Effect of chemically modified date palm leaf fiber on mechanical,thermal and rheological properties of polyvinylpyrrolidone

Polyvinylpyrrolidone/date palm leaf fiber (PVP/DPL) biocomposites were prepared by melt mixing fabrication technique with different weight percentage of fibers. DPL fibers were chemically modified by acrylic acid in order to have better dispersion and compatibility with PVP matrix. The interaction of DPL fibers with PVP matrix was studied by Fourier transforms infrared spectroscopy (FTIR). Field emission scanning electron microscope (FESEM) was used for the study the morphology of chemically modified DPL fibers and PVP/DPL biocomposites. Mechanical properties were improved with fiber loading due to strong interfacial adhesion between PVP and DPL fibers. The storage modulus, loss modulus and tan delta values of PVA/DPL biocomposites were measured by DMTA. The rheological properties were investigated to study the shearing storage and loss modulii along with complex viscosity of biocomposites. The thermal and conducting properties of biocomposites were measured and compared with that of virgin PVP.     

High frequency plantlet regeneration from nodal segment culture of female <Emphasis Type="Italic">Momordica dioica</Emphasis> (Roxb.)

An in vitro propagation method for female plants of Momordica dioica (Roxb.) has been established. The nodal segments were harvested and the cut ends of the explants were sealed with wax and then surface sterilized and cultured. Bud breaking occurred on Murashige and Skoog’s (MS) agar-gelled medium + 2.0 mg L⁻¹ 6-Benzylaminopurine (BAP) + 0.1 mg L⁻¹ Indole-3 acetic acid (IAA). The cultures were amplified by passages on MS medium supplemented with 1.0 mg L⁻¹ BAP + 0.1 mg L⁻¹ IAA. Further, shoot amplification (29.2 shoots per vessel) was achieved by subculturing of in vitro regenerated shoot clump on MS medium + 0.5 mg L⁻¹ BAP + 0.1 mg L⁻¹ IAA. The micropropagated shoots were subsequently transferred for root formation on half-strength MS medium + 2.0 mg L⁻¹ Indole-3 butyric acid (IBA) with 89% success rate. The in vitro-regenerated shoots were also rooted ex vitro with 34% success. These plantlets were hardened in the greenhouse and transferred to the field. The established protocol is suitable for true to type cloning of mature female plant of M. dioica.     

Novel antioxidant compounds from the aqueous extract of the roots of Decalepis hamiltonii (Wight and Arn.) and their inhibitory effect on low-density lipoprotein oxidation

Roots of Decalepis hamiltonii are consumed as pickles and as a health drink in southern India for their health benefits. The antioxidant properties of the root extracts have been shown previously; this paper reports the isolation of antioxidant compounds from the aqueous extract of the roots of D. hamiltonii. Five novel antioxidant compounds were isolated and characterized by NMR and MS. The compounds exhibited free radical scavenging activity in vitro and inhibited low-density lipoprotein oxidation. This study demonstrates that the root extract of D. hamiltonii is a cocktail of several antioxidant compounds with health implications.     

Induction of systemic resistance in banana (<Emphasis Type="Italic">Musa</Emphasis> spp.) against <Emphasis Type="Italic">Banana bunchy top virus</Emphasis> (BBTV) by combining chitin with root-colonizing <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis> strain CHA0

Pseudomonas fluorescens strains CHA0 and Pf1 were investigated for their biocontrol efficacy against Banana bunchy top virus (BBTV) in banana (Musa spp.) alone and in combination with chitin under glasshouse and field conditions. Bioformulation of P. fluorescens strain CHA0 with chitin was effective in reducing the banana bunchy top disease (BBTD) incidence in banana under glasshouse and field conditions. In addition to disease control, the bioformulation increased the economic yield significantly compared to the untreated control. Increased accumulation of oxidative enzymes, peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), pathogenesis-related (PR) proteins, chitinase, β-1,3-glucanase and phenolics were observed in CHA0 bioformulation amended with chitin-treated plants challenged with BBTV under glasshouse conditions. Indirect ELISA indicated the reduction in viral antigen concentration in P. fluorescens strain CHA0 with chitin-treated banana plants corresponding to reduced disease ratings. The present study revealed that induction of defence enzymes by P. fluorescens with chitin amendment reduced the BBTD incidence and increased bunch yield in banana.     

Management of Tibial Fractures Using a Circular External Fixator in Two Calves

Objectives: To report the repair of tibial diaphyseal fractures in 2 calves using a circular external skeletal fixator (CEF). Study Design: Clinical report. Animals: Crossbred calves (n=2; age: 6 months; weight: 55 and 60 kg). Methods: Mid‐diaphyseal tibial fractures were repaired by the use of a 4‐ring CEF (made of aluminum rings with 2 mm K‐wires) alone in 1 calf and in combination with hemicerclage wiring in 1 calf. Results: Both calves had good weight bearing with moderate lameness postoperatively. Fracture healing occurred by day 60 in 1 calf and by day 30 in calf 2. The CEF was well maintained and tolerated by both calves through fracture healing. Joint mobility and limb usage improved gradually after CEF removal. Conclusions: CEF provided a stable fixation of tibial fractures and healing within 60 days and functional recovery within 90 days. Clinical Relevance: CEF can be safely and successfully used for the management of selected tibial fractures in calves.     

Ribosome assembly factors prevent premature translation initiation by 40S assembly intermediates

Ribosome assembly in eukaryotes requires approximately 200 essential assembly factors (AFs) and occurs through ordered events that initiate in the nucleolus and culminate in the cytoplasm. Here, we present the electron cryo-microscopy (cryo-EM) structure of a late cytoplasmic 40S ribosome assembly intermediate from Saccharomyces cerevisiae at 18 angstrom resolution. We obtained cryo-EM reconstructions of preribosomal complexes lacking individual components to define the positions of all seven AFs bound to this intermediate. These late-binding AFs are positioned to prevent each step in the translation initiation pathway. Together, they obstruct the binding sites for initiation factors, prevent the opening of the messenger RNA channel, block 60S subunit joining, and disrupt the decoding site. These redundant mechanisms probably ensure that pre-40S particles do not enter the translation pathway, which would result in their rapid degradation.     

Preventive effects of amino acids on the toxicity of copper to Daphnia magna

The protective role of 18 amino acids on the acute toxicity of Cu in a fresh water cladoceran, Daphnia magna is reported. One hundred percent mortality in 48 hr of exposure occured at 0.56 mg L^?1 of Cu or higher. A dose of each tested amino acid (10 mg L^?1 was found to significantly neutralize the toxic effect of Cu as evidenced by a decrease in mortality and a significant increase in the median survival time (LT50) value). The 48 hr LC50 value was 0.093 mg L^?1 for Cu alone, while the LC50s with Cu plus amino acids ranged from 0.438 to 2.516 mg L^?1 of Cu, suggesting a 4.7 to 27 fold decrease in acute toxicity of Cu. A significant difference between LC50 of Cu alone and Cu with amino acids was observed. The role of amino acids for protection against heavy metal pollution stress in aquatic animals is discussed.     

Survival of Mycobacterium avium subsp. paratuberculosis in bovine monocyte-derived macrophages is not affected by host infection status but depends on the infecting bacterial genotype

In this study we investigated the ability of different Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) strains to survive in bovine monocyte-derived macrophages (MDMs) of cows naturally infected with M. paratuberculosis and control cows. We tested the hypotheses that infection status of cows affects macrophage killing ability and that survival of M. paratuberculosis in macrophages is dependent on the strain. Peripheral blood mononuclear cells (PBMC) were obtained from Johne's disease-positive (n = 3) and age and stage of lactation matched Johne's disease-negative (n = 3) multiparious cows. Following differentiation, MDMs were challenged in vitro with four M. paratuberculosis strains of different host specificity (cattle and sheep). Two hours and 2, 4, and 7 days after infection, ingestion, and intracellular survival of M. paratuberculosis strains were determined by fluorescence microscopy. There was no effect of the origin of MDMs (Johne's disease-positive or control animals) on phagocytosis, survival of bacteria, or macrophage survival. In contrast, important strain differences were observed. These findings suggest that some M. paratuberculosis strains interfere more successfully than others with the ability of macrophages to kill intracellular pathogens which may make it important to include strain typing when designing control programs.     

Micropropagation of Salvadora oleoides—An Oil Yielding Tree of Arid Forests

Salvadora oleoides is an ecologically important multipurpose tree of the arid forest that occurs in saline areas of northwest India. The seed of this plant yields non-edible commercially usable oil. Poor seed germination, low seed viability, and increasing industrialization are some of the constant factors which significantly affect the status of the natural population of this plant. Therefore, there is a great need to develop an efficient propagation system using the tissue culture technique. In the present communication, we demonstrate the development of an in vitro propagation system for S. oleoides. Multiple shoots were induced from nodal segments harvested from about 25- to 30- yr-old lopped trees of S. oleoides on MS medium + 0.1 mg L^?1 NAA (Naphthalene acetic acid) + 2.5 mg L^?1 BA (6-Benzylaminopurine) + additives. The shoots were multiplied by (a) repeated transfer of the mother explants on MS medium + 1.0 mg L^?1 BA + 0.1 mg L^?1 NAA + additives and (b) subculturing of shoot on MS + 1.0 mg L^?1 BA + additives. About 84% shoots rooted ex vitro on soilrite within 3–4 weeks when base (4–5 mm) of shoots was treated with 100 mg L^?1 of IBA (Indole-3-butyric acid) for 5 min. The plantlets were hardened successfully in the greenhouse and transferred to the pots and field. To the best of our knowledge, this is the first report of a regeneration protocol for S. oleoides from explants obtained from mature trees. Use of the ex vitro rooting technique for plant production serves as a more economical option as it reduces labor, cost, and time. We suggest that the methods developed and described in this article can be used for large-scale plant production and conservation of germplasm of this tree species.