Direct shoot organogenesis from hypocotyl explants of Jatropha curcas L. an important bioenergy feedstock

Multiple shoots were induced on hypocotyl segments reared from in vitro germinated seedlings of Jatropha curcas L., using Murashige and Skoog (MS) medium supplemented with N⁶‐benzyl adenine (BA) and kinetin (kin) either alone or in combination with indole‐3‐acetic acid (IAA). The combined treatment of 7.05 μm kin and 1.425 μm IAA resulted in maximum shoot production with an average shoot bud initiation of 12.1 per explant. The regenerated microshoots were transferred to root induction medium containing half‐strength MS salts supplemented with either indole‐3‐butyric acid (IBA) or IAA. Rooting of microshoots was best achieved on half‐strength MS medium supplemented with IBA (9.8 μm ). Rooted plantlets were subsequently acclimatized under green house condition and the plantlets showed 70% survival.     

Avian influenza (H5N1) virus of clade 2.3.2 in domestic poultry in India

South Asia has experienced regular outbreaks of H5N1 avian influenza virus since its first detection in India and Pakistan in February, 2006. Till 2009, the outbreaks in this region were due to clade 2.2 H5N1 virus. In 2010, Nepal reported the first outbreak of clade 2.3.2 virus in South Asia. In February 2011, two outbreaks of H5N1 virus were reported in the State of Tripura in India. The antigenic and genetic analyses of seven H5N1 viruses isolated during these outbreaks were carried out. Antigenic analysis confirmed 64 to 256-fold reduction in cross reactivity compared with clade 2.2 viruses. The intravenous pathogenicity index of the isolates ranged from 2.80-2.95 indicating high pathogenicity to chickens. Sequencing of all the eight gene-segments of seven H5N1 viruses isolated in these outbreaks was carried out. The predicted amino acid sequence analysis revealed high pathogenicity to chickens and susceptibility to the antivirals, amantadine and oseltamivir. Phylogenetic analyses indicated that these viruses belong to clade 2.3.2.1 and were distinct to the clade 2.3.2.1 viruses isolated in Nepal. Identification of new clade 2.3.2 H5N1 viruses in South Asia is reminiscent of the introduction of clade 2.2 viruses in this region in 2006/7. It is now important to monitor whether the clade 2.3.2.1 is replacing clade 2.2 in this region or co-circulating with it. Continued co-circulation of various subclades of the H5N1 virus which are more adapted to land based poultry in a highly populated region such as South Asia increases the risk of evolution of pandemic H5N1 strains.     

The study of microclimate in response to different plant community association in tropical moist deciduous forest from northern India

The data on microclimate were collected between 2010 and 2011 in five forest communities (dry miscellaneous, sal mixed, lowland miscellaneous, teak and savannah) in a tropical moist deciduous forest in Katerniaghat Wildlife Sanctuary, Uttar Pradesh, India to compare how vegetation structure affects microclimate. Diurnal variations in microclimatic variables [photosynthetically active radiation (PAR) at forest understory level, air temperature, soil surface temperature, ambient CO₂, air absolute humidity] were measured with LI-COR 840, LI-COR 191, LI-COR 190 SZ, LI-1400-101 and LI-1400-103 (LI-COR; Lincoln, NE, USA) at centre of three 0.5 ha plots in each forest community. The diurnal trend in microclimatic parameters showed wide variations among communities. PAR at forest floor ranged from 0.0024 to 1289.9 (μmol m⁻²s⁻¹) in post-monsoon season and 0.0012 to 1877.3 (μmol m⁻²s⁻¹) in mid-winter season. Among the five communities, the highest PAR value was observed in savannah and lowest in sal mixed forest. All the forest communities received maximum PAR at forest floor between 1000 and 1200 h. The ambient air temperature ranged from 19.15 to 26.69°C in post-monsoon season and 11.31 to 23.03°C in mid-winter season. Soil temperature ranged from 13.54 to 36.88°C in post-monsoon season and 6.39 to 29.17°C in mid-winter season. Ambient CO₂ ranged from 372.16 to 899.14 μmol mol⁻¹ in post-monsoon season and 396.65 to 699.65 μmol mol⁻¹ in mid-winter season. In savannah ecosystem, diurnal trend of ambient CO₂ was totally different from rest four communities. According to Canonical correspondence analysis, PAR and ambient CO₂ are most important in establishment of forest community, among microclimatic variables.     

In vivo USPIO magnetic resonance imaging shows that minocycline mitigates macrophage recruitment to a peripheral nerve injury

ABSTRACT: BACKGROUND: Minocycline has proven anti-nociceptive effects, and delays the development of allodynia/hyperalgesia after peripheral nerve injury. However, the mechanism by which this occurs remains unclear. Inflammatory cells, in particular macrophages, are critical components of the response to nerve injury. Using ultrasmall superparamagnetic iron oxide-magnetic resonance imaging (USPIO-MRI) to monitor macrophage trafficking, the purpose of this project is to determine whether minocycline modulates macrophage trafficking to the site of nerve injury in vivo and, in turn, results in altered pain thresholds. RESULTS: Animal experiments were approved by Stanford IACUC. A model of neuropathic pain was created using the Spared Nerve Injury (SNI) model that involves ligation of the left sciatic nerve in the left thigh of adult Sprague-Dawley rats. Animals with SNI and uninjured animals (control) were then injected with/without USPIOs (300umol/kg IV) and with/without minocycline (50mg/kg IP). Bilateral sciatic nerves were scanned with a volume coil in a 7T magnet 7 days after USPIO administration. Fluid-sensitive MR images were obtained, and ROIs were placed on bilateral sciatic nerves to quantify signal intensity. Pain behavior modulation by minocycline was measured using the Von Frey filament test. Sciatic nerves were ultimately harvested at day 7, fixed in 10% buffered formalin and stained for the presence of iron oxide-laden macrophages. Behavioral measurements confirmed the presence of allodynia in the neuropathic pain model while the uninjured and minocycline-treated injured group had significantly higher paw withdrawal thresholds (p<0.011). Decreased MR signal is observed in the SNI group that received USPIOs (3.3+/-0.5%) compared to the minocycline-treated SNI group that received USPIOs (15.2+/-4.5%) and minocycline-treated group (no USPIOs; 41.2+/-2.3%) (p<0.04). Histology of harvested sciatic nerve specimens confirmed the presence USPIOs at the nerve injury site in the SNI group without minocycline treatment. CONCLUSION: Animals with neuropathic pain in the left hindpaw show increased trafficking of USPIO-laden macrophages to the site of sciatic nerve injury. Minocycline appears to retard the migration of macrophages to the nerve injury site, which may partly explain its anti-nociceptive effects. USPIO-MRI is an effective in vivo imaging tool to study the role of macrophages in the development of neuropathic pain.     

Tuning the Optical and Rheological Properties of Fullerene C<Subscript>60</Subscript>/Poly (Vinyl Pyrrolidone) Nanofluids via Inclusion of Nanogold

In this article, development of nanogold (NG) containing fullerene C₆₀ nanofluids (NFs) with poly (vinyl pyrrolidone) PVP polymer in water via a wet chemical route is reported and studied their rheo-optical properties. An inclusion of NG into a C₆₀:PVP nanofluid thus results in a gold (Au) surface plasmon resonance (SPR) enhanced π?→?π* C₆₀ (sp²) electron transition over 250–450 nm of absorption spectrum in water. Evolution of a broad Au-SPR band in the 450–750 nm region signifies that a controlled Au³⁺?→?Au reduction reaction had occurred on it and was carried in C₆₀:PVP NFs. The average maximum wavelength value has thus varied along with a molar extinction coefficient in a function of the Au-uploads and shape and size of the flocculates in the resulting Au:C₆₀-PVP NFs. A systematic rheological study performed on the Au:C₆₀-PVP NFs in water by varying the NG content up to 85.0 μM reveals a non-Newtonian behavior with an enhanced yield stress is a signature of Bingham flow. NG of different shapes serves as filler in C₆₀:PVP NFs so as it adapts tailored shear viscosity. The shear viscosity relaxes slowly to the base value on increasing the shear rate from 10 to 100 s^?1 as it leads to breaking up of soft Au:C₆₀-PVP assemblies into a fine structures. Synthesis of Au:C₆₀-PVP NFs with various Au-contents could be potential nanostructure hybrid composite materials for development of photovoltaic nanodevices.     

Biomolecular changes during in vitro organogenesis of Asteracantha longifolia (L.) Nees--a medicinal herb

High frequency plant regeneration in A. longifolia (L.) was achieved from leaf explant implanted on MS basal medium supplemented with NAA (0.5 mg/l) + BA (2.0 mg/l) through intervening callus phase. Well-developed shoots (>3cm) were successfully rooted on MS medium supplemented with NAA (0.1 mg/l). Protein and total soluble sugar contents were maximum during organogenesis and multiple shoot induction phase compared with non-organogenic callus and root induction phase. Esterase and catalase activities were maximum during organogenic differentiation, while activities were minimum at non-differentiated callus stages. Peroxidase activities were higher during rhizogenesis. Contradiction to peroxidase activity, acid phosphatase activities were high during organogenesis and declined during rhizogenesis. SDS-PAGE analysis of total soluble proteins revealed expression of non-organogenic callus (97.9 kDa), organogenic callus (77.2, 74.1, 21.9 kDa), multiple shoot induction phase (106.6, 26.9, 11.6 kDa) and root induction phase (15.9 kDa) specific polypeptides. Esterase zymogram revealed one band (Rm 0.204) appeared in both organogenic callus and multiple shoot induction phase. Peroxidase zymogram detected two stage specific bands, one band (Rm 0.42) was specific to root induction phase, while another (Rm 0.761) was specific to multiple shoot induction. Catalase and acid phosphatase zymogram resolved one band (Rm 0.752 and 0.435, respectively) in differentiated stages including both multiple shoot induction phase and root induction phase, but absent in undifferentiated phases.     

Changes in the chlorophyll fluorescence characteristics of chloroplasts from intact pumpkin cotyledons, caused by organ excision and kinetin treatment

The chlorophyll (Chl) fluorescence emission as well as excitation and polarization characteristics of chloroplasts from intact cotyledons were determined in pumpkin seedlings after removal of one cotyledon (co-cotyledon) or apical bud or primary root, or after kinetin treatment of derooted seedlings. Qualitatively, the fluorescence emission and excitation spectra of chloroplasts were similar. The fluorescence emission spectra showed a maximum at 685 (F685) and a hump at 735 nm (F735), whereas the excitation spectra showed peaks at 439, 471, 485, and 676 nm. The fluorescence intensities at F685 and F735 differed in various groups of seedlings, as indicated by changes in their ratios. Similarly, the ratios of 471/439, 485/439, and 676/439 nm were also different. Variability in the Chl fluorescence intensity values and the fluorescence polarization of chloroplasts prepared from various seedling types may suggest a different degree of binding between the pigment complexes and light-harvesting Chl-protein (LHCP), resulting in different rates of photoexcitation energy loss in the form of fluorescence emission. Kinetin treatment improved the coupling of pigment complexes with reaction centre, as indicated by low polarization values in derooted and kinetin-treated seedlings, which suggests the development of a suntype chloroplast. This revised version was published online in June 2006 with corrections to the Cover Date.     

A unified model of ammonium oxidation rate at various initial ammonium strength and active ammonium oxidizer concentrations

This paper attempts to provide insight into the biological ammonium oxidation process applied to high-strength ammonium wastewater treatment. The ammonium oxidation process has been investigated at various ammonium and biomass concentrations. Using the oxygen uptake rate (OUR) method, a proportion of both active ammonium oxidizers (AAO) and nitrite oxidizers to the total suspended solids were separately estimated, and then tested to normalize the ammonium oxidation rate at various ammonium strengths and AAO concentrations. High-ammonium strength showed no significant inhibition to ammonium oxidation due to high-AAO concentration. It was demonstrated that the key factor deciding the specific ammonium oxidation rate was the ratio of ammonium concentration to the active nitrifiers (AN) concentration, but not the sole-variable such as initial ammonium concentration and AN concentration. Contois model was screened to suitably fit the ammonium oxidation kinetics under the high-ammonium loading condition, resulting in a half-saturation constant of 0.028 mg N mg^?1 AAO and a maximum specific ammonium oxidation rate of 3.56 g N g^?1 AAO d^?1.