Enhanced muscle regeneration in freshwater prawn Macrobrachium rosenbergii achieved through in vivo silencing of the myostatin gene

Myostatin (MSTN) is an interesting negative growth‐regulating gene that has been well characterized in vertebrates but scantly described in invertebrates. The current study focuses on the downregulation of the MrMSTN gene and subsequently records any histological changes for giant freshwater prawn, Macrobrachium rosenbergii (Mr). In addition, the study also deals with the MrMSTN gene's influence on other growth‐related genes, which include myosin heavy chain, dystrophin‐dystroglycoprotein complex, tropomyosin, farnesoic acid o‐methyl transferase, arginine kinase, cyclophilin, and acyl CoA desaturase. The preliminary histological analysis following MrMSTN silencing favors muscle regeneration, which supports its functional role as a negative growth regulator and its significant effect on the expression of other growth‐related genes. Overall, our results show that the MrMSTN gene could therefore be a potential target for gene manipulation aimed at enhancing the growth and muscle development of M. rosenbergii, which could be beneficial in increasing the total mass production in the postlarva phase at the hatchery level.     

Productivity and Sustainability of Cotton (Gossypium hirsutum L.)–Wheat (Triticum aestivum L.) Cropping System as Influenced by Prilled Urea, Farmyard Manure and Azotobacter

Field experiments were conducted at Indian Agricultural Research Institute, New Delhi, during 2001–2002 and 2002–2003, to study the effect of inorganic, organic and Azotobacter combined sources of N on cotton (Gossypium hirsutum L.) and their residual effect on succeeding wheat (Triticum aestivum L.) crop. The results indicated considerable increase in yield attributes and mean seed cotton yield (2.33 Mg ha^?1) with the combined application of 30 kg N and farmyard manure (FYM) at 12 Mg ha^?1 along with Azotobacter (M₄). The treatment in cotton that included FYM, especially when fertilizer N was also applied could either improve or maintain the soil fertility status in terms of available N, P and K. Distinct increase in yield attributes and grain yield of wheat was observed with the residual effect of integrated application of 30 kg N ha^?1 + FYM at 12 Mg ha^?1 + Azotobacter. Direct application of 120 kg N ha^?1 resulted 67.4 and 17.7 % increase in mean grain yield of wheat over no N and 60 kg N ha^?1, respectively. Integrated application of organic and inorganic fertilizer is therefore, recommended for higher productivity and sustainability of the cotton–wheat system.     

Design Characteristics of Spiral Aerator

In this study, the performance of a spiral aerator, a modified design of the paddlewheel aerator, was evaluated to determine its applicability in aquaculture ponds. The aeration characteristics of the spiral aerator were determined by conducting aeration experiments in a cement concrete tank of dimension 5 × 5 × 1.5 m. Nondimensional numbers related to oxygen transfer (E) and power consumption (Ne) were proposed and expressed as functions of geometric (number of handles per shaft, n) and dynamic (Froude and Reynolds number) parameters. Simulation equations for oxygen transfer and power consumption based on the Froude criterion were developed. The maximum brake power standard aeration efficiency was achieved at n = 13. Finally, an economic analysis was performed assuming a typical Indian major carp culture pond to determine the optimum rotational speed of the aerator at different pond volumes and dissolved oxygen concentration present in the pond at which the aeration cost is minimized. The results showed that the least aeration cost is achievable when rotational speed of the spiral aerator is only 70 rpm for pond volumes up to 700 m³ and from 120 to 220 rpm for pond volumes exceeding 700 m³.     

Application of silver nanoparticles to industrial sewing threads: Effects on physico-functional properties & seam efficiency

In this study, the role and impact of silver nanoparticles on industrial sewing threads have been investigated. Study of nanocoating on industrial sewing threads may be useful especially in the areas where skin comes in contact with the garments where anti-bacterial properties may be very useful. Silver particles are considered to have excellent anti bacterial properties. To understand the impact on sewability, investigation was focused to changes at the structural level, changes in physical and surface properties, tensile properties and anti-microbial properties of the nanotreated sewing threads. The structure and morphology of the silver nanoparticles on the sewing threads was observed by scanning electron microscopy (SEM) and quantitatively confirmed by fourier transform infrared spectroscopy (FT-IR). A number of experimental methods and mathematical formulae were used to test individual threads. Custom designed fixtures were used for the study. All the results have been statistically analyzed and found to be significant. The effect of silver nanoparticles on physical properties, functional properties and seam efficiency was illustrated. The difference of the impact of silver nanoparticles on cotton and polyester sewing threads has been compared. It was found that silver nanotreatment leads to a significant reduction of tensile strength. The warp-way seam strength increased where as weft-way seam strength decreased due to damage of yarn. Deformation properties of the threads are not influenced significantly by nanotreatment. The nanotreatment of threads improves its frictional properties significantly. The threads also acquire effective anti-microbial properties with silver nanotreatment. Study of the impact of nanotreatment on the properties of cotton and polyester samples showed a bigger impact on cotton samples than polyester samples. The effect was durable even after several laundering treatments.     

Geographical traceability of an important tropical timber (Neobalanocarpus heimii) inferred from chloroplast DNA

The inbuilt unique properties of DNA within the timber could serve as tracking and monitoring tools to verify the legality of a suspected timber in the context of illegal logging, forest certification and chain of custody certification. By using Neobalanocarpus heimii (Dipterocarpaceae) as an example, a population identification database and haplotype distribution map in Peninsular Malaysia were generated for authenticity testing based on four chloroplast DNA markers (trnL intron, trnG intron, trnK intron and psbK-trnS spacer). Twenty one haplotypes were identified from 10 significant intraspecific variable sites. The results clearly revealed that only northern and southern regions of Peninsular Malaysia were distinguishable. Thus, this database could only be used to determine the wood lot of unknown origin at the regional level. Statistical procedure based on the composition of wood lot was used to test whether a suspected timber conforms to a given regional origin. Overall, the observed type I and II errors of the database showed good concordance with the predicted 5% threshold, which might indicate that the database is useful to reveal provenance and establish conformity of wood lot from northern and southern regions of Peninsular Malaysia. Applications of this database for timber tracking are discussed.     

Diversified aeration facilities for effective aquaculture systems—a comprehensive review

The growing intensive aquaculture system around the world maintains a high stocking density, wherein it is essential to increase and sustain the optimum dissolved oxygen concentration (DO) through the provision of artificial aeration systems. The selection of an aerator is a crucial aspect of aquaculture operations. The selected aerator must be economically efficient and should be able to fulfill the requirement of oxygen supply in the pond water. The present study provides an extensive literature review on the importance of artificial aeration in aquaculture, the standard method of test for performance evaluation of an aerator, various aeration systems and their mechanisms, method to determine the numbers of aerator requirement, comparative studies of different type of aerators, and economic consideration in selection of aerators. In addition, a thorough analysis has been done to suggest the type of aerator that is economically viable and efficient for different pond volumes based on the performance data reported in the reviews. Therefore, this study may help the end-users (fish farmers) to select the best aerator based on their requirements.

     

DNA extraction from dry wood of Neobalanocarpus heimii (Dipterocarpaceae) for forensic DNA profiling and timber tracking

Wood can be a good source of DNA for various applications in forensic forestry and timber trade if high-quality DNA can be retrieved from the dry wood. In order to provide a general guideline for DNA authenticity testing established for Neobalanocarpus heimii, this study was designed to evaluate the potential of extracting DNA from the dry wood. Overall, the efficacy of DNA extraction was higher for the cambium and sapwood than for the heartwood tissues. In terms of DNA extraction protocols, the Qiagen kit and CTAB with PTB protocol showed higher PCR amplification rates. In order to safeguard the intactness of the DNA, the DNA extraction from dry wood is recommended to be carried out within 6?weeks after felling for logs and 6?months after felling for stumps. The results also showed that the amplicon size might not account for the PCR amplification success rate, and chloroplast genome yielded higher amplification success rate compared with nuclear genome. However, only the chloroplast region can be perfectly retrieved from heat-treated lumber.     

Identification of a putative cellulase gene in the giant freshwater prawn,Macrobrachium rosenbergii (De Man, 1879)

Nutrition plays an important role in the development of all organisms and in particular that of farmed aquatic species where costs associated with feed can often exceed 60% of total production costs. Crustacean species in addition, have the added metabolic requirement for regular moulting to allow normal growth and this requires large amounts of energy in the form of sugars (glucose). The current study explored the capacity of the giant freshwater prawn to produce endogenous cellulose‐degrading enzymes capable of extracting nutrients (simple sugars) from plant sources in formulated feeds used in the prawn aquaculture industry. We identified a putative cellulase cDNA fragment in the target organism of 1576 base pairs in length of non‐microbial origin that after protein modelling exhibited a TM‐score of 0.916 with a described cellulase reported from another crustacean species. The functional role of cellulase enzymes is to hydrolyse cellulose to glucose and the fragment identified in GFP was highly expressed in the hepatopancreas, the site of primary food digestion and absorption in crustaceans. Hepatopancreatic tissue from Macrobrachium rosenbergii also showed active digestion of cellulose to glucose following an endoglucanase assay. Cellulase gene(s) are present in the genomes of many invertebrate taxa and play an active role in the conversion of cellulose to available energy. Identification and characterization of endogenous cellulase gene(s) in giant freshwater prawn can assist development of the culture industry because the findings confirm that potentially greater levels of low‐cost plant‐material could be included in artificial formulated diets in the future without necessarily compromising individual growth performance. Ultimately, this development may contribute to more efficient, cost‐effective production systems for freshwater prawn culture stocks that meet the animal's basic nutritional requirements and that also support good individual growth rates.