Evaluation of plant growth promoting and colonization ability of endophytic diazotrophs from deep water rice

A study of the diversity of endophytic bacteria present in seeds of a deepwater rice variety revealed the presence of seven types of BOX-PCR fingerprints. In order to evaluate the plant growth promoting potential the presence of nitrogenase, indole acetic acid production and mineral phosphate solubilization were estimated in the representative BOX-PCR types. The seven representatives of BOX-PCR types produced indole acetic acid, reduced acetylene and showed specific immunological cross-reaction with anti-dinitrogenase reductase antibody. Only four types showed mineral phosphate solubilizing ability. Comparison of cellulase and pectinase activities showed differences among different BOX-PCR types. PCR fingerprinting data showed that one strain isolated from the surface sterilized seeds as well as the aerial parts of the seedlings of rice variety showed low cellulase and pectinase but relatively high ARA. On the basis of 16S rDNA nucleotide sequence and BIOLOG system of bacterial identification, this strain was identified as Pantoea agglomerans. For studying the endophytic colonization this strain was genetically tagged with the reporter gene, gusA. Histochemical analysis of the seedling grown in hydroponics showed that the tagged strain colonized the root surface, root hairs, root cap, points of lateral root emergence, root cortex and the stelar region. Treatment of the roots with 2,4-D produced short thickened lateral roots which showed better colonization by P. agglomerans.     

Mathematica numerical simulation of peristaltic biophysical transport of a fractional viscoelastic fluid through an inclined cylindrical tube

This paper studies the peristaltic transport of a viscoelastic fluid (with the fractional second-grade model) through an inclined cylindrical tube. The wall of the tube is modelled as a sinusoidal wave. The flow analysis is presented under the assumptions of long wave length and low Reynolds number. Caputo's definition of fractional derivative is used to formulate the fractional differentiation. Analytical solutions are developed for the normalized momentum equations. Expressions are also derived for the pressure, frictional force, and the relationship between the flow rate and pressure gradient. Mathematica numerical computations are then performed. The results are plotted and analysed for different values of fractional parameter, material constant, inclination angle, Reynolds number, Froude number and peristaltic wave amplitude. It is found that fractional parameter and Froude number resist the flow pattern while material constant, Reynolds number, inclination of angle and amplitude aid the peristaltic flow. Furthermore, frictional force and pressure demonstrate the opposite behaviour under the influence of the relevant parameters emerging in the equations of motion. The study has applications in uretral biophysics, and also potential use in peristaltic pumping of petroleum viscoelastic bio-surfactants in chemical engineering and astronautical applications involving conveyance of non-Newtonian fluids (e.g. lubricants) against gravity and in conduits with deformable walls.     

A Hamster-Derived West Nile Virus Isolate Induces Persistent Renal Infection in Mice

Background

West Nile virus (WNV) can persist long term in the brain and kidney tissues of humans, non-human primates, and hamsters. In this study, mice were infected with WNV strain H8912, previously cultured from the urine of a persistently infected hamster, to determine its pathogenesis in a murine host.

Methodology/Principal Findings

We found that WNV H8912 was highly attenuated for neuroinvasiveness in mice. Following a systemic infection, viral RNA could be detected quickly in blood and spleen and much later in kidneys. WNV H8912 induced constitutive IL-10 production, upregulation of IFN-β and IL-1β expression, and a specific IgM response on day 10 post-infection. WNV H8912 persisted preferentially in kidneys with mild renal inflammation, and less frequently in spleen for up to 2.5 months post infection. This was concurrent with detectable serum WNV-specific IgM and IgG production. There were also significantly fewer WNV- specific T cells and lower inflammatory responses in kidneys than in spleen. Previous studies have shown that systemic wild-type WNV NY99 infection induced virus persistence preferentially in spleen than in mouse kidneys. Here, we noted that splenocytes of WNV H8912-infected mice produced significantly less IL-10 than those of WNV NY99-infected mice. Finally, WNV H8912 was also attenuated in neurovirulence. Following intracranial inoculation, WNV persisted in the brain at a low frequency, concurrent with neither inflammatory responses nor neuronal damage in the brain.

Conclusions

WNV H8912 is highly attenuated in both neuroinvasiveness and neurovirulence in mice. It induces a low and delayed anti-viral response in mice and preferentially persists in the kidneys.     

Plasmon-Enhanced Light Trapping to Improve Efficiency of TiO2 Nanorod-Based Dye-Sensitized Solar Cell

Localized surface plasmon resonance incurred by silver nanoparticles is used to enhance the photoelectric conversion efficiency of a TiO₂ nanorod-based dye-sensitized solar cell (DSSC). Improved light transmission is observed experimentally in silver nanoparticle-coated FTO glass. The transmission data are used to explore the effect on electrical parameters of DSSC using theoretical model. Current density increased from 11.7 to 12.34 mA/cm² and open-circuit voltage increased from 704 to 709.5 mV. Overall efficiency enhancement of 6.67 % is observed in TiO₂ nanorod-based DSSC due to plasmon-induced light trapping.     

Effects of Late Administration of Pentoxifylline and Tocotrienols in an Image-Guided Rat Model of Localized Heart Irradiation

Radiation-induced heart disease (RIHD) is a long-term side effect of radiotherapy of intrathoracic, chest wall and breast tumors when radiation fields encompass all or part of the heart. Previous studies have shown that pentoxifylline (PTX) in combination with α-tocopherol reduced manifestations of RIHD in rat models of local heart irradiation. The relative contribution of PTX and α-tocopherol to these beneficial effects are not known. This study examined the effects of PTX alone or in combination with tocotrienols, forms of vitamin E with potential potent radiation mitigation properties. Rats received localized X-irradiation of the heart with an image-guided irradiation technique. At 3 months after irradiation rats received oral treatment with vehicle, PTX, or PTX in combination with a tocotrienol-enriched formulation. At 6 months after irradiation, PTX-treated rats showed arrhythmia in 5 out of 14 animals. PTX alone or in combination with tocotrienols did not alter cardiac radiation fibrosis, left ventricular protein expression of the endothelial markers von Willebrand factor and neuregulin-1, or phosphorylation of the signal mediators Akt, Erk1/2, or PKCα. On the other hand, tocotrienols reduced cardiac numbers of mast cells and macrophages, but enhanced the expression of tissue factor. While this new rat model of localized heart irradiation does not support the use of PTX alone, the effects of tocotrienols on chronic manifestations of RIHD deserve further investigation.     

NO and ROS implications in the organization of root system architecture

Over the past decades the role of nitric oxide (NO) and reactive oxygen species (ROS) in signaling and cellular responses to stress has witnessed an exponential trend line. Despite advances in the subject, our knowledge of the role of NO and ROS as regulators of stress and plant growth and their implication in signaling pathways is still partial. The crosstalk between NO and ROS during root formation offers new domains to be explored, as it regulates several plant functions. Previous findings indicate that plants utilize these signaling molecules for regulating physiological responses and development. Depending upon cellular concentration, NO either can stimulate or impede root system architecture (RSA) by modulating enzymes through post-translational modifications. Similarly, the ROS signaling molecule network, in association with other hormonal signaling pathways, control the RSA. The spatial regulation of ROS controls cell growth and ROS determine primary root and act in concert with NO to promote lateral root primordia. NO and ROS are two central messenger molecules which act differentially to upregulate or downregulate the expression of genes pertaining to auxin synthesis and to the configuration of root architecture. The investigation concerning the contribution of donors and inhibitors of NO and ROS can further aid in deciphering their role in root development. With this background, this review provides comprehensive details about the effect and function of NO and ROS in the development of RSA.     

Promising Polyphenols in Parkinson’s Disease Therapeutics

Neurochemical Research - Parkinson’s disease (PD) is a slow progressive, second most common neurodegenerative disease characterized by the loss of dopaminergic neurons from the nigrostriatal...     

Protective and survival efficacies of Rv0160c protein in murine model of Mycobacterium tuberculosis

The proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) multi-gene families code for approximately 10 % of the Mycobacterium tuberculosis (Mtb) genome. These proteins are thought to be virulence factors that participate in impounding the host immune responses. While some members have been studied, the functions of most PE/PPE proteins are yet to be explored. The studies presented here have specifically characterized the roles of one of the PE proteins of Mtb, Rv0160c (PE4), in mycobacterial persistence and in prophylactic efficacy. We have expressed Rv0160c in a non-pathogenic fast-growing Mycobacterium smegmatis strain and demonstrated that the protein improves the survival of mycobacteria in macrophages and in mice. The protein has also shown its effect under physiological stress of bacteria, as evidenced by elevated expression in acidic and in hypoxic conditions. In mice, the level of Rv0160c was noticeably high during the chronic stage of tuberculosis. The seroreactivity of the protein against different categories of tuberculosis patients revealed a strong B-cell humoral response in freshly infected pulmonary tuberculosis patients. In mice, it exhibited increased IL-2, TNF, and IL-6 production. The antigenic properties of the protein directed towards the protective efficacy against the Mtb challenge. All together, our findings have identified Rv0160c as an in vivo expressed immunodominant antigen which plays a crucial role in the pathogenesis of mycobacterial disease and could prove to be a good preventive antigen for tuberculosis.