bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of line transect methods to estimate abundance of benthic stream fishes
Authors: Ensign William E. , Angermeier Paul L. , Dolloff C. Andrew
Published: December 2007

Visual estimation of stream salmonid abundance using strip transect sighting models has become commonplace. Application of visual estimation to other stream fishes, particularly benthic forms, has been limited. Examination of the distribution of sighting distances for the Roanoke darter (Percina roanoka), Roanoke logperch (P. rex), and black jumprock (Moxostoma cervinum) indicates that strip transect sighting models that assume probability of sighting remaining constant out to the limits of observer visibility are not appropriate for these benthic species. Our datasets indicate that distance sampling models that assume decreased sighting probability with increasing distance of the target from the observer provide a reasonable alternative to strip transect sighting models. There was a strong positive correlation between abundance estimates calculated using two alternative distance sampling models, as well as between the distance sampling model estimates and an estimate of abundance obtained with a backpack electroshocker.
Determination of head losses in a surge chamber: Robert Bourassa power plant case study
Authors: Fuamba Musandji , Brosseau Gilles , Mainville Éric
Published: December 2007

Optimal management of power plant units is achieved when the global efficiency of the units and the minimization of the total hydraulic head losses through the water transportation systems can be combined. Evaluating these hydraulic head losses appears to be very difficult due to the complexity of the flow conditions through the hydraulic structures. A hydraulic energy based method to determine head losses in the surge chamber has been proposed in this paper, as well as a method to manage the opening of units which would optimize the production of electricity. This method was applied to a case study, and successful results have been obtained showing how the head loss varies in the surge chamber.Key words: hydraulic head losses, power plant unit, surge chamber, unit efficiency, three-dimensional flow conditions, turbulent flow models, computational fluid dynamics.
Rational design of an on-farm reservoir
Authors: Ojha C S.P , Singh K K , Gupta Sanjeev K.V
Published: December 2007

There is increasing concern to store water in on-farm reservoirs (OFRs) for meeting the supplemental irrigation requirements and (or) improving the irrigation efficiency of irrigation systems. The provision of OFRs leads to loss of a certain portion of agricultural land, but the economic viability of providing OFRs has been justified. As widely prevalent among designers, the volume of various shapes of OFRs is usually computed manually or using computer programs based on the trapezoidal or pyramidal formula. However, it has been found that the trapezoidal or pyramidal formula cannot be used for irregular geometries. For such cases, a method of superimposition has been proposed to compute volume accurately. A simplified approach is presented in this article for optimum design of OFRs. The relations between length and breadth are also developed for a variety of OFR shapes to guide farmers for minimum lining.Key words: on-farm reservoir, trapezoidal formula, pyramidal formula, superimposition, optimization.
Prediction of the fracture life of a wrinkled steel pipe subject to low cycle fatigue load
Authors: Das Sreekanta , Cheng J J. Roger , Murray David W
Published: December 2007

The economy of Canada depends largely on the performance of the hydrocarbon-based energy industry (oil and gas), which in turn is dependent on the performance of steel pipelines that are used for transporting crude oil, natural gas, and petroleum products. Field observations of buried pipelines indicate that it is not uncommon for geotechnical movements to impose large displacements on the pipelines, resulting in localized curvature, deformations, and strain in the pipe wall. Often these local deformations result in local buckling (wrinkling) in the pipe wall, and in the post-buckling range of response such wrinkles develop rapidly. Subsequent cyclic load histories may produce cyclic plastic strain reversals leading to the formation of fractures in the wrinkle region. This paper presents the development and application of a simple fracture-life assessment model that can be used successfully by the pipeline industries to assess the remaining life before fracture of wrinkled pipelines subject to strain reversals due to low cycle fatigue loadings.Key words: wrinkled pipeline, low cycle fatigue load, plastic strain reversal, fracture, hysteresis loop energy, fracture-life assessment model.
Three-dimensional study of spatial submerged hydraulic jump
Authors: Zare H K , Baddour R E
Published: December 2007

A three-dimensional (3D) study of spatial submerged hydraulic jumps (SSHJs) was carried out using a physical model for Froude numbers Fr1= 2.00 and 3.75 and width ratios α = 0.20 and 0.33. Three orthogonal components of the velocity field were obtained with an acoustic Doppler velocimeter (ADV). The 3D velocity field has indicated that the jump consisted of a central jet-like flow, close to the channel bottom, surrounded by vertical and horizontal circulations (rollers). The circulation was predominantly in vertical planes in the channel central region of the flow and in horizontal planes close to the walls. Vertical and horizontal profiles of stream-wise velocity characterized the 3D roller with two length scales, Lrvand Lrh. The strength of the roller was stronger close to the walls than at the centreline of the jump. Sequent depth and energy head loss for submerged symmetric hydraulic jumps are discussed in terms of the submergence ratio S = y3/y2.Key words: hydraulic jump, spatial, submerged, roller length, sequent depth, energy dissipation.
A simplified method for seismic analysis of rooftop telecommunication towers
Authors: Assi Rola , McClure Ghyslaine
Published: December 2007

A simplified method is presented in this paper for the estimation of forces at the base of telecommunication towers mounted on building rooftops due to seismic excitation. Although some codes and standards propose simplified methods for the evaluation of base shear forces for towers founded on ground, no method yet exists for the evaluation of overturning moments. The proposed simplified method is based on numerical simulations using truncated modal superposition, which is widely used for seismic analysis of linear structures. The method requires the prediction of input seismic acceleration at the building–tower interface, the definition of an acceleration profile along the building-mounted tower, and the determination or evaluation of the mass distribution of the tower along its height. The method was developed on the basis of detailed dynamic analyses of three existing towers assumed to be mounted separately on three buildings. It was found that the method yields conservative results, especially for the overturning moments.Key words: self-supporting towers, earthquake, horizontal excitation, dynamic analysis, acceleration, modal superposition.
"Barbs" for river bend bank protection: application of a three-dimensional numerical model
Authors: Minor B , Rennie C D , Townsend R D
Published: December 2007

A three-dimensional numerical model was used to examine the turbulent flow field and associated sediment transport due to a series of barbs (submerged groynes) in a channel bend. Model results were in good agreement with measured laboratory data and adequately simulated the important features of sediment transport. Statistical comparison of the predicted and measured equilibrium bed geometry found average regression coefficients of determination of 0.77 and 0.72 for the 90° and 135° channels, respectively. The predicted velocity data followed expected trends. The capability of a three-dimensional numerical model to simulate sediment transport through bend sections of a channel containing barbs was verified. This included the simulation of the effects of different arrangements of barb groups and an analysis of the data to determine the relation of the flow field to associated scour and deposition in a complex fluvial environment. These novel results are useful for improved analyses of the bank-protection capabilities of these structures and for the development and improvement of design guidelines.Key words: three-dimensional models, numerical models, movable bed models, channel bends, turbulence, secondary flow, scour, barbs, groynes.
Minimisation des surcoûts dans un contexte hors délai : cas des projets de construction dans les pays en développement
Authors: Louzolo-Kimbembé Paul , Pettang Chrispin , Tatiétsé Thomas Tamo
Published: December 2007

Cost overruns are frequent in the construction industry. They become greater the more the construction project is delayed. In developing countries, this situation is recurring and constitutes a significant financial problem. In a time-overrun context, our objective is to find a method that can enable us to reduce the delay while minimizing the subsequent cost overruns. We thus developed a mathematical model named CCOMTOC (construction cost optimisation model in time-overrun context). The model was tested and results reveal that the reduction of cost overruns is effective. We showed that in a time-overrun context, according to the importance of delay penalties, we obtain two distinct situations. On the basis of the reference cost calculated for a maximum compression of tasks within the normal duration, we note that, for low delay penalties, the total cost after further delays to the estimated completion time decreases as we deviate from the initial completion time. On the other hand, for relatively high delay penalties, the cost first passes by a minimum before increasing regularly during the further delays to the estimated completion time.Key words: time overrun, optimization, linear programming, time skid, delay make-up, cost overrun.
Comportement thermohydrique d’une paroi en béton : influence du type de béton, influence du type de chargement
Authors: Shekarchi M , Debicki G
Published: December 2007

Tests simulating “the accidental conditions” and the “test of heating,” without the contribution of humidity, have been carried out on test equipment that we designed and fabricated in the scope of this work. The tests have been carried out on laterally sealed and insulated cylindrical specimens of ordinary or high-performance concrete having a thickness of 1.3 m. Experimental results present temperature, pressure, and moisture distribution throughout the specimens and permit to characterize the hygrothermal behaviour of a concrete wall. The different aspects of the phenomena affecting a two-phase transfer (steam, water) in a porous medium are presented. Test results show that high-performance concrete exposed to an increase in temperature presents a particular hygrothermal behaviour, because of its microstructure, that is put into evidence, notably while looking at the role of the silica fume. The migration of water is not as rapid in high-performance concrete as in ordinary concrete, which is favourable for tightness. Numerical investigation consists of adapting a heat and mass transfer model, initially built for ordinary concrete, to the high-performance concrete used in this work.Key words: hygrothermal behavior, concrete wall, ordinary concrete, high-performance concrete, leak tightness, temperature distribution, pressure distribution, moisture distribution.
Effect of Ginkgo biloba extract on oxidative metabolism of valproic acid in hepatic microsomes from donors with theCYP2C9*1/*1genotypeThis article is one of a selection of papers published in this special issue (part 1 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Numa Andrew M. , Abbott Frank S. , Chang Thomas K.H.
Published: December 2007

We investigated the effect of Ginkgo biloba extracts and some of its individual constituents on the oxidative metabolism of valproic acid (VPA) in hepatic microsomes from donors with the CYP2C9*1/*1 genotype. G. biloba extract decreased 4-ene-VPA, 3-OH-VPA, 4-OH-VPA, and 5-OH-VPA formation with mean (± SE) IC50values of 340 ± 40 μg/mL, 370 ± 100 μg/mL, 180 ± 30 μg/mL, and 210 ± 20 μg/mL, respectively. This was associated with inhibition of not only CYP2C9*1, but also CYP2A6 and CYP2B6. Bilobalide, ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, quercetin-3-O-rutinoside, kaempferol-3-O-rutinoside, and isorhamnetin-3-O-rutinoside were not responsible for the inhibition of VPA metabolism by the extract. When analyzed as the sum of the aglycone and total glycosides present in the extract, quercetin decreased 4-ene-VPA, 4-OH-VPA, and 5-OH-VPA formation by 76%, 51%, and 70%, respectively, kaempferol decreased 4-ene-VPA, 4-OH-VPA, and 5-OH-VPA formation by 65%, 46%, and 49%, respectively, and isorhamnetin decreased 4-ene-VPA, 4-OH-VPA, and 5-OH-VPA formation by 29%, 26%, and 31%, respectively. The 3 aglycones did not affect 3-OH-VPA formation. In summary, G. biloba extract decreased hepatic microsomal formation of 4-ene-VPA, 4-OH-VPA, 5-OH-VPA, and 3-OH-VPA, but the effect was not due to the terpene trilactones or flavonol glycosides investigated in our study.
Live encapsulated Lactobacillus acidophilus cells in yogurt for therapeutic oral delivery: preparation and in vitro analysis of alginate–chitosan microcapsulesThis article is one of a selection of papers published in this special issue (part 1 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Urbanska Aleksandra Malgorzata , Bhathena Jasmine , Prakash Satya
Published: December 2007

Targeted delivery of live microencapsulated bacterial cells has strong potential for application in treating various diseases, including diarrhea, kidney failure, liver failure, and high cholesterol, among others. This study investigates the potential of microcapsules composed of two natural polymers, alginate and chitosan (AC), and the use of these artificial cells in yogurt for delivery of probiotic Lactobacillus acidophilus bacterial live cells. Results show that the integrity of AC microcapsules was preserved after 76 h of mechanical shaking in MRS broth and after 12 h and 24 h in simulated gastric and intestinal fluids. Using an in vitro computer-controlled simulated human gastrointestinal (GI) model, we found 8.37 log CFU/mL of viable bacterial cells were present after 120 min of gastric exposure and 7.96 log CFU/mL after 360 min of intestinal exposure. In addition, AC microcapsules composed of chitosan 10 and 100 at various concentrations were subjected to 4-week storage in 2% milk fat yogurt or 0.85% physiological solution. It was found that 9.37 log CFU/mL of cells encapsulated with chitosan 10 and 8.24 log CFU/mL of cells encapsulated with chitosan 100 were alive after 4 weeks. The AC capsule composed of 0.5% chitosan 10 provided the highest bacterial survival of 9.11 log CFU/mL after 4 weeks. Finally, an investigation of bacterial viability over 72 h in different pH buffers yielded highest survival of 6.34 log CFU/mL and 10.34 log CFU/mL at pH 8 for free and AC-encapsulated cells, respectively. We conclude from these findings that encapsulation allows delivery of a higher number of bacteria to desired targets in the GI tract and that microcapsules containing bacterial cells are good candidates for oral artificial cells for bacterial cell therapy.
From type 2 diabetes to antioxidant activity: a systematic review of the safety and efficacy of common and cassia cinnamon barkThis article is one of a selection of papers published in this special issue (part 1 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Dugoua Jean-Jacques , Seely Dugald , Perri Dan , Cooley Kieran , Forelli Taryn , Mills Edward , Koren Gideon
Published: December 2007

Common ( Cinnamomum verum , C. zeylanicum ) and cassia ( C. aromaticum ) cinnamon have a long history of use as spices and flavouring agents. A number of pharmacological and clinical effects have been observed with their use. The objective of this study was to systematically review the scientific literature for preclinical and clinical evidence of safety, efficacy, and pharmacological activity of common and cassia cinnamon. Using the principles of evidence-based practice, we searched 9 electronic databases and compiled data according to the grade of evidence found. One pharmacological study on antioxidant activity and 7 clinical studies on various medical conditions were reported in the scientific literature including type 2 diabetes (3), Helicobacter pylori infection (1), activation of olfactory cortex of the brain (1), oral candidiasis in HIV (1), and chronic salmonellosis (1). Two of 3 randomized clinical trials on type 2 diabetes provided strong scientific evidence that cassia cinnamon demonstrates a therapeutic effect in reducing fasting blood glucose by 10.3%–29%; the third clinical trial did not observe this effect. Cassia cinnamon, however, did not have an effect at lowering glycosylated hemoglobin (HbA1c). One randomized clinical trial reported that cassia cinnamon lowered total cholesterol, low-density lipoprotein cholesterol, and triglycerides; the other 2 trials, however, did not observe this effect. There was good scientific evidence that a species of cinnamon was not effective at eradicating H. pylori infection. Common cinnamon showed weak to very weak evidence of efficacy in treating oral candidiasis in HIV patients and chronic salmonellosis.
Effects of traditionally used anxiolytic botanicals on enzymes of the γ-aminobutyric acid (GABA) systemThis article is one of a selection of papers published in this special issue (part 1 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Awad R. , Levac D. , Cybulska P. , Merali Z. , Trudeau V.L. , Arnason J.T.
Published: December 2007

In Canada, the use of botanical natural health products (NHPs) for anxiety disorders is on the rise, and a critical evaluation of their safety and efficacy is required. The purpose of this study was to determine whether commercially available botanicals directly affect the primary brain enzymes responsible for γ-aminobutyric acid (GABA) metabolism. Anxiolytic plants may interact with either glutamic acid decarboxylase (GAD) or GABA transaminase (GABA-T) and ultimately influence brain GABA levels and neurotransmission. Two in vitro rat brain homogenate assays were developed to determine the inhibitory concentrations (IC50) of aqueous and ethanolic plant extracts. Approximately 70% of all extracts that were tested showed little or no inhibitory effect (IC50 values greater than 1 mg/mL) and are therefore unlikely to affect GABA metabolism as tested. The aqueous extract of Melissa officinalis (lemon balm) exhibited the greatest inhibition of GABA-T activity (IC50 = 0.35 mg/mL). Extracts from Centella asiatica (gotu kola) and Valeriana officinalis (valerian) stimulated GAD activity by over 40% at a dose of 1 mg/mL. On the other hand, both Matricaria recutita (German chamomile) and Humulus lupulus (hops) showed significant inhibition of GAD activity (0.11–0.65 mg/mL). Several of these species may therefore warrant further pharmacological investigation. The relation between enzyme activity and possible in vivo mode of action is discussed.
XP-828L (Dermylex), a new whey protein extract with potential benefit for mild to moderate psoriasisThis article is one of a selection of papers published in this special issue (part 1 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Drouin Réjean , Lamiot Éric , Cantin Kim , Gauthier Sylvie F. , Pouliot Yves , Poubelle Patrice E. , Juneau Christina
Published: December 2007

Natural health products (NHPs) or complementary and alternative medicine (CAM) are commonly used to prevent disorders or support the usual treatments of many diseases. XP-828L, a whey protein extract, has demonstrated potential benefits for the treatment of mild to moderate psoriasis. The aim of this study was to analyze further clinical data that demonstrated the clinical benefits and safety of the XP-828L in patients with psoriasis and the potential mechanism of action of this product in vitro. Oral administration (2.5 g, twice a day, over 112 days) of XP-828L in 42 human subjects with mild to moderate psoriasis improved their PGA scores (physician’s global assessment). Moreover, no significant changes in haematology or hepatic and renal parameters were observed throughout the study period, indicating the safety of the product. In vitro experiments showed that XP-828L decreased the proliferation of concanavalin A (ConA)-stimulated murine splenocytes and their production of interleukin (IL)-2 and interferon (IFN)-γ. Although the in vivo mechanism of action of XP-828L remains unknown, XP-828L represents an NHP to be used as an alternative or concomitant treatment for mild to moderate psoriasis and potentially for other immune-mediated diseases.
Magnesium tanshinoate B protects endothelial cells against oxidized lipoprotein-induced apoptosisThis article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Au-Yeung Kathy K.W. , O Karmin , Choy Patrick C. , Zhu Da-yuan , Siow Yaw L.
Published: December 2007

The activation of c-Jun N-terminal kinase (JNK) signaling pathway plays an important role in the induction of cell apoptosis. We previously reported that magnesium tanshinoate B (MTB), a compound purified from a Chinese herb danshen ( Salvia miltiorrhiza ), could inhibit ischemia/reperfusion-induced myocyte apoptosis in the heart. The objective of the present study was to investigate whether MTB can prevent oxidized lipoprotein-induced apoptosis in endothelial cells. Human umbilical vein endothelial cells (HUVECs) were incubated with copper-oxidized very low density lipoprotein (Cu-OxVLDL) or copper-oxidized low density lipoprotein (Cu-OxLDL). Treatment of cells with Cu-OxVLDL or Cu-OxLDL resulted in a 3-fold increase in the JNK activity. The amount of cytochrome c released and the activity of caspase-3 in cells treated with Cu-OxVLDL or Cu-OxLDL were significantly elevated, indicating the occurrence of apoptosis. The presence of MTB was able to abolish the JNK activation, cytochrome c release, and caspase-3 activation induced by Cu-OxVLDL or Cu-OxLDL, resulting in a marked reduction in apoptosis in endothelial cells. The data from this study indicate that oxidized lipoproteins induce apoptosis in endothelial cells. We postulate that the inhibition of the JNK signaling pathway by MTB is a key mechanism that protects these cells from oxidized lipoprotein-induced apoptosis.
Gene response of human monocytic cells for the detection of antimigraine activity of feverfew extractsThis article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Chen Chin-Fu , Leung Albert Y.
Published: December 2007

The herb feverfew is a folk remedy for various conditions, including inflammation, fever, psoriasis, rheumatism, and asthma. Like many herbal medicines, feverfew's mechanisms of action in the human body are largely unknown and its active ingredients remain elusive. Very often, different extraction methods of herb material produce different physical and biochemical properties and variation in clinical efficacy. We identified 3 major methods of extraction for feverfew aerial parts and used microarray technology to test the hypothesis that extracts produced by different methods elicit different gene expression profiles. We have identified approximately 200 genes that are consistently regulated by the 2 presumptive active antimigraine feverfew extracts but not associated with the inactive extract. Our results suggest that the presumptive active feverfew extracts potently stimulate more genes in human cells than the inactive extracts. We also identified several genes as unique signatures for these active extracts. All 3 feverfew extracts exhibited similar blockades on lipopolysaccharide-mediated TNF-α (tumor necrosis factor alpha) release, implicating that TNF-α is not responsible for the differences in the effects of the 3 feverfew extracts in human cells. In contrast, the active extracts more effectively suppressed CCL2 (also known as monocyte chemoattractant protein 1, MCP-1) than the inactive extracts, suggesting that CCL2 is a potential cellular target for feverfew’s antimigraine effects.
Echinacea purpurea L. in children: safety, tolerability, compliance, and clinical effectiveness in upper respiratory tract infectionsThis article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Saunders Paul Richard , Smith Fraser , Schusky Read Weaver
Published: December 2007

Echinacea purpurea (L.) Moench was mistakenly taken from North America to Germany in 1939 where it was cultivated and various extractions were prepared and subsequently used to treat upper respiratory tract infections. Parents often administer Echinacea to their children, but safety data on the use of Echinacea in Canadian children is lacking. A screening history, physical examination, and daily record of symptoms from an initial visit through to a the follow-up visit 13 days later were used to increase patient safety. Each subject was administered an aerial part Echinacea extract. The dose was based on age (2.5 mL three times per day for children aged 2–5 years, and 5 mL two times per day for children aged 6–12 years) and administered for 10 days in an open-label trial. A rating scale was used to measure tolerance to the treatment. We assessed the safety and compliance of use of the Echinacea extract by measuring the amount of extract returned at the end of the study, having the parents complete and return a daily symptom diary, and recording the subjects’ use of other natural health products or medications during the trial. Clinical effectiveness of the Echinacea extract could not be accurately assessed because of the small trial size and because the extract had been administered when some of the subjects had an upper respiratory tract infection that had begun 1 or more days prior to the study; however, each subject’s symptoms improved. No allergic or adverse reaction occurred and no safety issues arose.
In vitro activity of uva-ursi against cytochrome P450 isoenzymes and P-glycoproteinThis article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Chauhan B. , Yu C. , Krantis A. , Scott I. , Arnason J. T. , Marles R. J. , Foster B. C.
Published: December 2007

Some natural health products (NHPs) affect drug metabolism enzymes and transport proteins, potentially affecting the safety and efficacy of the drug or other NHPs. This study was undertaken to characterize the effect of uva-ursi ( Arctostaphylos uva-ursi ) on cytochrome P450 isozyme (3A4, 3A5, 3A7, 2C19, and 19)-mediated metabolism and P-glycoprotein (P-gp) transport. Three bulk and 2 capsulated uva-ursi samples were obtained from commercial outlets. The capsules were batched, and herbal samples were ground to a common consistency. Aqueous and methanol extracts were freshly prepared. Cytochrome P450 isozyme-mediated metabolism was determined by using in vitro bioassays. P-gp transport function was determined by using a rhodamine 123 (Rh123) uptake test in human (THP-1) monocytes and human Caco-2 cells. All products were analyzed by HPLC for arbutin, gallic acid, myricitrin, and isoquercetin. A large variation was observed in the biomarkers found between the bulk and capsulated samples. Our data indicate that both the aqueous and methanol extracts of all 5 uva-ursi products showed high cytochrome P450 isozyme inhibition, with the exception of the methanol extracts against cytochromes P3A4 and P19, which had low to moderate activity. The aqueous extracts of uva-ursi showed an inhibitory effect on Rh123 efflux by P-gp at 1 h and an inductive effect at 18 h for both cell lines. Our results show that the uva-ursi herbal products tested here have pharmacological properties, including the potential capacity to affect drug safety and efficacy. Further studies are warranted against a wider range of cytochrome P450 isozymes and to determine whether these effects are clinically significant.
Medicinal plants of Cree communities (Québec, Canada): antioxidant activity of plants used to treat type 2 diabetes symptomsThis article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Fraser Marie-Hélène , Cuerrier Alain , Haddad Pierre S. , Arnason John T. , Owen Patrick L. , Johns Timothy
Published: December 2007

Traditional medicines (TM) used to treat symptoms of diabetes by two Cree communities were assessed for their free radical scavenging activity using the stable 1,1-diphenyl-2-picrylhydrazyl radical, and their ability to protect human low-density lipoprotein from Cu2+-mediated oxidation by measuring lag time before the appearance of conjugated dienes and formation of thiobarbituric acid-reactive substances. Water-soluble phenolic content was also measured. A total of 20 medicinal plants from Whapmagoostui and 16 from Mistissini were compared with 16 extracts of plants that were not used medicinally. Medicinal plant extracts, particularly those from Larix laricina, displayed high antioxidant activity, comparable with ascorbic acid, Trolox, and the known antioxidant flavonoids quercetin, epicatechin, catechin. Extracts of Pinaceae and Ericaceae contained the highest levels of phenolics. Factors such as season and area of plant collection, as well as the plant part from which the extract was derived, affected antioxidant activity. Positive correlations were found between the established traditional knowledge of Cree Elders and Healers and the antioxidant activity for medicinal plants used in Mistissini (r = 0.3134; p = 0.058) and in Whapmagoostui (r = 0.5165; p = 0.001). Significant correlations between phenolic content were also seen with the existing ethnobotanical data (r = 0.5015; p = 0.003) and bioassays (r = 0.4178; p = 0.003). These results indicate that a clear majority of plants used by the Cree are excellent sources of antioxidants.
Synergistic cytotoxic effects of tamoxifen and black cohosh on MCF-7 and MDA-MB-231 human breast cancer cells: an in vitro studyThis article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products.
Authors: Al-Akoum Mahéra , Dodin Sylvie , Akoum Ali
Published: December 2007

Breast cancer cell cultures were exposed to different concentrations of black cohosh, estradiol (E2), and tamoxifen to examine the effect on cell proliferation; cytotoxicity was assessed by using sulforhodamine B (SRB) dye solution. E2 (10−10–10−8 mol/L) markedly stimulated the proliferation of MCF-7 cells (p < 0.01). Tamoxifen stimulated MCF-7 cell proliferation at 10−6 mol/L and 10−5 mol/L (p < 0.005) but inhibited in a dose-dependent fashion the proliferative effect of E2 (p < 0.001). Black cohosh alone did not show any stimulatory effect, but exhibited a cytotoxic effect, which was significant at 103 μg/mL (p < 0.001). Adding black cohosh at 100–103 μg/mL to E2 at 10−9 mol/L also resulted in a dose-dependent inhibition of E2 proliferative effect. Interestingly, the combination of black cohosh (100–103 μg/mL) with increasing tamoxifen concentrations further inhibited MCF-7 cell growth. On MDA-MB-231 cells, neither E2 nor tamoxifen displayed any detectable effect. However, black cohosh inhibited MDA-MB-231 cell proliferation at 103 μg/mL (p < 0.05), and this inhibitory effect was enhanced by increasing tamoxifen concentrations. This study reveals a cytotoxic effect of black cohosh on both estrogen-sensitive and estrogen-insensitive breast cancer cells and a synergism with tamoxifen for inhibition of cancerous cell growth.
Role of calmodulin and myosin light chain kinase in the activation of carbachol-activated cationic current in murine ileal myocytes
Authors: Kim Byung Joo , Jeon Ju-Hong , Kim Seon Jeong , So Insuk
Published: December 2007

We investigated the effect of calmodulin (CaM) and myosin light chain kinase (MLCK) on murine ileal myocytes using the whole-cell patch-clamp technique. Under the voltage clamp, at the holding potential of –60 mV, 50 μmol/L carbachol (CCh) induced inward currents (ICCh), and spontaneous decay of ICChoccurred. The peak inward currents induced by the repetitive application of CCh (50 μmol/L) tended to decrease in amplitude. Intracellular application of 0.2 mmol/L guanosine 5′-O-(γ-thio)triphosphate (GTPγS) from the patch electrode induced an inward current at a holding potential of –60mV, and the peak inward currents induced by the repetitive application of Cs tended to decrease slightly in amplitude. The amplitude of ICChwas reduced by pretreatment either with W-7, trifluoroperazine, W-5, and melittin (CaM inhibitors) or with ML-7 and ML-9 (selective MLCK inhibitors), and the inhibitory effects were reversible. However, when we pretreated with 50 μmol/L W-7 or 5 μmol/L ML-7 on GTPγS-induced inward currents, almost no inhibition was observed in the inward currents. Application of both Rho kinase inhibitor and MLCK inhibitor inhibited GTPγS-induced currents. We conclude that CaM and MLCK modulate the activation process of ICChin murine ileal myocytes and suggest that the classical type transient receptor potential (TRPC) channel 5 might be a candidate for nonselective cationic currents (NSCC) activated by muscarinic stimulation in gastrointestinal smooth muscle cells.
Hydrogen sulfide contributes to cardioprotection during ischemia–reperfusion injury by opening KATPchannels
Authors: Zhang Zhifei , Huang Haixia , Liu Ping , Tang Chaoshu , Wang Jun
Published: December 2007

The present study was undertaken to investigate the protective effect of H2S against myocardial ischemia–reperfusion (I/R) injury and its possible mechanism by using isolated heart perfusion and patch clamp recordings. Rat isolated hearts were Langendorff-perfused and subjected to a 30-minute ischemia insult followed by a 30-minute reperfusion. The heart function was assessed by measuring the LVDP, ±dP/dtmax, and the arrhythmia score. The results showed that the treatment of hearts with a H2S donor (40 μmol/L NaHS) during reperfusion resulted in significant improvement in heart function compared with the I/R group (LVDP recovered to 85.0% ± 6.4% vs. 35.0% ± 6.1%, +dP/dtmaxrecovered to 80.9% ± 4.2% vs. 43.0% ± 6.4%, and –dP/dtmaxrecovered to 87.4% ± 7.3% vs. 53.8% ± 4.9%; p < 0.01). The arrhythmia scores also improved in the NaHS group compared with the I/R group (1.5 ± 0.2 vs. 4.0 ± 0.4, respectively; p < 0.001). The cardioprotective effect of NaHS during reperfusion could be blocked by an ATP-sensitive potassium channel (KATP) blocker (10 μmol/L glibenclamide). In single cardiac myocytes, NaHS increased the open probability of KATPchannels from 0.07 ± 0.03 to 0.15 ± 0.08 after application of 40 μmol/L NaHS and from 0.07 ± 0.03 to 0.36 ± 0.15 after application of 100 μmol/L NaHS. These findings provide the first evidence that H2S increases the open probability of KATPin cardiac myocytes, which may be responsible for cardioprotection against I/R injury during reperfusion.
Functions, services and value of soil organic matter for human societies and the environment: a historical perspective
Authors: Feller C. , Manlay R. J. , Swift M. J. , Bernoux M.
Published: December 2007

Soil organic matter (SOM) contributes significantly to the chemical, physical and biological ecosystem functions of soil. It influences on plant growth, thus contributing to agricultural production, and performs environmentally valuable services such as carbon sequestration, regulation of the water cycle and detoxification of pollutants. Identification of the functions and services provided by SOM has a long and tumultuous history of scientific discoveries and struggles against false assumptions. This work reports the major steps of this history, with emphasis on two services secured by SOM: (1) the role of SOM in plant production and its connection to soil fertility and thence to the sustainability of cropping and farming systems; and (2) the recognition and assessment of the contribution of SOM to climate-change regulation. Finally, the work explores how SOM, as a multifunctional resource, may be allocated an economic value as a way of promoting its conservation.
Soil sealing and soil properties related to sealing
Authors: Burghardt Wolfgang
Published: December 2007

Sealing implies separation of soils from the atmosphere and above-ground biosphere by impermeable layers. Sealing has a strong impact on soils. The degree of sealing is related to the type of land use and to the population density. Sealed areas are still increasing, and it is often the most fertile soils which are sealed. The negative effects of sealing are partial or total loss of soils, e.g. for plant production and habitats, and an increase in floods, as well as an increase in health and social costs. On the other hand, sealed areas contribute hugely to the gross national product of a country. The most effective contributions for reducing soil sealing are expected to come from the engineering sciences. Other contributions could be made by the economic and social sciences. It is also important to address the problem at a political level, e.g. by passing an international convention to prevent soil consumption. Despite all these problems, soils can still exist underneath sealed areas. Their properties can be used to mitigate the negative effects of sealing.
Australian examples of the role of soils in environmental problems
Authors: Hazelton P. A.
Published: December 2007

Will everyone, please at some stage during the next few days take hold of a handful of soil and show it some respect? Grab
some, take a hard look at it, marvel at its workings, sing in praise of its chemistry, bless its bugs for being there and before
piacing it on the ground, say thank you. If ever the environment had a poor relation, it is the soil. It has none of the romance
of furry animals, birds or butterflies and yet it is fundamental to life on earth.

(Heiney 1997)
Seismic geomorphology - an overview
Authors: Posamentier H. W. , Davies R. J. , Cartwright J. A. , Wood L.
Published: December 2007

Seismic geomorphology, the extraction of geomorphic insights using predominantly three-dimensional seismic data, is a rapidly evolving discipline that facilitates the study of the subsurface using plan view images. A variety of analytical techniques is employed to image and visualize depositional elements and other geologically significant features. This volume presents key technical papers presented at a recent research conference - the Seismic Geomorphology Conference (10–11 February 2005), co-convened by the Society for Sedimentary Geology and The Geological Society (London). These papers cover a broad range of topics, from detailed depositional element analysis to big picture regional issues, from lithology prediction to diagenetic modification of the stratigraphic section. This discipline is only in its early stages of development and will henceforth expand rapidly in response to the growing availability to researchers of high-quality three-dimensional seismic data.
Geomorphology and age of the Oxygen isotope stage 2 (last lowstand) sequence boundary on the northwestern Gulf of Mexico continental shelf
Authors: Simms A. R. , Anderson J. B. , Milliken K. T. , Taha Z. P. , Wellner J. S.
Published: December 2007

The sequence boundary associated with the last glacial-eustatic lowstand was mapped across the northwestern Gulf of Mexico continental shelf. The geomorphology of incised fluvial valleys varies widely across the shelf. These differences are due to differences in shelf physiography and the interval of the eustatic cycle the valleys were occupied. Incision begins during the falling limb of sea level and results in terraced valleys. Rivers that abandoned their valleys during the fall in sea level to cut new valleys during the lowstand generally have u-shaped profiles. Incised valleys connected to turbidite systems only occurred in two valleys (the Colorado and Rio Grande), but this may be because sea level did not fall below the shelf break during the last eustatic cycle. Some valleys deepen in an offshore direction, others become shallower. The timing of fluvial incision was constrained using radiocarbon dates so that incision can be tied directly to the sea-level curve for the last glacial-eustatic cycle. The results show that the fluvial incision occurred throughout the falling limb of sea level and lowstand; however, maximum incision occurred during the lowest position of sea level. The resulting surface has significant relief, extends across the shelf, and has time significance. The associated conformable surface, on the other hand, is much harder to recognize and occurs at different stratigraphic levels relative to different shelf-margin deltas.
Seismic stratigraphic and geomorphic analysis of deep-marine deposition along the West African continental margin
Authors: Hadler-Jacobsen F. , Gardner M. H. , Borer J. M.
Published: December 2007

The West African continental margin evolution is preserved in a small source-distant setting (20 x 30 km area) by changes in lobe-channel-levee seismic geomorphological elements within a threefold seismic stratigraphic hierarchy. The
C
. 32 Ma depositional record of rift, drift and depositional outbuilding of the margin by gravity-driven adjustment, deformation and deposition produced a hierarchy of second- through fourth-order stratigraphic cycles bounded by laterally continuous fine-grained drapes inferred to record prolonged periods of sediment starvation. The margin outbuilding phase, the focus of this contribution, consists of three second-order adjustment bounded cycles (ABCs) that record major adjustment and/or modification of the deep-marine depositional system. Seven third-order cycles also show changes in depositional trend and seismic facies architecture. Ten fourth-order cycles, best resolved within the upper part of the succession, consist of multiple, wedge-shaped and compensating, lobe-channel-levee complexes up to 20 km wide. These complexes show an upward increase in channel-levee and decrease in lobe proportion. They also show an upward change from lobes incised by sinuous channels to channels deflected to lobe flanks. Outcrop and shallow core-calibrated analogues from the Permian Brushy Canyon Formation, and modern Amazon and Zaire Fans help constrain these patterns. Changes in the sediment composition and volume of subaqueous flows at their point of origin, and subsequent gravitational deformation, syn-sedimentary mass-wasting and large-scale fan avulsion punctuating deep-marine sedimentation, adjust deep-marine depositional pattern during basin margin outbuilding. Lobe-channel-levee distributions in this sediment source-distant setting record a progressive increase in local topographic relief and gradient related to the basinward migration of deformation during depositional outbuilding of the continental margin. Two important conclusions derived from this record include (1) the importance of local seabed topography and gradient on producing changes in depositional pattern, and (2) that repeated and cyclic changes in these patterns reflect adjustment/deformation within, and probably restricted to, the deep-marine record. Integrated seismic stratigraphic and geomorphic analysis delineates multiple scales of these adjustment-bounded cycles. The evolving map patterns record adjustment by shifts in geomorphic pattern and orientation. These local geomorphic changes can be used to predict longer-term and larger-scale changes in the depositional record of the continental margin evolution. This analytical approach should have general utility along high shelf-to-basin relief margins with similar gravity-driven deformation.
Using multi-attribute neural networks classification for seismic carbonate fades mapping: a workflow example from mid-Cretaceous Persian Gulf deposits
Authors: Baaske U. P. , Mutti M. , Baioni F. , Bertozzi G. , Naini M. A.
Published: December 2007

Seismic facies mapping in large seismic surveys can be time consuming, even if only a basic overview of the facies distribution is needed. Therefore this study outlines an approach for the use of volume-based seismic attributes from 2D surveys for automated seismic facies mapping within carbonate settings. The study area is located in the central Persian Gulf, offshore Iran. The interval of interest is the mid-Cretaceous Sarvak Formation, which is part of the extensive Cretaceous shallow-water carbonate platform of the eastern Arabian Plate. A set of nine volume-based seismic attributes, calculated from time, amplitude and frequency information of post-stacked 2D seismic data, was chosen to characterize geological information within the interval of interest. The volume-based attributes were supplemented by two grid-based attributes to highlight structural elements. The geological significance of each attribute was evaluated by comparing it with results of seismic sedimentological/geomorphological studies. Furthermore, statistical methods were applied to highlight direct relationships amongst the attributes. The results of these tests were then used to choose a limited set of attributes for neural network-based multi-attribute classifications. The results show that seismic attributes derived from 2D surveys can be used to map basic seismic facies types in carbonate settings and that the outlined, general approach might be applied in other studies.
A formal model of annotations of digital content
Authors: Agosti Maristella , Ferro Nicola
Published: December 2007

This article is a study of the themes and issues concerning the annotation of digital contents, such as textual documents, images, and multimedia documents in general. These digital contents are automatically managed by different kinds of digital library management systems and more generally by different kinds of information management systems.

Even though this topic has already been partially studied by other researchers, the previous research work on annotations has left many open issues. These issues concern the lack of clarity about what an annotation is, what its features are, and how it is used. These issues are mainly due to the fact that models and systems for annotations have only been developed for specific purposes. As a result, there is only a fragmentary picture of the annotation and its management, and this is tied to specific contexts of use and lacks-general validity.

The aim of the article is to provide a unified and integrated picture of the annotation, ranging from defining what an annotation is to providing a formal model. The key ideas of the model are: the distinction between the meaning and the sign of the annotation, which represent the semantics and the materialization of an annotation, respectively; the clear formalization of the temporal dimension involved with annotations; and the introduction of a distributed hypertext between digital contents and annotations. Therefore, the proposed formal model captures both syntactic and semantic aspects of the annotations. Furthermore, it is built on previously existing models and may be seen as an extension of them.