Predictive Ecological Modeling of Harmful Algal Blooms

We have thus far constructed a series of coupled ecological/physical models to predict the origin and fate of harmful algal blooms of the toxic dinoflagellate, Gymnodinium breve, on the West Florida shelf. We find that (1) the maximal population growth rate of G. breve must be ～0.80 day^?1 during initiation of a red tide, but as little as 0.08 day^?1 during its decay, (2) diatoms dominate when estuarine and shelf-break supplies of nitrate are made available to a model community of small and large diatoms, coccoid cyanophytes and Trichodesmium, non-toxic and red-tide dinoflagellates, microflagellates, and coccolithophores, (3) a numerical recipe for large red tides of G. breve requires DON supplies, mediated by iron-starved, nitrogen-fixers, while small blooms may persist on sediment sources of DON, (4) selective grazing must be exerted on the non-toxic dinoflagellates, and (5) vertical migration of G. breve in relation to seasonal changes of summer downwelling and fall/winter upwelling flow fields determines the duration and intensity of red tide landfalls along the barrier islands and beaches of the west coast of Florida, once other losses are specified. Given poorly known initial and boundary conditions and the expense of shipboard monitoring programs, however, bio-optical moorings or remote sensors are the most likely sources of model validation and improved HAB forecasts. Accordingly, the bio-optical implications of our ecological models must be included in future simulation analyses of HABs on both the West Florida shelf and within other coastal regions. Of particular importance for initiation of the coupled biophysical models is an improved understanding of the relationship of remotely sensed surface signals to shade-adapted dinoflagellates, aggregating below the first optical depth of the water column.     

Water quality assessment of the Siluko River,southern Nigeria

The water quality of the Siluko River, Edo State, Nigeria was investigated from March to August 2015 to determine its suitability for drinking and usage for domestic purposes. Water samples collected from three stations were tested for thirteen physico-chemical parameters using standard analytical procedures. Temperature, phosphate and chloride were significantly different across the three stations. All other parameters, with the exception of turbidity, dissolved oxygen and phosphate, were within the permissible limits recommended by the Nigerian Standard for Drinking Water Quality (NSDWQ) and World Health Organization (WHO). Water Quality Index (WQI) values ranged from 11.24 to 16.15, indicating excellent water quality. While the quality of the water from the Siluko River is suitable for drinking and domestic usage, to prevent future deterioration of the water, it is recommended that the regulating authorities monitor effluents discharged into the river from human activities.     

Determination of the antidepressant levoprotiline and its N-desmethyl metabolite in biological fluids by gas chromatography/mass spectrometry.

A specific and sensitive gas chromatographic/mass spectrometric method was developed and validated for the determination of the antidepressant levoprotiline in blood, plasma and urine and the simultaneous determination of levoprotiline and its desmethyl metabolite in urine. Deuterium-labelled analogues were used as internal standards. The compounds were isolated from the biological fluids by liquid-liquid extraction under basic conditions. Following derivatization with perfluoropropionic anhydride, the samples were analysed by capillary column gas chromatography/electron impact mass spectrometry with selected ion monitoring. The analysis of spiked samples demonstrated the high accuracy and precision of the method. Blood concentrations of levoprotiline down to 0.7 nmol l-1 (1 ml used for analysis) could be quantified with a coefficient of variation of 10% or less. The method is suitable for use in pharmacokinetic and bioavailability studies of levoprotiline in humans.     

Arabidopsis LIM Proteins: A Family of Actin Bundlers with Distinct Expression Patterns and Modes of Regulation

Recently, a number of two LIM-domain containing proteins (LIMs) have been reported to trigger the formation of actin bundles, a major higher-order cytoskeletal assembly. Here, we analyzed the six Arabidopsis thaliana LIM proteins. Promoter-β-glucuronidase reporter studies revealed that WLIM1, WLIM2a, and WLIM2b are widely expressed, whereas PLIM2a, PLIM2b, and PLIM2c are predominantly expressed in pollen. LIM-green fluorescent protein (GFP) fusions all decorated the actin cytoskeleton and increased actin bundle thickness in transgenic plants and in vitro, although with different affinities and efficiencies. Remarkably, the activities of WLIMs were calcium and pH independent, whereas those of PLIMs were inhibited by high pH and, in the case of PLIM2c, by high [Ca²⁺]. Domain analysis showed that the C-terminal domain is key for the responsiveness of PLIM2c to pH and calcium. Regulation of LIM by pH was further analyzed in vivo by tracking GFP-WLIM1 and GFP-PLIM2c during intracellular pH modifications. Cytoplasmic alkalinization specifically promoted release of GFP-PLIM2c but not GFP-WLIM1, from filamentous actin. Consistent with these data, GFP-PLIM2c decorated long actin bundles in the pollen tube shank, a region of relatively low pH. Together, our data support a prominent role of Arabidopsis LIM proteins in the regulation of actin cytoskeleton organization and dynamics in sporophytic tissues and pollen.     

Enhanced glutamate,IP3 and cAMP activity in the cerebral cortex of Unilateral 6-hydroxydopamine induced Parkinson's rats: Effect of 5-HT,GABA and bone marrow cell supplementation

Parkinson's disease is characterized by progressive cell death in the substantia nigra pars compacta, which leads to dopamine depletion in the striatum and indirectly to cortical dysfunction. Increased glutamatergic transmission in the basal ganglia is implicated in the pathophysiology of Parkinson's disease and glutamate receptor mediated excitotoxicity has been suggested to be one of the possible causes of the neuronal degeneration. In the present study, the effects of serotonin, gamma-aminobutyric acid and bone marrow cells infused intranigrally to substantia nigra individually and in combination on unilateral 6-hydroxydopamine induced Parkinson's rat model was analyzed. Scatchard analysis of total glutamate and NMDA receptor binding parameters showed a significant increase in B_max (P < 0.001) in the cerebral cortex of 6-hydroxydopamine infused rat compared to control. Real Time PCR amplification of NMDA2B, mGluR5, bax, and ubiquitin carboxy-terminal hydrolase were up regulated in cerebral cortex of 6-hydroxydopamine infused rats compared to control. Gene expression studies of GLAST, ά-Synuclien and Cyclic AMP response element-binding protein showed a significant (P < 0.001) down regulation in 6-OHDA infused rats compared to control. Behavioural studies were carried out to confirm the biochemical and molecular studies. Serotonin and GABA along with bone marrow cells in combination showed reversal of glutamate receptors and behaviour abnormality shown in the Parkinson's rat model. The therapeutic significance in Parkinson's disease is of prominence.