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Design Experiment (design + experiment)
Kinds of Design Experiment Selected AbstractsHow Design Experiments Can Inform Teaching and Learning: Teacher-Researchers as Collaborators in Educational ResearchLEARNING DISABILITIES RESEARCH & PRACTICE, Issue 4 2005Asha K. Jitendra In this commentary, I summarize my own research with colleagues to affirm Dr. Gersten's call for considering design experiments prior to conducting intervention research. I describe how design experiments not only can inform teaching and the learning of innovative approaches, but also hold the promise of effectively bridging the research-to-practice gap to produce meaningful change in practice when innovative practices are fine-tuned and validated by partnerships with teacher-researchers. [source] Statistical Analysis of Designed Experiments: Theory and Applications by Ajit C. TamhaneINTERNATIONAL STATISTICAL REVIEW, Issue 1 2010Norman R. Draper No abstract is available for this article. [source] Synergistic effect of insect herbivory and plant parasitism on the performance of the invasive tree Schinus terebinthifoliusENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2009Veronica Manrique Abstract Schinus terebinthifolius Raddi (Anacardiaceae) is an introduced tree from South America that has invaded many ecosystems throughout central and south Florida, USA. Exploratory surveys in the plant's native range identified several potential biocontrol agents, including the leaflet rolling moth, Episimus unguiculus Clarke (Lepidoptera: Tortricidae). The larval stages of E. unguiculus tie together the plant leaflets while feeding and can completely defoliate small plants. The native love vine, Cassytha filiformis L. (Lauraceae), has been found parasitizing S. terebinthifolius in Florida. Natural processes such as plant parasitism may be one of the components of an integrated approach for S. terebinthifolius management in Florida. Thus, the objective of this study was to evaluate the combined effects of insect herbivory and plant parasitism on the performance of S. terebinthifolius. A factorial design experiment was conducted in the greenhouse to determine the effect of C. filiformis parasitism and E. unguiculus feeding damage on the growth and biomass of S. terebinthifolius. Results showed that plant parameters, including leaflet biomass, growth rate, and flower production, were negatively affected by plant parasitism and insect herbivory. Moreover, the decrease in S. terebinthifolius performance was greater when these two factors were combined, indicative of a synergistic relationship. In addition, the combined effect of C. filiformis and E. unguiculus suppressed plant performance for at least 2 months after the moths were removed. Therefore, increased control of S. terebinthifolius stands may be achieved in those areas where C. filiformis is present in Florida (e.g., pinelands, hammock forests) if the biocontrol agent E. unguiculus is approved for release. [source] The importance of social structure and social interaction in stereotype consensus and content: is the whole greater than the sum of its parts?EUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 1 2004Clifford Stott This paper addresses the hypothesis derived from self-categorization theory (SCT) that the relationship between groups and stereotyping will be affected by the social structural conditions within which group interaction occurs. A mixed design experiment (n=56) measured low-status groups' stereotypes and preferences for conflict with a high-status outgroup prior to and after within-group discussion across varying social structural conditions. Over time, participants in [open] conditions consensualized around positive conceptions of the outgroup and endorsed acceptance of their own [low status] position. However, in [closed] conditions participants consensualized around positive conceptions of the ingroup, negative conceptions of the outgroup, and tended towards preferences for collective protest. It is argued that the data support S-CT's contention that stereotyping and group processes are fundamentally interlinked and that neither can be properly understood in isolation from the dynamics of the surrounding intergroup context. Copyright © 2004 John Wiley & Sons, Ltd. [source] Effect of N Fertilization Rate on Sugar Yield and Non-Sugar Impurities of Sugar Beets (Beta vulgaris) Grown Under Mediterranean ConditionsJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 5 2005J. T. Tsialtas Abstract For three successive growing seasons (1999,2001), a completely randomized block design experiment was established at the surrounding area of each of four sugar beet processing plants of Hellenic Sugar Industry SA, Greece (a total of 12 experiments). Nitrogen was applied at five rates (0, 60, 120, 180 and 240 kg N ha,1) and six replications per rate. Nitrogen fertilization had site-specific effects on quantitative (fresh root and sugar yields) and qualitative (sucrose content, K, Na, , -amino N) traits. When data were combined over years and sites, fresh root and sugar yields were maximized at high N rates (330.75 and 295 kg N ha,1 respectively), as derived from quadratic functions fitted to data. In three trials, increased N rates had negative effects on root and sugar yield. These sites were characterized by high yield in control plots, light soil texture (sand > 50 %) and low CEC values. When data were converted into relative values (the ratio of the trait values to the control mean of each experiment), root and sugar yield was found to be maximized at higher N rates (350 and 316 kg N ha,1, respectively). Sucrose content was strongly and linearly reduced by the increased N rates when data were combined but a significant reduction with increasing N rates was found in only two sites. Non-sugar impurities (K, Na, , -amino N) were positively related to the increased N rates when data were combined. Sodium and , -amino N showed to be most affected by N fertilization as positive relationships were found in six and eight of 12 locations, respectively. Increased N supply resulted in higher soil NO3 -N concentrations (0,90 cm depth) at harvest which were related with amino N contents in sugar beet roots (in 1999 and 2001). [source] Funds of knowledge and discourses and hybrid spaceJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 1 2009Angela Calabrese Barton Abstract The findings reported on in this manuscript emerged from a design experiment conducted at a low-income urban middle school intended to support the teacher in incorporating pedagogical practices supportive of students' everyday knowledge and practices during a 6th grade unit on food and nutrition from the LiFE curriculum. In studying the impact of the design experiment we noticed qualitative shifts in classroom Discourse marked by a changing role and understandings of the funds of knowledge students brought to science learning. Using qualitative data and grounded theory we present an analysis of the different types of funds of knowledge and Discourse that students brought into science class. We focus on how the students' strategic use of these funds augmented the learning experience of the students and the learning community as well as the learning outcomes. We discuss the implications these funds of knowledge and Discourses had on the development of three related third space transformations: physical, political, and pedagogical. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 46: 50,73, 2009 [source] Production of luteolin extracts from Reseda luteola and assessment of their dyeing propertiesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2002Alfonso Cerrato Abstract In this work, several experiments were performed sequentially in 50,cm3 shaken tubes and a 1,dm3 stirred extractor, thus allowing methanol to be selected as the most appropriate leaching solvent for luteolin from leaves, stems and flowers of weld (Reseda luteola). The extraction capability of methanol at 25,°C was found to be about 7 times greater than that of boiling water at pH 10. A composite design experiment allowed the effects of particle size and liquid/solid ratio to be determined, thus resulting in an optimal luteolin extraction yield of 8.6,±,0.2,g,kg,1 dried weld material when leaching plant particles sieved through 0.5,mm openings with 40,dm3 methanol kg,1. Preliminary dyeing tests on pre-mordanted raw cotton and wool standard specimens gave rise to dyed specimens with the same greenish-yellow hue but greater or smaller values of lightness and chroma respectively. Despite all dyed specimens exhibiting a minimum resistance to a simulated acid perspiration solution, the resistance to fading of dyed wool specimens was generally greater than that of cotton ones. © 2002 Society of Chemical Industry [source] Effects of viscosity and surface roughness on gear contact tribological layersLUBRICATION SCIENCE, Issue 1 2007T. C. Jao Abstract The increasing dependence on more robust additive chemistry to improve gear pitting resistance requires the additive technology development to rely less on a trial-and-error approach and more on a better basic understanding of the influence of additive chemistry on tribological contact layers' physical and chemical changes. The use of secondary neutral mass spectrometry (SNMS) and nanoindenter to analyse tribological contact layers had been carried out by Inacker and co-workers at NMI. They found that the alkyl structure of zinc dithiophosphate (ZDTP) and the type of cation have a profound effect on the thickness and nanohardness of the tribological layer. An extension to that study has been carried out in this investigation, which involves a design experiment of two variables (oil viscosity and surface roughness) while keeping the additive chemistry constant to determine their impact on the tribological layer. The methods used to analyse the tribological layers include SNMS, nanoindenter and SEM coupled with focused ion beam imaging of the rectangular well-shaped cross section. The results in general are in agreement with the findings of Inacker and his co-workers, namely greater micropitting reduces the thickness of the tribological layer and brings closer the depth of nanohardness maximum to the surface. Copyright © 2006 John Wiley & Sons, Ltd. [source] The effects of urea-treated potato pulp (PP) ensiled with beet pulp or wheat bran pellets to reduce moisture of PP and flake density of corn grain supplemented with the PP silage on digestibility and ruminal fermentation in beef steersANIMAL SCIENCE JOURNAL, Issue 3 2010Masahito SUGIMOTO ABSTRACT The effects of adding beet pulp or wheat bran to urea-treated potato pulp (PP) in order to reduce moisture of PP silage and flake density of corn grain on digestibility and ruminal fermentation in beef steers were studied in a split-plot design experiment. The whole-plot treatments were PP silage mixed with 0% added pellets (CON), 9% (as-fed basis) beet pulp pellets (BP) or 9% (as-fed basis) wheat bran pellets (WB) as water-absorbing materials. The subplot treatments consisted of supplements formulated to contain either high-density corn (HDC) or low-density corn (LDC). BP steers consumed more (BP vs WB, P = 0.011) concentrate than did WB steers, whereas hay intake did not differ between the treatments. Dry matter (BP vs WB, P = 0.023) and organic matter (BP vs WB, P = 0.029) digestibility were higher for BP steers than for WB steers. Starch digestibility was higher (P = 0.006) for LDC than for HDC. There were no differences in the concentration of ruminal ammonia nitrogen among the treatments. Molar proportions of ruminal acetate were higher for BP steers than for WB steers (BP vs WB, P = 0.030). Conversely, molar proportions of propionate were lower for BP steers than for WB steers (BP vs WB, P = 0.044). Flake density of corn did not affect ruminal characteristics. In conclusion, from the viewpoint of feed intake and digestibility, BP is superior to WB as a moisture control material for urea-treated PP silage, and flake density of corn supplemented with urea-treated PP silage does not alter ruminal fermentation. [source] Effects of starch and protein sources on starch disappearance in the gastrointestinal tract of Hanwoo (Korean native) steersANIMAL SCIENCE JOURNAL, Issue 3 2010Kyoung Hoon KIM ABSTRACT Hanwoo (Korean native) steers (274.8 ± 4.6 kg) with ruminal and duodenal cannulae were used in a 4 × 4 Latin square design experiment to examine the effects of dietary treatments on starch disappearance in the gastrointestinal tract. Dietary treatments consisted of concentrate that were based on ground corn with soybean meal (C-SBM), ground corn with corn gluten meal (C-CGM), ground barley with soybean meal (B-SBM) and ground barley with corn gluten meal (B-CGM). Although the intakes of starch and protein for steers fed experimental diets were different, it did not change ruminal pH and total volatile fatty acid concentrations. Average duodenal CP flow and quantity of CP apparently digested post-ruminally was higher (P = 0.001) for CGM-based diets than SBM-based diets. There were increases in quantity (P < 0.001) and percentage (P < 0.001) of corn starch digested post-ruminally compared to barley starch. Synchronized diets showed higher percentages (P = 0.03) of starch apparently digested post-ruminally than asynchronization. Hanwoo steers fed a corn-based diet with a large quantity of starch reaching the duodenum and fed C-CGM supplying great amounts of protein to the small intestine may have contributed to increased post-ruminal starch digestion. [source] Effects of maize (Zea mays L.) silage feeding on dry matter intake and milk production of dairy buffalo and cattle in Tarai, NepalANIMAL SCIENCE JOURNAL, Issue 4 2009Yoshiaki HAYASHI ABSTRACT To identify the effects of whole crop maize silage (MS) as a substitute for rice straw (RS) on feed intake and milk production of mid-late lactating buffalo and cattle in Tarai, Nepal, eight Murrah and eight Jersey-Hariana were fed the basal diet, RS (ad libitum) with concentrate (0.68% of bodyweight [BW] on a dry matter [DM] basis). A 4 × 4 Latin square design experiment was conducted in each animal species with graded levels of MS substitution for RS (0%, T1; 33%, T2; 67%, T3 and 100%, T4). The MS had higher digestibility and total digestible nutrient (TDN) than RS. The DM intake per BW of the both species was highest in T3. The substitution of MS for RS increased the crude protein intake and the TDN intake in the both species. Although the buffalo showed the highest milking performance in T4, the cattle showed no significant differences in their milking performance among the treatments. The substitution of MS for RS improved the feed intake and milk production in the buffalo. On the other hand, the milk yield was not raised in the cattle, though the feed intake was increased by the substitution. [source] Effects of urea treatment of potato pulp and inclusion levels of potato pulp silage in supplements on digestibility and ruminal fermentation in beef steersANIMAL SCIENCE JOURNAL, Issue 6 2007Masahito SUGIMOTO ABSTRACT Six Wagyu (Japanese Black) steers fitted with a ruminal cannula were used in a split-plot design experiment comprising a 3 × 3 Latin square design (whole plot) and a randomized blocks design (subplot) to determine the effect of the treatment of potato pulp (PP) with urea and the effect of inclusion levels of PP silage in feed supplement on digestibility, ruminal in situ degradation and ruminal fermentation. The whole plot consisted of 20%, 50% and 80% PP silage (dry matter (DM) basis), with PP silage replacing formula feed. The subplot included untreated or 0.5% (on an as-fed basis) urea-treated PP. The treatment of PP with urea showed no effect on DM intake and digestibility. The percentage of the rapidly degradable DM fraction of the urea-treated PP silage was higher (P < 0.01) and the percentage of its slowly degradable DM fraction was lower (P < 0.01) than for the untreated PP silage. Ruminal ammonia concentration was greater (P < 0.01) for steers fed urea-treated PP silage than that for steers fed the untreated PP silage. The treatment of PP with urea caused a decrease in the molar proportion of acetate and an increase in the proportion of propionate in ruminal fluid after feeding. The rate of DM degradations in hay (linear, P < 0.01) and in PP silage decreased (linear, P < 0.01) as the inclusion level of PP silage increased. Increasing the inclusion level of PP silage in supplement decreased the effective degradability of DM in hay (linear, P < 0.05) and in PP silage (linear, P < 0.05). An increase in the amount of PP silage increased the molar proportion of acetate (linear, P < 0.01) and decreased the butyrate proportion (linear, P < 0.05) in ruminal fluid. The results suggest that urea treatment of PP facilitates microbial access to starch of PP silage in the rumen and that surplus level of PP silage in supplement have adverse effect on ruminal digestion. [source] Development of a minimal defined medium for recombinant human interleukin-3 production by Streptomyces lividans 66BIOTECHNOLOGY & BIOENGINEERING, Issue 1 2008Keyvan Nowruzi Abstract A systematic approach was developed to identify and optimize the essential amino acids in defined minimal medium for the production of recombinant human interleukin 3 (rHuIL-3) by Streptomyces lividans. Starvation trials were carried out initially to narrow down the number of probable essential amino acids from an initial number of 20 to 8. Then a screening mixture experiment was designed and performed with the eight identified amino acids and distance-based multivariate analysis was employed to rank the probable essential amino acids regarding both growth and product formation. Following this procedure, the search was narrowed to four amino acids (Asp, Leu, Met, and Phe). Finally, a mixture design experiment known as the simplex lattice design was carried out and the composition of the optimum minimal medium was found (Asp 53%, Met 5%, and Phe 42%). Biotechnol. Bioeng. 2008;99: 214,222. © 2007 Wiley Periodicals, Inc. [source] Cell Separator Operation within Temperature Ranges To Minimize Effects on Chinese Hamster Ovary Cell Perfusion CultureBIOTECHNOLOGY PROGRESS, Issue 6 2007Hans Drouin A cell retention device that provides reliable high-separation efficiency with minimal negative effects on the cell culture is essential for robust perfusion culture processes. External separation devices generally expose cells to periodic variations in temperature, most commonly temperatures below 37 °C, while the cells are outside the bioreactor. To examine this phenomenon, aliquots of ,5% of a CHO cell culture were exposed to 60 s cyclic variations of temperature simulating an acoustic separator environment. It was found that, for average exposure temperatures between 31.5 and 38.5 °C, there were no significant impacts on the rates of growth, glucose consumption, or t-PA production, defining an acceptable range of operating temperatures. These results were subsequently confirmed in perfusion culture experiments for average exposure temperatures between 31.6 and 38.1 °C. A 25,1 central composite factorial design experiment was then performed to systematically evaluate the effects of different operating variables on the inlet and outlet temperatures of a 10L acoustic separator. The power input, ambient temperature, as well as the perfusion and recycle flow rates significantly influenced the temperature, while the cell concentration did not. An empirical model was developed that predicted the temperature changes between the inlet and the outlet of the acoustic separator within ±0.5 °C. A series of perfusion experiments determined the ranges of the significant operational settings that maintained the acoustic separator inlet and outlet temperatures within the acceptable range. For example, these objectives were always met by using the manufacturer-recommended operational settings as long as the recirculation flow rate was maintained above 15 L day,1 and the ambient temperature was near 22 °C. [source] The dynamics of an online knowledge building community: A 5-year longitudinal studyBRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Issue 3 2010Jarkko Mylläri This paper reports a 5-year design experiment on cumulative knowledge building as part of an international project. Through a longitudinal study and analysis of cumulative research data, we sought to answer the question, ,what happened and why in knowledge building?' Research data constitute messages which participants have written into a shared knowledge building database. A multi-method approach combing quantitative and qualitative data was adopted which integrated analysis of message generation, content analysis, network analysis, structure of message threads, discourse analysis and interviews. Conclusions are based on analysis of almost 2000 messages. Qualitative content analysis reveals 14 main categories of data. When the content of the messages are analysed, quantitatively cumulative trends emerge. When the frequencies of messages are plotted against time, peaks and troughs of message writing are revealed. The explanations for these patterns and variations are sought through interviews. Social network analysis shows that the network is centralised. The research literature suggests that decentralised networks are ideal, but in this particular case, the expert centralisation was beneficial for knowledge building in the collaborative and associated professional networks. The reasons for this are discussed. [source] Synergistic effect of chemical preservatives with ethanol on the microbial shelf life of bread by factorial designINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2008George Katsinis Summary The shelf life, particularly the mould-free shelf life (MFSL) of bread, was evaluated either by adding a conventional chemical preservative or by spraying the surface of bread, in which a chemical preservative was added. As bread making is a complex process and bread is a multicomponent system, the investigation was based on statistical design experiments. Using first-order factorial designs, reliable models were constructed, revealing the effects of some common ingredients of bread (such as salt, sugar, glycerol, potassium sorbate, calcium propionate) and their interactions on the MFSL (optimisation parameter) with and without ethanol surface spraying. The effectiveness of preservation was ranked as potassium sorbate + ethanol > calcium propionate + ethanol > potassium sorbate > calcium propionate. Ethanol addition led to MFSL prolongation of 43.5% and 38.5% compared with MFSL of potassium sorbate and calcium propionate, respectively, when all the factors were fixed to their basic levels. [source] How Design Experiments Can Inform Teaching and Learning: Teacher-Researchers as Collaborators in Educational ResearchLEARNING DISABILITIES RESEARCH & PRACTICE, Issue 4 2005Asha K. Jitendra In this commentary, I summarize my own research with colleagues to affirm Dr. Gersten's call for considering design experiments prior to conducting intervention research. I describe how design experiments not only can inform teaching and the learning of innovative approaches, but also hold the promise of effectively bridging the research-to-practice gap to produce meaningful change in practice when innovative practices are fine-tuned and validated by partnerships with teacher-researchers. [source] Synthesis and Properties of a Superabsorbent Polymer Prepared by Copolymerization of Sodium Acrylate with Sodium 1-(Acryloyloxy)propan-2-yl PhosphateMACROMOLECULAR REACTION ENGINEERING, Issue 2 2007Zhenbin Chen Abstract A novel monomer, 1-(acryloyloxy)propan-2-yl phosphoryl dichloride, was synthesized and characterized in this work. Thereafter, the monomer was neutralized with sodium hydroxide and copolymerized with sodium acrylate to obtain a superabsorbent polymer. The superabsorbent polymer was then modified to improve its swelling properties (i.e., the water absorbency under load, the hydrogel strength, the resilience and the dispersion). Both single factor and orthogonal design experiments were adopted to obtain optimal conditions. The superabsorbent polymer prepared under the optimal conditions showed improved water absorbency in physiological saline [17 g,·,g,1 under load (P,=,2,×,103 Pa) and 65 g,·,g,1 at atmospheric pressure] and other swelling properties, such as hydrogel strength, resilience and dispersion, also improved. [source] The influence of algal ration and larval density on growth and survival of blacklip pearl oyster Pinctada margaritifera (L.) larvaeAQUACULTURE RESEARCH, Issue 8-9 2000M S Doroudi This paper reports on two factorial design experiments conducted to examine the combined effects of algal ration and larval density on growth and survival of black lip pearl oyster Pinctada margaritifera (L.) larvae. In the first experiment, 1-day-old larvae were cultured for 7 days at densities of 1, 2 and 5 mL,1 and fed algal rations of 0, 2.5, 5 or 12.5 × 103 cells mL,1. In the second experiment, 13-day-old larvae were cultured for 7 days at the above densities and fed algal rations of 0, 7.5, 15 and 37.5 × 103 cells mL,1. Algal rations in both experiments were composed of a 1:1 mixture of the flagellates Isochrysis aff. galbana clone T.ISO and Pavlova salina. Response surface contour diagrams were generated from growth and survival data to estimate optimal culture conditions. Results showed that, within a suitable larval density range, growth of P. margaritifera larvae was significantly (P <,0.01) influenced by algal ration. At the end of the first experiment, greatest survival occurred at a ration of 4.5,11.5 × 103 cells mL,1 and at a larval density of ,,3 mL,1. Greatest antero-posterior shell length was shown by larvae fed between 4.5 × 103 and 11.5 × 103 algal cells mL,1. In the second experiment, greatest antero-posterior shell length occurred within an algal ration range of 15,32 × 103 cells mL,1. The greatest survival occurred below an algal ration of <,2.5 × 103 cells mL,1; however, this algal ration supported poor algal growth. The results indicate that, to maximize growth and survival, P. margaritifera larvae should be fed at an algal ration of ,,8 × 103 cells mL,1 and cultured at a density of three larvae mL,1 up to 8 days of age. Older (13- to 20-day-old) larvae should be cultured at a density of <,2 mL,1 and fed an algal ration of ,,25 × 103 cells mL,1. [source] Michael Hensel; Frei Otto;ARCHITECTURAL DESIGN, Issue 2 2006Achim Menges Abstract Achim Menges presents a range of morphogenetic design techniques and technologies that synthesise processes of formation and materialisation. Through a series of design experiments, he explains his research into an understanding of form, materials and structure, not as separate elements, but rather as complex interrelations in polymorphic systems resulting from the response to varied input and environmental influences, and derived through the logics of advanced manufacturing processes. Copyright © 2006 John Wiley & Sons, Ltd. [source] Packed Bed Column Fermenter and Kinetic Modeling for Upgrading the Nutritional Quality of Coffee Husk in Solid-State FermentationBIOTECHNOLOGY PROGRESS, Issue 6 2001Débora Brand Studies were carried out to evaluate solid-state fermentation (SSF) for the upgradation of the nutritional quality of coffee husk by degrading the caffeine and tannins present in it. SSF was carried out by Aspergillus niger LPBx in a glass column fermenter using factorial design experiments and surface response methodology to optimize bioprocess parameters such as the substrate pH and moisture content and aeration rate. The first factorial design showed that the moisture content of the substrate and aeration rate were significant factors for the degradation of toxic compounds, which was confirmed by the second factorial design too. The kinetic study showed that the degradation of toxic compounds was related to the development of the mold and its respiration and also to the consumption of the reducing sugars present in coffee husk. From the values obtained experimentally for the oxygen uptake rate and CO2 evolved, the system determined a biomass yield (Yx/o) of 3.811 (g of biomass)·(g of consumed O2),1 and a maintenance coefficient (m) of 0.0031 (g of consumed O2)·(g biomass of biomass),1·h,1. The best results on the degradation of caffeine (90%) and tannins (57%) were achieved when SSF was carried out with a 30 mL·min,1 aeration rate using coffee husk having a 55% initial moisture content. The inoculation rate did not affect the metabolization of the toxic compounds by the fungal culture. After SSF, the protein content of the husk was increased to 10.6%, which was more than double that of the unfermented husk (5.2%). [source] Light scattering in the C57BL/6 mouse lensACTA OPHTHALMOLOGICA, Issue 2 2007Linda M. Meyer Abstract. Purpose:, To characterize inherent light scattering in the C57BL/6 mouse lens. Methods:, Lenses from 20 6-week-old female C57BL/6 mice were extracted from freshly enucleated globes and microsurgically cleaned of remnants of the ciliary body. Lens light scattering was measured quantitatively with a light dissemination meter (LDM). Morphological properties of the mouse lenses were documented using grid- and dark-field illumination photography. Analysis of variance was performed to establish variance for animals, variance between left and right eyes and variance for measurements. Results:, Average inherent light scattering in the C57BL/6 mouse lens is 0.16 ± 0.02 tEDC (transformed equivalent diazepam concentration). The mean size of a mouse lens at 6 weeks is 1.9 mm in diameter. Two lenses featured pre-existing cortical lens opacities. Variance for animals was assessed to be 7.9 10, 4 tEDC2, variance for measurements was 1.6 10, 4 tEDC2, and variance between left and right eyes was 8.8 10, 4 tEDC2. The tolerance limit for non-pathological light scattering was determined to 0.26 tEDC. No significant difference in light scattering between left and right mouse lenses was found. The minimum number of C57BL/6 mice required for detection of a 10% experimentally induced change in light scattering intensity was estimated to be 50 for independent group experiments and 25 for paired design experiments. Conclusions:, The C57BL/6 mouse is a suitable animal in which to conduct experiments on light scattering or cataractogenesis with high precision at reasonable sample sizes. Before including C57BL/6 mice into a study on cataractogenesis, pre-existing lens opacities such as congenital cataract must be excluded. [source] | ||||||||||||||||||||||||||||