Effects of dietary protein and essential amino acid deficiencies on growth,body composition,and digestive enzyme activities of silvery-black porgy (Sparidentex hasta)

International Aquatic Research - A 6-week feeding trial was conducted to evaluate the effects of protein-free (PF) and essential amino-acid-deficient (EAAD) diets on the growth performance and...     

Simulating long-term effect of Hyrcanian forest loss on phosphorus loading at the sub-watershed level

Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus(P) nutrient, thus impacting the water quality. Modeling the effect of forest loss on surface water quality provides valuable information for forest management. This study predicts the future impacts of forest loss between 2010 and 2040 on P loading in the Tajan River watershed at the sub-watershed level. To understand drivers of the land cover, we used Land Change Modeler(LCM) combining with the Soil Water Assessment Tool(SWAT) model to simulate the impacts of land use change on P loading. We characterized priority management areas for locating comprehensive and cost-effective management practices at the sub-watershed level. Results show that agricultural expansion has led to an intense deforestation. During the future period 2010–2040, forest area is expected to decrease by 34,739 hm~2. And the areas of pasture and agriculture are expected to increase by 7668 and 27,071 hm~2, respectively. In most sub-watersheds, P pollution will be intensified with the increase in deforestation by the year 2040. And the P concentration is expected to increase from 0.08 to 2.30 mg/L in all of sub-watersheds by the year 2040. It should be noted that the phosphorous concentration exceeds the American Public Health Association′s water quality standard of 0.2 mg/L for P in drinking water in both current and future scenarios in the Tajan River watershed. Only 30% of sub-watersheds will comply with the water quality standards by the year 2040. The finding of the present study highlights the importance of conserving forest area to maintain a stable water quality.     

Prediction of water quality effect on saturated hydraulic conductivity of soil by artificial neural networks

This study was conducted to investigate the impact of water salinity (EC_w) and sodicity (SAR_w) on saturated (K_s) and relative (K_r) hydraulic conductivities in two clay (C) and sandy clay loam (SCL) soils. The results showed that the K_s decreased with increasing SAR_w, and in all of water quality treatments, the K_s of SCL soil was higher than that of the C soil. Sodicity effect (even at high SAR_w) on the K_r of clay soil was minimized by high salinity. Although K_r of both soils similarly responded to EC_w and SAR_w, microstructure of clay soil was more sensitive to water quality. Effect of EC_w on soil structure was greater than that of SAR_w. In order to assess the applicability of artificial neural networks (ANNs) in estimating K_s and K_r, two types of FFBP and CFBP ANNs and two training algorithms, namely Levenberg–Marquardt (LM) and Bayesian regulation, were employed with two strategies of uniform threshold and different threshold functions. Multiple linear regressions were also used for K_s and K_r prediction. Based on the ANN results of second strategy, best topology (4–5–4–1) was belonged to CFBP network with LM algorithm, LOGSIG–LOGSIG–TANSIG threshold functions, and values of MAE and R² are equal to 0.1761 and 0.9945, respectively. Overall, the efficacy of ANNs is much greater than regression method for K_s prediction.     

Nutritional and Functional Properties of Two Dried Brown Seaweeds Sirophysalis trinodis and Polycladia myrica

Sirophysalis trinodis and Polycladia myrica, two brown seaweeds present on the southeast coast of Iran, were evaluated for their nutritional and functional properties after drying. Fourier transform-infrared spectroscopy (FTIR) analysis of crude polysaccharides revealed the characteristic absorption bands of phenol, O–H, C–H, C–O–S, C–O, C=O, C–H groups, and β-glycosidic linkages from cellulose, with the sulfate contents estimated as 4.89 ± 0.11% and 6.96 ± 0.05% of SO₄^?2. Results of nutritional profiles revealed all of the essential amino acids, especially methionine, isoleucine, leucine, lysine, threonine, valine, phenyl alanine, and arginine. In addition, important fatty acids such as linolenic acid, palmitic acid, and oleic acid were found in high amounts. The other nutritional components present in high amounts were proline and minerals such as calcium, magnesium, iron, manganese, copper, and zinc. The antibacterial activity was weak, but the result of antioxidant activities (hydroxyl and superoxide radicals scavenging and ferrous-ion chelating ability) of crude polysaccharides was considerable. In general, the findings of this study recommend that S. trinodis and P. myrica dried seaweeds have a potent nutritional value and might be used as a valuable source of nutrient supplements for humans and animals.     

Photooxidation Properties of Photosensitizer/Direct Dye Patterned Polyester/Cotton Fabrics

Towards the goal of developing anti-infective textiles based on a photodynamic inactivation mechanism, here we present the design, dyeing procedure, characterization, substrate photooxidation studies, and antibacterial efficacy of methylene blue-dyed polyester fabrics, termed MB-polyester. Dye-uptake and apparent K/S (absorption and scattering coefficient) values as a function of MB concentration % (o.w.f) were determined, and were found to correlate. Photooxidation studies employing the model substrate 1,5-dihydroxynaphthalene (1,5-DHN) revealed that the MB-polyester fabrics were able to generate singlet oxygen in an illumination time-dependent manner. Antibacterial efficacy was evaluated against Staphylococcus aureus (ATCC-29213), with our best results achieving a 99.89 % (~3 log units) reduction in Colony-Forming Units (CFU)/mL after only 30 min illumination (Xenon lamp, 3500 mW/cm², 420–780 nm). On the basis of these results with MB-polyester, we subsequently designed patterned dual-dyed polyester/cotton fabrics, wherein an alternating pattern of MBdyed polyester was combined with direct dyes-dyed cotton, and showed that their ability to sensitize singlet oxygen (¹O²) in the photooxidation reaction of 1,5-DHN was maintained. Taken together, these findings suggest that MB is a suitable photosensitizer (PS) against S. aureus for the practical development of low-cost polyester-based antimicrobial textiles, and can potentially be used in the production of diverse form-patterned textiles that possess a photodynamic antimicrobial inactivation mechanism.     

Utilization of Site-Specific Recombination in Biopharmaceutical Production

Mammalian expression systems, due to their capacity in post-translational modification, are preferred systems for biopharmaceutical protein production. Several recombinant protein systems have been introduced to the market, most of which are under clinical development. In spite of significant improvements such as cell line engineering, introducing novel expression methods, gene silencing and process development, expression level is unpredictable and unstable because of the random location of integration in the genome. Site-specific recombination techniques are capable of producing stable and high producer clonal cells; therefore, they are gaining more importance in the biopharmaceutical production. Site-specific recombination methods increase the recombinant protein production by specifically inserting a vector at a locus with specific expression trait. The present review focused on the latest developments in site-specific recombination techniques, their specific features and comparisons.     

Analysis of genetic diversity and population structure of confectionery sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.) native to Iran

Genetic diversity within and among 50 populations of confectionery sunflower (Helianthus annuus L.) collected from different geographical areas of Iran was evaluated by using microsatellite and retrotransposon markers. The number of alleles (Na) in SSR loci ranged from 2 to 3 with an average of 2.1. The polymorphic bands in retrotransposon markers ranged from 7 in locus CR-UR1 to 15 in locus CR-816 with a mean value of 11.33. Herarchical clustering of individuals (50 × 5 = 250) by neighbor joining method in DARwin5 software subdivided them into three groups. Using Bayesian method in the software pakage of Structure, the studied individuals were subdivided into two sub-populations. Principal coordinate analysis revelaed that the two first components explaine 7.86 and 6.16% of the total variance, respectively. Analysis of molecular variance revealed a higher level of genetic variation within (70%) than between (30%) populations. High molecular variation among individuals within population possibly is due to high allogamy nature of the sunflower plant. Low genetic variation observed between populations could be considered as a consequence of genetic equilibrium that has occurred over the long period of cultivation of confectionery sunflower in this area as well as seed exchange among regions. The traditional assumption that selecting genotypes of different geographical origin will maximize the diversity available to a breeding project does not hold in confectionery sunflower.     

Solubility and Phytoavailability of Phosphorus and Lead in a Contaminated Soil Amended with Two Phosphorus Fertilizers

Application of some chemical amendments such as diammonium phosphate (DP) and triple superphosphate (TP) to contaminated soils is an effective technique to stabilize Pb and decrease its uptake by plants. A calcareous soil was spiked with the rates of 0, 250, 500, and 750 mg of lead (Pb) kg^?1 soil as Pb acetate, treated with 760 mg of P kg^?1 soil as DP and TP, and incubated for 120 days. The results showed that available phosphorus (P) increased immediately after addition of DP or TP to soil, but it declined sharply after only a few days of incubation time. Pot experiment was conducted on sorghum and spinach. The accumulation of Pb was significantly (P ≤ 0.05) lower in sorghum than in spinach, and also was lower in soil amended with DP than TP. The decreased Pb accumulation in the plants by application of both amendments was mainly attributed to the formation of chloropyromorphite.