Links between Phytoplankton and Bacterial Community Dynamics in a Coastal Marine Environment

Bacteria and phytoplankton dynamics are thought to be closely linked in coastal marine environments, with correlations frequently observed between bacterial and phytoplankton biomass. In contrast, little is known about how these communities interact with each other at the species composition level. The purpose of the current study was to analyze bacterial community dynamics in a productive, coastal ecosystem and to determine whether they were related to phytoplankton community dynamics. Near-surface seawater samples were collected in February, May, July, and September 2000 from several stations in the Bay of Fundy. Savin et al. (M.C. Savin et al., Microb Ecol 48: 51-65) analyzed the phytoplankton community in simultaneously collected samples. The attached and free-living bacterial communities were collected by successive filtration onto 5 m and 0.22 m pore-size filters, respectively. DNA was extracted from filters and bacterial 16S rRNA gene fragments were amplified and analyzed by denaturing gradient gel electrophoresis (DGGE). DGGE revealed that diversity and temporal variability were lower in the free-living than the attached bacterial community. Both attached and free-living communities were dominated by members of the Roseobacter and Cytophaga groups. Correspondence analysis (CA) ordination diagrams showed similar patterns for the phytoplankton and attached bacterial communities, indicating that shifts in the species composition of these communities were linked. Similarly, canonical CA revealed that the diversity, abundance, and percentage of diatoms in the phytoplankton community accounted for a significant amount of the variability in the attached bacterial community composition. In contrast, ordination analyses did not reveal an association between free-living bacteria and phytoplankton. These results suggest that there are specific interactions between phytoplankton and the bacteria attached to them, and that these interactions influence the composition of both communities.     

Building a Comprehensive Mill-Level Database for the Industrial Sectors Integrated Solutions (ISIS) Model of the U.S. Pulp and Paper Sector

Air emissions from the U.S. pulp and paper sector have been federally regulated since 1978; however, regulations are periodically reviewed and revised to improve efficiency and effectiveness of existing emission standards. The Industrial Sectors Integrated Solutions (ISIS) model for the pulp and paper sector is currently under development at the U.S. Environmental Protection Agency (EPA), and can be utilized to facilitate multi-pollutant, sector-based analyses that are performed in conjunction with regulatory development. The model utilizes a multi-sector, multi-product dynamic linear modeling framework that evaluates the economic impact of emission reduction strategies for multiple air pollutants. The ISIS model considers facility-level economic, environmental, and technical parameters, as well as sector-level market data, to estimate the impacts of environmental regulations on the pulp and paper industry. Specifically, the model can be used to estimate U.S. and global market impacts of new or more stringent air regulations, such as impacts on product price, exports and imports, market demands, capital investment, and mill closures. One major challenge to developing a representative model is the need for an extensive amount of data. This article discusses the collection and processing of data for use in the model, as well as the methods used for building the ISIS pulp and paper database that facilitates the required analyses to support the air quality management of the pulp and paper sector.     

The occurrence of caulonema-specific proteins in different moss species

Soluble proteins extracted with Tris-buffer pH 8.8 from different mosses are analysed by microgelelectrophoretic method for comparison to the specific proteins present only in the caulonema of Funaria hygrometrica. The protein patterns are also compared with those of liverwort, fern gametophytes and sporophytes and tobacco. It is observed that the caulonema specific proteins are only present in the caulonema of these mosses and are absent in other plants.Abbreviations CSP caulonema specific proteins     

Direct rooting and hardening of tea microshoots in the field

Micropropagation of tea (Camellia sinensis (L.) O. Kuntze) has been widely attempted but commercial exploitation of this method is limited by heavy losses during the hardening procedures. In the present study, optimization of time of harvesting (spring and early summer) of microshoots, shoot size, soil pH (4.0–6.4), plant growth regulator treatment (IBA; 500 mg l^-1, 30 min) CO₂ (9.09/10×10⁻⁵ mol l^-1 to 10.22/10×10^-5 mol l^-1 and 20/11×10⁻⁵ mol l^-1 to 80/13×10⁻⁷ mol l^-1) enrichment and light (15 μ mol m^-2 s^-1) conditions in specially designed hardening chambers, made a significant impact on the percent of success for hardening. Following the standardized procedure, up to 71.6% root induction and 73% survival could be achieved. Successful field transfer was also accomplished. This revised version was published online in June 2006 with corrections to the Cover Date.     

Selective cytotoxicity of Pancratistatin-related natural <Emphasis Type="Italic">Amaryllidaceae</Emphasis> alkaloids: evaluation of the activity of two new compounds

Background  

Pancratistatin (PST), a compound extracted from an Amaryllidaceae (AMD) family plant, has been shown to specifically induce apoptosis in cancer cells with no/minimal toxic effect on normal cells. A systematic synthetic approach has indicated that the minimum cytotoxic pharmacophore comprises the trans-fused b/c-ring system containing the 2, 3, 4-triol unit in the C-ring. To further explore the structure-activity relationship of this group of compounds we have investigated the anti-cancer efficacy and specificity of two PST-related natural compounds, AMD4 and AMD5. Both of these compounds lack the polyhydroxylated lycorane element of PST instead having a methoxy-substuituted crinane skeleton.     

Chemoarchitectonics of metencephalon of Testudo elegant

Histoenzymological study of acid phosphatase (GP-AI), 5-nucleotidase (AMP-A), adenosine triphosphatase (ATP-A) and beta-galactosidase (GLAC-A) of the metencephalon of turtle shows a pattern of distribution of enzymes similar to amphibians and mammalian metencephalon which provides indication of homology of the nuclei and tracts such as nucleus raphe, nuclei cerebelli fasciculus longitudinalis medialis, commissura ansulata and internal arcuate fibers. The nerve fibers, tracts and commissures demonstrate strong activity of GLAC-A as demonstrated in frog and bat by the author in previous studies.     

Interactions in human casein systems: self-association of nonphosphorylated human beta-casein

Since caseins were originally defined as phosphoproteins, nonphosphorylated beta-casein, comprising nearly 5% of the total beta-casein in the isoelectric precipitate from human milk, appears to be unique. Despite the relatively small amount present, its properties suggest that it may play an important role in micelle formation and structure. It has a partial specific volume, v, of 0.749 +/- 0.008 and an absorbance, E1% 1 cm,280 nm of 6.2 +/- 0.2. Sedimentation and viscosity data yield a solvation of 3 g H2O/g protein and an axial ratio of about 5 for the monomer. This would be consistent with a prolate ellipsoid of 10 nm length and 2 nm width. Equilibrium in the system is attained quite slowly and the temperature-dependent polymerization was found to be reversible. With calcium, the solubility behavior reflects an increased hydrophobicity and lower electrostatic repulsion in the molecule. There is essentially no strong calcium binding to this protein but there is evidence which strongly suggests that calcium binds to nonphosphate groups at higher concentrations. Increasing the temperature from 4 to 37 degrees C causes an apparent conformational change and an increase in protein aggregation which is further increased by addition of NaCl at 37 degrees C until a limiting size is reached at about 0.1 M NaCl. This limiting size polymer contains about 75 monomers and is nearly spherical with a radius of about 12 nm and a solvation of 1.5 g H2O/g protein. Laser light scattering measurements on the solution in 0.25 M NaCl revealed a relatively homogeneous particle size with a corrected diffusion coefficient, D20,w, of 2.8 X 10(-7) cm2/s.