bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in the Concentration of Nutrients and Other Chemical Properties of Shrimp Pond Soils as a Function of Pond Use
Authors: Ritvo Gad , Shitumbanuma Victor , Samocha Tzachi M.
Published: April 2007

Several soil nutrients, pH, organic carbon, and total soluble salts from the upper 10 cm of soil samples from 72 shrimp ponds in Texas were analyzed. Large increases in sediment concentrations of C, N, Mg, K, Na, Fe, Mn, Zn, Cu, B, nitrate, and water‐soluble salts was observed after one production cycle, followed by an asymptotic increase in older ponds. An approximately linear increase in soil concentration of S and P with pond age was observed. The pH showed a marked decrease in ponds that had been used for one production cycle, but stabilized in older ponds. No correlation between Ca and growing cycle was observed. Calculated recovery rates for elements supplied in feed were less than 10% in several cases and 15% for P. No measurable negative effect on shrimp production by the increase of elemental concentrations was measured.
Production of Nile Tilapia Oreochromis niloticus and Freshwater Prawn Macrobrachium rosenbergii Stocked at Different Densities in Polyculture Systems in Brazil
Authors: Santos Marcel J. M. dos , Valenti Wagner C.
Published: April 2007

Abstract.— The effect of stocking prawns Macrobrachium rosenbergii at increasing densities in ponds with Nile tilapia Oreochromis niloticus reared at low density was evaluated. Twelve 0.01‐ha earthen ponds were stocked with 1 tilapia/m2 and 0, 2, 4, or 6 postlarvae prawn/m2. Three replicates were randomly assigned to each prawn density. Postlarval prawns were stocked a week prior to tilapia juveniles and both were harvested 175 d after the beginning of the experiment. Tilapia final average weight, survival, production, and food conversion rates did not differ significantly among treatments (P > 0.05); the averages were 531 g, 67%. 3,673 kg/ha, and 1.91, respectively. Prawn survival rates did not differ for the three stocking densities (mean 90%). However, final weight and production were significantly different (P < 0.05) as follows: 34.0, 23.0, and 14.7 g and 639, 909, and 818 kg/ha, respectively for 2. 4, and 6 prawns/m2 densities. Stocking densities up to 6 prawn/m2 did not affect tilapia production and required neither additional feeding nor significant changes in management. The polyculture system allowed an increase in total production with the same amount of supplied feed, thus improving the system sustainability.
Effect of Fish Density During Transportation on Stress and Mortality of Juvenile Tambaqui Colossoma macropomum
Authors: Gomes Levy C. , Roubach Rodrigo , Araujo‐Lima Carlos A. R. M. , Chippari‐Gomes Adriana R. , Lopes Nívia P. , Urbinati Elisabeth C.
Published: April 2007

The increased demand for juvenile tambaqui Colossoma macropomum for grow‐out ponds and stocking programs in the Amazon state of Brazil has increased the transportation of this species. This study was designed to determine the optimum density of juvenile tambaqui during transportation in closed containers. Fish (51.9 ± 3.3 g and 14.9 ± 0.4 cm) were packed in sealed plastic bags and transported for 10 h at four densities: 78, 156, 234, and 312 kg/m3. After transportation, fish from each density were kept in separate 500‐L tanks for 96 h. Mortality, 96‐h cumulative mortality, water quality, and blood parameters (hematocrit, plasma cortisol, and glucose) were monitored. Fish mortality after transportation was significantly lower at densities of 78 and 156 kg/m3 than at 234 and 312 kg/m3. Cumulative mortality was significantly lower at a density of 78 kg/m3. Dissolved oxygen after 10 h of transportation remained high at a density of 78 kg/m3, but reached critically low values at all other densities. Ammonia concentration was highest at the lowest density and was lower at higher densities. Carbon dioxide concentration was lowest at the density of 78 kg/m3 but higher in the other treatments. Plasma glucose and cortisol increased significantly immediately after transportation at densities of 156, 234, and 312 kg/m3, returning to control values by 24 h. The best density for juvenile tambaqui during a 10‐h transportation haul in a closed container was 78 kg/m3. At this density there was no fish mortality, water quality was kept within acceptable values, and fish were not stressed.
Dietary Effects on Sperm Quality of Litopenaeus vannamei Broodstock
Authors: Perez‐Velazquez Martin , Gonzáez‐Félix Mayra L. , Lawrence Addison L. , Bray William A. , Gatlin Delbert M.
Published: April 2007

A 56‐d feeding trial was conducted to investigate the effect of diet on sperm quality of Pacific white shrimp Litopenaeus vannamei broodstock. Dietary treatments consisted of a combination of 75% dry maturation diet and 25% fresh‐frozen squid (dry‐weight basis). Supplemental nutrients of the maturation diet were selectively deleted and replaced with wheat starch to produce the following treatments: 1) 75% basal maturation diet plus 25% squid (control); 2) 75% maturation diet without supplemental vitamins plus 25% squid; 3) 75% maturation diet without supplemental cholesterol and phospholipids plus 25% squid; 4) 75% maturation diet without supplemental astaxanthin plus 25% squid; and 5) a fresh diet composed of 60% squid and 40% Maine bloodworms. Shrimp fed the control diet and the diet without supplemental astaxanthin had significantly higher mean (± SEM) change in sperm count (4.6 ± 3.2 million sperm cells and 2.9 ± 2.5 million sperm cells, respectively), with respect to baseline (8.7 ± 1.0, 6.4 ± 1.0, 9.0 ± 1.3, 6.6 ± 0.7, and 6.0 ± 0.8 million sperm cells for treatments 1, 2, 3, 4, and 5, respectively), than shrimp fed the diet without supplemental vitamins (‐1.7 ± 2.6 million sperm cells), but not significantly higher than those of shrimp receiving the diets without supplemental cholesterol‐phospholipids (1.2 ± 2.5 million sperm cells) and the fresh diet (1.3 ± 1.6 million sperm cells). Dietary deficiencies also were reflected in weight gain of shrimp fed the diet without supplemental vitamins (‐2.0 g) and the fresh diet (‐0.8 g). which were significantly lower than weight gain of shrimp fed the control diet (1.1 g) and the diet without supplemental cholesterol‐phospholipids (0.8 g). No significant differences were detected among treatments for percentage of abnormal sperm and survival data. Results demonstrated a significant effect of diet on reproductive quality of male L. vannamei and indicated that the typical combination of fresh‐food organisms used is not nutritionally optimal for male broodstock.
Effects of Low Salinities on Oxygen Consumption of Selected Euryhaline and Stenohaline Freshwater Fish
Authors: Altinok Ilhan , Grizzle John M.
Published: April 2007

The amount of energy required for osmoregulation depends on the difference between internal and external concentrations of ions (Rao 1968; Farmer and Beamish 1969), changes in corticosteroid hormone levels (Morgan and Iwama 1996), glomerular filtration rates (Furspan et al. 1984), gill and kidney Na+, K+‐ATPase activity (McCormick et al. 1989; Morgan and Iwama 1998), tissue permeability to water and ions, and gill ventilation, perfusion, and functional surface area (Rankin and Bolis 1984). Differences in the energetic cost of osmoregulation play a significant role in the difference in growth rate between seawater‐and freshwater‐adapted fish (Morgan and Iwama 1991; Ron et al. 1995; Wang et al. 1997). Oxygen consumption is an indirect indicator of metabolic rate in fish (Cech 1990) and can be used to determine effects of salinity changes on energy costs.
Association with Underwater Structures in Hatchery‐reared and Wild Red Snapper Lutjanus campechanus Juveniles
Authors: Masuda Reiji , Keller Karl , Ziemann David A. , Ogle John
Published: April 2007

Behavioral observations were conducted with red snapper juveniles to improve release strategies for stock enhancement of this species. Association with an underwater structure was compared between hatchery‐reared and wild juveniles using video recording. Both hatchery‐reared and wild fish tended to stay inside the structure in the daytime and outside it at night. Hatchery‐reared fish spent longer periods inside the structure in the daytime, hut showed less association with the structure at night compared to the wild fish. We concluded that association behavior is innate but can be fine‐tuned through experience.
Effect of Dietary Phospholipids on the Choline Requirement ofLitopenaeus vannamei Juveniles
Authors: Gong Hui , Lawrence Addison L. , Jiang Dong‐Huo , Gatlin Delbert M.
Published: April 2007

An 8‐wk feeding trial was conducted with a 3 ± 4 factorial design for evaluating the nutritional relationship between phospholipids (lecithin at 0, 1.5% or 3% of diet) and choline chloride (0, 1,000, 2,000, or 4,000 mg/kg diet) in juvenile Litopenaeus vannamei. In addition, diets with five graded levels of choline chloride (0, 500, 1,000, 2,000, and 4,000 mg/kg) without supplemental phospholipids or cholesterol were fed for determining the dietary choline requirement. Overall survival was 99% with no difference among the dietary treatments. The choline requirement was estimated to be 871 mg/kg diet without dietary phospholipids. No choline requirement was evident when lecithin was provided at 1.5% and 3% of diet. Shrimp growth significantly increased with incremental dietary phospholipids regardless of choline chloride level. These results indicate that lecithin could effectively provide choline. Conversely, synthesis of phospholipids from choline could not meet the phospholipids requirement of shrimp. Both dietary lecithin and choline chloride supplementation reduced lipid in shrimp muscle. However, only lecithin supplementation increased lipid in hepatopancreas, and dietary choline chloride decreased the level of other phospholipids (except phosphatidylcholine) in shrimp muscle.
Growth and Feed Utilization of Captive Wild Black Sea Bass Centropristis striata at Four Different Densities in a Recirculating Tank System
Authors: Copeland Kimberly A. , Watanabe Wade O. , Carroll Patrick M. , Wheatley Kerr S. , Losordo Thomas M.
Published: April 2007

A study to determine the effects of four stocking densities on growth and feed utilization of wild‐caught black sea bass Centropristis striata was conducted in a pilot‐scale recirculating tank system. The outdoor system consisted of 12 insulated fiberglass tanks (dia. = 1.85 m; vol. = 2.17 m3) supported by biological filters, UV sterilizers, and heat pumps. Subadults (N= 525; ×± SD = 249 ± 16.8 g) were stocked at densities of 4.6 fish/m3 (1.18 kg/m3), 16 fish/ m3 (3.91 kg/m3), 25.3 fish/m3 (6.83 kg/m3), and 36 fish/m3 (7.95 kg1m3), with three replicate tanks per treatment. Fish were grown under 35 ppt salinity, 21‐25 C, and under ambient photoperiod conditions. A commercial flounder diet containing 50% protein and 12% lipid was hand‐fed twice daily to satiation for 201 d.

Mean (range) total ammonia‐nitrogen, 0.61 (0‐2.1) mg/L, nitrite‐nitrogen, 0.77 (0.04‐3.6) mg/L, and nitrate‐nitrogen 40.1 (0‐306) mg/L were significantly higher (P < 0.0001) in the 25.3 and 36 fish/m3 treatments than in the 4.6 and 16 fish/m3 treatments [0.19 (0.05‐0.5), 0.1 (0.24‐0.63), and 11.9 (1.3‐82.2) mg/L, respectively]. However, there were no significant differences (P > 0.05) in growth (RGR = 196.8‐243.1%; DWG = 2.55‐2.83 g/d; and SGR = 0.55‐0.61%/d), coefficient of variation of body weight (CwtV., = 0.24‐0.25), condition factor (K = 2.2‐2.4), feed consumption (FC = 1.45‐1.65%/d), and feed conversion ratio (FCR = 1.45‐1.52) among stocking densities. Final biomass densities on day 201 reached 3.48, 12.0, 21.1, and 27.2 kg/m3 at stocking densities of 4.6, 16, 25.3, and 36 fish/m3, respectively. Survival (83.8‐99.1%) did not differ among treatments. Apparent net protein retention (ANPR) was significantly higher (P < 0.005) for fish stocked at the lower densities of 4.6 and 16 fish/m3 (22.5‐23.7%) than for those stocked at 25.3 and 36 fish/m3 (21‐20.1%). There were no significant differences (P > 0.05) in apparent net energy retention (ANER = 55.9‐59.1 %) among stocking densities. Final whole body protein (15.3‐16.3%) and lipid (23.1‐26.4%) levels did not differ significantly (P > 0.05) among treatments.

The results demonstrated that growth, survival, and feed utilization were not impaired under stocking densities ranging from 4.6‐36 fish/m3 (3.48‐27.2 kg/m3), despite a slight reduction in water quality at the higher densities. In addition, growth variation and final whole body protein and lipid levels were not influenced by these densities. The results suggest that black sea bass are tolerant of crowding and moderate variations in water quality during intensive culture in recirculating tank systems and that higher stocking densities are possible.
Broodstock Rearing and Controlled Reproduction of Reeves Shad Tenualosa reevesii
Authors: Wang Han‐Ping , Xiong Bang‐Xi , Wei Kai‐Jing , Yao Hong
Published: April 2007

Reeves shad Tenualosa reevesii is one of China's best known anadromous fish, but is presently on the verge of extinction. There is an urgent need for conservation of this species through artificial reproduction and culture. In this study, shad broodstock were held in captivity then were induced to spawn with serial injections of luteinizing hormone‐releasing hormone analogue (LHRHa) following GtH priming by implantations of 17‐methytestosterone (T) combined with environmental manipulations. Induced maturation of 4, 5, and 6‐year‐old females reached 83.3%, 87.5%, and 100%, respectively, while fish in control treatments remained immature. During the gonadal development priming period, mean serum 17‐estradiol levels in the T treatment were significantly higher than the LHRHa treatment and control fish. Gonadal development of females was suppressed when their mesenteric fat index was below 1.5% by April. The effective accumulating temperatures for female and male maturation were 3,995 ± 31.4 C/d and 2,278 ± 8.9 C/d, respectively. Two injections of LHRHa in combination with domperidone (DOM) and environmental regulations were effective in inducing ovulation. About 800,000 fertilized ova were obtained (fertilization 75%) in 1995, and 5,000 fry were hatched in 1996. These results are an important step to develop shad culture and save this endangered species.
Restricted and Satiate Feeding of Two Genetically Isolated Strains of Juvenile Channel Catfish Ictalurus punctatus Reared on 28% and 32% Protein Diets
Authors: Jackson L. Scoit , Robinson Edwin H. , Li Menghe H. , Wolters William R. , McKee David A.
Published: April 2007

A 10‐wk growth comparison trial of two strains of channel catfish Ictalurus punctatus was conducted in 40 120‐L flow‐through aquaria using a 2 ± 2 × 2 factorial experiment design. The three factors evaluated were: strain (Norris and NWAC103), dietary protein level (28% and 32%), and feeding rate (restricted and satiate). Average initial weight (× SD) for the Norris strain was 3.0 ± 0.08 g/fish, while that of the NWAC103 strain was 4.7 ± 0.13 g/fish. The feeding rate for the satiated group was adjusted based on feeding observations. The feeding rate for the restricted group was adjusted to about 2/3 of the satiate level. For both satiate and restricted feeding regimens, the NWAC103 strain consumed more feed than the Norris strain. Fish of Norris strain fed the 32% protein diet consumed more feed than fish fed the 28% protein diet; however, there were no differences in feed consumption in the NWAC103 fish fed the two protein diets. Regardless of feeding rate, the NWAC103 fish gained more weight and converted feed more efficiently than the Norris fish. Fillet composition was not affected by fish strain. Fish fed the 28% protein diet had a lower level of fillet protein than fish fed the 32% protein diet. In fish fed to satiation, a 32% protein diet resulted in a lower fillet fat level than a 28% protein diet, but no differences were observed in fillet fat levels between fish fed the two dietary protein levels for the restricted group. Results from the present study demonstrate that under laboratory conditions, the NWAC103 strain of channel catfish is superior to Norris strain in feed consumption, growth rate, and feed efficiency. Our data also indicate that either a 28% or 32% protein diet can be fed to either strain of channel catfish whether they are fed to satiation or fed a restricted ration with no detrimental effects on growth.
Effects of Salinity on Growth, Survival, and Selected Hematological Parameters of Juvenile Cobia Rachycentron canadum
Authors: Denson Michael R. , Stuart Kevin R. , Smith Theodore I. J. , Weirlch Charles R. , Segars Al
Published: April 2007

Cobia Rachycentron canadum juveniles (119.7 mm TL, weight 8.5 g) were reared for 10 wk at three salinity levels: 5 ppt, 15 ppt. and 30 ppt. Growth and survival were determined through biweekly sampling. Blood samples obtained at termination of the study were analyzed to determine hematocrit, blood osmolality, and total protein. Results indicated that the overall growth of fish was significantly affected by salinity. Mean (± SE) total length (TL) and weight of fish reared at a salinity of 30 ppt were 201.7 ± 2.6 mm and 47.6 ± 1.9 g, respectively, followed by fish reared at 15 ppt (182.2 ± 1.7 mm, 34.1 ± 1.6 g). and 5 ppt (168.3 ± 5.8 mm TL, 28.3 ± 2.3 g). Differences in specific growth rates among treatments for the 10‐wk period were also significant. No differences were detected in mean survival among fish reared at salinities of 5, 15, and 30 ppt (84, 94, and 94%, respectively). However, fish reared at salinity 5 ppt appeared to be in poor health as skin lesions, fin erosion, and discoloration were evident. Analysis of blood revealed that, while no differences existed among treatments with respect to plasma total protein, fish reared at a salinity of 5 ppt exhibited significantly reduced hematocrit (25% vs. > 30%) and plasma osmolality values (318 vs. > 353 mmolkg) relative to fish reared at higher salinities. Cobia can tolerate exposure to low salinity environments for short periods of time without mortality; however, moderate to high salinities are required for sustained growth and health of this species.
Influence of Nursery Period on the Growth and Survival of Litopenaeus vannamei Under Pond Production Conditions
Authors: Garzade Yta Antonio , Rouse David B. , Davis D. Allen
Published: April 2007

Techniques for head starting or nursing postlarvae (PL) has received considerable attention with regards to nursery protocols, yet there is little data pertaining to the effects of nursery period on the final growout of shrimp to marketable size. This study was performed to investigate the influence of nursery duration on survival and growth of Litopenaeus vannamei during subsequent pond culture. For this research, a single population of high health PL were received from a commercial hatchery and held in a tank for acclimation, quantification, and distribution to nursery tanks or ponds. Treatments included direct stocking of 10‐d‐old postlarvae (PL10) into production ponds as well as the nursing of PL in a covered greenhouse nursery system for an additional 10 or 20 d. After nursing, the PL were harvested, quantified, and transferred to growout ponds. All ponds were stocked at a density of 35 PL/m2 and maintained under standardized conditions. Shrimp were fed with a 35% protein shrimp feed, twice daily during the 112‐d growth trial. Ponds were aerated as needed using a maximum of 19 hp/ha to maintain adequate dissolved oxygen (DO > 3.0). No statistical differences (P >0.05) were found in survival, yield, or growth between treatments. At harvest, survivals during growout were generally higher in ponds with nursed shrimp (77% for PL20 and 79% for PL30) than in ponds receiving PL10 shrimp (67%). Yields were similar between treatments, ranging from 3,525 for direct stocked shrimp to 3,747 kg/ha for those that were nursed for 10 d. Although growth rates of PL under pond conditions will be faster than that of a nursery system, results suggest that a nursery period of at least 10 d helps improve survival during pond production and promotes better size uniformity. Shrimp nursed for 20 d showed little improvement in survival over shrimp nursed for 10 d but did result in a more uniform size of shrimp at harvest.
Effect of Dietary Phosphorus Levels on Growth, Body Composition, Muscle and Bone Mineral Concentrations for Orange‐Spotted Grouper Epinephelus coioides Reared in Floating Cages
Authors: Zhou Qi C. , Liu Yong J. , Mai Kang S. , Tian Li X.
Published: April 2007

A feeding experiment was conducted in floating cages (1.5 ± 1.0 ± 2.0 m) to determine the requirement of dietary phosphorus by juvenile orange‐spotted grouper Epinephelus coicodes. Five isonitrogenous (approximately 54% CP) fishmeal‐casein‐based diets that contained 0.68, 0.77, 0.86, 1.02 and 1.21% total phosphorus from ingredients and supplemental monocalcium phosphate (MCP: 0, 0.75,1.51,2.26,3.02%) were fed to the fish previously fed a basal diet (0.68% total phosphorus) for 2 wk. Fish were fed in triplicate cages with one of the diets twice daily to satiation. After 8 wk of feeding, survival ranged from 70.0% to 81.7% with no significant difference among dietary treatments. The relative weight gain, specific growth rate, muscle lipid, ash, calcium, iron, zinc and phosphorus, bone ash, phosphorus, iron, and zinc were significantly affected by dietary phosphorus level. There were no significant effects of increasing total dietary phosphorus on hepatosomatic index, viscerasomatic index, condition factor, muscle moisture and protein, muscle magnesium, and manganese; and bone calcium, magnesium and manganese. Based on relative weight gain, specific growth rate and bone phosphorus, a dietary level of 0.86% total phosphorus is recommended for juvenile grouper growing in floating cages.
Using Scope‐For‐Growth Estimates to Compare the Suitability of Feeds Used in Shrimp Aquaculture
Authors: Saoud I. Patrick , Anderson Gary
Published: April 2007

The scope‐for‐growth (SFG) of an animal is the portion of assimilated energy used for secondary production after maintenance requirements are met. The SFG of Penaeus setiferus was calculated as the difference between absorption (A), and the sum of the respiration (R) and excretion (U) [SFG = A ‐ (R+U)]. Protocols were developed and SFG determinations were replicated 18 times for shrimp maintained on an experimental feed (diet 1), and 18 times for shrimp maintained on a commercial feed (diet II). Somatic growth of the shrimp was determined by direct weight measurements and by conversions of SFG results into wet weight and the two values were compared. Results yielded a SFG of 99.8 ± 16.03 J/g per d and 33.78 ± 7.64 J/g per d for diets I and II, respectively. Scope‐for‐growth estimates appear to be suitable for comparisons of effects of various culture conditions on shrimp.
Effects of Microbial Phytase Supplementation and Dosage on Apparent Digestibility Coefficients of Nutrients and Dry Matter in Soybean Product‐Based Diets for Rainbow Trout Oncorhynchus mykiss
Authors: Cheng Zongjia J. , Hardy Ronald W. , Verlhac Viviane , Gabaudan Jacques
Published: April 2007

Three experiments were conducted to evaluate the effects of microbial phytase (Ronozyme P(L) and dosage on apparent digestibility coefficients of dry matter, crude protein, amino acids, and minerals in soybean product‐based diets for rainbow trout Oncorhynchus mykiss. In experiments 1 and 2, fish were fed soy protein concentrate and soybean meal‐based semi‐purified diets, respectively. In experiment 3, fish were fed soybean meal‐based practical diets. A total of 900 fish (average body weight 100.1 ± 7.4 g) were stocked into 30 150‐L fiberglass tanks with 30 fish per tank and two tanks per diet. Phytase was supplemented into soybean product‐based diets at 0, 500, 1,000, 2,000, and 4,000 FTU/kg diet. Yttrium oxide (0.01%) was used as inert marker. Feces were collected by hand stripping three times at 3‐d intervals. Results of experiments 1 and 2 showed that phytase supplementation significantly increased apparent digestibility coefficients of minerals (except copper and iron), but not dry matter. Experiment 3 showed that phytase supplementation significantly increased apparent digestibility coefficients of dry matter, crude protein, amino acids (except tryptophan and tyrosine), and minerals (except copper and iron). The optimum level of phytase supplementation in rainbow trout diets was approximately 500 FTU/kg diet.
Copper Concentrations in Channel Catfish Ictalurus punctatus Ponds Treated with Copper Sulfate
Authors: McNevin Aaron A. , Boyd Claude E.
Published: April 2007

Copper sulfate (CuSO45H2O) is used to reduce the abundance of blue‐green algae and combat off‐flavor in channel catfish culture. Copper sulfate usually is applied at a concentration of one‐one hundredth of the total alkalinity. A study was performed at the Auburn University Fisheries Research Unit to determine the duration of elevated copper (Cu) concentration following copper sulfate applications. Two alkalinity treatments, 20‐40 mg/L and 110‐130 mg/L (as CaCO3), were examined. Copper sulfate was applied biweekly for 14 wk at 03 mg/L for the low alkalinity treatment and 1.2 mg/L for the high alkalinity treatment. Total copper concentrations in pond waters declined to the background level by 48‐h post treatment. In addition, total copper concentrations were determined in waters of 38 catfish production ponds located in west central Alabama. The mean and standard deviation were 0.0092 ± 0.0087 mg Cu/L. Copper quickly precipitates from the water or is absorbed by sediments following copper sulfate treatment. Although concentrations of copper in pond waters increase immediately following copper sulfate treatment, they rapidly decrease and seldom exceed the United States Environmental Protection Agency's National Recommended Water Quality Criteria for Priority Toxic Pollutants of 0.013‐mg Cu/L. Findings of this study suggest that copper sulfate treatment will not contaminate effluent from catfish ponds because of the short time that applied copper remains in the water column. Furthermore, the most frequent applications of copper sulfate occur in late summer months when rainfall is minimal and pond overflow is rare.
Apparent Digestibility Coefficients of Various Feed Ingredients for Grouper Epinephelus coioides
Authors: Lin Heizhao , Liu Yongjian , Tian Lixia , Wang Jiteng , Zheng Wenhui , Huang Jiannan , Chen Peiji
Published: April 2007

Apparent digestibility coefficients (ADC) of dry matter, crude protein, lipid, gross energy, amino acids, and fatty acids in white fish meal, brown fish meal, soybean meal, peanut meal, and yeast were determined for grouper Epinephelus coioides. Apparent digestibility was determined using a reference diet with 0.5% chromic oxide indicator and test diets that contained 70% reference diet and 30% of the feed ingredient being evaluated. The fish, averaging 12.0 g, were held in 250‐L tanks at a density of 30 fish per tank. Feces were collected from three replicate groups‐of fish.

Apparent dry matter digestibility of ingredients was 78.85 ± 2.43, 79.11 ± 0.61, 69.85 ± 3.60, 73.67 ± 2.30 and 57.70 ± 4.69% for white fish meal, brown fish meal, soybean meal, peanut meal, and yeast, respectively. Apparent gross energy digestibility of ingredients was 93.27 ± 2.90, 89.48 ± 1.78, 70.52 ± 4.01, 73.13 ± 2.41 and 51.67 ± 2.01% for white fish meal, brown fish meal, soybean meal, peanut meal, and yeast, respectively. Apparent protein digestibility of ingredients was 89.82 ± 1.24, 87.34 ± 1.25, 83.97 ± 1.92, 80.79 ± 1.95, and 61.14 ± 0.54% for white fish meal, brown fish meal, soybean meal, peanut meal, and yeast, respectively. White fish meal and brown fish meal showed higher protein digestibility among ingredients tested (P ± 0.01). Lipid digestibility of ingredients was high (90.66‐94.48%) and not significantly different except for yeast. Amino acid availability values for test ingredients were similar to values of protein digestibility. Amino acid availability values of white fish meal and brown fish meal were higher than other ingredients. Fatty acid availability values for test ingredients were similar to values of lipid digestibility. In general, the digestibility of most fatty acids was over 80% in all ingredients, except for 14:0 in yeast and 18:0 in peanut meal, PUFA + HUFA > MUFA > SFA. Longer‐chain saturated fatty acids were less digestibility, except for 14:0, with digestibilities diminishing as fatty acid chain length increased. Apparent digestibility of dry matter, crude protein, lipid, gross energy, amino acids, and fatty acids in yeast was the lowest among the ingredients.
Cryogenic and Refrigerated Storage of Rainbow Smelt Osmerus mordax Spermatozoa
Authors: DeGraaf J. Dana , Berlinsky David L.
Published: April 2007

The effects of extender composition, cryoprotectant, and freezing rate on post‐thaw rainbow smelt Osmerus mordax sperm motility were examined, and the fertilization capacity of fresh and post‐thaw sperm were compared. The highest post‐thaw motility (75%) was obtained when milt was diluted 1:3 with an extender containing 600 mM sucrose supplemented with 10% dimethyl sulfoxide and 1.5% bovine serum albumin and frozen at a rate of –20 C/min. Post‐thaw motility for sperm stored in this extender was similar to fresh sperm and did not change after 90 d of storage. Furthermore, there were no differences in fertilization rate or embryo survival to the eyed stage between fresh and post‐thaw sperm frozen in this extender. The lowest post‐thaw motility was observed when sperm were frozen with methanol at a rate of ‐30 C/min. Refrigerated sperm diluted 1:3 with the 600 mM sucrose extender remained motile for 30 d. These data demonstrate that rainbow smelt spermatozoa can be effectively used following short and long‐term storage using a simple, sucrose‐based extender.
Apparent Digestible Energy and Nutrient Digestibility Coefficients of Diet Ingredients for Pacu Piaractus brachypomus
Authors: Fernandes Joāto Batista K. , Lochmann Rebecca , Bocanegra Fernando Alcantara
Published: April 2007

The digestible energy and apparent nutrient digestibility coefficients of common diet ingredients were determined for pacu Piaractus brachypomus (370.21 ± 17.56 g). Fish were fed with pelleted practical diets to apparent satiation and the feces were collected by siphoning. The digestibility value for each ingredient was determined by comparison of the digestibility of a test diet with a reference diet (24.5% crude protein and 1% chromic oxide). The digestible energy values of soybean meal (SBM), fish meal (FM), corn (CN), and wheat bran (WB) were 2382. 3826, 3353, and 1784 kcal/kg, respectively. The apparent dry matter digestibility coefficients were 83.72, 90.14, 89.13, and 82.05% for SBM, FM, CN, and WB, respectively. The apparent crude protein digestibility coefficients were 75.88, 90.49, 85.06, and 61.62% for SBM. FM, CN, and WB, respectively. The apparent lipid digestibility coefficients were 63.03, 77.00, 83.01, and 82.45% for SBM, FM, CN, and WB, respectively. The digestibility of protein, lipid, and energy from SBM were somewhat low compared to values for other warmwater omnivorous fishes, but similar to values reported for pacu‐caranha P. mesopotamicus. Otherwise, the nutrient and energy availability of the ingredients to P. brachypomus was similar to that of other fish. This information will be useful in formulating nutritious, economical diets for pacus.
Quantitative Protein Requirements of the Edible Snail Pomacea urceus (Muller)
Authors: Ramnarine Indar W.
Published: April 2007

Six isocaloric, semi‐purified diets containing 15, 20, 25, 30, 35, and 40% crude protein were formulated and fed to juvenile Pomacea urceus (mean length 34.8 mm, mean weight 7.35 g) at the daily rate of 4% biomass over an 18‐wk period. The best weight gain of 230% was obtained with the test diet containing 30% crude protein, but was not significantly different from the weight gain of 228% obtained with the 20% protein diet. A lower feed conversion ratio (1.77 compared with 1.90) was obtained with the test diet containing 20% crude protein. A diet containing 20% crude protein is recommended for the culture of Pomacea urceus.
A Biomechanical Study of Periacetabular Defects and Cement Filling
Authors: Li Zuoping , Butala Neha B. , Etheridge Brandon S. , Siegel Herrick J. , Lemons Jack E. , Eberhardt Alan W.
Published: April 2007

Periacetabular bone metastases cause severe pain and functional disability in cancer patients. Percutaneous acetabuloplasty (PCA) is a minimally invasive, image-guided procedure whereby cement is injected into lesion sites. Pain relief and functional restoration have been observed clinically; however, neither the biomechanical consequences of the lesions nor the effectiveness of the PCA technique are well understood. The objective of this study was to investigate how periacetabular lesion size, cortex involvement, and cement modulus affect pelvic bone stresses and strains under single-legged stance loading. Experiments were performed on a male cadaver pelvis under conditions of intact, periacetabular defect, and cement-filling with surface strains recorded at three strain gage locations. The experimental data were then employed to validate three-dimensional finite element models of the same pelvis, developed using computed tomography data. The models demonstrated that increases in cortical stresses were highest along the posterior column of the acetabulum, adjacent to the defect. Cortical stresses were more profoundly affected in the presence of transcortical defects, as compared to those involving only trabecular bone. Cement filling with a modulus of 2.2GPa was shown to restore cortical stresses to near intact values, while a decrease in cement modulus due to inclusion of BaSO4 reduced the restorative effect. Peak acetabular contact pressures increased less than 15% for all simulated defect conditions; however, the contact stresses were reduced to levels below intact in the presence of either cement filling. These results suggest that periacetabular defects may increase the vulnerability of the pelvis to fracture depending on size and cortical involvement and that PCA filling may lower the risk of periacetabular fractures.
Deterministic Material-Based Averaging Theory Model of Collagen Gel Micromechanics
Authors: Chandran Preethi L. , Barocas Victor H.
Published: April 2007

Mechanics of collagen gels, like that of many tissues, is governed by events occurring on a length scale much smaller than the functional scale of the material. To deal with the challenge of incorporating deterministic micromechanics into a continuous macroscopic model, we have developed an averaging-theory-based modeling framework for collagen gels. The averaging volume, which is constructed around each integration point in a macroscopic finite-element model, is assumed to experience boundary deformations homogeneous with the macroscopic deformation field, and a micromechanical problem is solved to determine the average stress at the integration point. A two-dimensional version was implemented with the microstructure modeled as a network of nonlinear springs, and 500 segments were found to be sufficient to achieve statistical homogeneity. The method was then used to simulate the experiments of Tower et al. (Ann. Biomed. Eng., 30, pp. 1221–1233) who performed uniaxial extension of prealigned collagen gels. The simulation captured many qualitative features of the experiments, including a toe region and the realignment of the fibril network during extension. Finally, the method was applied to an idealized wound model based on the characterization measurements of Bowes et al. (Wound Repair Regen., 7, pp. 179–186). The model consisted of a strongly aligned “wound” region surrounded by a less strongly aligned “healthy” region. The alignment of the fibrils in the wound region led to reduced axial strains, and the alignment of the fibrils in the healthy region, combined with the greater effective stiffness of the wound region, caused rotation of the wound region during uniaxial stretch. Although the microscopic model in this study was relatively crude, the multiscale framework is general and could be employed in conjunction with any microstructural model.
Effects of Initial-Fixed Charge Density on pH-Sensitive Hydrogels Subjected to Coupled pH and Electric Field Stimuli: A Meshless Analysis
Authors: Ng T. Y. , Li Hua , Yew Y. K. , Lam K. Y.
Published: April 2007

In this paper, we study the effects of initial fixed-charge density on the response behavior of pH-sensitive hydrogels subjected to coupled stimuli, namely, solution pH and externally applied electric field. This is the first instance in which a coupled stimuli numerical analysis has been carried out for these polymer gels, which are used as active sensing/actuating elements in advanced biomicroelectromechanical systems devices. In this work, a chemo-electro-mechanical formulation, termed the multi-effect-coupling pH-stimulus (MECpH) model, is first presented. This mathematical model takes into account the ionic species diffusion, electric potential coupling, and large mechanical deformation. In addition, a correlation between the diffusive hydrogen ions and fixed-charge groups on the hydrogel polymeric chains is established based on the Langmuir absorption isotherm, and incorporated accordingly into the MECpH model. To solve the resulting highly nonlinear and highly coupled partial differential equations of this mathematical model, the Hermite-Cloud method, a novel true meshless technique, is employed. To demonstrate the accuracy and robustness the MECpH model, computed numerical results are compared with experimental data available from literature. Following this validation, several numerical studies are carried out to investigate the effects of initial fixed-charge density on the volumetric variations of these pH-stimulus-responsive hydrogels when immersed in buffered solutions.
Strong and Selective Inhibitors of Hepatitis B Virus Replication among Novel N
4
-Hydroxy- and 5-Methyl-β-
l
-Deoxycytidine Analogues
Authors: Matthes E. , Funk A. , Krahn I. , Gaertner K. , von Janta-Lipinski M. , Lin L. , Will H. , Sirma H.
Published: April 2007

Novel N
4
-hydroxy- and 5-methyl-modified β-
l
-deoxycytidine analogues were synthesized and evaluated as anti-hepatitis B virus (HBV) agents. Their in vitro efficiencies were investigated in HepG2.2.15 cells stably transfected with HBV. β-
l
-2′,3′-Didehydro-2′,3′-dideoxy-N
4
-hydroxycytidine (β-
l
-Hyd4C) was most effective in reducing secreted HBV DNA (50% effective concentration [EC
50
], 0.03 μM), followed by β-
l
-2′,3′-dideoxy-3′-thia-N
4
-hydroxycytidine (EC
50
, 0.51 μM), β-
l
-2′,3′-dideoxy-N
4
-hydroxycytidine (EC
50
, 0.55 μM), and β-
l
-5-methyl-2′-deoxycytidine (EC
50
, 0.9 μM). The inhibition of the presumed target, the HBV DNA polymerase, by the triphosphates of some of the β-
l
-cytidine derivatives was also assessed. In accordance with the cell culture data, β-
l
-Hyd4C triphosphate was the most active inhibitor, with a 50% inhibitory concentration of 0.21 μM. The cytotoxicities of some of the 4-NHOH-modified β-
l
-nucleosides were dramatically lower than those of the corresponding cytidine analogues with the unmodified 4-NH
2
group. The 50% cytotoxic concentrations for β-
l
-Hyd4C in HepG2 and HL-60 cells were 2,500 μM and 3,500 μM, respectively. In summary, our results demonstrate that at least β-
l
-Hyd4C can be recommended as a highly efficient and extremely selective inhibitor of HBV replication for further investigations.
Spread in an Italian Hospital of a Clonal
Acinetobacter baumannii
Strain Producing the TEM-92 Extended-Spectrum β-Lactamase
Authors: Endimiani Andrea , Luzzaro Francesco , Migliavacca Roberta , Mantengoli Elisabetta , Hujer Andrea M. , Hujer Kristine M. , Pagani Laura , Bonomo Robert A. , Rossolini Gian Maria , Toniolo Antonio
Published: April 2007

Clinical isolates of
Acinetobacter baumannii
(
n
= 470) were collected during a 7-year period and investigated for the genetic determinants of resistance to expanded-spectrum β-lactams. Thirty-one isolates produced the TEM-92 extended-spectrum β-lactamase (ESBL) and were clonally related. This is the first report of
A. baumannii
producing a TEM-type ESBL.
Mutant Prevention Concentrations of Fluoroquinolones for
Enterobacteriaceae
Expressing the Plasmid-Carried Quinolone Resistance Determinant
qnrA1
Authors: Rodríguez-Martínez J. M. , Velasco C. , García I. , Cano M. E. , Martínez-Martínez L. , Pascual A.
Published: April 2007

The influence of
qnrA1
on the development of quinolone resistance in
Enterobacteriaceae
was evaluated by using the mutant prevention concentration parameter. The expression of
qnrA1
considerably increased the mutant prevention concentration compared to strains without this gene. In the presence of
qnrA1
, mutations in
gyrA
and
parC
genes were easily selected to produce high levels of quinolone resistance.
Controlled Trial of a 5-Day Course of Telithromycin versus Doxycycline for Treatment of Mild to Moderate Scrub Typhus
Authors: Kim Dong-Min , Yu Ki Dong , Lee Ji Hyun , Kim Hyun Kuk , Lee Seung-Hyun
Published: April 2007

New antibiotics are required to have the antibacterial activity against doxycycline-resistant
Orientia tsutsugamushi
. An in vitro sensitivity study showed that telithromycin was more effective than erythromycin for
Rickettsia
,
Bartonella
, and
Coxiella burnetii
. In this prospective, open-label, randomized trial, we enrolled patients with mild-to-moderate scrub typhus. We compared the efficacy and safety of a 5-day telithromycin therapy with those of a 5-day doxycycline therapy at Chosun University Hospital or one of its two community-based affiliated hospitals (Jangheung Hospital and Cheomdan Hospital), which are all located in southwestern Korea, between September and December 2005. A total of 92 patients were randomly assigned to either the telithromycin group (
n
= 47) or the doxycycline group (
n
= 45). After the treatment, fever control time was 20.45 ± 12.9 h in the telithromycin group and 22.60 ± 21.44 h in the doxycycline group (
P
> 0.05). After the treatment, the cure rate was 100% in the telithromycin group and 97.8% in the doxycycline group (
P
> 0.05). Furthermore, there were no significant differences in time elapsed until such symptoms as headache, myalgia, and rash disappeared. No serious adverse events or death were noted following the treatment in both groups. There were no significant differences in adverse events. In conclusion, the efficacy and safety of a 5-day once-a-day regimen of 800 mg telithromycin were equivalent to those of a 5-day twice-a-day regimen of 100 mg doxycycline in patients with mild-to-moderate scrub typhus. Telithromycin could be considered a promising new antibacterial agent for patients with scrub typhus.
RNA Interference-Mediated Silencing of theYPS3Gene ofHistoplasma capsulatumReveals Virulence Defects
Authors: Bohse Megan L. , Woods Jon P.
Published: April 2007

TheYPS3gene ofHistoplasma capsulatumencodes a protein that is both surface localized in the cell wall ofH. capsulatumand released into the culture medium. This protein is produced only during the pathogenic yeast phase of infection and is also expressed differentially inH. capsulatumstrains of different virulence levels. In this study, we silenced theYPS3transcript by using an interfering-RNA strategy and examined the silenced mutants for phenotypic differences in vitro and during infection. The mutants showed no growth defect during in vitro culture in a defined medium at 37°C and appeared to have normal virulence in a RAW 264.7 murine macrophage-like cell line. In a C57BL/6 mouse model of infection, however, the mutants caused significantly decreased fungal burdens, particularly in the peripheral phagocyte-rich tissues of livers and spleens. This defect in organ colonization was evident within 3 days of infection; however, it appeared to be exacerbated at later time points.
Kikuchi’s disease displaying a t(2:16) chromosomal translocation
Authors: Robertson Katherine E , Forsyth Peter D , Batstone Paul J , Levison David A , Goodlad John R
Published: April 2007

Kikuchi’s disease is a rare self-limiting lymphoproliferative condition of unknown aetiology, characterised by acute or subacute necrotising lymphadenitis. It is a benign condition that can mimic malignant lymphoma. In this report, a case of Kikuchi’s disease associated with a chromosomal abnormality is described. This is the first report in the literature of such a case and it highlights an important learning point; benign lymphoproliferative conditions can be associated with chromosomal abnormalities that are more typically associated with malignant lymphoproliferative conditions such as malignant lymphoma. The report illustrates the necessity for interpreting cytogenetic data in the relevant clinical and histopathological context in a multidisciplinary setting to avoid misdiagnosis and inappropriate treatment.
Metastatic retroperitoneal epithelioid angiomyolipoma
Authors: Gupta Chakshu , Malani Ashok K , Gupta Vikram , Singh Jaswinder , Ammar Hussam
Published: April 2007

Angiomyolipoma (AML) is a rare benign neoplasm that usually arises in the kidneys, but may rarely originate in sites such as the retroperitoneum, liver and bone. It is characterised by an intimate admixture of blood vessels, smooth muscle and fat. This multiphasic composition allows for its recognition on ultrasound and CT scan examination. Metastases are exceedingly uncommon, and only one other case of metastatic extrarenal AML exists in the literature. Histological variants of AML such as epithelioid angiomyolipoma (EAML) are considered to be locally aggressive. A unique case of an EAML of the retroperitoneum that metastasised to the liver and bone in an 80-year-old woman is described.
Optimal Treatment of Obesity-Related Hypertension
Authors: Scholze Jürgen , Grimm Elmar , Herrmann Dana , Unger Thomas , Kintscher Ulrich
Published: April 2007

Background—

Current guidelines for the treatment of hypertension do not provide specific recommendations for obese hypertensive patients. To identify an optimal treatment regimen for obese hypertensive patients, we studied the interactions between a drug-based weight loss approach by sibutramine and different antihypertensive drug regimens.

Methods and Results—

This was a prospective, 16-week double-blind placebo-controlled randomized multicenter study in 171 obese hypertensive patients. After a 2-week run-in period, patients receiving 1 of the 3 antihypertensive combination therapies (felodipine 5 mg/ramipril 5 mg [n=57], verapamil 180 mg/trandolapril 2 mg [n=55], or metoprolol succinate 95 mg/hydrochlorothiazide 12.5 mg [metoprolol/hydrochlorothiazide; n=59]) were assigned randomly to sibutramine (15 mg) or placebo. Sibutramine treatment resulted in a significantly greater decrease in body weight, body mass index, and waist circumference and a significant increase in diastolic blood pressure during 24-hour blood pressure monitoring compared with placebo treatment. Sibutramine-induced weight loss and reduction of visceral obesity were markedly attenuated in the metoprolol/hydrochlorothiazide group compared with the other groups. Consistently, improvement in glucose tolerance and hypertriglyceridemia by sibutramine was abrogated in the cohort treated with metoprolol/hydrochlorothiazide compared with the other groups.

Conclusions—

The present study demonstrates for the first time that an antihypertensive combination therapy regimen with angiotensin-converting enzyme inhibitors and calcium channel blockers is more advantageous than a β-blocker/diuretic–based regimen in supporting the weight-reducing actions and concomitant metabolic changes induced by sibutramine in obese hypertensive patients. These data may help to develop future comprehensive treatment strategies and guidelines for this high-risk patient population.