bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes of knowledge, attitudes, beliefs, and preference of bar owner and staff in response to a smoke-free bar law: Table 1
Authors: Tang H , Cowling D W , Stevens C M , Lloyd J C
Published: February 2004

Objective:To examine attitudinal changes of bar owners and staff regarding a smoke-free bar law.

Design:Bar owners and staff were random selected and telephone interviewed in June 1998, shortly after a smoke-free bar law was enacted, and October 2002. Similar instruments were used in both surveys to collect data on attitudes related to secondhand smoke (SHS) and behaviours related to the smoke-free bar law.

Participants:651 and 650 respondents worked for either stand alone bars or combination bars.

Measures:Preference of working in a smoke-free environment, concerns of the effect of SHS, and how to comply with the law.

Results:The percentage of bar owners or staff working in stand alone bars who prefer to work in a smoke-free environment increased from 17.3% in 1998 to 50.9% in 2002 (p < 0.001). Significantly more respondents (45.5%) working in stand alone bars were concerned about the effects of SHS on their health, comparing to 21.6% in 1998 (p < 0.001). When patrons smoked in the bar, 82.1% of stand alone bar owners or staff in the 2002 survey would ask them to stop or to smoke outside, increased from only 43.0% in the 1998 survey (p < 0.001).

Conclusion:A positive and significant attitudinal change related to the smoke-free bar law occurred among California bars.
Lawsuits and secondhand smoke: Table 1
Authors: Sweda E L
Published: February 2004

Objective:This paper describes secondhand smoke (SHS) litigation over the past quarter century where non-smoking litigants have prevailed and attempts to decipher trends in the law that may impact the course of future cases.

Methods:Since the early 1980s, the author has sought and examined legal cases in which SHS exposure is an important factor. Law library searches using the official reporter system (for example,Shimp v. New Jersey Bell Telephone Co., 368 A.2d 408) have more recently been combined with computerised online searches using LexisNexis and Westlaw. The author has learned of other cases through personal correspondence and from articles in newspapers. Over 420 cases involving exposure to SHS were identified. Each case was reviewed and summarised.

Results:Since 1976, the year of the first reported SHS lawsuit, this type of litigation has increased both in number and in scope with increasing success. While it is common for initial cases to lose in a new area where the law eventually evolves, litigants and their lawyers who later bring similar cases can learn from those previous, unsuccessful cases. It is now apparent that the judicial branch has begun to recognise the need to protect the public—especially some of the most vulnerable members of our society—from the serious threat to their health that is exposure to SHS.

Conclusions:Successful cases brought on behalf of individuals exposed to SHS produce an additional benefit for the public health by both paving the way for other non-smoking litigants to succeed in their cases and persuading business owners and others voluntarily to make their facilities 100% smoke-free.
Telephone assistance for smoking cessation: one year cost effectiveness estimations
Authors: McAlister A L , Rabius V , Geiger A , Glynn T J , Huang P , Todd R
Published: February 2004

A randomised trial evaluated the American Cancer Society’s telephone counselling service to assist smoking cessation. Counselling nearly doubles a smokers’ odds of quitting and maintaining cessation for one year. The estimated cost for each case of maintained smoking cessation attributable to counselling availability is approximately $1300.
Designated “no smoking” areas provide from partial to no protection from environmental tobacco smoke
Authors: Cains T , Cannata S , Poulos R , Ferson M J , Stewart B W
Published: February 2004

Objective:To determine the efficacy of designated “no smoking” areas in the hospitality industry as a means of providing protection from environmental tobacco smoke (ETS), and whether certain design features assist in achieving this end.

Methodology:In the greater metropolitan region of Sydney, a representative group of 17 social and gaming clubs, licensed to serve alcoholic beverages and in which, apart from designated areas, smoking occurs, agreed to participate. In each establishment, simultaneous single measurements of atmospheric nicotine, particulate matter (10 μm; PM10) and carbon dioxide (CO2) levels were measured in a general use area and in a designated “no smoking” area during times of normal operation, together with the levels in outdoor air (PM10 and CO2only). Analyses were made of these data to assess the extent to which persons using the “no smoking” areas were protected from exposure to ETS.

Results:By comparison with levels in general use areas, nicotine and particulate matter levels were significantly less in the “no smoking” areas, but were still readily detectable at higher than ambient levels. For nicotine, mean (SD) levels were 100.5 (45.3) μg/m3in the areas where smoking occurred and 41.3 (16.1) μg/m3in the “no smoking” areas. Corresponding PM10 levels were 460 (196) μg/m3and 210 (210) μg/m3, while outdoor levels were 61 (23) μg/m3. The reduction in pollutants achieved through a separate room being designated “no smoking” was only marginally better than the reduction achieved when a “no smoking” area was contiguous with a smoking area. CO2levels were relatively uninformative.

Conclusion:Provision of designated “no smoking” areas in licensed (gaming) clubs in New South Wales, Australia, provides, at best, partial protection from ETS—typically about a 50% reduction in exposure. The protection afforded is less than users might reasonably have understood and is not comparable with protection afforded by prohibiting smoking on the premises.
“The contemporary, irreverent brand of youth with an independent streak”: BAT’s youth promotions in Myanmar
Authors: Chapman S
Published: February 2004

“British American Tobacco strongly believes children should not smoke, and smoking should only be for adults who understand the risks associated with it. Our Group companies support and run programmes worldwide tackling underage smoking, and we are committed to pooling our resources and experience globally with others in the tobacco industry—and with governments and NGOs—to help prevent youth smoking. Along with the other two largest international tobacco groups—Philip Morris International and Japan Tobacco International—our Group companies have funded and supported more than 130 Youth Smoking Prevention (YSP) programmes in more than 70 countries. ...We fully support laws and regulations on a minimum age for buying tobacco products, and penalties for retailers who break the law. Our company policy worldwide is not to market to anyone under 18 years old, or more if the law in a particular country sets the age higher.”—BAT website November 2003
Design and evaluation of a new bond-type anchorage system for fiber reinforced polymer tendons
Authors: Zhang Burong , Benmokrane Brahim
Published: February 2004

Corrosion resistance, high strength, and advantageous strength-to-weight ratio enable fiber reinforced polymers (FRPs) to have substantial potential to replace steel tendons in prestressed applications. One of the main technical obstacles to wide use of FRPs in the construction industry is the methodology to anchor FRP tendons to achieve their full strength. High tensile to compression and shear strength ratios make it necessary to develop a new anchorage design concept for FRP tendons. This paper gives a literature review of bond-type anchorage systems and the mechanics of stress transfer by bond from FRP tendons to grout and reports an experimental study on a newly developed bond-type anchorage system with carbon fiber reinforced polymer (CFRP) Leadline 8-mm-diameter rods. The test program consisted of nine monotonic tensile tests, two pullout tests, and two proving tests on the anchorage system with Leadline single- or 9-rod tendons. The test results showed that the developed anchorage system with 250-mm bond length ensures full development of the tensile strength of Leadline mono-rod tendons. The bond strength of Leadline 9-rod tendons is 14 MPa for a bond length of 95 mm, 62% of that of mono-rod ones with a bond length of 80 mm. The anchorage system with a 400-mm bond length gives at least 90% of the tensile strength of Leadline 9-rod tendons and also demonstrates an acceptable sustained loading behaviour in accordance with existing codes.Key words: anchorage, bond stress, creep, grout, polymers, rod, slip, tendon.
Comparison of computed water hammer pressures with test results for the Çatalan power plant in Turkey
Authors: Selek Bülent , Kirkgöz M Salih , Selek Zeliha
Published: February 2004

The closure of a flow control mechanism at the end of a penstock may cause significant transient pressures. The governing equations of this unsteady flow phenomenon, the conservation of mass and conservation of momentum, are solved by the method of characteristics using various computational schemes. A study was carried out to compare the computational results of the transient pressures with measured prototype data for the Çatalan Power Plant in Turkey. Prototype data were collected during the closure of the wicket gates of a Francis turbine from the test procedures of "load rejection", "emergency shut down", and "quick stop". The numerical results for the transient pressures just upstream of the turbine are compared with the measured data. The general agreement between the theoretical and experimental results is found to be quite reasonable.Key words: transient pressure, water hammer, power plant, Francis turbine, penstock, method of characteristics.
A spectral density approach for modelling continuous vertical forces on pedestrian structures due to walking
Authors: Brownjohn J M.W , Pavic A , Omenzetter P
Published: February 2004

Existing walking models used for vibration serviceability assessment of structures carrying pedestrians are typically based on measurements of single footfalls replicated at precise intervals. This assumed perfect periodicity allows walking forces to be modelled as a Fourier series based on the walking pace and its integer multiples. This paper examines real continuous walking forces obtained from an instrumented treadmill and the effect of their random imperfections through time simulations of structural response and shows that there are significant differences between responses due to the imperfect real walking forces and the equivalent perfectly periodic simulation. These differences are most significant for higher harmonics where the simulated vibration response is overestimated. As a realistic representation of imperfect walking is an auto-spectral density function, the random character naturally leads to a stochastic approach to treatment of pedestrian loading applied in the frequency domain. The approach can be used for single pedestrians as well as crowd loading where correlation between pedestrians as well as statistics of their pacing rates is used.Key words: vibration, coherence, loading, footbridges, gait, floors, pedestrians, spectral density.
Application of grey correlation analysis for evaluating the artificial lake site in Pingtung Plain, Taiwan
Authors: Yeh Yi-Lung , Chen Ting-Chien
Published: February 2004

The overuse of groundwater in coastal areas of Taiwan has caused serious land subsidence, seawater intrusion, and soil salinification. Artificial lakes are one of the alternatives that increase groundwater water resources. The Pingtung Plain is one of the most bountiful groundwater resource areas in Taiwan. The grey correlation method was used to evaluate the four optimal sites in the Pingtung Plain. Evaluations were based on hydraulic conductivity, the amount and quality of source water, the distance between the potential artificial lake site and the source water intake position, and the quantity and quality of gravel dug from the potential artificial lake site. Based on groundwater recharge and water storage, the grey correlation method showed that site D (Dar-Shiang-Yung) was the best choice.Key words: artificial lake, grey correlation analysis, groundwater recharge, Pingtung Plain.
An evaluation of pile cap design methods in accordance with the Canadian design standard
Authors: Cavers William , Fenton Gordon A
Published: February 2004

There are a number of design methods that have been described for the design of pile caps, but there has been no consensus on which method provides the best approach for the working designer. This paper describes a study conducted to establish the performance of several pile cap design methods, particularly with respect to the Canadian standard, CSA A23.3-94. Previous research was examined to determine the basis of the design methods and the state of current research. The design methods identified were then applied to pile caps for which test data were available. The theoretical loads obtained using the various design methods were compared with the experimental loads. The results of this study indicate that two design models of the five examined are the most suitable. This study also indicates that the provisions of the Canadian design standard are adequate. A possible refinement of the strut-and-tie model incorporating a geometric limit is also outlined.Key words: building codes, footings, pile caps, reinforced concrete, structural design.
Analysis of effects of air pocket on hydraulic failure of urban drainage infrastructure
Authors: Zhou F , Hicks F , Steffler P
Published: February 2004

The effects of trapped air on flow oscillations and pressure surges in a model trunk sewer–manhole system subject to rapid filling are investigated. The study reveals the detrimental impacts of entrapped air during severe storm events under which pipelines are likely overloaded. The results of the investigation indicated huge peak pressures and severe pressure oscillations inside the system.Key words: trapped air, flow transient, rapid filling, sewers.
Role of the construction sector in the economy of a city
Authors: Kennedy Christopher , He Wenxi Olivia , Fung Manson
Published: February 2004

The need to renew civil infrastructure is particularly acute in urban centres. However, investment in infrastructure renewal has different economic implications compared with new construction, mainly having multiplier effects as opposed to real effects. Statistical techniques are used to study the factors that influence private sector commercial, industrial, and residential construction starts in the Greater Toronto Area (GTA). Regression equations for the construction sector are incorporated into a macroeconomic model of the GTA. This model is used to study the impacts of public construction spending on the GTA economy. Impacts produced by infrastructure investment are not limited to the construction industry but are seen over the whole economy. In the model simulation, a CAN$1.75 billion road investment in the second quarter of 1994 produced an additional CAN$375 million increase in regional gross domestic product (GDP).Key words: infrastructure investment, infrastructure renewal, regional economics, Greater Toronto Area.
Study of shear provisions for stiffened plate girders
Authors: Loov Robert , Parthasarathi Narayana
Published: February 2004

Steel design in Canada generally follows the provisions of CSA-S16-01 "Limit states design of steel structures" (CSA 2001). The provisions in this standard governing the shear design of stiffened plate girders set limits to the choice of web thickness, girder depth, and the spacing of intermediate stiffeners. This paper reviews the influence of each of the equations that govern the shear design of stiffened plate girders. The study reveals that many of the equations are unlikely to have any effect. Of the 13 equations that could restrict the design, only 3 are likely to have any influence on a typical design. This reveals avenues for possible simplification of design procedures.Key words: anchor panel, shear design, stiffened plate girder, tension field panel.
Construction probabiliste de scénarios d'apports à un réservoir
Authors: Seidou O , Robert B , Marche C , Rousselle J , Lefebvre M
Published: February 2004

The behaviour of a hydric system depends on three factors : (i) the state of the installation, (ii) the operating rules, and (iii) the inflows. While the first two factors are (in theory) known to the manager, the third can only be estimated by means of more or less precise forecasts. A significant part of the risk, to which is subjected the system at a given time, is induced by the uncertainty in the future inflows. The evaluation of this uncertainty is therefore a first step in the incorporation of risk into management. Its evaluation is then a stage preliminary to the integration of the risk in management. A method of construction of inflow scenarios starting from an arbitrary date t of the year is developed in this paper. It uses a Markovian process formerly developed by the authors to model short-term uncertainty in stream flow. These scenarios, which are not equiprobable, are built to reproduce the statistical behaviour of the river or reservoir and have the shape of an event tree whose structure is defined by the user before application of the method. Two examples of application on two rivers located in Quebec, Canada, are presented.Key words: reservoir operation, previsions, inflows, risk, uncertainty.
Enhancing struvite crystallization from anaerobic supernatant
Authors: Wu Qingzhong , Bishop Paul L
Published: February 2004

Nutrient recovery in the form of struvite from anaerobic supernatant will not only eliminate the operation and maintenance nuisance caused by struvite formation, but can also generate a valuable agricultural fertilizer. However, the struvite crystallization process is generally slow. In this research, different Mg2+ supplement chemicals — Mg(OH)2 and MgCl2 — and different seeding materials — sand and struvite — were tested in an effort to speed up the struvite precipitation/crystallization process. The research results showed that (1) both seeding materials were instrumental in enhancing the reaction rate, with struvite being better than sand; (2) the more surface area provided by the seeding material, the faster the precipitation is; (3) both Mg(OH)2 and MgCl2 were beneficial in speeding up the precipitation process, but MgCl2 was more effective than Mg(OH)2; (4) compared with simple aeration to remove CO2, pre-acidification helped speed up the precipitation and could lower the final phosphate level; and (5) if Mg(OH)2 is to be used, pre-acidification can be eliminated but the Mg(OH)2 needs to be mixed with the wastewater at an earlier stage in the treatment process.Key words: struvite, crystallization, anaerobic supernatant, centrate, filtrate, sludge dewatering.
The application of the perfluorinated bonded alumina phase for natural organic matter catalytic ozonation
Authors: Kasprzyk-Hordern B , Dabrowska A , Świetlik J , Nawrocki J
Published: February 2004

An investigation into the efficiency of natural organic matter ozonation in the presence of alumina modified with perfluorooctanoic acid (PFOA) was the goal of this paper. UV254-absorbance analysis indicated that the PFOA/O3 system increases the efficiency of colour removal from treated water when compared with ozonation alone and ozonation in the presence of alumina. The total organic carbon (TOC) analysis proved that the PFOA/O3 system is also responsible for natural organic matter (NOM) degradation in water due to two significant processes that take place during the ozonation step: adsorption and reaction with ozone. Both an increase of carbonyl compounds formation and changes in molecular size distribution of NOM treated with ozone in the presence of PFOA were found to be another evidence for catalytic activity of the PFOA/O3 system. Key words: ozone, drinking water treatment, catalytic ozonation, perfluorooctyl alumina, PFOA, natural organic matter.
Preliminary evaluation of the use of fatty acid ratios for tracking the potential for nitrite accumulation in nitrifying reactors with low carbon to nitrogen ratio
Authors: Simm R A , Ramey W D , Mavinic D S
Published: February 2004

This paper reports on the use of fatty acid analysis for tracking the relative proportion of nitrifiers in reactors treating high strength ammonia wastewater with low carbon to nitrogen ratio. These results suggest the ratio of cis-9-hexadecenoic acid to cis-11-hexadecenoic acid may be useful for a number of acclimation responses including proliferation of small populations and appearance of new genotypes. This method is proposed as a supplement to molecular methods. The fact that fatty acid analysis has a much lower cost per sample and much higher sample throughput relative to most molecular methods makes it particularly suited as a prescreening tool when choosing samples to be submitted for the more costly analysis. Key words: nitrification, fatty acid methyl esters, Nitrospira, free ammonia, nitrite, ammonia inhibition.
Recent developments in the production of extracellular fungal peroxidases and laccases for waste treatment
Authors: Ikehata Keisuke , Buchanan Ian D , Smith Daniel W
Published: February 2004

The use of enzymes for the treatment or the removal of environmental and industrial pollutants has attracted increasing attention because of their high efficiency, high selectivity, and environmentally benign reactions. Of these enzymes studied for such purposes, extracellular fungal peroxidases, such as lignin peroxidase, manganese peroxidase and Coprinus cinereus peroxidase, and fungal laccases are the two major classes of enzymes that have been evaluated for the removal of toxic phenolic compounds from industrial wastewater and the degradation of recalcitrant xenobiotics. Numerous reports have been published recently on the improvements of the production of these enzymes, such as discovery of new fungal strains, modification of growth conditions, use of inducers, and use of cheaper growth substrates such as agricultural and food wastes. In this review, these recent advances in the production of extracellular fungal peroxidases and laccases, along with brief summaries of background of these enzymes and their applications, are discussed. Key words: Arthromyces ramosus peroxidase, Coprinus peroxidase, degradation, fermentation, laccase, lignin peroxidase, manganese peroxidase, phenols, wastewater treatment, xenobiotics.
Enzyme activities associated with oxidative stress inMetarhizium anisopliaeduring germination, mycelial growth, and conidiation and in response to near-UV irradiation
Authors: Miller Charles D , Rangel Drauzio , Braga Gilberto UL , Flint Stephan , Kwon Sun-Il , Messias Claudio L , Roberts Donald W , Anderson Anne J
Published: February 2004

Metarhizium anisopliae isolates have a wide insect host range, but an impediment to their commercial use as a biocontrol agent of above-ground insects is the high susceptibility of spores to the near-UV present in solar irradiation. To understand stress responses in M. anisopliae, we initiated studies of enzymes that protect against oxidative stress in two strains selected because their spores differed in sensitivity to UV-B. Spores of the more near-UV resistant strain in M. anisopliae 324 displayed different isozyme profiles for catalaseperoxidase, glutathione reductase, and superoxide dismutase when compared with the less resistant strain 2575. A transient loss in activity of catalaseperoxidase and glutathione reductase was observed during germination of the spores, whereas the intensity of isozymes displaying superoxide dismutase did not change as the mycelium developed. Isozyme composition for catalaseperoxidases and glutathione reductase in germlings changed with growth phase. UV-B exposure from lamps reduced the activity of isozymes displaying catalaseperoxidase and glutathione reductase activities in 2575 more than in 324. The major effect of solar UV-A plus UV-B also was a reduction in catalaseperoxidases isozyme level, a finding confirmed by measurement of catalase specific activity. Impaired growth of M. anisopliae after near-UV exposure may be related to reduced abilities to handle oxidative stress.Key words: catalaseperoxidase, germination, glutathione reductase, Metarhizium anisopliae, near-UV, protein oxidation, superoxide dismutase.
Biodegradation of Maya crude oil fractions by bacterial strains and a defined mixed culture isolated from Cyperus laxus rhizosphere soil in a contaminated site
Authors: Díaz-Ramírez I J , Ramírez-Saad H , Gutiérrez-Rojas M , Favela-Torres E
Published: February 2004

Ten bacterial strains were isolated by enrichment culture, using as carbon sources either aliphatics or an aromatic–polar mixture. Oxygen uptake rate was used as a criterion to determine culture transfer timing at each enrichment stage. Biodegradation of aliphatics (10 000 mg L–1) and an aromatic–polar mixture (5000 mg L–1, 2:1) was evaluated for each of the bacterial strains and for a defined culture made up with a standardized mixture of the isolated strains. Degradation of total hydrocarbons (10 000 mg L–1) was also determined for the defined mixed culture. Five bacterial strains were able to degrade more than 50% of the aliphatic fraction. The most extensive biodegradation (74%) was obtained with strain Bs 9A, while strains Ps 2AP and UAM 10AP were able to degrade up to 15% of the aromatic–polar mixture. The defined mixed culture degraded 47% of the aliphatics and 6% of the aromatic–polar mixture. The defined mixed culture was able to degrade about 40% of the aliphatic fraction and 26% of the aromatic fraction when grown in the presence of total hydrocarbons, while these microorganisms did not consume the polar hydrocarbons fraction. The proposed strategy that combines enrichment culture together with oxygen uptake rate allowed the isolation of bacterial strains that are able to degrade specific hydrocarbons fractions at high consumption rates.Key words: biodegradation, defined mixed culture, enrichment culture, hydrocarbon fractions, oxygen uptake.
Thermodependence of growth and enzymatic activities implicated in pathogenicity of twoErwinia carotovorasubspecies (Pectobacteriumspp.)
Authors: Smadja Bruno , Latour Xavier , Trigui Sameh , Burini Jean François , Chevalier Sylvie , Orange Nicole
Published: February 2004

Erwinia carotovora subsp. atroseptica and Erwinia carotovora subsp. carotovora can cause substantial damage to economically important plant crops and stored products. The occurrence of the disease and the scale of the damage are temperature dependent. Disease development consists first of active multiplication of the bacteria in the infection area and then production of numerous extracellular enzymes. We investigated the effects of various temperatures on these two steps. We assayed the specific growth rate and the pectate lyase and protease activities for eight strains belonging to E. carotovora subsp. atroseptica and E. carotovora subsp. carotovora in vitro. The temperature effect on growth rate and on pectate lyase activity is different for the two subspecies, but protease activity appears to be similarly thermoregulated. Our results are in agreement with ecological data implicating E. carotovora subsp. atroseptica in disease when the temperature is below 20 °C. The optimal temperature for pathogenicity appears to be different from the optimal growth temperature but seems to be a compromise between this temperature and temperatures at which lytic activities are maximal.Key words: temperature, Pectobacterium atrosepticum, Pectobacterium carotovorum, growth, pectate lyases, proteases.
Eight Gram-negative bacteria are 10 000 times more sensitive to cationic detergents than to anionic detergents
Authors: Rajagopal Soumitra , Eis Nicole , Nickerson Kenneth W
Published: February 2004

In liquid culture, eight typical Gram-negative bacteria were ca. 10 000-fold more sensitive to cationic detergents than to the anionic detergent sodium dodecyl sulfate. Cetyltrimethylammonium bromide (CTAB) was inhibitory at concentrations ranging from 0.0006% to 0.01%. Four pseudomonads able to form biofilms were ca. 1000-fold more resistant to CTAB on Luria–Bertani agar plates than they were in liquid culture. A lasI mutant of Pseudomonas aerugi nosa was only able to tolerate 0.1% CTAB on Luria–Bertani agar plates but could tolerate 5% CTAB when supplemented with homoserine lactone containing culture supernatants.Key words: sodium dodecyl sulfate, cetyltrimethylammonium bromide, bacterial detergent resistance, homoserine lactones, Pseudomonas biofilms.
Butyrivibriocin AR10, a new cyclic bacteriocin produced by the ruminal anaerobeButyrivibrio fibrisolvensAR10: characterization of the gene and peptide
Authors: Kalmokoff M L , Cyr T D , Hefford M A , Whitford M F , Teather R M
Published: February 2004

The gene (bviA) encoding the ruminal bacteriocin butyrivibriocin AR10 was cloned from an EcoRI library by using an oligonucleotide probe based on a partial peptide sequence of the previously isolated peptide. The gene encoded an 80 amino acid prebacteriocin that demonstrated significant identity with the cyclic bacteriocin gassericin A. Negative ion time of flight mass spectroscopic analysis (ESI/MS) indicated a mass of 5981.5 Da for the isolated bacteriocin, a molecular mass that could not be generated by removal of a leader peptide alone. However, an N- to C-terminal cyclization of the predicted mature bacteriocin resulted in a peptide that conformed to the determined mass and charge characteristics. Northern blotting confirmed that expression of bviA mirrored the production of the bacteriocin in both liquid and solid media.Key words: Butyrivibrio fibrisolvens AR10 rumen bacteriocin.
Wastewater-grown duckweed may be safely used as fish feed
Authors: Islam M S , Kabir M S , Khan S I , Ekramullah M , Nair G B , Sack R B , Sack D A
Published: February 2004

Duckweed has been used for the treatment of wastewater and as fish feed. A comparative study was carried out to determine (i) the efficacy of duckweed in treating hospital-based wastewater and (ii) the level of the microbial contamination of fish fed on wastewater-grown duckweed. There were two groups of ponds where fish farming was done. In one group of ponds (control ponds), duckweed that was grown using artificial fertilizer was used as fish feed; in another group (study ponds), wastewater-grown duckweed was used as fish feed. The faecal contamination of water, duckweed, and fish from study and control ponds were monitored by faecal coliform estimation. The presence of enteric pathogens among handlers, water, duckweed, and fish samples was also examined. It was observed that the faecal coliform counts of raw wastewater were 4.7 Log10CFU/mL, which was reduced to <1 Log10CFU/mL after treating with duckweed. There was no significant difference (P > 0.05) in faecal coliform counts in water collected from duckweed ponds and fish ponds of study and control areas. The wastewater-grown duckweed did not pose any health hazard to the handlers. These results demonstrated that the wastewater-treated duckweed may be safely used as fish feed.Key words: wastewater, duckweed, fish feed, contamination, safety.
Identification of indole-3-acetic acid producing freshwater wetland rhizosphere bacteria associated withJuncus effususL.
Authors: Halda-Alija Lidija
Published: February 2004

Production of indole-3-acetic acid (IAA), a key physiological feature of culturable, O2-tolerant bacteria associated with the freshwater macrophyte Juncus effusus L., was examined over a period of 2 years. Up to 74% of rhizobacteria identified and tested produced IAA. The number of indoleacetic acid producers decreased in winter. IAA was produced even when L-tryptophan, a precursor of IAA, was not added to the medium. Most of the IAA-producing strains were dominated by strains that were not identifiable to species level on the basis of API testing. Based on 16S rRNA gene sequencing and fatty acid analysis, it was found that IAA-producing rhizosphere bacteria associated with the freshwater wetland plant Juncus effusus L. are representatives of several families, including the Enterobacteriaceae, Pseudomonadaceae, Aeromonadaceae, Burkholderiaceae, and Bacillaceae. This study identifies numerous potentially important bacterial physiological groups of freshwater wetlands. Additionally, the study provides a baseline for monitoring and assessing the mutualistic relationships of wetland plants with rhizosphere bacteria in freshwater wetlands.Key words: wetlands, rhizosphere bacteria, IAA, 16S rRNA sequencing.
Mutagenic DNA repair potential inPseudomonasspp., and characterization of therulABPcoperon from the highly mutable strainPseudomonas cichorii302959
Authors: Zhang Shouan , Sundin George W
Published: February 2004

We assessed the tolerance to ultraviolet B (UVB; 290-320 nm) radiation and UVB-induced mutability in 28 Pseudomonas spp. and four Burkholderia cepacia strains. The UVB survival of 23 (72%) of the strains was elevated (>46% survival following irradiation with a 2250 J m-2dose), and 17 (53%) strains were defined as mutable by UVB. A mutagenic DNA repair determinant was cloned and characterized from the highly mutable strain P. cichorii 302959 and shown by sequence analysis to be an allele of rulAB, a mutagenic DNA repair determinant previously characterized from Pseudomonas syringae. Phylogenetic analyses of RulA- and RulB-related sequences indicated that the sequences identified in environmental bacteria shared a common ancestor with UmuDC-like sequences from enteric bacteria but were considerably diverged. The dynamics of UVB-induced mutability to nalidixic acid resistance (NalR) and rifampicin resistance (RifR) were studied in replicate populations of P. cichorii 302959 subjected to a daily UVB dose of 2250 J m-2for 14 consecutive days. While there was an initial spike in the frequency of NalRand RifRmutants recovered on Days 1 and 2 of two separate experiments, the frequencies were sharply reduced and then fluctuated throughout the duration of both experiments. These experimental results are intriguing because they point to the possibility that P. cichorii possesses additional mechanisms to curtail the induction of spontaneous mutants following repeated episodes of UVB irradiation.Key words: phyllosphere, UVB survival, UVB mutability, long-term mutability, translesion synthesis, Y family DNA polymerase.
Characterization and regulation of the γ-glutamyl transpeptidase gene from the fission yeast Schizosaccharomyces pombe
Authors: Park Hey-Jung , Lim Hye-Won , Kim Kanghwa , Kim Il-Han , Park Eun-Hee , Lim Chang-Jin
Published: February 2004

The structural gene for the putative γ-glutamyl transpeptidase (GGT) was isolated from the chromosomal DNA of the fission yeast Schizosaccharomyces pombe. The determined sequence contained 3324 bp and encoded the predicted 630 amino acid sequence of GGT, which resembles counterparts in Homo sapiens, Rattus norvegicus, Saccharomyces cerevisiae, and Escherichia coli. The S. pombe cells harboring the cloned GGT gene showed about twofold higher GGT activity in the exponential phase than the cells harboring the vector only, indicating that the cloned GGT gene was functional. To monitor the expression of the S. pombe GGT gene, we fused the fragment 1085 bp upstream of the cloned GGT gene into the promoterless β-galactosidase gene of the shuttle vector YEp367R to generate the fusion plasmid pGT98. The synthesis of β-galactosidase from the fusion plasmid in S. pombe cells was enhanced by treatments with NO-generating sodium nitroprusside (SN), L-buthionine-(S,R)-sulfoximine (BSO), and glycerol. The GGT mRNA level in the S. pombe cells was increased by SN and BSO. Involvement of Pap1 in the induction of the GGT gene by SN and BSO was observed.Key words: fission yeast, genomic DNA, γ-glutamyl transpeptidase, Pap1, regulation, Schizosaccharomyces pombe.
Oral administration of D-003, a mixture of very long chain fatty acids prevents casein-induced endogenous hypercholesterolemia in rabbits
Authors: Menéndez R , Más R , Pérez J , González R M , Jiménez S
Published: February 2004

D-003 is a mixture of very long chain saturated fatty acids (VLCSFA) purified from sugar cane wax with cholesterol-lowering effects proven in animal models and healthy volunteers. D-003 inhibits cholesterol biosynthesis through the regulation of HMG-CoA reductase activity. Rabbits fed diets enriched with casein develop endogenous hypercholesterolemia (EH), making them a very useful model for determining the mechanism of action of drugs affecting lipids. We examined whether D-003 prevented EH. Rabbits were fed a casein diet for 4 weeks, administered simultaneously with D-003 (5, 50, and 100 mg·kg–1·day–1). As expected, nontreated rabbits became hipercholesterolemic; however, as early as 15 days following administration, the treated group (50 and 100 mg·kg–1·day–1) had significantly decreased total cholesterol and low-density lipoprotein cholesterol (LDL-C). Triglycerides were not affected; however, at study completion, HDL-C levels significantly increased at all the doses assayed. D-003 inhibited de novo synthesis of cholesterol, since the incorporation of3H2O into sterols in the liver and proximal small bowel was significantly depressed. Also, D-003 significantly raised the rate of removal of [125I]-LDL from serum and significantly elevated [125I]-LDL binding activity to liver homogenates. Taken together, these results show that the efficacy of D-003 in reducing casein-derived hypercholesteromeia could involve, at least partially, an inhibition of hepatic cholesterol bio synthesis, which may elicit a decreased cholesterol concentration in hepatocytes, preventing the loss of hepatic LDL receptors induced by casein administration. However, since casein-induced hypercholesterolemia is also a consequence of a stimulation of cholesterol absorption in the lumen and an increase of the output of cholesterol associated with LDL, the effect of D-003 on cholesterol absorption and LDL synthesis by the liver should be investigated.Key words: D-003, very long chain saturated fatty acids, casein-fed rabbits, LDL-C, cholesterol biosynthesis, LDL clearance, LDL receptor.
Apoptose radio-induite: une nouvelle approche par microspectroscopie infrarouge
Authors: Gault Nathalie , Poncy Jean-Luc , Lefaix Jean-Louis
Published: February 2004

Purpose: to characterize radiation-induced apoptosis in human cells using Fourier transform infrared microspectroscopy (FT-IRM) as a new analytical tool. Material and methods: Normal human circulating lymphocytes were given a γ ray dose of 6 Gy, or treated with t-butyl hydroperoxide (t-BuOH). HaCaT keratinocytes were given a dose of 20 Gy. Cells were deposited on ZnS windows for infrared spectral acquisition 2 days and 2 h after irradiation and 2 h after t-BuOH treatment. Apoptosis was simultaneously assessed by flow cytometry analysis of cells displaying annexin-V-positive staining. Results. The flow cytometry study showed that about 90% of sham and irradiated cells were annexin-V negative 2 h after irradiation. Two days after irradiation, 68% of lymphocytes and 76% of HaCaT cells were apoptotic, as well as 43% of lymphocytes treated with t-BuOH. In infrared spectra of these apoptotic cells, qualitative and quantitative changes were observed. In the 960–1245 and 1690–1720 cm–1 ranges, mainly attributed to nucleic acids, changes corresponding to conformational changes in DNA were associated with a decrease in the amount of detectable DNA. Conformational changes were also observed in secondary protein structure, in particular an increase in the amount of β structures. These DNA and protein changes were associated with an increase in the detectable amount of lipids in apoptotic HaCaT cells only. Two hours after irradiation, depending on the dose and (or) the cell type, qualitative and quantitative changes were observed in the IR spectra in the amide I and amide II bands, mainly attributed to proteins. These changes were associated with a significant decrease in the 1700–1750 cm–1 range, mainly attributed to the –C=O ester groups of DNA and phospholipids, in the irradiated HaCaT cells only. Conclusion: Our results are in agreement with biochemical published data on radiation-induced apoptosis, and show that DNA is the first cellular target of radiation-induced apoptosis, which, however, also requires conformational changes and synthesis of cell proteins. They also demonstrate that FT-IRM may be useful for assessing the early radiation damage at the molecular level in human cells.Key words: apoptosis, Fourier transform infrared microspectroscopy, γ irradiation, human lymphocytes, HaCaT keratinocytes.
Characterization of three types of calcium channel in the luminal membrane of the distal nephron
Authors: Brunette M G , Leclerc M , Couchourel D , Mailloux J , Bourgeois Y
Published: February 2004

We previously reported a dual kinetics of Ca2+transport by the distal tubule luminal membrane of the kidney, suggesting the presence of several types of channels. To better characterize these channels, we examined the effects of specific inhibitors (i.e., diltiazem, an L-type channel; ω-conotoxin MVIIC, a P/Q-type channel; and mibefradil, a T-type channel antagonist) on 0.1 and 0.5 mM Ca2+uptake by rabbit nephron luminal membranes. None of these inhibitors influenced Ca2+uptake by the proximal tubule membranes. In contrast, in the absence of sodium (Na+), the three channel antagonists decreased Ca2+transport by the distal membranes, and their action depended on the substrate concentrations: 50 µM diltiazem decreased 0.1 mM Ca2+uptake from 0.65 ± 0.07 to 0.48 ± 0.06 pmol·µg–1·10 s–1(P < 0.05) without influencing 0.5 mM Ca2+transport, whereas 100 nM ω-conotoxin MVIIC decreased 0.5 mM Ca2+uptake from 1.02 ± 0.05 to 0.90 ± 0.05 pmol·µg–1·10 s–1(P < 0.02) and 1 µM mibefradil decreased it from 1.13 ± 0.09 to 0.94 ± 0.09 pmol·µg–1·10 s–1(P < 0.05); the latter two inhibitors left 0.1 mM Ca2+transport unchanged. Diltiazem decreased the Vmaxof the high-affinity channels, whereas ω-conotoxin MVIIC and mibefradil influenced exclusively the Vmaxof the low-affinity channels. These results not only confirm that the distal luminal membrane is the site of Ca2+channels, but they suggest that these channels belong to the L, P/Q, and T types.Key words: renal calcium transport, calcium channels, diltiazem, mibefradil, ω-conotoxin.
4-Aminopyridine activates calcium influx through modulation of the pore-forming purinergic receptor in human peripheral blood mononuclear cells
Authors: Lajdova Ingrid , Chorvat, Jr. Dusan , Spustova Viera , Chorvatova Alzbeta
Published: February 2004

We investigated whether 4-aminopyridine (4AP), a drug recently linked to calcium influx and apoptosis, also affected purinergic receptor channels that are known to play an important role in the activation of T lymphocytes. The application of 4AP induced a rise in [Ca2+]i that was sensitive to nickel. This action was also observed in cells in which calcium reserves were emptied using thapsigargin (Tg). However, it was not present in the absence of extracellular Ca2+, despite full internal reserves. Adenosine trisphosphate (ATP), a partial agonist and a physiological activator of purinergic receptors, also stimulated Ca2+ entry independently of the calcium release from internal compartments. The effects of 4AP and ATP were not additive when studied on the same population of cells. KN-62 inhibited an increase in calcium entry induced by 4AP, while brilliant blue G (BBG) prevented it, supporting the hypothesis that purinergic P2X7 receptors are involved in this action. Furthermore, 4AP allowed entry of ethidium bromide (314 Da) but not propidium iodide (415 Da) into the cell, also corroborating the involvement of P2X7 pores. The presented results demonstrate, for the first time in human mononuclear cells isolated from healthy volunteers, that the P2X7 channel pore is involved in the action of 4AP and intervenes in the sustained calcium entry induced in response to 4AP.Key words: calcium, human lymphocytes, 4-aminopyridine, purinergic receptors.
Role of Ba2+-resistant K+ channels in endothelium-dependent hyperpolarization of rat small mesenteric arteries
Authors: Breyne Joke , Vanheel Bert J
Published: February 2004

In rat small mesenteric arteries, the influence of modulation of basal smooth muscle K+ efflux on the mechanism of endothelium-dependent hyperpolarization was investigated. The membrane potentials of the vascular smooth muscle cells were measured using conventional microelectrode techniques. Incubation of resting arteries with the gap junction uncoupler carbenoxolone (20 µM) decreased the endothelium-dependent hyperpolarization elicited by a submaximal concentration of acetylcholine (3 µM) to about 65% of the control. In the presence of Ba2+ (200 µM), which depolarized the membrane potential by 10 mV, the acetylcholine-induced membrane potential response was doubled in magnitude, reaching values not different from control. Moreover, the hyperpolarization was more resistant to carbenoxolone in these conditions. Finally, both in the absence and in the presence of carbenoxolone, the combined application of Ba2+ and ouabain (0.5 mM) did not abolish the acetylcholine response. These results suggest that gap junctional coupling plays a role in endothelium-dependent hyperpolarization of smooth muscle cells of resting rat small mesenteric arteries. Additionally, these findings show that the hyperpolarization does not rely on activation of inward rectifying K+ channels. Although a minor contribution of Na–K pumping cannot be excluded, the Ba2+ experiments show that the membrane electrical response is mediated by activation of a Ba2+-resistant K+ conductance.Key words: EDHF, carbenoxolone, potassium channels, vascular smooth muscle cell membrane potential, vasodilation.
Effect of Ginkgo biloba extract on rat hepatic microsomal CYP1A activity: role of ginkgolides, bilobalide, and flavonols
Authors: Kuo I fan , Chen Jie , Chang Thomas K.H
Published: February 2004

The present study investigated the in vitro effect of Ginkgo biloba extracts and some of the individual constituents (ginkgolides, bilobalide, and flavonols such as kaempferol, quercetin, isorhamnetin, and their glycosides) on CYP1A-mediated 7-ethoxyresorufin O-dealkylation in hepatic microsomes isolated from rats induced with β-naphthoflavone. G. biloba extract competitively inhibited CYP1A activity, with an apparent Ki value of 1.6 ± 0.4 µg/mL (mean ± SE). At the concentrations present in the G. biloba extracts, ginkgolides A, B, C, and J and bilobalide did not affect CYP1A activity, whereas kaempferol (IC50 = 0.006 ± 0.001 µg/mL, mean ± SE), isorhamnetin (0.007 ± 0.001 µg/mL), and quercetin (0.050 ± 0.003 µg/mL) decreased this activity. The monoglycosides (1 and 10 µg/mL) and diglycosides (10 µg/mL) of kaempferol and quercetin but not those of isorhamnetin also inhibited CYP1A activity. The order of inhibitory potency was kaempferol ~ isorhamnetin > quercetin, and for each of these flavonols the order of potency was aglycone >> monoglycoside > diglycoside. In summary, G. biloba extract competitively inhibited rat hepatic microsomal CYP1A activity, but the effect was not due to ginkgolides A, B, C, or J, bilobalide, kaempferol, quercetin, isorhamnetin, or the respective flavonol monoglycosides or diglycosides.Key words: bilobalide, CYP1A, cytochrome P450, Ginkgo biloba, ginkgolide, flavonol.