Each test specimen consisted of a 4.2 m square slab with a 355 mm square column protruding 1.5 m above and below the slab. The slab thickness was 152 mm. The specimen with partially debonded reinforcement exhibited more lateral drift capacity (4.5%) than did the specimen with fully bonded reinforcement (3.5%). The lateral load capacity of the debonded specimen was approximately 20% greater than that of the bonded control specimen. With partial debonding of the flexural reinforcement, cyclic load appeared to produce less damage to the connection in the vicinity of the slab–column joint.
Adsorption of a jet fuel on a model organic–clay soil: Application of small angle neutron scatteringA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Hanley H.J.M. , Payne T.E.
Published: March 2009

Small angle neutron scattering (SANS) data are reported from a system that models the contamination of a clay – organic matter soil from a fuel spillage. The soil was represented as an aqueous dispersion of the synthetic clay mineral Laponite coated with lysine, and the contaminant was a representative jet fuel, quadricyclane, mixed with the detergent cetyltrimethylammonium bromide (CTAB). The adsorbed surface coverage on the clay was estimated. It is shown that the presence of adsorbed lysine considerably enhances the subsequent adsorption of both CTAB and quadricyclane. It is demonstrated that the SANS technique can contribute to the general problem of environmental remediation and retention by probing the interactions of pollutants and clay surfaces.
Dissolution kinetics of struvite pellets grown in a pilot-scale crystallizerA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Bhuiyan M.I.H. , Mavinic D.S. , Beckie R.D.
Published: March 2009

Dissolution kinetics of struvite are important for optimizing intentional struvite crystallization, as well as for ensuring the efficient use of the crystallized products. Dissolution experiments were carried out for struvite pellets grown in a pilot-scale fluidized bed reactor. To determine the kinetics and mechanism of the dissolution process in a batch reactor system, two different theoretical models were tested. The experimental values were found to fit well with both models. In a mixed flow-through reactor system, the constituents release became stoichiometric when the input solution had an alkaline pH. The dissolution rates for struvite pellets were found to decrease with increasing pH due to proton promoted dissolution. After a transition from around 7.5 to 8, the rate of dissolution increased with the increase in pH, because of the hydroxyl promoted dissolution.
ON TIME-DEPENDENT BLACK HOLES AND COSMOLOGICAL MODELS FROM A KALUZA–KLEIN MECHANISM
Authors: CASTRO C. , NIETO J. A. , RUIZ L. , SILVAS J.
Published: March 2009

Novel static, time-dependent and spatial–temporal solutions to Einstein field equations, displaying singularities, with and without horizons, and in several dimensions, are found based on a dimensional reduction procedure widely used in Kaluza–Klein-type theories. The Kerr–Newman black hole entropy as well as the Reissner–Nordstrom, Kerr and Schwarzschild black hole entropy are derived from the corresponding Euclideanized actions. A very special cosmological model based on the dynamical interior geometry of a black hole is found that has no singularities at t = 0 due to the smoothing of the mass distribution. We conclude with another cosmological model equipped also with a dynamical horizon and which is related to Vaidya's metric (associated with the Hawking radiation of black holes) by interchanging t ↔ r, which might render our universe a dynamical black hole.
COVARIANT FORMULATION OF NOETHER'S THEOREM FOR κ-MINKOWSKI TRANSLATIONS
Authors: AGOSTINI ALESSANDRA
Published: March 2009

The problem of finding a formulation of Noether's theorem in noncommutative geometry is very important in order to obtain conserved currents and charges for particles in noncommutative space–times. In this paper, we formulate Noether's theorem for translations of κ-Minkowski noncommutative space–time on the basis of the five-dimensional κ-Poincaré covariant differential calculus. We focus our analysis on the simple case of free scalar theory. We obtain five conserved Noether currents, which give rise to five energy–momentum charges. By applying our result to plane waves it follows that the energy–momentum charges satisfy a special-relativity dispersion relation with a generalized mass given by the fifth charge. In this paper, we provide also a rigorous derivation of the equation of motion from Hamilton's principle in noncommutative space–time, which is necessary for the Noether analysis.
NEW PROPERTIES OF z-SCALING: FLAVOR INDEPENDENCE AND SATURATION AT LOW z
Authors: ZBOROVSKÝ I. , TOKAREV M. V.
Published: March 2009

Experimental data on inclusive cross-sections of particles produced in high energy proton–(anti)proton collisions at ISR, RHIC and Tevatron are analyzed in the framework of z-scaling. New features of the scaling function ψ(z) are established. These are flavor independence of ψ(z) including particles with heavy flavor content and saturation at low z. The flavor independence means that the shape of the scaling function ψ(z) is the same for different hadron species. The saturation corresponds to flattening of ψ(z) for z < 0.1. Relations of model parameters used in data z-presentation with some thermodynamical quantities (entropy, specific heat, temperature) are discussed. It is shown that behavior of the particle spectra at low z is controlled by a parameter c interpreted as a specific heat of the created medium associated with production of the inclusive particle. The saturation regime of ψ(z) observed at low z is assumed to be preferable in searching for phase transitions of hadron matter and for study of nonperturbative QCD in high energy proton–(anti)proton collisions at U70, RHIC, Tevatron and LHC.
BATALIN–VILKOVISKY YANG–MILLS THEORY AS A HOMOTOPY CHERN–SIMONS THEORY VIA STRING FIELD THEORY
Authors: ZEITLIN ANTON M.
Published: March 2009

We show explicitly how Batalin–Vilkovisky Yang–Mills action emerges as a homotopy generalization of Chern–Simons theory from the algebraic constructions arising from string field theory.
SYNTHESIS, GROWTH, STRUCTURAL, SPECTROSCOPIC, OPTICAL, THERMAL AND MECHANICAL STUDIES OF A SEMI-ORGANIC NONLINEAR OPTICAL CRYSTAL: L-GLUTAMIC ACID HYDROCHLORIDE
Authors: SELVARAJU K. , KIRUBAVATHI K. , VIJAYAN N. , KUMARARAMAN S.
Published: March 2009

The semi-organic nonlinear optical single crystal of L-glutamic acid hydrochloride was grown by slow evaporation solution growth technique at room temperature. The cell parameters of the grown crystal were estimated by single crystal X-ray diffraction analysis. The presence of various functional groups was identified from Fourier transform infrared analysis. The transmission spectrum of this crystal show that the lower cut-off wavelength lies at 248 nm. Thermal analysis was performed to study the thermal stability of the grown crystal. The Kurtz powder second harmonic generation test shows that the crystal is a potential candidate for optical second harmonic generation. Mechanical properties of the grown crystal were determined and Vickers' hardness number was calculated.
EFFECT OF EXCESS NEGATIVE IONS ON ANODIC OXIDATION IN MICROARC OXIDATION OF TITANIUM
Authors: LEE YONG K. , JUNG TAEHO
Published: March 2009

The effects of the electrical bias conditions on oxide film during titanium MAO (microarc oxidation) were investigated. Since DC voltage showed very low stabilized currents but produced oxide films with poor quality, the magnitude of applied voltages, duty cycles, and frequencies were modulated to control the quality of the oxide film. Pulsed voltage showed increased stabilized currents but produced better oxide films. The change in the stabilized currents was attributed to the change of the resistances of the film and local electrolyte adjacent to the anode. Analysis of the film thickness and the resistances of the film calculated from the experiments led to conclusion that the resistance of the electrolyte adjacent to the anode was increased if the negative ions attracted towards the anode were not reacted as fast as the positive ions at the cathode. The increase in resistance was attributed to the excess negative ions repelling other negative ions. In order to relax the negative ions, it appeared that a pulsed voltage source was essential. However, higher off-duty cycle was not the best choice to produce good oxide films indicating that the electrical bias condition depended on the experimental configuration.
QUANTUM ANALOG OF THERMOHALINE CONVECTION IN ATOMIC AND MOLECULAR CONDENSATES
Authors: ROY MAHENDRA NATH SINHA
Published: March 2009

We study the possibility of the emergence of a spatiotemporal pattern in a gas of ultra bosons, where atomic and molecular condensates can coexist due to the presence of Feshbach resonance and nonlinear interactions in the condensates. These patterns exhibit features which are very similar to those that have been seen in thermohaline convection in salt water. The experimental identification of these patterns in the condensates will be highly interesting.
High serum testosterone levels are associated with excessive erythrocytosis of chronic mountain sickness in men
Authors: Gonzales Gustavo F. , Gasco Manuel , Tapia Vilma , Gonzales-Castañeda Cynthia
Published: March 2009

Chronic mountain sickness (CMS) is characterized by excessive erythrocytosis (EE) secondary to hypoventilation. Erythropoietin (Epo) and testosterone regulate erythrocyte production. Low thyroid hormone levels are also associated to hypoventilation. Hence, these hormones can play a role in etiopathogeny of EE. The purpose of this study was to elucidate the effect of sexual and thyroid hormones and Epo in residents from Lima (150 m) and Cerro de Pasco (4,340 m), Peru, and the response to human chorionic gonadotrophin stimulation (hCG). Three groups, one at low altitude and two at high altitude [1 with hemoglobin values >16–21 g/dl and the second with Hb ≥21 g/dl (EE)], were studied. hCG was administered intramuscularly in a single dose (1,000 IU), and blood samples were obtained at 0, 6, 12, 24, 48, and 72 h after injection. High-altitude natives present similar levels of gonadotropins and thyroid hormones but lower dehydroepiandrosterone sulphate (DHEAS) levels ( P < 0.01) and greater Epo ( P < 0.01), 17α-hydroxyprogesterone ( P < 0.01), and testosterone levels ( P < 0.01) than those at 150 m. Serum testosterone levels (524.13 ± 55.91 μg/dl vs. 328.14 ± 53.23 ng/dl, means ± SE; P < 0.05) and testosterone/DHEAS ratios are higher (7.98 ± 1.1 vs. 3.65 ± 1.1; P < 0.01) and DHEAS levels lower in the EE group (83.85 ± 14.60 μg/dl vs. 148.95 ± 19.11 ug/dl; P < 0.05), whereas Epo was not further affected. Testosterone levels were highest and DHEAS levels lowest in the EE group at all times after hCG stimulation. In conclusion, high androgen activity could be involved in the etiopathogeny of CMS. This evidence provides an opportunity to develop new therapeutic strategies.
The First Metal Complexes of 4,6‐diamino‐1‐hydro‐	5‐hydroxy‐pyrimidine‐2‐thione: Preparation, Physical and Spectroscopic Studies, and Preliminary Antimicrobial Properties
Authors: Mostafa Sahar I. , Papatriantafyllopoulou Constantina , Perlepes Spyros P. , Hadjiliadis Nick
Published: March 2009

The new complexes ,   (3), [ML3] · xH2O (M = Rh, x = 2, 4; M = Ir, x = 1, 5), (ClO4) · 2H2O  (6), [PdL2] · 2H2O  (7), [PdL(phen)]Cl · H2O  (8), [Re OL2(PPh3)]Cl  (9) and [UO2L2]  (10) are reported, where LH is 4,6‐diamino‐1‐hydro‐5‐hydroxy‐pyrimidine‐2‐thione.
The complexes were characterized by elemental analyses, physical techniques
(molar conductivity, room‐temperature magnetic susceptibility), and spectroscopic
(IR, Raman, UV/VIS/ligand field, NMR, mass) methods. The ligand L− is in its thione form and behaves as a bidentate chelate with the deprotonated
(hydroxyl) oxygen and the nitrogen of one amino group as donor atoms.
Oxobridged dinuclear (1, 2) and various mononuclear (3–10) structures are assigned for the complexes in the solid state. The metal ion coordination geometries are octahedral (1–6, 9, 10) or square planar (7, 8). The free ligand LH and complexes 1, 4, 7, and 8 were assayed in vitro for antimicrobial activity against two bacterial and two fungal cultures.
Symmetric and Transitive Registration of Image Sequences
Authors: Škrinjar Oskar , Bistoquet Arnaud , Tagare Hemant
Published: March 2009

This paper presents a method for constructing symmetric and transitive algorithms for registration of image sequences from
image registration algorithms that do not have these two properties. The method is applicable to both rigid and nonrigid registration
and it can be used with linear or periodic image sequences. The symmetry and transitivity properties are satisfied exactly (up to
the machine precision), that is, they always hold regardless of the image type, quality, and the registration algorithm as long as
the computed transformations are invertable. These two properties are especially important in motion tracking applications since
physically incorrect deformations might be obtained if the registration algorithm is not symmetric and transitive. The method was tested on two sequences of cardiac magnetic resonance images using two different nonrigid image registration
algorithms. It was demonstrated that the transitivity and symmetry errors of the symmetric and transitive modification of the
algorithms could be made arbitrary small when the computed transformations are invertable, whereas the corresponding errors
for the nonmodified algorithms were on the order of the pixel size. Furthermore, the symmetric and transitive modification of the
algorithms had higher registration accuracy than the nonmodified algorithms for both image sequences.
Embedded Systems Programming: Accessing Databases from Esterel
Authors: White David , Lüttgen Gerald
Published: March 2009

A current limitation in embedded controller design and programming is the lack of database support in development tools such as Esterel Studio. This article proposes a way of integrating databases and Esterel by providing two application programming interfaces (APIs) which enable the use of relational databases inside Esterel programs. As databases and Esterel programs are often executed on different machines, result sets returned as responses to database queries may be processed either locally and according to Esterel's synchrony hypothesis, or remotely along several of Esterel's execution cycles. These different scenarios are reflected in the design and usage rules of the two APIs presented in this article, which rely on Esterel's facilities for extending the language by external data types, external functions, and procedures, as well as tasks. The APIs' utility is demonstrated by means of a case study modelling an automated warehouse storage system, which is constructed using Lego Mindstorms robotics kits. The robot's controller is programmed in Esterel in a way that takes dynamic ordering information and the warehouse's floor layout into account, both of which are stored in a MySQL database.