Essais d'adaptation de production massive de juvéniles de Clarias gariepinus en conditions rurales

Adaptive Trials for Intensive Clarias gariepinus fingerling to Rural Conditions. Artificial reproduction and fingerling production of the African catfish Clarias gariepinus (Burchell 1822) have been tested under less controlled conditions to adapt the intensive technology used by Aquafarm (Tihange, Belgium) to rural conditions present in developing countries. The main aim was to compare the efficiency of ovaprim a synthesised hormone with catfish pituitary extracts. Fecundity and quality of eggs (egg weight) were not significantly different. Incubation results on water hyacinth and on mosquito mesh frames were compared to those obtained in Zoug jars; the latter showed a higher hatching rate (67%) than water hyacinth (39%) and mosquito mesh frames (44%). Larvae were stocked at different stocking rates in ponds (T1: 800 larvae.m-3 and T2: 1600 larvae. m-3 ) and in tanks (T3: 3200 larvae.m-3 et T4: 6400 larvae.m-3). After a 50-day nursing period, no significant difference (P> 0.05) was observed for specific growth rate (SGR) and survival rate, but better SGR were observed in ponds (18.34%.d-1) than in tanks (16.81%.d-1). In general, production was slightly higher in tanks than in ponds being related to a higher stocking density. Significantly higher harvests were obtained from tanks with higher stocking densities but the sizes of the larvae were very heterogeneous. In such case, it is recommended to grade the larvae at 6 or 7 days intervals using different mesh sizes (from 3 to 5 mm). These less intensive rearing conditions gave nevertheless good fingerling productions

Experiment on an Integrated Ricefish Polyculture System (6 Species, 1- 2 fish/m2) in the Mekong Delta

Our ricefish polyculture (6 species) results at two stocking densities (1 and 2 fish/m2) show that: The water quality in a ricefish polyculture system, such as water temperature (29.1 – 29.0 °C), water pH (6.6 – 6.7), water transparency (18.0 – 20.8 cm), dissolved O2 (4.7 – 4.6 ppm), CO2 (22.8 – 23.1 ppm), COD (11.9 – 12.7 ppm), are similar at both densities and acceptable for the 6 tropical fish species. Ammonium and phosphorus concentrations are statistically higher at 1 fish/m2 (0.4 and 0.2 ppm). The primary productivity is similar for both densities (6.5 – 6.8 g O2/m3/day) and suitable for fish culture. The phytoplankton biodiversity is relatively high and at the same level for both treatments (74 – 63 taxa), but the densities of phytoplankton, of zooplankton, and the biomass of zoobenthos are lower at the highest density (2 fish/m2), probably due to a higher predation by fish.The fish yield (808 kg/ha) at 2 fish/m2 is higher than at 1 fish/m2 (482 kg/ha). The cost ratio benefit (1.84) and the cost ratio profit (1.81) for farm households at 1 fish/m2 are lower than those values at 2 fish/m2 (2.1 and 2.05 respectively). Regarding the aquaculture extension program, the model of the ricefish polyculture (6 species) system with the stocking density of 2 fish/m2 could be extended in the rice fields to improve farmer's income in the Mekong delta

Age and growth of Distichodus antonii (Schilthuis, 1891) (Pisces, Teleostei, Distichontidae) in Pool Malebo, Congo River

The estimation of demographic parameters of Distichodus antonii, in Pool Malebo (Congo River), was obtained from analysis of 36 good scales samples. L‡ was estimated at 107.91 cm, K at 0.10 .year-1 and t0 at -0.67 year-1. The growth parameters calculated from this method revealed that this fish has a slow growth rate and it reaches a large size. The analysis of marginal increase shows that the formation of annulus takes place to the dry season. During the dry season, the environmental conditions are disturbed and the access to food becomes difficult. This is probably the base of the stress that induces the formation of annuli on the scales

Biologie de la reproduction du Cyprinidae, Barbus callensis dans le lac de barrage Hamiz (Algérie)

Reproductive Biology of the Cyprinidae, Barbus callensis in an Algerian Dam. The freshwater fish, Barbus callensis (Valenciennes, 1842) was studied from 2005 to 2007 for the first time in Hamiz dam. This species endemic of North African continent is widely spread in the rivers of Algeria. This reservoir is situated in Boumerdes 35 km southeast of Algiers. During these three years, the monthly sampling was carried out by trammel nets, fishing near the dike during one night. At the same time, the fry was captured with a transparent plastic bottle baited with breadcrumbs put down near the lakeshore. The monthly follow-up of the gonadosomatic ratio (RGS) reveals that the spawning period occurred between April and May. The evolution of the condition factor (K) shows low seasonal variations. However, a lower value appears in spring when the temperature increases and the breeding begins. The sex ratio is higher for the adult females (1:2.8, more than 26 cm). The first sexual maturity size (L50) is lower for males (19.6 cm) than for females (27.7 cm)

Partial replacement of fish meal with Azolla meal in diets for Nile tilapia (Oreochromis niloticus L.) affects growth and whole body fatty acid composition

The replacement of fishmeal (FM) with Azolla meal (AM) in diets on growth and fatty acid in Nile tilapia, Oreochromis niloticus (initial mean weight: 16.4 g) was studied. Fish were fed with six isonitrogenous (29.2% CP) and isoenergetic (16.9 kJ.g-1) diets containing 0%, 10%, 20%, 30%, 40% and 50% AM respectively, as partial FM substitute. Diet A0 acted as a control. The final weight (51.0-88.3 g), the weight gain (210.8-438.3%) and the SGR (1.3-1.9%day-1) decreased when AM level higher than 10% in diets (P < 0.05). The FCR (1.44 to 2.35) significantly increased when AM level exceeded 20% (P < 0.05). The protein efficiency ratio and the apparent net protein utilization decreased consequently. The fatty acids in the whole fish were significantly influenced by the diets. The replacement of FM by AM produced fish with lower (n-3) highly unsaturated fatty acids mainly docosahexaenoic acid, and higher arachidonic acid (P < 0.05). The n-3/n-6 fatty acid ratio ranged from 0.08 to 0.17, and was lower in fish fed A40 and A50 (P < 0.05). The findings suggest that high AM in diets affects Nile tilapia growth and the fern could be incorporated in diets up to 30% without any adverse effect on fish fatty acid composition. However, alternative additional source of lipid must be used to improve the quality of fish fed AM-diets.Keywords: Azolla, Fish meal replacement, Growth, Fatty acids, Oreochromis niloticus, bioconversio

Is Ankyrin a genetic risk factor for psychiatric phenotypes?

Background Genome wide association studies reported two single nucleotide polymorphisms in ANK3 (rs9804190 and rs10994336) as independent genetic risk factors for bipolar disorder. Another SNP in ANK3 (rs10761482) was associated with schizophrenia in a large European sample. Within the debate on common susceptibility genes for schizophrenia and bipolar disorder, we tried to investigate common findings by analyzing association of ANK3 with schizophrenia, bipolar disorder and unipolar depression. Methods We genotyped three single nucleotide polymorphisms (SNPs) in ANK3 (rs9804190, rs10994336, and rs10761482) in a case-control sample of German descent including 920 patients with schizophrenia, 400 with bipolar affective disorder, 220 patients with unipolar depression according to ICD 10 and 480 healthy controls. Sample was further differentiated according to Leonhard's classification featuring disease entities with specific combination of bipolar and psychotic syndromes. Results We found no association of rs9804190 and rs10994336 with bipolar disorder, unipolar depression or schizophrenia. In contrast to previous findings rs10761482 was associated with bipolar disorder (p = 0.015) but not with schizophrenia or unipolar depression. We observed no association with disease entities according to Leonhard's classification. Conclusion Our results support a specific genetic contribution of ANK3 to bipolar disorder though we failed to replicate findings for schizophrenia. We cannot confirm ANK3 as a common risk factor for different diseases

Gene Expression Profile of Neuronal Progenitor Cells Derived from hESCs: Activation of Chromosome 11p15.5 and Comparison to Human Dopaminergic Neurons

BACKGROUND: We initiated differentiation of human embryonic stem cells (hESCs) into dopamine neurons, obtained a purified population of neuronal precursor cells by cell sorting, and determined patterns of gene transcription. METHODOLOGY: Dopaminergic differentiation of hESCs was initiated by culturing hESCs with a feeder layer of PA6 cells. Differentiating cells were then sorted to obtain a pure population of PSA-NCAM-expressing neuronal precursors, which were then analyzed for gene expression using Massive Parallel Signature Sequencing (MPSS). Individual genes as well as regions of the genome which were activated were determined. PRINCIPAL FINDINGS: A number of genes known to be involved in the specification of dopaminergic neurons, including MSX1, CDKN1C, Pitx1 and Pitx2, as well as several novel genes not previously associated with dopaminergic differentiation, were expressed. Notably, we found that a specific region of the genome located on chromosome 11p15.5 was highly activated. This region contains several genes which have previously been associated with the function of dopaminergic neurons, including the gene for tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, IGF2, and CDKN1C, which cooperates with Nurr1 in directing the differentiation of dopaminergic neurons. Other genes in this region not previously recognized as being involved in the functions of dopaminergic neurons were also activated, including H19, TSSC4, and HBG2. IGF2 and CDKN1C were also found to be highly expressed in mature human TH-positive dopamine neurons isolated from human brain samples by laser capture. CONCLUSIONS: The present data suggest that the H19-IGF2 imprinting region on chromosome 11p15.5 is involved in the process through which undifferentiated cells are specified to become neuronal precursors and/or dopaminergic neurons

Omega-3 polyunsaturated fatty acids favourably modulate cardiometabolic biomarkers in type 2 diabetes: a meta-analysis and meta-regression of randomized controlled trials

BACKGROUND: Randomized controlled trials (RCTs) suggest that supplementation with omega-3 polyunsaturated fatty acids (n-3PUFAs) may favourably modify cardiometabolic biomarkers in type 2 diabetes (T2DM). Previous meta-analyses are limited by insufficient sample sizes and omission of meta-regression techniques, and a large number of RCTs have subsequently been published since the last comprehensive meta-analysis. Updated information regarding the impact of dosage, duration or an interaction between these two factors is therefore warranted. The objective was to comprehensively assess the effect of n-3PUFAs supplementation on cardiometabolic biomarkers including lipid profiles, inflammatory parameters, blood pressure, and indices of glycaemic control, in people with T2DM, and identify whether treatment dosage, duration or an interaction thereof modify these effects. METHODS: Databases including PubMed and MEDLINE were searched until 13th July 2017 for RCTs investigating the effect of n-3PUFAs supplementation on lipid profiles, inflammatory parameters, blood pressure, and indices of glycaemic control. Data were pooled using random-effects meta-analysis and presented as standardised mean difference (Hedges g) with 95% confidence intervals (95% CI). Meta-regression analysis was performed to investigate the effects of duration of supplementation and total dosage of n-3PUFAs as moderator variables where appropriate. RESULTS: A total of 45 RCTs were identified, involving 2674 people with T2DM. n-3PUFAs supplementation was associated with significant reductions in LDL [ES: - 0.10, (95% CI - 0.17, - 0.03); p = 0.007], VLDL (ES: - 0.26 (- 0.51, - 0.01); p = 0.044], triglycerides (ES: - 0.39 (- 0.55, - 0.24; p ≤ 0.001] and HbA1c (ES: - 0.27 (- 0.48, - 0.06); p = 0.010]. Moreover, n-3PUFAs supplementation was associated with reduction in plasma levels of TNF-α [ES: - 0.59 (- 1.17, - 0.01); p = 0.045] and IL-6 (ES: - 1.67 (- 3.14, - 0.20); p = 0.026]. All other lipid markers, indices of glycaemic control, inflammatory parameters, and blood pressure remained unchanged (p > 0.05). CONCLUSIONS: n-3PUFAs supplementation produces favourable hypolipidemic effects, a reduction in pro-inflammatory cytokine levels and improvement in glycaemia. Neither duration nor dosage appear to explain the observed heterogeneity in response to n-3PUFAs. Trial registration This trial was registered at http://www.crd.york.ac.uk as CRD42016050802

Milk and dairy consumption and risk of cardiovascular diseases and all-cause mortality: dose-response meta-analysis of prospective cohort studies

With a growing number of prospective cohort studies, an updated dose-response meta-analysis of milk and dairy products with all-cause mortality, coronary heart disease (CHD) or cardiovascular disease (CVD) have been conducted. PubMed, Embase and Scopus were searched for articles published up to September 2016. Random-effect meta-analyses with summarised dose-response data were performed for total (high-fat/low-fat) dairy, milk, fermented dairy, cheese and yogurt. Non-linear associations were investigated using the spine models and heterogeneity by subgroup analyses. A total of 29 cohort studies were available for meta-analysis, with 938,465 participants and 93,158 mortality, 28,419 CHD and 25,416 CVD cases. No associations were found for total (high-fat/low-fat) dairy, and milk with the health outcomes of mortality, CHD or CVD. Inverse associations were found between total fermented dairy (included sour milk products, cheese or yogurt; per 20 g/day) with mortality (RR 0.98, 95% CI 0.97-0.99; I2 = 94.4%) and CVD risk (RR 0.98, 95% CI 0.97-0.99; I2 = 87.5%). Further analyses of individual fermented dairy of cheese and yogurt showed cheese to have a 2% lower risk of CVD (RR 0.98, 95% CI 0.95-1.00; I2 = 82.6%) per 10 g/day, but not yogurt. All of these marginally inverse associations of totally fermented dairy and cheese were attenuated in sensitivity analyses by removing one large Swedish study. This meta-analysis combining data from 29 prospective cohort studies demonstrated neutral associations between dairy products and cardiovascular and all-cause mortality. For future studies it is important to investigate in more detail how dairy products can be replaced by other foods

Interplay between n-3 and n-6 long-chain polyunsaturated fatty acids and the endocannabinoid system in brain protection and repair.

The brain is enriched in arachidonic acid (ARA) and docosahexaenoic acid (DHA), long-chain polyunsaturated fatty acids (LCPUFA) of the n-6 and n-3 series, respectively. Both are essential for optimal brain development and function. Dietary enrichment with DHA and other long-chain n-3 PUFA, such as eicosapentaenoic acid (EPA) have shown beneficial effects on learning and memory, neuroinflammatory processes and synaptic plasticity and neurogenesis. ARA, DHA and EPA are precursors to a diverse repertoire of bioactive lipid mediators, including endocannabinoids. The endocannabinoid system comprises cannabinoid receptors, their endogenous ligands, the endocannabinoids, and their biosynthetic and degradation enzymes. Anandamide (AEA) and 2-archidonoylglycerol (2-AG) are the most widely studied endocannabinoids, and are both derived from phospholipid-bound ARA. The endocannabinoid system also has well established roles in neuroinflammation, synaptic plasticity and neurogenesis, suggesting an overlap in the neuroprotective effects observed with these different classes of lipids. Indeed, growing evidence suggests a complex interplay between n-3 and n-6 LCPUFA and the endocannabinoid system. For example, long-term DHA and EPA supplementation reduces AEA and 2-AG levels, with reciprocal increases in levels of the analogous endocannabinoid-like DHA and EPA-derived molecules. This review summarises current evidence of this interplay and discusses the therapeutic potential for brain protection and repair