Surface Treated Jute Fiber Induced Foam Microstructure Development in Poly(lactic acid)/Jute Fiber Biocomposites and their Biodegradation Behavior

Poly(lactic acid) (PLA)/jute fiber biocomposites with: i) untreated jute fiber, ii) NaOH treated jute fiber, and iii) (NaOH+silane) treated jute fibers were prepared by melt extrusion process. Microcellular foaming of the injection molded samples was carried out by using single stage batch process. The effects of jute fiber content as well as that of matrix-fiber phase adhesion, in composites with surface treated jute fibers, on the foam microstructure were studied. Further, water absorption, thickness swelling, and biodegradation behavior of the foamed biocomposites were studied and correlated with their foam microstructures. It was observed that on increasing jute fiber content in PLA/JFU biocomposites, cell density increased from 6.5×10⁷ to 8.1×10⁷, while the cell size and expansion ratio decreased from 40 to 23 μm and 2.41 to 1.45, respectively. Again, on increasing the extent of the jute fiber surface treatment in the biocomposites, cell size and expansion ratio increased from 40 to 78 μm and 2.41 to 2.80 respectively. This study also revealed that the rate of biodegradation accelerated with increase in the jute fiber content in the biocomposites while the same retarded with increase in the extent of jute fiber surface treatment.     

Studying the extent of genetic diversity among Gossypium arboreum L. genotypes/cultivars using DNA fingerprinting

Genetic diversity is an area of concern for sustaining crop yield. Information on genetic relatedness/diversity among Gossypium arboreum L. cultivars/genotypes is scanty. We have used random amplified polymorphic DNA (RAPD) analysis to assess the genetic divergence/relationship among 30 genotypes/cultivars of G. arboreum. Of 45 primers surveyed, 63% were polymorphic. Out of the total number of loci amplified, 36% were polymorphic. The calculated genetic similarity between the cultivars/genotypes was in the range of 47.05–98.73%. Two genotypes, HK-244 and Entry-17, were the most distantly related. The average genetic relatedness among all the genotypes was 80.46%. However, most of the cultivated varieties showed a close genetic relationship, indicating a narrow genetic base in comparison to the non-cultivated germplasm. The calculated coefficients were used to construct a dendrogram using the unweighted pair group of arithmetic means (UPGMA) algorithm, which grouped the genotypes/cultivars into two major and three smaller clusters. The study is the first comprehensive analysis of the genetic diversity of G. arboreum germplasm and identifies cultivars that will be useful in extending the genetic diversity of cultivated varieties and future genome mapping projects.     

Genetics of resistance to cotton leaf curl disease in Gossypium hirsutum

Twenty-two cotton varieties were screened for resistance to cotton leaf curl disease (CLCuD), a disease of viral origin, using three procedures: field evaluation, whitefly transmission assay and graft inoculation. Viral infection of cotton varieties was determined by visual symptom assessment as well as dot-blot and multiplex PCR diagnostic techniques. Crosses were made between the most susceptible variety (S-12) and highly resistant varieties (CP-15/2, LRA-5166 and CIM-443). All F₁ plants of these crosses were resistant, showing dominant expression of the resistance as well as the absence of extrachromosomal inheritance. The F₂ plants of the crosses CP-15/2 × S12, LRA-5166 × S-12 and CIM-443 × S12 exhibited a ratio of 13 resistant (symptomless) to three susceptible (with symptoms). Screening of the F₂ generation for virus infection by multiplex PCR further subdivided the resistant class into those exhibiting a high level of resistance (HR; PCR-negative) and those exhibiting resistance (R; symptomless, yet showing virus replication by PCR analysis). Hence, the final ratio was 3:10:3 (HR:resistant:susceptible). The F₃ progeny of susceptible F₂ plants segregated for resistance, indicating the probable presence of a suppressor gene ( S ). These findings are consistent with three genes being involved in G. hirsutum resistance to CLCuD, two for resistance ( R _1CLCuDhir and R _2CLCuDhir ) and a suppressor of resistance ( S _CLCuDhir ).     

Biofloc technology: an eco-friendly “green approach” to boost up aquaculture production

The rapid intensification of the aquaculture system has led to several environmental impacts involving water quality deterioration, pollution, and disease outbreaks. Consequently, an eco-friendly technique is inevitable that could ensure better production with less impact on the environment by minimizing the effluent discharge from aquaculture practice. Biofloc technology is such a kind breakthrough that would be easy to perform; operation and establishment procedure is quite simple at a relatively low cost that would be convenient to fish farmers. It can serve as a perfect solution for aquaculture species through improving its all characteristics such as substantial biomass density, survival, and disease resistance ability to the pathogen by an immunostimulatory effect of microbial floc on the immune system that would assure the biosecurity and sustainability of this extraordinary technique.

     

Tunable functional properties on polyester fabric using simultaneous green reduction of graphene oxide and silver nitrate

Here, a novel method is introduced to create tunable properties on the polyester fabric through diverse chemical modifications. The polyester fabric was primarily modified with NaOH or ethylenediamine to enhance the surface activity. This will produce diverse chemical groups on the polyester fabric surface including carboxylate, hydroxyl and amine groups. The fabric was treated with grahene oxide through exhaustion method. The silver nitrate was then added and simultaneously reduced with grapheme oxide using ascorbic acid and ammonia to produce reduced graphen oxide/silver nanocomposites (rGO/Ag) on the fabric surface. The synthesized nanocomposites were characterized by TEM and Raman spectra. The presence and uniform distribution of the nanocomposites on the fabric surface was also confirmed by SEM images and EDX patterns. The electrical resistivity was varied on the raw and modified polyester fabric due to the diverse formation of the graphene nanosheets network on the fabric surface. More Ag particles were formed on the surface of the alkali hydrolyzed polyester whereas more graphene nanosheets deposited on the aminolyzed polyester fabric. Also the hydrolyzed polyester fabric exhibited higher antibacterial properties with the lowest silver nitrate in the processing solution. The aminolyzed fabric showed a lower electrical resistance than the hydrolyzed and raw fabrics with the same amount of GO in the procedure bath. The aminolyzed polyester fabric indicated higher affinity towards GO produced higher antibacterial properties before reduction and without silver nitrate however lower electrical resistance obtained after reduction comparing with other samples.     

Mitochondrial biogenesis and PGC‐1α gene expression in male broilers from ascites‐susceptible and ‐resistant lines

Ascites is a cardiovascular metabolic disease characterized by accumulation of fluid around the heart and in the abdominal cavity that eventually leads to death. This syndrome is the end‐point result of a series of metabolic incidents that are generally caused by impaired oxygen availability. Mitochondria are the major sites of oxygen consumption, therefore major contributors to oxidative stress. Genetic, metabolic and dietary factors can influence variations in mitochondrial biogenesis (mitochondrial size, number and mass) that might have an effect on oxygen consumption and reactive oxygen species production. This study evaluated the effect of genotype on PGC‐1α mRNA gene expression and mitochondrial biogenesis. These parameters were examined in male broiler chickens at 22 weeks of age from the SUS and RES lines divergently selected for ascites phenotype. From each line, five birds were sampled for right ventricle and breast muscle. Gene expression and mtDNA copy number were assessed by quantitative PCR. Results showed that birds from SUS had significantly higher PGC‐1α mRNA gene (p = .033) and mitochondrial DNA copy number (p = .038) in breast muscle. There was no difference in right ventricle PGC‐1α expression or mitochondrial DNA copy number between the two lines. These findings indicate that mitochondrial biogenesis and PGC‐1α mRNA gene expression differ between male broiler chickens from RES and SUS lines in a tissue‐specific manner.     

Interactive effects of temperature and dietary supplementation of arginine or guanidinoacetic acid on nutritional and physiological responses in male broiler chickens

1. The aim of this experiment was to study the interactive effect of rearing temperature and dietary supplementation of arginine (Arg) or guanidinoacetic acid (GAA) on performance, gut morphology and ascites indices in broiler chickens raised under the same condition in the first 2 weeks and then reared under normal (23–26°C) or subnormal (17°C) ambient temperatures for the next 3 weeks.

2. This experiment was conducted as a split plot with 900 Ross 308 male broiler chicks that were allocated to two houses (as main plots); each consisted of 5 treatments (as sub-plots) with 6 replicates of 15 birds. The 5 diets were (1) control, (2) control + 0.60 g/kg GAA, (3) control + 1.20 g/kg GAA, (4) control + 0.86 g/kg Arg and (5) control + 1.72 g/kg Arg.

3. Feed intake (0–35 d) of birds fed on a diet containing 1.2 g GAA/kg and reared under normal temperature was reduced compared to control fed birds. Birds fed on a diet containing 1.72 g/kg Arg and reared under subnormal temperature had higher weight gain compared to those fed on control or GAA-added diets in overall study period.

4. Supplementation of diets with Arg alleviated the adverse effect of cold stress as reflected by reduction in blood haematocrit (41% vs. 37%), and right ventricle to total ventricle ratio (0.28 vs. 0.25) at 35 d of age. Addition of Arg to the diet of birds reared under cold stress resulted in a higher jejunal villus surface area compared to those fed on control or GAA-added diets.

5. Findings of this study revealed that Arg or GAA supplementation of diets did not affect performance of birds under normal temperatures, but Arg supplementation of the diet significantly alleviated the adverse effect of cold stress on performance, gut development and ascites syndrome. In addition, GAA supplementation at 1.2 g/kg improved jejunal villus surface area in birds raised under subnormal temperature.     

Mapping of quantitative trait loci controlling cotton leaf curl disease resistance in upland cotton

Cotton leaf curl disease (CLCuD) is a major threat to cotton production in Asia and Africa. Using marker-assisted breeding can be the best sustainable approach to tackle CLCuD. Identification of new QTLs in the indigenous cotton germplasm is necessary to combat CLCuD. The current study was designed to construct a genetic linkage map of bi-parental F2:F3 populations developed from highly tolerant MNH-886 and highly susceptible S-12 cotton cultivars. One hundred seven CLCuD-associated simple sequence repeat (SSR) marker alleles were identified as polymorphic and three new QTLs were found on chromosomes C11, C19 and C21. Two QTLs on chromosomes C11 and C19 were detected in both F2 and F3 populations in the region flanked by SSR markers CIR316 and BNL4094, and BNL285 and BNL3348, respectively. Whereas, one QTL on chromosome C21 was detected in the region flanked by SSR markers JESPR158 and JESPR135 in both F2 and F3 generations. The CLCuD-associated QTLs identified in this study can help fine-tune the molecular mapping of the QTLs on the cotton genome against CLCuD.