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Selected AbstractsDefining and measuring braiding intensityEARTH SURFACE PROCESSES AND LANDFORMS, Issue 14 2008Roey Egozi Abstract Geomorphological studies of braided rivers still lack a consistent measurement of the complexity of the braided pattern. Several simple indices have been proposed and two (channel count and total sinuosity) are the most commonly applied. For none of these indices has there been an assessment of the sampling requirements and there has been no systematic study of the equivalence of the indices to each other and their sensitivity to river stage. Resolution of these issues is essential for progress in studies of braided morphology and dynamics at the scale of the channel network. A series of experiments was run using small-scale physical models of braided rivers in a 3 m , 20 m flume. Sampling criteria for braid indices and their comparability were assessed using constant-discharge experiments. Sample hydrographs were run to assess the effect of flow variability. Reach lengths of at least 10 times the average wetted width are needed to measure braid indices with precision of the order of 20% of the mean. Inherent variability in channel pattern makes it difficult to achieve greater precision. Channel count indices need a minimum of 10 cross-sections spaced no further apart than the average wetted width of the river. Several of the braid indices, including total sinuosity, give very similar numerical values but they differ substantially from channel-count index values. Consequently, functional relationships between channel pattern and, for example, discharge, are sensitive to the choice of braid index. Braid indices are sensitive to river stage and the highest values typically occur below peak flows of a diurnal (melt-water) hydrograph in pro-glacial rivers. There is no general relationship with stage that would allow data from rivers at different relative stage to be compared. At present, channel count indices give the best combination of rapid measurement, precision, and range of sources from which measurements can be reliably made. They can also be related directly to bar theory for braided pattern development. Copyright © 2008 John Wiley & Sons, Ltd. [source] The optimization of the extrusion process when using maize flour with a modified amino acid profile for making tortillasINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2006Jorge Milán-Carrillo Summary Maize with a modified amino acid profile, i.e. greater amounts of lysine and tryptophan than normal, is known as ,quality protein maize' (QPM). The objective of this work was to find the best combination of extrusion process variables to produce QPM flour for making tortillas. QPM grits were mixed with lime and water and had a moisture content of 28%. The single screw extruder operation conditions were selected from factorial combination of three process variables: extrusion temperature (ET, 70,100 °C), lime concentration (LC, 0.1,0.3% of the maize weight) and screw velocity (SV, 80,250 rpm). Response surface methodology was used as an optimization technique. In vitro protein digestibility (PD); total colour difference (,E) of the flours, and tortilla puffing (TP) were chosen as response variables. A graphical method was used to obtain maximum PD, TP and minimum ,E. The optimum combination of process variables was: ET = 85 °C/LC = 0.21%(w/w)/SV = 240 rpm. Tortillas from QPM flour had similar chemical composition, physicochemical and sensory properties to tortillas from commercial nixtamalized maize flour; however, the former had the highest (P , 0.05) available lysine content and were therefore better nutritionally. [source] Etude comparative de la disponibilité de l'eau en irrigation goutte à goutteIRRIGATION AND DRAINAGE, Issue 3 2001A.V. Ould Mohamed El-Hafedh goutteur; écartement; durée d'irrigation; fréquence d'arrosage Abstract Dans le but de déterminer la meilleure combinaison entre période et durée d'irrigation pour différents écartements inter-goutteurs, nous avons essayé d'analyser la disponibilité de l'eau au sein de la zone racinaire d'une culture de tomate irriguée à l'aide d'une rampe de goutteurs débitant chacun 4 l h,1. Trois écartements ont été étudiés à savoir 30, 50 et 70 cm. Lorsqu'on a pris une durée d'arrosage systématique de 4h30mn, nous avons observé à la fin des irrigations des teneurs en eau volumiques moyennes dépassant la capacité au champ pour les trois écartements. En effet, à l'examen de l'évolution des teneurs en eau au sein du bulbe, il est remarqué que la teneur en eau à la capacité au champ a été atteinte après 25 minutes, 50 minutes et deux heures respectivement pour 30, 50 et 70 cm. Mais l'humidification de toute la ligne de culture n'a été observée qu'après des temps respectifs d'une heure, deux heures et quatre heures (Ould Mohamed El-Hafedh et al., 2000). Les irrigations ont été reprises avec ces durées réduites (une heure, deux heures et quatre heures respectivement pour les écartements 30, 50 et 70 cm) en vue d'évaluer et comparer les consommations en eau de la culture sous les différents traitements. Dans le cas de l'irrigation d'une durée de 4h30mn, la période séparant deux arrosages successifs a été de cinq, quatre et trois jours respectivement pour les écartements 30, 50 et 70 cm. Pour les irrigations des durées réduites, on a constaté qu'il est impératif d'irriguer après trois jours pour les deux écartements 50 et 70 cm et après deux jours pour l'écartement 30 cm. En comparant les consommations en eau pour les durées réduites et la durée systématique de 4h30mn, on a observé une économie d'eau de l'ordre de 20, 15 et 5% respectivement pour 30, 50 et 70 cm d'écartement. D'autre part, la comparaison entre les durées réduites montre que la plus importante économie en eau a été réalisée avec 50 cm d'écartement. Copyright © 2001 John Wiley & Sons, Ltd. In order to determine the best combination between duration and frequency of drip irrigation for various inter-dripper spacing, we analysed the availability of water within the root zone of a tomato culture irrigated using lateral drippers each outputting 4 l h,1 discharge rate. Three spacings were studied, namely 30, 50 and 70 cm. Studying systematic irrigation duration of 4½ hours, we observed at the end of each irrigation average volumetric water contents exceeding the field capacity. Indeed, with the examination of the evolution of the water contents within the bulb, it is noticed that the water content at the field capacity was reached after 25 minutes, 50 minutes and 2 hours respectively for 30, 50 and 70 cm spacing. But the humidification of the whole culture line was observed only after the respective times of 1, 2 and 4 hours (Ould Mohamed El-Hafedh et al., 2000). The irrigations were taken again with these reduced durations (1, 2 and 4 hours for 30, 50 and 70 cm spacing respectively) in order to evaluate and compare water consumption of the culture under the various treatments. In case of systematic irrigation duration, the period separating two successive waterings was five, four and three days for 30, 50 and 70 cm spacing respectively. For the reduced irrigation durations, it is imperative to irrigate after three days for the 50 and 70 cm spacings and after two days for the 30 cm spacing. Comparing water consumption for the reduced durations and those of the systematic duration, we observed water savings of about 20, 15 and 5% respectively for 30, 50 and 70-cm spacing. The comparison between the reduced durations shows that the most significant water saving was obtained with the 50 cm spacing. Copyright © 2001 John Wiley & Sons, Ltd. [source] Integration of colour and textural information in multivariate image analysis: defect detection and classification issuesJOURNAL OF CHEMOMETRICS, Issue 1-2 2007J. M. Prats-Montalbán Abstract In industrial processes, the detection and visualisation of defects and the development of efficient automated classification tools are strategic issues, especially when dealing with random colour textures (RCTs). This paper discusses the benefits of integrating colour and spatial (i.e. textural) information of digital RGB colour images in multivariate image analysis (MIA) to deal with these topics. Regarding the first one, a simple and computational cost-effective monitoring procedure based on colour-textural MIA merged with multivariate statistical process control (MSPC) ideas is outlined. Two novel computed images: T2 and RSS Images are proposed. The procedure is applied on digital RGB colour images from artificial stone plates. With respect to the second issue, when colour-textural MIA is used for image classification a lot of factors (e.g. pre-processing, modelling,,,) likely affecting the success rate in the classification (SRC) show up. This paper presents a methodology based on the combination of experimental design and logistic regression for choosing the best combination of factors to maximise the SRC of different types of images. Digital RGB colour images from ceramic tiles and orange fruits are used to illustrate the potential of the proposed methodology. Copyright © 2007 John Wiley & Sons, Ltd. [source] INHIBITION OF STALING IN CHAPATI (INDIAN UNLEAVENED FLAT BREAD)JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2008IRSHAD M. SHAIKH ABSTRACT Chapati is an unleavened Indian flat bread made from whole wheat flour usually consumed immediately after preparation as it becomes hard on keeping because of staling. Large-scale mechanized preparation of ready-to-eat chapatis will have to address this problem. Investigations were made to study the effect of sodium stearoyl-2-lactylate (SSL), glycerol monostearate, propylene glycol, sorbitol, ,-amylase, xylanase, maltodextrin and guar gum when added to chapati dough, on the inhibition of staling in chapatis stored at 29 ± 1C and 4 ± 1C. Chapatis were prepared from whole wheat flour dough containing (salt, 5% oil, appropriate preservatives and the aforementioned additives. Chapatis were packed in self-sealing low-density polyethylene bags and were stored for 10 days at 29 ± 1C and 4 ± 1C. Stored chapatis were analyzed for various staling parameters such as moisture content, texture, water-soluble starch, in vitro enzyme digestibility, enthalpy change (,H) and sensory quality. Staling of chapatis at 29 ± 1C and at 4 ± 1C of storage was inhibited by all additives to different extents; the extent of staling was less at 4 ± 1C. Maltodextrin at 0.3% (w/w) was found to be the most effective. Several combinations of additives were also studied, and the best combination was (100 ppm) + SSL (0.375%) levels. PRACTICAL APPLICATIONS Chapati, a traditional staple food of Indians, is unleavened flat bread made from whole wheat flour. With rapidly changing lifestyles, changing socio-economic trends and increasing urbanization and consumerism there is a rising demand for convenience foods which require minimum or no preparation time particularly the ready-to-eat (RTE) type of foods. Chapatis are generally baked fresh twice a day for lunch and dinner, and unless eaten immediately after baking, these stale rapidly and become difficult to chew. The most important parameter of chapati quality is its texture. The texture is generally evaluated in terms of tenderness, flexibility and its suitability to be folded into a spoon shape for eating with curried preparation. RTE chapatis are the latest addition to the species of "convenience foods." Keeping this in mind the research was undertaken to improve quality of chapati with the addition of various additives and improvements for the inhibition of staling in chapati. [source] An in vitro wear study of posterior denture tooth materials on human enamelJOURNAL OF ORAL REHABILITATION, Issue 5 2001Y. Abe This in vitro study evaluated the wear effects of five posterior denture tooth materials on human enamel. The tooth specimen was cusp shaped and enamel specimen was formed as a 10 Ç 10 Ç 5 mm plate. All material-enamel combinations were tested using a machine designed to produce sliding contact 20 Ç 104 times at 60 cycles min,1 and a 4-mm sliding distance per stroke in the bucco-lingual direction under a load of 1 kg. Wear analysis was measured as the total height loss of each combination. In addition, the surface roughness (Ra) of each worn specimen was also evaluated. The least total height loss occurred with poly (methyl methacrylate) (PMMA) enamel pair, and the greatest did with porcelain (Po)-enamel pair. The lowest compound Ra value was measured in high-strength resin (HR)-enamel pair, and the highest in Po-enamel pair. These findings suggest that the best combination is PMMA-enamel, and the poorest combination is Po-enamel. [source] Fracture Resistance of Fiber-Reinforced PMMA Interim Fixed Partial DenturesJOURNAL OF PROSTHODONTICS, Issue 4 2006Tamer A. Hamza BDS Purpose: To compare different fiber reinforcements on fracture toughness of interim polymethyl methacrylate materials and then use the best combination to determine the optimal position for fiber placement in an interim 3-unit fixed partial denture (FPD). Materials and Methods: In the first stage of the study, five groups of notched fracture toughness specimens were fabricated and loaded to failure (Instron): (1) unreinforced (control); (2) reinforced with pre-impregnated silanized E-glass fibers (Fibrestick); (3) cold plasma-treated woven polyethylene fibers (Ribbond triaxial); (4) pre-impregnated silanized plasma-treated woven polyethylene fibers (Construct); and (5) 1.0-mm-diameter stainless steel wire. In the second stage, the optimal position (occlusal, middle, or cervical third of pontic) for reinforcement with glass fibers (regimen 2) was tested by loading a 3-unit FPD to failure. All groups were compared with analysis of variance (, < 0.05). Results: The fracture toughness (in MPam1/2) for each reinforced group (Fibrestick 2.74 ± 0.12, Construct fibers 2.59 ± 0.28, Ribbond triaxial 2.13 ± 0.20, and orthodontic wire 1.66 ± 0.09) was statistically greater (p< 0.05) than for the unreinforced group (control = 1.25 ± 0.006). Fracture loads for FPDs were greatest when the fiber reinforcements were placed in the cervical third (cervical = 1165 N). Conclusions: The use of fiber and, to a lesser extent, orthodontic wire is an effective method to reinforce interim restoration resins. [source] Evaluation of Stocking Density and Feeding Regime on Production of Red Swamp Crawfish in Outdoor MesocosmsJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2010Robert P. Romaire Seven stocking densities and three feeding regimes were evaluated, in combination, to determine their effects on production and relative condition of red swamp crawfish, Procambarus clarkii, in outdoor mesocosms. Juveniles were grown from November through June at densities of 5 to 35/m2 with either no cultivated rice, cultivated rice, or cultivated rice+formulated pellets as food resources. Crawfish size was influenced primarily by stocking density, survival was equally influenced by density and feeding regime, and yield was affected mostly by feeding regime. Individual harvest weight and survival decreased with an increase in stocking density. Most crawfish exceeded 20 g at 5 and 10/m2 in treatments with cultivated rice, but significant stunting occurred in all feeding regimes at 15/m2 or higher. Survival decreased with increased density, and was significantly less in the no-rice system, presumably from starvation and cannibalism. Mean crawfish yield in rice (1549 kg/ha) and rice+feed (1629 kg/ha) treatments was about 2.5 times higher than in the no-rice treatment (618 kg/ha). Formulated feed did not prevent stunting at high densities, but crawfish provided feed were in better physiological condition. Planted rice with an initial population density of about 10/m2 appears to provide the best combination to maximize both size and yield. [source] On Processing and Impact Deformation Behavior of High Density Polyethylene (HDPE),Calcium Carbonate NanocompositesMACROMOLECULAR MATERIALS & ENGINEERING, Issue 2 2009Qiang Yuan Abstract Different processing approaches were adopted to obtain the best combination of strength and toughness. The approach that yielded superior properties was examined in detail to study the mechanical response of nanoscale calcium carbonate-reinforced high density polyethylene in conjunction with unreinforced high density polyethylene. The reinforcement of high density polyethylene with nanoscale calcium carbonate increases impact strength and is not accompanied by decrease in yield strength. The addition of nanoscale calcium carbonate to high density polyethylene alters the micromechanism of deformation from crazing-tearing in high density polyethylene to fibrillation in high density polyethylene,calcium carbonate nanocomposite. [source] Propulsive activity induced by sequential electrical stimulation in the descending colon of the pigNEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2005C. Sevcencu Abstract, This work was performed to study electrically induced contractions in the descending colon of pigs. Contractions were monitored using impedance planimetry and manometry. The luminal pressure, cross-sectional area (CSA), latency and velocity of CSA decrease were compared when using 3 ms, 9, 12, 15 or 30 mA pulses at 10 Hz for 10 s, and 15 mA, 0.03, 0.3 or 3 ms pulses at 10 Hz for 10 s. Stimulation was performed prior and after the application of N(G)-nitro- l - arginine methyl ester (l - NAME) and atropine. In the untreated colon, contraction was always of an ,off' type. A current increase from 9 to 30 mA increased the pressure. An increase of pulse duration from 0.03 to 3 ms shortened the latency, accelerated contraction and increased pressure. By sequential stimulation, contractions were coordinated to propel semi-fluid and solid luminal contents. l - NAME increased the magnitude of CSA decrease. Atropine induced inhibitory effects on contractions elicited by 3 ms pulses and abolished contractions induced by 0.03 and 0.3 ms pulses. In conclusion: (i) electrical stimulation evokes,off' colon contractions, which can be coordinated to result in propulsion; (ii) the best combination for current and pulse duration to induce propulsive contractions is 15 mA and 3 ms; (iii) nitrergic and cholinergic pathways mediate responses to electrical stimulation. [source] Mapping the Coronary Sinus and Great Cardiac VeinPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4 2002MICHAEL GIUDICI GIUDICI, M., et al.: Mapping the Coronary Sinus and Great Cardiac Vein. The purpose of this study was to develop a better understanding of the pacing and sensing characteristics of electrodes placed in the proximal cardiac veins. A detailed mapping of the coronary sinus (CS) and great cardiac vein (GCV) was done on 25 patients with normal sinus rhythm using a deflectable electrophysiological catheter. Intrinsic bipolar electrograms and atrial and ventricular pacing voltage thresholds were measured. For measurement purposes, the GCV and the CS were each subdivided into distal (D), middle (M), and proximal (P) regions, for a total of six test locations. Within the CS and GCV, the average atrial pacing threshold was always lower (P < 0.05) than the ventricle with an average ventricular to atrial ratio > 5, except for the GCV-D. The average atrial threshold in the CS and GCV ranged from 0.2, to 1.0-V higher than in the atrial appendage. Diaphragmatic pacing was observed in three patients. Atrial signal amplitude was greatest in the CS-M, CS-D, and GCV-P and smaller in the CS-P, GCV-M, and GCV-D. Electrode spacing did not significantly affect P wave amplitude, while narrower electrode spacing attenuated R wave amplitude. The average P:R ratio was highest with 5-mm-spaced electrodes compared to wider spaced pairs. The P:R ratio in the CS was higher (P < 0.05) than in all positions of the GVC. It is possible to pace the atrium independent of the ventricle at reasonably low thresholds and to detect atrial depolarization without undue cross-talk or noise using closely spaced bipolar electrode pairs. The areas of the proximal, middle, and distal CS produced the best combination of pacing and sensing parameters. [source] Nonparametric confidence intervals for Tmax in sequence-stratified crossover studiesPHARMACEUTICAL STATISTICS: THE JOURNAL OF APPLIED STATISTICS IN THE PHARMACEUTICAL INDUSTRY, Issue 1 2008Susan A. Willavize Abstract Tmax is the time associated with the maximum serum or plasma drug concentration achieved following a dose. While Tmax is continuous in theory, it is usually discrete in practice because it is equated to a nominal sampling time in the noncompartmental pharmacokinetics approach. For a 2-treatment crossover design, a Hodges,Lehmann method exists for a confidence interval on treatment differences. For appropriately designed crossover studies with more than two treatments, a new median-scaling method is proposed to obtain estimates and confidence intervals for treatment effects. A simulation study was done comparing this new method with two previously described rank-based nonparametric methods, a stratified ranks method and a signed ranks method due to Ohrvik. The Normal theory, a nonparametric confidence interval approach without adjustment for periods, and a nonparametric bootstrap method were also compared. Results show that less dense sampling and period effects cause increases in confidence interval length. The Normal theory method can be liberal (i.e. less than nominal coverage) if there is a true treatment effect. The nonparametric methods tend to be conservative with regard to coverage probability and among them the median-scaling method is least conservative and has shortest confidence intervals. The stratified ranks method was the most conservative and had very long confidence intervals. The bootstrap method was generally less conservative than the median-scaling method, but it tended to have longer confidence intervals. Overall, the median-scaling method had the best combination of coverage and confidence interval length. All methods performed adequately with respect to bias. Copyright © 2007 John Wiley & Sons, Ltd. [source] Thermal history regulates methylbutenol basal emission rate in Pinus ponderosaPLANT CELL & ENVIRONMENT, Issue 7 2006DENNIS W. GRAY ABSTRACT Methylbutenol (MBO) is a 5-carbon alcohol that is emitted by many pines in western North America, which may have important impacts on the tropospheric chemistry of this region. In this study, we document seasonal changes in basal MBO emission rates and test several models predicting these changes based on thermal history. These models represent extensions of the ISO G93 model that add a correction factor Cbasal, allowing MBO basal emission rates to change as a function of thermal history. These models also allow the calculation of a new emission parameter Estandard30, which represents the inherent capacity of a plant to produce MBO, independent of current or past environmental conditions. Most single-component models exhibited large departures in early and late season, and predicted day-to-day changes in basal emission rate with temporal offsets of up to 3 d relative to measured basal emission rates. Adding a second variable describing thermal history at a longer time scale improved early and late season model performance while retaining the day-to-day performance of the parent single-component model. Out of the models tested, the Tamb,Tmax7 model exhibited the best combination of day-to-day and seasonal predictions of basal MBO emission rates. [source] Strategic shotgun proteomics approach for efficient construction of an expression map of targeted protein families in hepatoma cell linesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 12 2003Chih-Lei Lee Abstract An expression map of the most abundant proteins in human hepatoma HepG2 cells was established by a combination of complementary shotgun proteomics approaches. Two-dimensional liquid chromatography (LC)-nano electrospray ionization (ESI) tandem mass spectrometry (MS/MS) as well as one-dimensional LC-matrix-assisted laser desorption/ionization MS/MS were evaluated and shown that additional separation introduced at the peptide level was not as efficient as simple prefractionation of protein extracts in extending the range and total number of proteins identified. Direct LC-nanoESI MS/MS analyses of peptides from total solubilized fraction and the excised gel bands from one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis fractionated insolubilized fraction afforded the best combination in efficient construction of a nonredundant cell map. Compiling data from multiple variations of rapid shotgun proteomics analyses is nonetheless useful to increase sequence coverage and confidence of hits especially for those proteins identified primarily by a single or two peptide matches. While the returned hit score in general reflects the abundance of the respective proteins, it is not a reliable index for differential expression. Using another closely related hepatoma Hep3B as a comparative basis, 16 proteins with more than two-fold difference in expression level as defined by spot intensity in two-dimensional gel electrophoresis analysis were identified which notably include members of the heat shock protein (Hsp) and heterogeneous nuclear ribonucleoprotein (hnRPN) families. The observed higher expression level of hnRNP A2/B1 and Hsp90 in Hep3B led to a search for reported functional roles mediated in concert by both these multifunctional cellular chaperones. In agreement with the proposed model for telomerase and telomere bound proteins in promoting their interactions, data was obtained which demonstrated that the expression proteomics data could be correlated with longer telomeric length in tumorigenic Hep3B. This biological significance constitutes the basis for further delineation of the dynamic interactions and modifications of the two protein families and demonstrated how proteomic and biological investigation could be mutually substantiated in a productive cycle of hypothesis and pattern driven research. [source] Tramadol for prevention of postanaesthetic shivering: a randomised double-blind comparison with pethidineANAESTHESIA, Issue 2 2009M. Mohta Summary The present study was conducted with the aims of comparing intravenous tramadol 1, 2 and 3 mg.kg,1 with pethidine 0.5 mg.kg,1 for prophylaxis of postanaesthetic shivering and to find a dose of tramadol that could provide the dual advantage of antishivering and analgesic effect in the postoperative period. The study included 165 patients, randomly allocated to five groups of 33 each. Tramadol in doses of 1, 2 and 3 mg.kg,1, pethidine 0.5 mg.kg,1 or normal saline were administered at the time of wound closure. All three doses of tramadol were effective and comparable to pethidine in preventing postanaesthetic shivering. Tramadol 2 mg.kg,1 had the best combination of antishivering and analgesic efficacy without excessive sedation and thus appeared to be a good choice to be administered at the time of wound closure to provide antishivering effect and analgesia without significant side effects in the postoperative period. [source] Factors affecting methane production and mitigation in ruminantsANIMAL SCIENCE JOURNAL, Issue 1 2010Masaki SHIBATA ABSTRACT Methane (CH4) is the second most important greenhouse gas (GHG) and that emitted from enteric fermentation in livestock is the single largest source of emissions in Japan. Many factors influence ruminant CH4 production, including level of intake, type and quality of feeds and environmental temperature. The objectives of this review are to identify the factors affecting CH4 production in ruminants, to examine technologies for the mitigation of CH4 emissions from ruminants, and to identify areas requiring further research. The following equation for CH4 prediction was formulated using only dry matter intake (DMI) and has been adopted in Japan to estimate emissions from ruminant livestock for the National GHG Inventory Report: Y = ,17.766 + 42.793X , 0.849X2, where Y is CH4 production (L/day) and X is DMI (kg/day). Technologies for the mitigation of CH4 emissions from ruminants include increasing productivity by improving nutritional management, the manipulation of ruminal fermentation by changing feed composition, the addition of CH4 inhibitors, and defaunation. Considering the importance of ruminant livestock, it is essential to establish economically feasible ways of reducing ruminant CH4 production while improving productivity; it is therefore critical to conduct a full system analysis to select the best combination of approaches or new technologies to be applied under long-term field conditions. [source] Plant regeneration through the direct induction of shoot buds from petiole explants of Jatropha curcas: a biofuel plantANNALS OF APPLIED BIOLOGY, Issue 3 2010N. Kumar An efficient and reproducible method for the regeneration of Jatropha curcas plants has been developed. The method employed direct induction of shoot buds from petiole explants, without the formation of an intervening callus using a Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ). The best induction of shoot buds (58.35%) and the number of shoot buds per explant (10.10) were observed when in vitro petiole explants were placed horizontally on MS medium supplemented with 2.27 µM TDZ after 6 weeks. The induced shoot buds were transferred to MS medium containing 10 µM kinetin (Kn), 4.5 µM 6-benzyl aminopurine (BAP) and 5.5 µM ,-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with different concentrations and combinations of BAP, indole-3-acetic acid (IAA), NAA and indole-3-butyric acid (IBA). MS medium supplemented with 2.25 µM BAP and 8.5 µM IAA was found to be the best combination for shoot elongation and 3.01,3.91 cm elongation was achieved after 6 weeks. However, significant differences in plant regeneration and shoot elongation were observed among the genotypes studied. The orientation (horizontal or vertical) and source (in vitro or in vivo) of explants also significantly influenced plant regeneration. The elongated shoots could be rooted on half-strength MS medium supplemented with 2% sucrose, different concentrations and combinations of IBA, IAA and NAA, and 0.25 mg L,1 activated charcoal. Half-strength MS medium supplemented with 2% sucrose, 15 µM IBA, 5.7 µM IAA, 5.5 µM NAA and 0.25 mg L,1 activated charcoal was found to be the best for promoting rooting. The rooted plants could be established in soil with more than 90% survival. [source] Colour constancy based on texture similarity for natural imagesCOLORATION TECHNOLOGY, Issue 6 2009Bing Li Colour constancy is a classical problem in computer vision. Although there are a number of colour constancy algorithms based on different assumptions, none of them can be considered as universal. How to select or combine these available methods for different natural image characteristics is an important problem. Recent studies have shown that the texture feature is an important factor to consider when selecting the best colour constancy algorithm for a certain image. In this paper, Weibull parameterisation is used to identify the texture characteristics of colour images. According to the texture similarity, the best colour constancy method (or best combination of methods) is selected out for a specific image. The experiments were carried out on a large data set and the results show that this new approach outperforms current state-of-the-art single algorithms, as well as some combined algorithms. [source] A response surface methodology approach to optimise pretreatments to prevent enzymatic browning in potato (Solanum tuberosum L) cubesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2002C Reyes-Moreno Abstract The objective of this work was to find the best combinations of ascorbic acid concentration/soaking time (Pretreatment 1), 4-hexylresorcinol concentration/soaking time (Pretreatment 2) and ascorbic acid concentration,4-hexylresorcinol concentration/soaking time (Pretreatment 3) to prevent the development of enzymatic browning in raw potato cubes (10,mm,×,10,mm,×,10,mm). Potato variety Alpha was used as study model because of its low susceptibility to enzymatic browning. Response surface methodology was applied in all pretreatments on two response variables (Hunter L value and total colour difference) to find the best conditions for carrying out the pretreatments. The various pretreatments had variation levels for ascorbic acid (AA) concentration (1 and 3) and 4-hexylresorcinol (4HR) concentration (2 and 3) of 1,4 and 0.04,0.20,g,l,1 respectively; in all pretreatments the variation level for soaking time was 3,6,h. A central composite experimental design with two factors at five levels was used. Predictive models for Hunter L value and total colour difference were developed as a function of process or independent variables. The optimisation technique was applied to obtain maximum Hunter L values and minimum values of total colour difference. Surface superposition of these variables allowed identification of the best combinations of process variables for each pretreatment as (1) 2.9,g,l,1 AA/4.8,h, (2) 0.04,g,l,1 4HR/2.6,h and (3) 2.42,g,l,1 AA,0.15,g,l,1 4HR/5.41,h. © 2001 Society of Chemical Industry [source] A method to assess the sensitivity of sedimentary communities to fishing activitiesAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 3 2009Harvey Tyler-Walters Abstract 1.Methods of sensitivity assessment to identify species and habitats in need of management or protection have been available since the 1970s. 2.The approach to sensitivity assessment adopted by the Marine Life Information Network (MarLIN) assumes that the sensitivity of a community or biotope is dependent on the species within it. However, the application of this approach to sedimentary communities, especially offshore, is complex because of a lack of knowledge of the structural or functional role of many sedimentary species. 3.This paper describes a method to assess the overall sensitivity of sedimentary communities, based on the intolerance and recoverability of component species to physical disturbance. A range of methods were applied to identify the best combinations of abundant, dominant or high biomass species for the assessment of sensitivity in the sedimentary communities examined. 4.Results showed that reporting the most frequent species' sensitivity assessment, irrespective of the four methods used to select species, consistently underestimated the total sensitivity of the community. In contrast, reporting the most sensitive assessment from those species selected resulted in a range of biotope sensitivities from very low to very high, that was better able to discriminate between the sensitivities of the communities examined. 5.The assumptions behind the methodology, its limitations and potential application are discussed. © Crown copyright 2008. Reproduced with permission of Her majesty's stationery office. Published by John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||