Substitution of fish meal by soybean meal in diets for juvenile marbled spinefoot,Siganus rivulatus

The present work was performed to assess whether soybean meal (SBM) could replace fish meal (FM) as a source of dietary protein in diets of the marine herbivore Siganus rivulatus. Five iso-nitrogenous (40% protein) and iso-energetic (14 MJ/Kg) diets were prepared with SBM replacing fish meal at 0%, 25%, 50%, 75%, and 100% dietary protein. A 60-day feeding trial was conducted with 240 juvenile S. rivulatus (initial body mass 1.74 ± 0.03 g). Survival, growth, feed, and protein efficiency and hematological parameters were assessed. Growth correlated negatively with increase in dietary SBM. All production parameters measured were negatively affected at all levels of SBM inclusion. There were no effects on total or differential blood counts, hemoglobin, or plasma protein, but hematocrit values were negatively correlated with SBM addition. Results suggest that total replacement of FM by SBM without adding other supplements is not recommended, even for an herbivorous marine fish such as S. rivulatus.     

Survival and respiration of marbled rabbitfish (Siganus rivulatus) fingerlings at various oxygen tensions

Marbled rabbitfish, Siganus rivulatus, is an economically valuable herbivorous fish and a potential candidate for warmwater aquaculture. This study was carried out to: (1) assess the effect of various oxygen concentrations on survival and behaviour of S. rivulatus fingerlings and (2) investigate the response of S. rivulatus to hypoxia and determine its critical oxygen tension (P_crit). In the first experiment, groups of rabbitfish (15 fish per group) were maintained for 1 h in waters of various oxygen concentrations. They were then transferred to well‐aerated tanks and observed for 72 h. Survival was recorded, fish behaviour at low oxygen concentrations observed, and LC₅₀ after 1‐h hypoxia and 72‐h recovery evaluated. In the second experiment, a series of stop‐flow respirometry experiments were performed during which dissolved oxygen was allowed to drop to 0.5 mg L^?1 and respiration rate recorded at various oxygen concentrations. In the first experiment, all fish survived for 1 h at oxygen concentration of 1.44 mg L^?1 and greater, but started dying at oxygen concentrations below 0.65 mg L^?1 (16% survival). The LC₅₀ of S. rivulatus fingerlings was 0.6 mg L^?1. Results of the second experiment showed that S. rivulatus is an oxyregulator until P_crit (1.7 mg L^?1 O₂) is reached, becoming an oxyconformer below this concentration. Findings allow for a better understanding of environmental oxygen tolerances and minimum acceptable oxygen concentration in rabbitfish aquaculture.     

Hepatotoxic responses of 4-nonylphenol on African catfish (<Emphasis Type="Italic">Clarias gariepinus</Emphasis>): antixoidant and histochemical biomarkers

4-Nonylphenol (NP) toxicity in fish attracts much attention due to its ability in targeting several organs; however, the researches regarding its potential hepatotoxicity are conflicting and still require further investigation. Therefore, the objective of this study is to focus on this issue from the histophysiological point of view using NP intoxicated African catfish (Clarias gariepinus) as a model of hepatotoxicity. Twelve adult fish (6 per group) were divided into two groups; the first was considered as a control and the second was exposed to NP dissolved in water at a dose of 0.1 mg/kg BW for 3 weeks. A significant reduction in the hepatic alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase levels was observed in NP-exposed fish. Concerning the oxidant/antioxidant balance, a significant depletion in superoxide dismutase, catalase, and glutathione peroxidase was found along with a significant elevation in total peroxide and malondialdhyde. The histopathological examination of the hepatic tissues revealed that NP had marked hepatotoxic effects including hepatitis, centrilobular and focal hydropic and fatty degeneration, fatty change (steatosis), hepatic coagulative necrosis, and nuclear alterations in addition to apoptosis of hepatocytes and necrosis of endothelial cells. Depletion of the glycogen and increased in pigments (lipofuscin and hemosiderin) content in the hepatocytes were also recorded. Hemosiderosis and proliferation of the connective tissue around the blood vessels and branches of bile ducts and in the portal areas were also observed. In light of these findings, it was concluded that NP has a well-defined hepatotoxic impact paving the road towards other studies to investigate other detrimental cyto-physiological influences of this aquatic pollutant.     

Gallium arsenide (GaAs) nanofibers by electrospinning technique as future energy server materials

Gallium arsenide (GaAs) does have superior electronic properties compared with silicon. For instant, it has a higher saturated electron velocity and higher electron mobility. Weak mechanical properties and high production cost are the main drawbacks of this interesting semiconductor. In this study, we are introducing production of GaAs nanofibers by electrospinning methodology as a very low cost and yielding distinct product technique. In general, nano-fibrous shape is strongly improving the physical properties due to the high surface area to volume ratio of this nanostructure. The mechanical and environmental properties of the GaAs compound have been modified since GaAs nanofibers have been produced as a core inside a poly(vinyl alcohol) (PVA) shell. GaAs/PVA nanofibers were prepared by electrospinning of gallium nitrate/PVA solution in presence of arsenic vapor. The whole process was carried out in a closed hood equipped with nitrogen environment. FT-IR, XPS, TGA and UV-Vis spectroscopy analyses were utilized to confirm formation of GaAs compound. Transmission electron microscope (TEM) analysis has revealed that the synthesized GaAs compound is crystalline and does have nano-fibrous shape as a core inside PVA nanofibers. To precisely recommend the prepared GaAs nanofiber mats to be utilized in different applications, we have measured the electric conductivity and the band gap energies of the prepared nanofiber mats. Overall, the obtained results affirmed that the proposed strategy successfully remedied the drawbacks of the reported GaAs structures and did not affect the main physical properties of this important semiconductor.     

Effects of silver content and morphology on the catalytic activity of silver-grafted titanium oxide nanostructure

As titanium oxide is a well-known photocatalyst, we investigated the effects of silver content and nanostructural morphology on the photocatalytic degradation of two dyes, methylene blue and rhodamine B. Two nano-formulations were utilized, including nanofibers and nanoparticles. Silver-grafted titanium oxide nanofibers were synthesized using the electrospinning of silver nitrate/titanium isopropoxide/poly(vinyl acetate) sol-gel. The nanoparticulate form was obtained by calcination of a ground powder prepared from the same electrospun sol-gel. The results affirmed the advantage of the silver-grafted titanium oxide nanostructures over the silver-free ones. Increasing the silver content in the nanofibers led to increases in their surface area, which is an important parameter in heterogeneous catalytic chemical reactions. Therefore, the results strongly suggest the use of silver-grafted titanium oxide in a nanofibrous form. These results further support utilizing Agloaded titanium oxide nanofibers as a photocatalyst.     

The inheritance of patterned white flowers in zonal pelargoniums

White flowered cultivars have petals which are either pure white, or patterned white with coloured markings localized within clearly defined zones on the upper surface of the petals. Five patterns are identified. The bar pattern has pigment localized within a small zone on both sides near the base of each of the lower triplet of petals. The centre pattern has a V-shaped coloured zone in the basal half of all petals filling in the centre of the flower. The picotee pattern colours the edges of all petals. The ring pattern is a coloured zone running across the basal half of all petals. The vein pattern consists of two prominent coloured veins running from the base of the upper pair of petals. The expression of these patterns is controlled by the dominant alleles of four genes: the bar, picotee and vein patterns by the genes Baiba, Celce or PH pi, and Ve/ve respectively, and the centre and ring patterns by the interaction of the products of two genes Ce with Ve and Ba with Ve respectively. The homozygous recessive states of these genes are epistatic to the red- marking gene, Rm/rm, responsible for controlling the synthesis of anthocyanin pigments that fill the marked zones. Other colour marking genes are probably responsible for variations in colour, especially pink which was a frequent alternative to red. In the absence of the colour marking genes, the pattern zones may sometimes become lightly pigmented from other sources providing the pattern gene itself is present. The zones are considered to be areas of pigment accumulation rather than centres for pigment synthesis.     

Effect of body mass index on severity and prevalence of varicocele

Varicocele is classified as grade I-III regarding its severity. This study was aimed to determine the correlation between height and weight with varicocele grade in 18-30 years age group. We enrolled 400 persons aged 18-30 years referred to the specialist's clinics of Tabriz Medical Sciences University or Medical Commission Since Sep. 2004 to Mar. 2005. First we divided the volunteers in two groups including Varicocele Group and Non-varicocele Group, then varicocele patients were classified to three grades considering the severity of the disease: severe (Grade III), moderate (Grade II) and mild (Grade I). Finally, the correlation between height, weight and Body Mass Index (BMI) was evaluated. There was a significant relation between height and grades of left-side varicocele; in other words the severity of disease was increased with height (p = 0.004). Also, height increased the prevalence ofvaricocele (p = 0.011). On the other hand, low weight and BMI increased the prevalence of varicocele (p = 0.000, p = 0.004) but did not affect the severity of disease (p = 0.364, p = 0.172). In conclusion, the height of patients directly affected the prevalence and severity of left-side varicocele which probably is related to length of left internal spermatic veins in these patients and increased hydrostatic pressure in taller patients. Also, the weight and BMI is effective on the prevalence of varicocele. It seems that slim and tall persons will benefit from evaluation while puberty.     

Protective effects of crocin against cisplatin-induced acute renal failure and oxidative stress in rats

Background. The major side effect of cisplatin, used in some tumours, is nephrotoxicity. Reactive oxygen species and oxidative damage are the most important factors in cisplatin-induced acute renal failure. The main purpose of this study is to investigate the protective effects of crocin against cisplatin-induced acute renal failure and oxidative stress in rat. Methods. In this study, animals were randomly divided into 5 groups (6 each). Group one received normal saline (2 ml/day, i.p.). Group two received a single dose of cisplatin (5 mg/kg, i.p.). Groups 3 to 5 received crocin (100, 200 and 400 mg/kg, i.p., respectively, for 4 consecutive days one hour before a single dose of cisplatin (5 mg/kg) only at the first day. Blood samples were taken out (on the fifth day) for measuring the level of urea and creatinine. The kidneys were removed for histopathological and biochemical examinations. Furthermore, 24-hour urinary factors were measured. Results. Blood urea, creatinine and urinary glucose and protein concentrations in crocin-treated groups were significantly lower than those of cisplatin-treated group in a dose-dependent manner. Histopathological studies showed a massive damage in S3 segment of proximal tubules in cisplatin-treated group. No damage was observed in crocin-treated groups. Crocin treatment resulted in a significant and dose-dependent reduction in malondialdehyde concentration as compared to the cisplatin-treated group. Moreover, crocin produced a significant elevation in total thiol and glutathione peroxidase concentrations, as compared with cisplatin-treated group. Conclusion. The results of the present study suggest that crocin has a protective effect against cisplatin-induced acute renal failure and relative oxidative stress.     

Bioassay Procedure for the Evaluation of Erythromycin Activity in Aquaculture Environments

A new bioassay procedure was developed for the detection of erythromycin in aquaculture samples using a strain of a Stenotrophomonas as an indicator organism. Conventional disk-plate and well-plate radial diffusion assay procedures were developed, as well as a third procedure using the same indicator organism in Luria-Bertani (LB) broth, supplemented with the indicator dye Brilliant Black (40 μg/mL) in a multi-well microtiter plate. For both the disk-plate and well-plate radial diffusion assays, the response reflected in the size (width) of the growth inhibition zone, which was linear over the tested concentration range of 0.05 to 2.0 μg erythromycidml. The limit of quantitation of the bioassay was at 0.05 μg erythro-mycidml. Among the three methods of assay tested with Stenotrophomonas sp., the semi-quantitative dye reduction method is easy to read and is not diffusion dependent. This method allows for processing of more samples and more replication on a single titer plate. This new indicator organism is specific for erythromycin when tested in the presence of other antibacterial agents, i.e., oxytetracycline (Terramycin®) and/or Romet-Ma. This new bioassay procedure is suitable for quantitation of low concentrations of erythromycin in aquaculture water and sediment samples.