14,797 research outputs found

    Development and assessment of a locally designed fish smoking kiln using insulating materials

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    The origin of fish smoking dates back to antiquity. In ancient times, fish was hung over a fire which helped to reduce its moisture content. Further advancement was made traditionally by the erection of mud, bricks or corrugated iron angle bar. The gas smoking kiln has been developed using locally available materials in the study area towards improving the existing fish smoking kiln techniques. The objective of this work is to improve the quality of smoked fish in Kainji Lake Basin Area in Nigeria at minimum production cost. The preliminary test performance of the kiln has been conducted using Clarias gariepinus, known generally as catfish. The result obtained shows that the kiln is less labour intensive and can handle different sizes of fish faster with better appearance of the end product than the conventional smoking methods

    PHYSIOLOGICAL EFFECTS OF LEAD ,CADMIUM AND THEIR MIXTURE ON SOME ORGANS OF Alburnus Mossulensis FISH

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     Alburnus mossulensis has been exposed to lead and cadmium for (96)h in order to determination lethal concentration 50 (LC50) value. A total of 140 fish used in this experiment divided into two groups each group contain 70 fishes .The first group exposure to pbcl2 while the second group exposure to cdcl2. Method of Finney Probit Analysis used to analysis data. LC50  value for PbCl2 and CdCl2 was (57.8 and 29.6) mg/l respectively. Then used about 200  fishes divided into 4 groups, the first group exposure to 1/2LC50  of PbCl2 ,the second group exposure to 1/2LC50 CdCl2 while the third groups contained (1/2LC50 PbCl2+1/2LC50 of CdCl2) as so as control group for peroids (1,4,7 and 14) days to determination level of antioxidants Glutathione (GSH) and the level of lipid peroxidation (Malondialdehyde MDA) . The testes were carried out as three replications, lead ,cadmium and their mixture induced  oxidative stress . The results of this study  explained significant decrease of the level Glutathione and significant increase (Tukey test, P˂0.05)  of the level of Malondialdehye compared with control in all treatments .  It is possible to conclude that lead and Cadmium have cytotoxic effects, Fish mortality rates increase with increasing concentrations used and increasing exposure periods

    ROLE OF VITAMIN C AND E ON GENOTOXICITY, HEMATOLOGICAL AND BIOCHEMICAL INVESTIGATION IN CYPRINUS CARPIO L. FOLLOWING ZINC OXIDE NANOPARTICLES EXPOSURE

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    This study was aimed to evaluate the role of vitamins C and E on genotoxicity, biochemical and hematological indices in common carp, Cyprinus carpio following zinc oxide nanoparticles exposure. Zinc oxide nanoparticles were synthesized (size was < 34nm) and characterized using Fourier Transform Infrared Spectra (FTIR) and X-Ray Diffraction (XRD) analysis. About 120 common carp (weight 20.0-32.0 g) were randomly divided into 12 tanks at rate of 10 fish/tank (two (replicates/treatment); fish were fed diet as follows: Control (C) were fed basal diet; T1 fish were fed basal diet mixed with vitamins C and E (400 mg/kg); T2 and T3 fish were fed basal diet mixed with 10%and 15% ZnONPs respectively; T4 and T5  fish were fed basal diet mixed with ZnONPs 10% and 15% plus vitamins C and E (400 mg/kg dw) respectively. Post 40 d feeding trail, variable changes were registered in blood indices (“Hb content, PCV%, WBCs and RBCs numbers”) in all treated groups compared to C and T1 groups. The highest DNA damage (% tail DNA using Comet assay) was seen in T2 and T3 which asserted highly significant increased (P≀0.01) compared to C and to treated groups. As well as, glutathione peroxidase (GPx) activity exhibited highly significant increase (P≀0.01) in T2 and T3 groups relative to C, T4, T1, T5 respectively. This investigation clearly proved that sub-lethal doses (10 and 15% in diet) of ZnONPs were able to induce an oxidative stress in carp fish as reflected by significantly increase of DNA damage to erythrocytes and “the combination of vitamins C and E was able to alleviate the oxidative stress generated due to exposure to ZnONPs.

    Assessing the species boundary and ecological niche in freshwater gastropods of the family Physidae (Gastropoda, Hygrophila)

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    The present thesis contributed to increasing the knowledge about the diversity of the neotropical freshwater mollusks. Through the use of different methodologies for analyzing molecular and geographical occurrence data, we address important taxonomic issues and show new paths for future taxonomic research on the Physidae family. This family for a long time had classification proposals based only on morphological characters of the shell and, later, on the anatomy of the soft parts. The application of molecular delimitation methods based on coalescence showed the inadequacy of morphological criteria in discriminating intraspecific variability (overestimating family diversity) and in detecting the existence of cryptic species complexes (underestimating family diversity). The data on the occurrence along with the use of georeferencing tools, modeling, and ecological niche analyses applied to South American physid species, indicated the possibility of errors in species identification and the need to reassess the distribution of these physids using other operational criteria such as molecular approaches to access the actual family diversity and distribution for the continent.A presente tese contribuiu para ampliar o conhecimento sobre a diversidade da malacofauna dulcĂ­cola neotropical. AtravĂ©s do emprego de diferentes metodologias de anĂĄlise de dados moleculares e de ocorrĂȘncia geogrĂĄfica abordamos importantes questĂ”es taxonĂŽmicas e mostramos novos caminhos para futuras pesquisas taxonĂŽmicas da famĂ­lia Physidae. FamĂ­lia essa que por muito tempo teve propostas de classificação embasadas apenas em caracteres morfolĂłgicos da concha e, posteriormente, na anatomia das partes moles. A aplicação de mĂ©todos de delimitação molecular baseados em coalescĂȘncia, evidenciou a insuficiĂȘncia dos critĂ©rios morfolĂłgicos em discriminar a variabilidade intraespecĂ­fica (superestimando a diversidade da famĂ­lia) e, em detectar a existĂȘncia de complexos de espĂ©cies crĂ­pticas (subestimando a diversidade da famĂ­lia). A abordagem de busca intensiva por dados de ocorrĂȘncia junto a utilização de ferramentas de georreferenciamento, modelagem e anĂĄlises de nicho ecolĂłgico aplicadas Ă s espĂ©cies de fisĂ­deos sul-americanos, indicaram a possibilidade de erros de identificação de espĂ©cies e a necessidade de reavaliar a distribuição desses fisĂ­deos usando outros critĂ©rios operacionais, incluindo abordagens moleculares, para acessar a diversidade e distribuição reais da famĂ­lia para o continente

    How can nanomicelle-curcumin modulate aluminum phosphide-induced neurotoxicity?: Role of SIRT1/FOXO3 signaling pathway

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    Aluminum phosphide (ALP) is among the most significant causes of brain toxicity and death in many countries. Curcumin (CUR), a major turmeric component, is a potent protective agent against many diseases, including brain toxicity. This study aimed to examine the probable protection potential of nanomicelle curcumin (nanomicelle-CUR) and its underlying mechanism in a rat model of ALP-induced brain toxicity. A total of 36 Wistar rats were randomly divided into six groups (n = 6) and exposed to ALP (2 mg/kg/day, orally) + CUR or nanomicelle-CUR (100 mg/kg/day, orally) for 7 days. Then, they were anesthetized, and brain tissue samples were dissected to evaluate histopathological alterations, oxidative stress biomarkers, gene expression of SIRT1, FOXO1a, FOXO3a, CAT and GPX in brain tissue via hematoxylin and eosin (H&E) staining, biochemical and enzyme-linked immunosorbent assay (ELISA) methods and Real-Time PCR analysis. CUR and nanomicelle-CUR caused significant improvement in ALP-induced brain damage by reducing the MDA levels and induction of antioxidant capacity (TTG, TAC and SOD levels) and antioxidant enzymes (CAT, GPX), modulation of histopathological changes and up-regulation of gene expression of SIRT1 in brain tissue. It was concluded that nanomicelle-CUR treatment ameliorated the harmful effects of ALP-induced brain toxicity by reducing oxidative stress. Therefore, it could be considered a suitable therapeutic choice for ALP poisoning

    The role of small-scale fisheries in Nigeria’s food system

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    This discussion paper draws together recent data on fish and aquatic foods, and nutrition in Nigeria, to examine how small-scale fisheries fit within and contribute to Nigeria’s food system. Much of the analysis and exploration we present here are of very recent data from global, national, and local initiatives. This discussion paper has a particular focus on Sustainable Development Goals 2, and other goals and targets related to human nutrition, food security, and sustainable food production and supplies

    Effects of Stocking Density, Size, and External Stress on Growth and Welfare of African catfish (Clarias gariepinus Burchell, 1822) in a Commercial RAS

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    The effects of semi-intensive (100 kg m&minus;3), intensive (200 kg m&minus;3), and super-intensive (400 kg m&minus;3) stocking densities on the growth and welfare of African catfish (Clarias gariepinus) were investigated under commercial production conditions. Plasma cortisol, glucose, and selected transcripts following a stress challenge, lactate, as well as skin lesions, were analyzed at regular intervals (from 12 g juveniles to 1.5&ndash;2.0 kg). The fish grew well, but after 23 weeks, the semi-intensively stocked fish had a mean final weight of 1,830.5 g, significantly higher than the super-intensively stocked fish with 1,615.4 g, and considerably higher than the intensively stocked fish with 1,664.8 g (p &gt; 0.05). Cortisol and glucose responses significantly differed between stressed and unstressed fish, but not between treatment groups. An unforeseen external stressor (nearby demolition noise) caused stress responses among all treatment groups, but was similarly coped with. Mortality ranged between 3.8&ndash;9.2%. In the juveniles, skin lesions were reduced under intensive or super-intensive densities, with the least under semi-intensive densities in outgrown fish. Expression profiles of 22 genes were compared in the spleen at semi-intensive and super-intensive densities. The transcript concentrations of most genes remained unchanged, except for slc39a8 and mtf1, which were significantly downregulated in stressed catfish under semi-intensive conditions. We demonstrated that African catfish growth performance and welfare depend on age and stocking density, also reacting to demolition noise. This supports farm management to optimize stocking densities during the grow-out of African catfish in RAS and suggests avoiding external stress

    Effects of Stocking Density, Size, and External Stress on Growth and Welfare of African Catfish (<i>Clarias gariepinus</i> Burchell, 1822) in a Commercial RAS

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    The effects of semi-intensive (100 kg m−3), intensive (200 kg m−3), and super-intensive (400 kg m−3) stocking densities on the growth and welfare of African catfish (Clarias gariepinus) were investigated under commercial production conditions. Plasma cortisol, glucose, and selected transcripts following a stress challenge, lactate, as well as skin lesions, were analyzed at regular intervals (from 12 g juveniles to 1.5–2.0 kg). The fish grew well, but after 23 weeks, the semi-intensively stocked fish had a mean final weight of 1830.5 g, significantly higher than the super-intensively stocked fish with 1615.4 g, and considerably higher than the intensively stocked fish with 1664.8 g (p > 0.05). Cortisol and glucose responses significantly differed between stressed and unstressed fish, but not between treatment groups. An unforeseen external stressor (nearby demolition noise) caused stress responses among all treatment groups, but was similarly coped with. Mortality ranged between 3.8–9.2%. In the juveniles, skin lesions were reduced under intensive or super-intensive densities, with the least under semi-intensive densities in outgrown fish. Expression profiles of 22 genes were compared in the spleen at semi-intensive and super-intensive densities. The transcript concentrations of most genes remained unchanged, except for slc39a8 and mtf1, which were significantly downregulated in stressed catfish under semi-intensive conditions. We demonstrated that African catfish growth performance and welfare depend on age and stocking density, also reacting to demolition noise. This supports farm management to optimize stocking densities during the grow-out of African catfish in RAS and suggests avoiding external stress

    Morphology of migrating telocytes and their potential role in stem cell differentiation during cartilage development in catfish (Clarias gariepinus)

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    Telocytes (TCs) are present in a broad range of species and regulate processes including homeostasis, tissue regeneration and immunosurveillance. This novel study describes the morphological features of migrating TCs and their role during cartilage development within the air-breathing organ in Clarias gariepinus, the African sharptooth catfish. Light microscopy (LM), transmission electron microscopy (TEM), and immunohistochemistry (IHC) were used to examine the TCs. TCs had a cell body and telopodes which formed 3D networks in the cartilage canals and extended their telopodes to become the foremost cellular elements penetrating the cartilage matrix. The TCs were also rich in lysosomes that secreted products to the extracellular matrix (ECM). In addition, TCs formed a homocellular synaptic-like structure that had a synaptic cleft, and the presynaptic portion consisted of a slightly expanded terminal of the telopodes which contained intermediate filaments and secretory vesicles. Gap junctions were also identified between TCs, which also connected to mesenchymal stem cells, differentiating chondrogenic cells, macrophages, apoptotic cells, and endothelial cells. In addition to describing the basic morphology of TCs, the current study also investigated migrating TCs. The TC telopodes acquired an irregular contour when migrating rather than exhibiting an extended profile. Migrating TCs additionally had ill-defined cell bodies, condensed chromatin, thickened telopodes, and podoms which were closely attached to the cell body. The TCs also expressed markers for MMP-9, CD117, CD34 and RhoA. In conclusion, TCs may play multiple roles during development and maturation, including promoting angiogenesis, cell migration, and regulating stem cell differentiation

    Evaluation de l’Effet des Eaux UsĂ©es Industrielles sur la QualitĂ© de l’Eau de la RiviĂšre Klou au Centre du BĂ©nin

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    La prĂ©sente Ă©tude a pour objectif d’évaluer l’impact des eaux usĂ©es industrielles sur la qualitĂ© de l’eau de la riviĂšre Klou. Pour cela, des prĂ©lĂšvements d’eau ont Ă©tĂ© effectuĂ©s avec une frĂ©quence mensuelle sur des stations tĂ©moins et exposĂ©es. Les analyses physico-chimiques et le calcul de l’indice de Pollution Organique (IPO) ont Ă©tĂ© effectuĂ©s. En pĂ©riode pluvieuse, les valeurs des paramĂštres physico-chimiques (pH, conductivitĂ©, TDS, ammonium, DBO5, nitrate, nitrite et orthophosphates) etaient faibles. De plus, les fortes valeurs des paramĂštres Ă©tudiĂ©s sont observĂ©es sur les stations plus exposĂ©es. Les rĂ©sultats de l’analyse en composantes principales (ACP) sur les paramĂštres physico-chimiques ont rĂ©vĂ©lĂ© deux groupes&nbsp; de stations. Le premier est constituĂ© des deux stations tĂ©moins caractĂ©risĂ©es par les faibles valeurs des paramĂštres Ă©tudiĂ©s alors que le second est composĂ© des stations plus exposĂ©es et celles de l’aval avec les fortes valeurs des paramĂštres Ă©tudiĂ©s. L’indice de pollution organique a rĂ©vĂ©lĂ© une pollution modĂ©rĂ©e au niveau des stations tĂ©moins et une pollution organique forte et trĂšs forte respectivement au niveau des stations plus exposĂ©es et celles de l’aval. Il est nĂ©cessaire alors de mettre en place une politique de&nbsp; restauration de la qualitĂ© Ă©cologique des eaux de cette riviĂšre et des centres d’épuration opĂ©rationnels et efficaces. &nbsp; The objective of this study was to assess the impact of industrial wastewater on the water quality of the Klou River. For this purpose, water sampling was conducted with a monthly frequency on control and exposed stations. Physico-chemical analyses and the calculation of the Organic Pollution Index (IPO) were carried out. In rainy periods, the values of the physico-chemical parameters (pH, conductivity, TDS, ammonium, BOD5, nitrate, nitrite and orthophosphates) were low. Moreover, the high values of the studied parameters were observed at the more exposed stations. The results of the principal component analysis (PCA) on the physico-chemical parameters revealed two groups of stations. The first consists of the two control stations characterized by low values of the studied parameters, while the second consists of the more exposed stations and those downstream with high values of the studied parameters. The organic pollution index revealed moderate pollution at the control stations and strong and very strong organic pollution respectively at the more exposed stations and those downstream. It is then necessary to put in place a mechanism to restore the ecological quality of the waters of this river and operational and effective purification centres
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