The Effect of Dietary Protein Level on the Growth Performance and Digestive Protease Activity in Juvenile Bluegill (Lepomis macrochrius)

A 16-week feeding experiment was conducting in an indoor recirculating aquaculture system (RAS) to determine the effects of dietary protein level on the growth and digestive protease activity in juvenile bluegills. Six isocaloric experimental diets were forumalted with 32%, 35%, 38%, 41%, 44%, and 47% levels of protein. Menhdaen fish meal was use as the sole protein source. Juvenile bluegills of 24.91 ± 0.50 g initial weight were distributed into 24 151 L tanks with 12 fish each. Each diet had four replications. Fish were fed to satiation three times a day by hand. At the termination, there no mortalities in fish fed 38% through 47% protein diet. Bluegill fed 38% or 47% protein diet had significant higher body weight gain and specific growth rate (SGR) than fish fed 32% or 35% [rotein diet. No significant differences (p\u3e0.05) were found in weight gain, SGR, and FCR among the fish fed 38% or higher protein diets. Protein efficiency ratio decreased with increasing dietary protein level from 32% to 47%. Acid protease activity of complete digestive tract increased in trend with increasing dietary protein level from 32% to 47%. No significant differences were detected in the protease activity at different pH level among the treatments. The optimal dietary protein requirement for juvenile bluegill was about 38.3%.https://bluetigercommons.lincolnu.edu/lucer-pubs/1001/thumbnail.jp

The Molecular Basis of Radial Intercalation during Tissue Spreading in Early Development

Radial intercalation is a fundamental process responsible for the thinning of multilayered tissues during large-scale morphogenesis; however, its molecular mechanism has remained elusive. Using amphibian epiboly, the thinning and spreading of the animal hemisphere during gastrulation, here we provide evidence that radial intercalation is driven by chemotaxis of cells toward the external layer of the tissue. This role of chemotaxis in tissue spreading and thinning is unlike its typical role associated with large-distance directional movement of cells. We identify the chemoattractant as the complement component C3a, a factor normally linked with the immune system. The mechanism is explored by computational modeling and tested in vivo, ex vivo, and in vitro. This mechanism is robust against fluctuations of chemoattractant levels and expression patterns and explains expansion during epiboly. This study provides insight into the fundamental process of radial intercalation and could be applied to a wide range of morphogenetic events

Optimal Feeding Time and Duration of Hybrid Crappie Kept Indoors

Crappie (Pomoxis spp.) is a popular sport fish with food fish potential. Feeding behavioral patterns should be considered prior to nutrtitional studies. The objective of this study was to determine the best feeding time and duration for hybrid crappie raised in indoor recirculating aquaculture systems. Three feeding treatments with three replciates consisted of two 12 hour feeding periods initiated at 0800 (12h-amLD) and 1700 (12h-pmLD) and a 24 feeding period started at 0800 (24h-amLD). Treatments in experimental tanks were arranged in a random block design and stocked with 14 hybrid fingerlings fed for 12 weeks. Fingerling fish were spwaned in pongs using previously feed trained black crappe females (P. nigromaculatus) and white crappie males (P. annularis). Weight gain, feed conversion ratio (FCR), survival rate, consumption rate and proximate analysis of fish flesh and visceral were measured. Mean mass weight gains for 12h-amLD, 12h-pmLD, and 24-amLD were 153, 196, and 139g. There were no significant differences (p ≥ 0.05) among weight gains. Mean FCR were 1.69, 1.82, and 2.57 for 12h-amLD, 12h-pmLD, and 24-amLD, respectively. A significant diffference in FCR occured between 24h and the two 12 hour treaments. There were no significant differences in survival rate, feed consumption, or composition of fish flesh among treatments. The only significant difference in visceral was between 12h treatments for ash. This study indicated that feeding times or durations did not affect hybrid crappies body weight gain. However, there could be a FCR advantage with the 12 hour feeding schedules.https://bluetigercommons.lincolnu.edu/lucer-pubs/1008/thumbnail.jp

Effects of Chemical Preservatives on Weights and Lengths of Bluegill Larvae

Measuring the lenghts and weights of live fish larvae can be tedious and time-consuming. This constraint could be alleviated by preserving the fish larvae in appropriate chemicals for later measurements. There is little or no information on the effects of preservatives on Bluegill larvae. The objective of this study was to determine the effects of five different common preservatives on Bluegill larvae. Individual weights and lengths of fish were measured and then the larvae were preserved for 7 or 26 days. Preservatives were 5% formalin, 10% formalin, 30% ethanol at -19 *C, 70% ethanol, and 90% ethanol. Preliminary average weights of the larvae preserved for 7d were 1.63, 1.30, 4.02, -0.63, and -4.15g in 5% formalin, 10% formalin, 30% ethanol at -19 *C, 70% ethanol, and 90% ethanol, respectively. The average lengths for 26d were -0.63, -0.39, -0.12, -0.03, and 0.22 in 5% formalin, 10% formalin, 30% ethanol at -19 *C, 70% ethanol, and 90% ethanol, respectively. This study indicated that 70% ethanol had the least effect on weights and lengths of Bluegill larvae preserved for 7 and 26d.https://bluetigercommons.lincolnu.edu/lucer-pubs/1000/thumbnail.jp

The Distribution of α-Amylase Activity along the Digestive Tract of Juvenile Bluegill (Lepomis macrochirus) and its Comparison with Selected Fish Species

Carbohydrates are the least expensive form of dietary energy for animals. Although fish don\u27t have specific requirements for dietary carbohydrates, they must be provided with the appropriate levels of carbohydrates in their diets. Moderate levels of carbohydrate could support fishs\u27 better growth performance and may decrease the use of the more expensive protein and lipids in the diet. Different fish have different ability to utilize digestible carbohydrates, which may relate to the relative amount of amylase activity present in the digestive system of the various species. α-amylase is a key enzyme for carbohydrate digestion. Bluegill, an important forage and recreational as well as a newly emerged food fish, is the most commonly produced sunfish in the North Central Region. Information on the digestive amylase activity and the dietary carbohydrates utilization in Bluegill is lacking. The objective of this study was to determine the distribution of α-amylase activity along the digestive tract of juvenile Bluegill and to compare its activity with slecte fish species. The α-amylase analysis followed Worthington (1993) with a slight modification. α-amylase was detected in the stomach, pyloric cecum, proximal intestine, mid intestine, and distal intestine in Bluegill. The lowest α-amylase activity was found in the stomach. No difference in α-amylase among the three parts of intestine was detected. α-amylase activity in Bluegill along the digestive tract is higher than that in Black Crappie, but significantly lower than that in Grass Carp (p \u3c 0.05). Knowledge of α amylase may provide useful information for estimating the carbohydrates level for juvenile Bluegill diets.https://bluetigercommons.lincolnu.edu/lucer-pubs/1004/thumbnail.jp

Learning Radiology in an Integrated Problem-Based Learning (PBL) Curriculum

Background: The Faculty of Medicine (FoM) has been training health professions in Uganda since 1924. Five years ago, it decided to change the undergraduate curriculum from traditional to Problem Based Learning (PBL) and adopted the SPICES model. Radiology was integrated into the different courses throughout the 5 year program. The objective was to improve the implementation of the integration of Radiology in the integrated PBL curriculum.Methods: This was a cross sectional descriptive study of radiologists and medical students using interviews and semi-structured questionnaires respectively.Results: Radiologists’ and students’ perceptions and opinions on Radiology training were gathered. A Radiology training rationale was developed. Learning outcomes for Radiology were defined and learning formats were chosen. Learning materials were identified and strategies to improve the implementation were formulated.Conclusions: This work has culminated into changes in Radiology integration in the curriculum and training at the FOM

Biweekly Growth Characteristics of Juvenile Bluegill Fed Different Protein Diets

This study evaluated growth rates of juvenile bluegill (Lepomis macrochius) fed different protein levels, raised indoors. Six experimental diets containing protein levels of 32, 35, 38, 41, 44, and 47% with 346 kcal/g energy were fed to four replicates of 12 fish with initial mean weight of 24.9±0.51g. Fish were fed by hand to satiation three times daily for 16 weeks. Percent weight gain, for fish fed 32, 35, 38, 41, 44, and 47% protein diets were 180.5±43.8, 203.6±32.33, 256.4±19.4, 235.8±20.63, 249.1±19.59, and 275.2±47.3, and specific growth rates 0.91±0.15, 0.98±0.10, 1.13±0.05, 1.08±0.05, 1.11±0.05, and 1.17±0.11, respectively for the study. Biweekly mean weight differences (p ≤ 0.05) occured after week eight, with fish fed 47% diet consistently havingh higher mean wight than those fed 32%. Biweekly weight gain was connsistently different after week two between fish fed 47% and 32% protein. However, fish fed 38 and 44% diets sometimes had significantly more gain than those fed 32 and 35%. Biweekly feed consumption differed after week ten with fish fed 47 and 38% consistently consumed more food than fish fed 32% protein. Feed conversion ratio differences occurred at every period with the most common differences seen between the 32 and 47% groups. This study indicated that growth characteristics could be improved with higher protein diets in juvenile bluegill.https://bluetigercommons.lincolnu.edu/lucer-pubs/1006/thumbnail.jp

Influence of social networks on the adoption of climate smart technologies in East Africa: Findings from two surveys and participatory exercises with farmers and local experts

As part of the Policy Action for Climate Change Adaptation (PACCA) project, this info note summarizes findings of a project activity entitled “Influencing and linking policies and institutions from national to local level for the development and adoption of climate‐resilient food systems in East Africa” undertaken by researchers from Bioversity International and Arizona State University. By conducting a network analysis and participatory exercises with district officials and farmers in Lushoto (Tanzania) and Rakai (Uganda), the study assesses the extent to which farmers are adopting agricultural practices and correlates the findings about the size and “make up” of the networks in which the farmers are embedded

Adoption of climate smart technologies in East Africa: Findings from two surveys and participatory exercises with farmers and local experts

As part of the “Policy Action for Climate Change Adaptation” (PACCA) project this info note summarizes findings of a project activity entitled “Influencing and linking policies and institutions from national to local level for the development and adoption of climate‐resilient food systems in East Africa” undertaken by researchers from Bioversity International and Arizona State University. By conducting a network analysis and participatory exercises with district officials and farmers, the study assesses the extent to which farmers are adopting agricultural practices and correlates the findings about the size and “make up” of the networks in which the farmers are embedded

Determination of longitudinal aerodynamic derivatives using flight data from an icing research aircraft

A flight test was performed with the NASA Lewis Research Center's DH-6 icing research aircraft. The purpose was to employ a flight test procedure and data analysis method, to determine the accuracy with which the effects of ice on aircraft stability and control could be measured. For simplicity, flight testing was restricted to the short period longitudinal mode. Two flights were flown in a clean (baseline) configuration, and two flights were flown with simulated horizontal tail ice. Forty-five repeat doublet maneuvers were performed in each of four test configurations, at a given trim speed, to determine the ensemble variation of the estimated stability and control derivatives. Additional maneuvers were also performed in each configuration, to determine the variation in the longitudinal derivative estimates over a wide range of trim speeds. Stability and control derivatives were estimated by a Modified Stepwise Regression (MSR) technique. A measure of the confidence in the derivative estimates was obtained by comparing the standard error for the ensemble of repeat maneuvers, to the average of the estimated standard errors predicted by the MSR program. A multiplicative relationship was determined between the ensemble standard error, and the averaged program standard errors. In addition, a 95 percent confidence interval analysis was performed for the elevator effectiveness estimates, C sub m sub delta e. This analysis identified the speed range where changes in C sub m sub delta e could be attributed to icing effects. The magnitude of icing effects on the derivative estimates were strongly dependent on flight speed and aircraft wing flap configuration. With wing flaps up, the estimated derivatives were degraded most at lower speeds corresponding to that configuration. With wing flaps extended to 10 degrees, the estimated derivatives were degraded most at the higher corresponding speeds. The effects of icing on the changes in longitudinal stability and control derivatives were adequately determined by the flight test procedure and the MSR analysis method discussed herein