Microbial mineralization of organic phosphate in soil

Summary Phosphate-dissolving microorganisms were isolated from non-rhizosphere and rhizosphere of plants. These isolates included bacteria, fungi and actinomycetes. In broth cultures, Gram-negative short rod,Bacillus andStreptomyces species were found to be more active in solubilizing phosphate thanAspergillus, Penicillium, Proteus, Serratia, Pseudomonas andMicrococcus spp. The sterile soils mixed with isolated pure culture showed slower mineralization of organic phosphate than that of non-sterile soil samples at all incubation periods. Maximum amount of phosphate mineralization by isolated microorganisms were obtained at the 60th and the 75th day of incubation in sterile and non-sterile soils respectively. The mixed cultures were most effective in mineralizing organic phosphate and individuallyBacillus sp. could be ranked next to mixed cultures. Species ofPseudomonas andMicrococcus were almost the same as that of the control under both sterile and non-sterile conditions.     

An Eye-Shaped Ultra-Sensitive Localized Surface Plasmon Resonance–Based Biochemical Sensor

Plasmonics - This research illustrates a parametric study based on surface plasmon resonance of a slightly gold-coated photonic crystal fiber (PCF). In verifying sensing accuracy, the proposed...     

Use of polyethylenimine-adenovirus complexes to examine triplex formation in intact cells

Triplex-forming oligonucleotides (TFOs) show potential for sequence-specific DNA binding and inhibition of gene expression. We have applied this antigene strategy using a TFO incorporating an Auger-emitting radionucleotide, 125I, to study the production of double-strand breaks (dsb) in the rat aquaporin 5 (rAQP5) cDNA. 125I-TFO bound to the pCMVrAQP5 plasmid in vitro in a dose-dependent manner and formed stable triplexes up to 65 degrees C and in the presence of 140 mM KCl. Further, 125I-TFO resulted in a predictable dsb when analyzed by Southern hybridization. To deliver TFOs to epithelial cells, we employed 125I-TFO-polyethyleneimine-adenovirus (125I-TFO-PEI-Ad) complexes. We hypothesized that these complexes would take advantage of adenoviral characteristics to transfer 125I-TFO to the cell nucleus. Adenovirus-containing complexes brought about greater uptake and nuclear localization of TFOs compared with delivery with 125I-TFO-PEI complexes alone. No significant degradation of 125I-TFO was found after delivery into cells using PEI-Ad complexes and freezing and thawing. We next used PEI-Ad complexes to deliver 125I-TFO and pCMVrAQP5 separately to epithelial cells to determine if triplexes can form de novo within cells, resulting in the specific dsb in the rAQP5 cDNA. After delivery, cell pellets were stored at -80 degrees C for more than 60 days. Thereafter, plasmid DNA was isolated from cells and analyzed for dsb by Southern hybridization. However, none were detected. We conclude that under the experimental conditions employed, effective triplexes, with 125I-TFO and pCMVrAQP5, do not form de novo inside cells.     

A Qualitative Stakeholder Analysis of Avian Influenza Policy in Bangladesh

Avian influenza is a major animal and public health concern in Bangladesh. A decade after development and implementation of the first national avian influenza and human pandemic influenza preparedness and response plan in Bangladesh, a two-stage qualitative stakeholder analysis was performed in relation to the policy development process and the actual policy. This study specifically aimed to identify the future policy options to prevent and control avian influenza and other poultry-related zoonotic diseases in Bangladesh. It was recommended that the policy should be based on the One Health concept, be evidence-based, sustainable, reviewed and updated as necessary. The future policy environment that is suitable for developing and implementing these policies should take into account the following points: the need to formally engage multiple sectors, the need for clear and acceptable leadership, roles and responsibilities and the need for a common pool of resources and provision for transferring resources. Most of these recommendations are directed towards the Government of Bangladesh. However, other sectors, including research and poultry production stakeholders, also have a major role to play to inform policy making and actively participate in the multi-sectoral approach.     

Cholinergic receptor-mediated differential cytoskeletal recruitment of actin- and integrin-binding proteins in intact airway smooth muscle

We tested the hypothesis that cholinergic receptor stimulation recruits actin- and integrin-binding proteins from the cytoplasm to the cytoskeleton-membrane complex in intact airway smooth muscle. We stimulated bovine tracheal smooth muscle with carbachol and fractionated the tissue homogenate into pellet (P) and supernatant (S) by ultracentrifugation. In unstimulated tissues, calponin exhibited the highest basal P-to-S ratio (P/S; 2.74 ± 0.47), whereas vinculin exhibited the lowest P/S (0.52 ± 0.09). Cholinergic receptor stimulation increased P/S of the following proteins in descending order of sensitivity: -actinin > talin metavinculin > -smooth muscle actin > vinculin calponin. Carbachol induced ERK1/2 phosphorylation by 300% of basal value. U0126 (10 µM) completely inhibited carbachol-induced ERK1/2 phosphorylation but did not significantly affect the correlation between -actinin P/S and carbachol concentration. This observation indicates that cytoskeletal/membrane recruitment of -actinin is independent of ERK1/2 mitogen-activated protein kinase activation. Metavinculin and vinculin are splice variants of a single gene, but metavinculin P/S was significantly higher than vinculin P/S. Furthermore, the P/S of metavinculin but not vinculin increased significantly in response to cholinergic receptor stimulation. Calponin and -actinin both belong to the family of calponin homology (CH) domain proteins. However, unlike -actinin, the calponin P/S did not change significantly in response to cholinergic receptor stimulation. These findings indicate differential cytoskeletal/membrane recruitment of actin- and integrin-binding proteins in response to cholinergic receptor stimulation in intact airway smooth muscle. -Actinin, talin, and metavinculin appear to be key cytoskeletal proteins involved in the recruitment process. actinin; mitogen-activated protein kinase; metavinculin; vinculin     

Cohesin defects lead to premature sister chromatid separation,kinetochore dysfunction,and spindle-assembly checkpoint activation

Scc1/Mcd1 is a component of the cohesin complex that plays an essential role in sister chromatid cohesion in eukaryote cells. Knockout experiments of this gene have been described in budding yeast, fission yeast, and chicken cells, but no study has been reported on human Scc1 thus far. In this study, we found that an N-terminally truncated human Scc1 shows a dominant-negative effect, and we examined the phenotypes of human cells defective in Scc1 function. Scc1 defects led to failure of sister chromatid cohesion in both interphase and mitotic cells. Interestingly, four chromatids derived from two homologues occupied four distinct territories in the nucleus in chromosome painting experiments. In mitotic Scc1-defective cells, chromatids were disjoined with normal condensation, and the spindle-assembly checkpoint was activated. We also found that, although the disjoined kinetochore (half-kinetochore) in Scc1-defective cells contains CENP-A, -B, -C, and -E normally, it apparently does not establish the kinetochore-microtubule association. These results indicate that Scc1 is essential for the association of kinetochores with microtubules.