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Second Trial (second + trial)
Selected AbstractsVariation in performance reveals discharge-related energy costs for foraging Atlantic salmon (Salmo salar) parrECOLOGY OF FRESHWATER FISH, Issue 4 2006P. S. Kemp Abstract,,, The energetic costs associated with foraging and social interaction for Atlantic salmon (Salmo salar) parr was estimated by measuring gross differences in performance (growth and lipid content) during two experimental trials conducted in an artificial river channel, under similar food input at two discharges. The discharges provided velocities within the range commonly experienced by salmon in the wild. Fish growth (second trial) and lipid content (first trial) were the highest at the lower discharge. Fish were less active and used a smaller area of the experimental arena under high flow. These behavioural adjustments are consistent with the reduction of energy costs at high discharge. However, there was no effect of discharge on aggressive behaviour or food intake. Therefore, despite evidence of energy economy in response to high discharge and velocity, the energetic costs of foraging were sufficiently high to cause substantial reduction in performance. In common with the findings of previous studies, dominance status was associated with individual variation in performance and habitat use. [source] ,Rescue' Therapy with Rifabutin after Multiple Helicobacter pylori Treatment FailuresHELICOBACTER, Issue 2 2003Javier P. Gisbert abstract Aim. Eradication therapy with proton pump inhibitor, clarithromycin and amoxicillin is extensively used, although it fails in a considerable number of cases. A ,rescue' therapy with a quadruple combination of omeprazole, bismuth, tetracycline and metronidazole (or ranitidine bismuth citrate with these same antibiotics) has been recommended, but it still fails in approximately 20% of cases. Our aim was to evaluate the efficacy and tolerability of a rifabutin-based regimen in patients with two consecutive H. pylori eradication failures. Patients and Methods. Design: Prospective multicenter study. Patients: Consecutive patients in whom a first eradication trial with omeprazole, clarithromycin and amoxicillin and a second trial with omeprazole, bismuth, tetracycline and metronidazole (three patients) or ranitidine bismuth citrate with these same antibiotics (11 patients) had failed were included. Intervention: A third eradication regimen with rifabutin (150 mg bid), amoxicillin (1 g bid) and omeprazole (20 mg bid) was prescribed for 14 days. All drugs were administered together after breakfast and dinner. Compliance with therapy was determined from the interrogatory and the recovery of empty envelopes of medications. Outcome: H. pylori eradication was defined as a negative 13C-urea breath test 8 weeks after completing therapy. Results. Fourteen patients have been included. Mean age ± SD was 42 ± 11 years, 41% males, peptic ulcer (57%), functional dyspepsia (43%). All patients took all the medications and completed the study protocol. Per-protocol and intention-to-treat eradication was achieved in 11/14 patients (79%; 95% confidence interval = 49,95%). Adverse effects were reported in five patients (36%), and included: abdominal pain (three patients), nausea and vomiting (one patient), and oral candidiasis (one patient); no patient abandoned the treatment due to adverse effects. Conclusion. Rifabutin-based rescue therapy constitutes an encouraging strategy after multiple previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole and tetracycline. [source] RDP58 is a novel and potentially effective oral therapy for ulcerative colitisINFLAMMATORY BOWEL DISEASES, Issue 8 2005Simon Travis FRCP Abstract Background: RDP58 is a novel anti-inflammatory d-amino acid decapeptide that inhibits synthesis of proinflammatory cytokines by disrupting cell signaling at the pre-MAPK MyD88-IRAK-TRAF6 protein complex. We therefore evaluated its efficacy and safety in parallel multicenter, double-blind, randomized concept studies in ulcerative colitis (UC). Methods: In the first trial, 34 patients with mild to moderate active UC were randomized (1:2) to placebo (n = 13) or RDP58 100 mg (n = 21). In the second trial, 93 similar patients were randomized (1:1:1) to placebo (n = 30) RDP58 200 mg (n = 31), or RDP 300 mg (n = 32). In both studies, treatment success was defined as a simple clinical colitis activity index score of no more than 3 at 28 days. Sigmoidoscopy and rectal biopsy (at baseline and 28 days) and safety measures (baseline and 28 and 56 days) were other endpoints. Results: Treatment success on RDP 100 mg was 29% versus 46% on placebo (P = 0.46). There were no significant differences in sigmoidoscopy or histology score. In the second study, treatment success on the higher doses of RDP58 (200 and 300 mg) was 71% and 72%, respectively, versus 43% on placebo (P = 0.016). Improvements in sigmoidoscopy scores (41% on 200 mg and 46% on 300 mg versus 32% on placebo) did not reach significance, but histology scores improved significantly (P = 0.002) versus placebo. Overall, adverse events were no different between placebo (3.3 ± 2.4) and RDP58 (2.7 ± 1.4, 300-mg group). Conclusions: RDP58 at a dose of 200 or 300 mg, but not 100 mg, was effective in mild-to-moderate UC. RDP58 was safe and well tolerated, and its novel action makes it an attractive potential therapy. [source] Short-term dominance: stability and consequences for subsequent growthJOURNAL OF FISH BIOLOGY, Issue 10 2009K. Tiira Dominance status was determined among groups of four fish by using individuals from eight brown trout Salmo trutta populations. Subsequent growth of the fish was later recorded in larger groups. Seven months after the first set of trials, an additional set of dominance trials was performed by using the same fish. Social status affected subsequent growth; individuals having the lowest ranks grew less when compared to the higher ranking fish. Furthermore, the short term dominance hierarchy was rather stable between the two trials. This was especially the case with the lowest ranking fish, which tended to remain in the lowest position also in the second trial. The results suggest that the short term dominance trials done among few conspecifics reflect relatively well not only the subordinates' relative but also absolute social status. [source] Immunization of rainbow trout, Oncorhynchus mykiss (Walbaum), with a low molecular mass fraction isolated from Flavobacterium psychrophilumJOURNAL OF FISH DISEASES, Issue 12 2008E Högfors Abstract Flavobacterium psychrophilum, the causative agent of rainbow trout fry syndrome has become a widespread fish pathogen in freshwater aquaculture worldwide. In this study, a low molecular mass fraction (P25-33), with an approximate weight of 25,33 kDa, was identified among F. psychrophilum strains in an immunoblotting analysis with anti- F. psychrophilum sera. The immunogenic efficacy of the isolated and extracted P25-33 was investigated in two intraperitoneal immunization trials with rainbow trout, Oncorhynchus mykiss (Walbaum). The first trial included immunizations using P25-33 with Freund's complete adjuvant (FCA) and the second trial included immunizations using P25-33, formalin-inactivated whole and sonicated F. psychrophilum cell preparations without FCA. In both trials, antibody titres against F. psychrophilum were analysed with an enzyme-linked immunosorbent assay and the efficacy of the immunizations was determined by a challenge with F. psychrophilum. The P25-33 was shown to give rise to a protective immune response in rainbow trout after immunization with FCA, but not without FCA when a low concentration of P25-33 was used. Instead formalin-inactivated whole and sonicated cells of F. psychrophilum were able to protect the immunized fish more effectively when immunized without FCA. The results suggest that whole or sonicated F. psychrophilum cells could be better candidates for a cost-effective water-based injection vaccine than the immunogenic fraction. [source] When superior courts reach different conclusions in the same child sexual abuse cases,is there a lesson to be learned?JOURNAL OF INVESTIGATIVE PSYCHOLOGY AND OFFENDER PROFILING, Issue 3 2008Frank Lindblad Abstract The objective of this study was to analyse Swedish child sexual abuse cases from 1989 to 2004 characterised by the following: (1) conviction in first trial in a court of appeal; (2) the Supreme Court later accepted a petition for a new trial; and (3) acquittal in second trial in the same court of appeal (with new judges). The study was conducted to determine what criteria were used for evaluating psychological child-related information and how they were applied. Eight argument themes were identified in the reasoning of the courts: (1) ability to perceive, remember, and communicate about experiences in a reliable way; (2) influence before first forensic interview; (3) influence during forensic interview/s; (4) motives for disclosing/retracting; (5) statement characteristics; (6) disclosure process; (7) behaviour and/or emotions related to investigations/interviews; and (8) psychological symptoms. The arguing of the courts was classified as belonging to one of three categories for each argument theme: (1) supporting/challenging the allegations; (2) opposing a conceivably supportive/challenging argument; and (3) indifferent. In six of the nine cases, arguments belonging to the same theme were presented in both court proceedings. Diametrically opposite conclusions were reached in 15 of 20 of these examples and same conclusion in one case. The evaluation method/s seemingly underlying the child psychological arguments of the courts may have a low reliability. Copyright © 2009 John Wiley & Sons, Ltd. [source] Comparison of iron chelates and complexes supplied as foliar sprays and in nutrient solution to correct iron chlorosis of soybeanJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 1 2010Patricia Rodríguez-Lucena Abstract The application of synthetic chelates is the most efficient remedy for correcting iron (Fe) chlorosis. However, chelates are usually expensive and nondegradable products. Recently, new degradable chelates have been proposed for their use as Fe fertilizers. Also, Fe complexes cheaper than synthetic chelates and derived from natural products are also used to correct Fe deficiencies. Fifteen products, including five different synthetic chelates (Fe-EDDS, Fe-IDHA, and three Fe-EDTA formulations) and ten natural complexes (humates, lignosulfonates, amino acids, glycoproteins, polyamines, citrate, and gluconate), have been compared when applied at low concentration to soybean (Glycine max L.) chlorotic plants grown in hydroponics under controlled conditions. In the first experiment, Fe compounds were applied to the nutrient solution, while in the second trial, Fe was foliar-supplied. Dry matter, Fe concentration in shoots and roots, and SPAD values were used to evaluate the effectiveness of the Fe in the different products. In the nutrient-solution experiment, synthetic chelates provided better plant growth, Fe concentration, and SPAD values than complexes. Among the Fe complexes, transferrin generally provided good plant responses, similar to those obtained with synthetic chelates. After foliar application, the highest regreening was observed for plants treated with synthetic chelates and amino acid complexes, but the translocation to roots only occurred for Fe lignosulfonate. Fe-EDDS and Fe-EDTA performed in a similar way when applied in nutrient solution or as foliar sprays. [source] Starch and fibre distribution in maize silages in relation to particle sizeJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2003I Fernandez Abstract In a first trial the particle size distribution of four maize silages was measured by two different sieving methods, dry and wet sieving. Particle size distribution was quantified by three values, mean particle size, extent of dispersion, and proportion of large particles. Wet sieving separated particles better than dry sieving and was more suitable for measuring maize silage particle size. In a second trial the particle size distribution of 10 maize hybrids grown in the same conditions was measured by wet sieving. Starch proportion in large particles varied widely between maize hybrids, from 39.7 to 82.4%, against a variation from 75.4 to 100% for cell wall proportion in the same class of particles, and these variations might be predicted by dry matter distribution. © 2003 Society of Chemical Industry [source] Effects of Dietary Heat-killed Lactobacillus plantarum on Larval and Post-larval Kuruma Shrimp, Marsupenaeus japonicus BateJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2010Ha Thanh Tung Two feeding trials were conducted to evaluate the effects of heat-killed Lactobacillus plantarum (HK-LP) on larval and post-larval kuruma shrimp, Marsupenaeus japonicus Bate. Five microbound diets were formulated to contain levels of a preparation containing 20% HK-LP (HK-LP Prep): 0, 0.001, 0.01, 0.1, and 1 g/kg. In the first experiment, zoea1 stage larvae were fed test diets for 8 d. Some parameters such as survival, developmental stage, metamorphosis to post-larvae, and formalin stress resistance were evaluated. In second trial, post-larval shrimp (16 ± 0.04 mg) were fed test diets for 30 d. Survival, body weight gain, specific growth rate, feed efficiency ratio, individual dry weight, total body length, osmotic and formalin stress resistances, and protease activity were evaluated. Results indicated that the larvae that received HK-LP Prep at 0.1 and 1 g/kg diets showed significantly (P < 0.05) higher survival than that of the control group. For the post-larval trial, shrimp that received HK-LP Prep at 1 g/kg diet were significantly higher than the control group in most of the growth parameters and stress resistance. However, shrimp that received HK-LP Prep at 0.1 g/kg diet were significantly higher than the control group in survival only. For protease activity, there was no significant difference detected among groups. [source] The Effects of Osmolality, Cryoprotectant and Equilibration Time on Striped Bass Morone saxatilis Sperm MotilityJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2003Shuyang He Four experiments were designed to evaluate the effects of osmolality, cryoprotectant, and equilibration time on striped bass sperm motility. In the first experiment, solutions of NaCI or KCI with osmolalities ranging from 0 to 700 mmol/kg were tested on sperm activation. Over 60% of the sperm were activated by isotonic NaCI and KCI solutions with a treatment osmolality of 350 mmol/kg. Sperm remained motile until osmolality increased to 600 mmol/ kg. In the second and third experiments, Extenders 1, 2 and 3 with osmolalities of 350, 500, and 600 mmol/kg, respectively, were tested. Sperm samples stored in Extender 2 showed significantly higher (P 0.01) sperm motility after 10 min of exposure as well as greater (P < 0.01) post-thaw motility when compared to samples stored in Extenders 1 and 3. In the fourth experiment, two trials were carried out to evaluate the effects of cryoprotectant and equilibration time. In the first trial, methanol with a concentration of 5% and 10% yielded the highest (P < 0.05) sperm motility prior to freezing at all equilibration times examined. However, 5% DMSO yielded the highest (P < 0.01) post-thaw motility (38 ± 3.6%). DMSO with concentrations of 10% and 15% resulted in 17 ± 2.3% and 6 ± 1.0% post-thaw motility, respectively. Both methanol and DMA, at all concentrations tested, resulted in less than 10% post-thaw motility. In the second trial, four DMSO concentrations with three different equilibration times were examined. We observed a significant (P < 0.001) interaction effect between DMSO concentration and equilibration time. Post-thaw motility was significantly greater (P < 0.01) with a concentration of 5% DMSO at all equilibration times examined, compared to 1.25, 2.5, and 10% DMSO. An average post-thaw motility of 40 ± 2.9% was achieved after 10 min equilibration using 5% DMSO. [source] Third-line rescue therapy with levofloxacin is more effective than rifabutin rescue regimen after two Helicobacter pylori treatment failuresALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 10 2006J. P. GISBERT Summary Background In patients with a first eradication failure, a second (rescue) therapy still fails in > 20% of cases. Aim To compare rifabutin and levofloxacin rescue regimens in patients with two consecutive Helicobacter pylori eradication failures. Methods Patients, in whom first treatment with omeprazole,clarithromycin,amoxicillin and a second trial with omeprazole,bismuth,tetracycline,metronidazole (or ranitidine bismuth citrate with these antibiotics) had failed, received 10 days of treatment with either rifabutin (150 mg b.d.) or levofloxacin (500 mg b.d.), plus amoxicillin (1 g b.d.) and omeprazole (20 mg b.d.). Cure rates were evaluated by the 13C-urea breath test. Results Twenty patients received rifabutin, and 20 levofloxacin. All the patients returned for follow-up. Compliance in the rifabutin group was 100%. Four patients in the levofloxacin group did not take the medication correctly (in two cases due to adverse effects: myalgia and rash). Side effects in the rifabutin and levofloxacin groups were reported in 60% and 50% of the cases, respectively. Five patients (25%) treated with rifabutin presented with leucopenia, and six (30%) treated with levofloxacin presented with myalgias. Per-protocol cure rates were 45% (95% confidence interval, 26,66%) in the rifabutin group, and 81% (57,93%) in the levofloxacin group (P < 0.05). Intention-to-treat cure rates were, 45% (26,66%) and 85% (64,95%), respectively (P < 0.01). Conclusions After two previous H. pylori eradication failures, a 10-day triple levofloxacin-based rescue regimen is more effective than the same regimen with rifabutin. [source] Protective immunization of calves against Ostertagia ostertagi using fourth stage larval extractsPARASITE IMMUNOLOGY, Issue 9-10 2010A. M. HALLIDAY Summary ConA lectin was used to isolate glycoproteins from detergent extracts of fourth stage Ostertagia ostertagi larvae. This preparation contained proteins additional to those observed in a similar fraction prepared from adult O. ostertagi. Two vaccine trials were conducted with this preparation, and sub-fractions thereof, in groups of 6,8 worm-free calves. All groups were challenged with 50 000 O. ostertagi larvae 1 week after the final immunization, and protection was assessed by comparing the egg and worm counts of the immunized groups with their respective controls. Immunization with the ConA-binding antigen or its sub-fractions induced high titre serum antibody responses. In the first trial, the cumulative egg count of the group immunized with unfractionated antigen was 60% lower than the corresponding control value, and worm counts were 47% lower. In the second trial, the cumulative egg counts of the vaccinated groups ranged from 70% to 85% lower than the corresponding controls, with worm counts up to 64% lower. It was concluded that detergent-soluble, ConA-binding extracts prepared from O. ostertagi fourth stage larvae contained protective immunogens that were as effective as the best antigens published for O. ostertagi to date. [source] Chromosomal location of Fusarium head blight resistance genes and analysis of the relationship between resistance to head blight and brown foot rotPLANT BREEDING, Issue 1 2000A. Mentewab Abstract In order to identify chromosomes involved in resistance to Fusarium head blight, a set of 21 substitution lines of Triticum macha (resistant) chromosomes into ,Hobbit''sib'(susceptible) were evaluated in trials over 2 years. For the first year's trial, all plants were inoculated on the same day with a conidial suspension of F. culmorum. For the second trial, individual plants were inoculated precisely at mid anthesis of each plant over a period of 2 weeks. The disease level was assessed by visual scoring, relative ear weight and F. culmorumn -specfic quantitative polymerase chain reaction. The results showed that T. macha chromosomes 1B, 4A and 7A conferred good overall resistance, suggesting that they carry important genes for resistance. In two additional trials, T. macha and ,Hobbit''sib' were evaluated for resistance to brown foot rot. The results showed that T. macha was more susceptible than ,Hobbit',sib', indicating that stem base disease response is not correlated with head blight resistance in these cultivars. [source] Farm-scale trials to compare the entomopathogenic fungus Beauveria bassiana with pirimiphos methyl + deltamethrin and essential oil of lemon grass for protection of stored cowpea against Callosobruchus maculatus (Coleoptera: Bruchidae)ANNALS OF APPLIED BIOLOGY, Issue 1 2007A.J. Cherry Abstract In trials conducted in Benin, conidia of Beauveria bassiana were evaluated as a control method against the cowpea weevil, Callosobruchus maculatus, in stored cowpea. In the first trial using a high artificial infestation of C. maculatus in 8-kg batches of cowpea in jerry cans under typical conditions, concentrations of 1 × 109 and 1 × 1011 conidia kg,1 were compared with lemon grass oil at 2 mL kg,1 and the synthetic pesticide mixture of 1.5% pirimiphos methyl + 0.05% deltamethrin at 0.5 g kg,1. After 2 months of storage, seed losses (SD) were 20.63 (5.3)% in the untreated control, 8.04 (3.2)% in the low-dose B. bassiana group, 3.12 (1.3)% in the high-dose B. bassiana group, 2.52 (0.4)% in the lemon grass oil group and 0% in the pirimiphos methyl + deltamethrin group. In a second trial with natural infestations in 50-kg batches of cowpea in 200-L drums, treatment with B. bassiana 1 × 1011 conidia kg,1 was compared with pirimiphos methyl + deltamethrin at 0.5 g kg,1. After 6 months of storage on six farms, losses reached 30.76 (1.5)% in the control, 1.28 (0.2)% in the pirimiphos methyl + deltamethrin group and 3.69 (0.6)% in the B. bassiana group. [source] Dietary intake of probiotics and maslinic acid in juvenile dentex (Dentex dentex L.): effects on growth performance, survival and liver proteolytic activitiesAQUACULTURE NUTRITION, Issue 4 2006M.C. HIDALGO Abstract Two feeding trials were carried out to evaluate the efficiency of probiotics and maslinic acid, on growth and survival of juvenile dentex; liver proteolytic activities were also investigated in the second trial. For experiment 1, triplicate groups were fed six diets with two probiotics (Bacillus toyoi, T, and B. cereus, E) at increasing levels (0.5, 1 and 2 g kg,1 diet) and a control diet. Growth and feed conversion were not significantly influenced by the probiotics. The diet T1 produced the lower mortality, whereas diet E1 rendered the higher mortality. It was concluded that no significant effects on growth and survival were found following the addition of two kinds of probiotics to dentex diets. However, the diet E0.5 showed a tendency to ameliorate the growth and feed utilization of the diet. In a second trial, triplicate groups were fed four diets with increasing levels of maslinic acid (0, 20, 40 and 80 mg kg,1 diet). Growth of fish given diets with the highest level of maslinic acid (D80) was slightly but not significantly lower than those from the other groups. Furthemore, mortality of fish fed diet D40 was the lowest. Changes in liver proteasome and endoprotease activities measured on sodium dodecyl sulphate (SDS)/gelatin gels were also detected in a dose-dependent manner. It was concluded that a dietary maslinic acid at a level of 80 mg kg,1 diet seems to be too high for juvenile dentex to maintain a maximal growth and survival rate. [source] Comparison of different types and levels of commercial soybean lecithin supplemented in semipurified diets for juvenile Litopenaeus vannamei BooneAQUACULTURE NUTRITION, Issue 1 2001H. Gong Two 6-week growth trials were conducted to determine the dietary phospholipids (PL) requirement of Litopenaeus vannamei juveniles and to compare the effect of different types of soybean lecithin on shrimp growth and survival. In the first trial, a basal diet and diets containing 1.5, 3 or 5% (dry-weight basis) of Type I lecithin (97.6% PL) and 1.5 or 3% of Type II lecithin (71.4% PL) were evaluated. In the second trial, the basal diet and diets containing 1, 2 or 4% of either Type I or Type II lecithin and 1 or 2% of Type III lecithin (48.4% PL) were evaluated. Results showed that there was no interaction between lecithin type and PL level on shrimp growth or survival. Shrimp growth increased with PL levels up to 3,5% of diet. No significant differences were observed for instantaneous growth rate (IGR) of shrimp fed the different types of lecithin at the same inclusion level, and no effect of PL level and lecithin type on shrimp survival was found. Thus, the recommended level of PL supplementation in diets for L. vannamei juveniles ranges from 3 to 5% of diet. [source] Use of commercial fermentation products as a highly unsaturated fatty acid source in practical diets for the Pacific white shrimp Litopenaeus vannameiAQUACULTURE RESEARCH, Issue 7 2010Tzachi M Samocha Abstract Removal or reduction of marine ingredients (MI) from feed formulations is critical to the sustainability of the aquaculture industry. By removing MI, diets may become limiting in several nutrients including highly unsaturated fatty acids (HUFA) such as docosahexaenoic acid (DHA) and arachidonic acid (ArA). To reduce reliance on MI in shrimp diets, two trials were conducted with Litopenaeus vannamei juveniles to determine the feasibility of using fermentation meals rich in DHA and ArA as the primary source for HUFA. A practical diet with no MI was formulated with/without DHA and ArA supplements and fed in the first trial. A diet with menhaden fish oil or a combination of plant oil with/without DHA and ArA supplements was used in the second trial. To determine whether HUFA is only needed in the early growth stages, we also fed one group a HUFA-supplemented diet to 5 g and then switched them to a HUFA-supplement-free diet. In both trials, the weights were reduced when HUFA supplements were not provided either throughout the trial or from 5 g to harvest (<16 g). These results suggest that supplementation of plant oils with DHA- and ArA-rich oils from fermented products is a viable option to replace marine fish oil for L. vannamei. [source] Effects of bottom substrate and presence of shelter in experimental tanks on growth and survival of signal crayfish, Pacifastacus leniusculus (Dana) juvenilesAQUACULTURE RESEARCH, Issue 4 2003R Savolainen Abstract The effects of tank bottom substrates and presence of shelter on growth, survival and condition of cheliped in the juvenile (stage 2) signal crayfish, Pacifastacus leniusculus (Dana), with an initial stocking density of 200 individuals m,2 were investigated. In the first trial, three different tank bottom substrates with or without shelter were used. The three bottom types were loose gravel, glued gravel and bare bottom. The fastest growth both in terms of wet weight and carapace length was observed on loose gravel bottom. Also survival (range 30.1% to 49.8%) was affected by bottom type being higher on gravel bottoms than on bare bottom. Shelter improved survival only on loose gravel bottom. Bottom type influenced also the number of animals with cheliped injuries. The highest proportion of animals with no injuries (59.5%) was found on bare bottom and the proportion was about 12% and 13% units less on loose gravel and on glued gravel bottom. The presence of shelter had a marginal probability in increasing the number of animals without injuries. In the second trial, the substitution of ordinary gravel as tank bottom substrate with crushed limestone was studied. The mean final wet weights were 0.517 g on ordinary gravel bottom and 0.481 g on limestone bottom. The survivals were about 74% and 80% respectively. Limestone bottom decreased marginally final wet weight, and increased survival but did not affect the final carapace length that had a mean value of 13.6 mm. We conclude from the present experiments that the type of tanks and the rearing system used supported good growth of juvenile signal crayfish. The best growth results could be obtained by using loose gravel (or loose limestone) on the bottom of the tanks with a sufficient quantity of hiding places. However, there appears to be an increased risk for cheliped injuries on bottoms with loose materials. [source] Plasma lysozyme levels in sheatfish Silurus glanis (L.) subjected to stress and experimental infection with Edwardsiella tardaAQUACULTURE RESEARCH, Issue 12 2002D Caruso Abstract Two experiments were conducted to assess plasma lysozyme levels, leucocrit and haematocrit in juvenile sheatfish (90,140 g) under experimentally induced stress and infection. Stress was provoked by random modification of environmental light for 15 min, 16 times a day with a halogen lamp (500 W) and by holding fish in a net for 3 min twice a day. In the first trial, repeated measuring of marked sheatfish showed a progressive significant decrease in plasma lysozyme level, a significant increase in leucocrit and a significant decrease in haematocrit. After a rest period of 1 week, only the leucocrit value was back to the prestress value. In the second trial, light-induced stress did not lead to any variation in lysozyme, leucocrit or haematocrit values. However, after intraperitoneal injection of Edwardsiella tarda (7 × 108 cfu), a strong increase in plasmatic lysozyme in both stressed and unstressed groups of sheatfish was observed. The increase was significant vs. prechallenge levels 3 and 6 days after contamination, but no significant difference was detected between stressed and unstressed fish, despite the strongest stress (light+handling stress) applied to the fish at the beginning of contamination. Decreases in haematocrit values were observed in both groups of fish. A clear increase in leucocrit appeared in unstressed fish, whereas stressed fish showed a significant decrease in leucocrit values. Condition factor was significantly decreased by all kinds of stress. There were no difference in mortality between stressed and unstressed groups. [source] Weight gain and lipid deposition in Atlantic salmon, Salmo salar, during compensatory growth: evidence for lipostatic regulation?AQUACULTURE RESEARCH, Issue 12 2001S J S Johansen Abstract Feed-restricted fish gain less body mass and storage reserves than well-fed fish, and reduced rates of gain often trigger compensatory responses, characterized by increased appetite (hyperphagia) and growth rate. The results of previous investigations have introduced a hypothesis in which adipose tissue (fat stores) had a regulatory role in governing appetite. An extension of this suggests that hyperphagia may relate to the severity of the feed restriction, and that the compensatory responses will cease once fat reserves are restored relative to body size. This was tested in two trials in which feed-restricted or -deprived postsmolt Atlantic salmon, Salmo salar, became hyperphagic after transfer to excess feeding. At the end of the first trial, previously feed-restricted fish had fully compensated for their lost weight gain compared to continuously fed control fish, but had a leaner body composition (i.e. reduced energy stores) and were still showing signs of compensatory growth. In the second trial, feed deprivation drained body lipids and caused a stronger hyperphagic response than restrictive feeding, although it took longer to develop. Feed intake became coincident when fish had a similar body composition for size, but this occurred at different times. Hence, the fish that had been deprived of feed were smaller than the restricted fish at the end of the trial. The results of the present study demonstrate a link between the magnitude of lipid stores, feed intake and weight gain, and provide some evidence for lipostatic appetite regulation in fish. [source] | |||||||||||||||||||