bStreptococcal pathogens, such as the group B streptococcus (GBS) Streptococcus agalactiae, are an important cause of systemic disease, which is facilitated in part by the presence of a polysaccharide capsule. The CpsA protein is a putative transcriptional regulator of the capsule locus, but its exact contribution to regulation is unknown. To address the role of CpsA in regulation, full-length GBS CpsA and two truncated forms of the protein were purified and analyzed for DNA-binding ability. Assays demonstrated that CpsA is able to bind specifically to two putative promoters within the capsule operon with similar affinity, and full-length protein is required for specificity. Functional characterization of CpsA confirmed that the ⌬cpsA strain produced less capsule than did the wild type and demonstrated that the production of full-length CpsA or the DNA-binding region of CpsA resulted in increased capsule levels. In contrast, the production of a truncated form of CpsA lacking the extracellular LytR domain (CpsA-245) in the wild-type background resulted in a dominant-negative decrease in capsule production. GBS expressing CpsA-245, but not the ⌬cpsA strain, was attenuated in human whole blood. However, the ⌬cpsA strain showed significant attenuation in a zebrafish infection model. Furthermore, chain length was observed to be variable in a CpsA-dependent manner, but could be restored to wild-type levels when grown with lysozyme. Taken together, these results suggest that CpsA is a modular protein influencing multiple regulatory functions that may include not only capsule synthesis but also cell wall associated factors.

Po and 210 Pb assay in the oceanThe 210 Pb (t 1/2 = 22.3 y) and 210 Po (t 1/2 = 138 d) parent and granddaughter radionuclide pair has proven to be effective tracers of oceanographic processes. Studies of particulate and dissolved 210 Po and 210 Pb in the marine environment have been used for quantifying the scavenging and removal of particle-reactive species including organic carbon integrated over sub-annual time scales not attainable by direct measurement synthesized in Verdeny et al. (2009).The GEOTRACES (Geochemical Trace Element/Isotope Studies) program has been initiated to study trace elements and isotopes (TEIs) and to quantify processes across major ocean boundaries. The 210 Po and 210 Pb radionuclide pair is a useful suite of radiometric TEIs that are both geochemically (e.g., Pb) and biochemically (e.g., Po) active. Thus these isotopes complement the other particle reactive nuclides operating on comparable time scales (e.g., 234 Th, 228 Th) included in GEOTRACES. As such, 210 Po and 210 Pb were identified as priority tracers by the U.S. GEOTRACES Scientific Steering Committee in their "Principles and Pri- Pb in seawater aliquots distributed between up to eight international laboratories that followed individual protocols. Dissolved and particulate samples were provided by GEOTRACES during two IC cruises at baseline stations in the North Atlantic and North Pacific oceans. Included were surface and/or deep dissolved and particulate samples at each site, plus complete profiles analyzed by the laboratory of the lead author. An unspecified solid phase standard was also distributed with Po activities reported n = 8) for the standard were very similar with a relative standard deviation (RSD) of 3.6% and mean value indistinguishable from the certified value, confirming accurate calibration of Po spikes. For seawater samples, the agreement was strongly dependent for both nuclides on the activity of the samples. The agreement was relatively good for dissolved seawater samples (RSD = 9% to 29%, n = 4), moderate for the particulate samples (RSD = 12% to 80%, n = 8), and poor for particulate dip blanks (RSD = 50% to 200%, n = 8). Noted is the higher apparent affinity of 210 Po versus 210 Pb for polysulphone filter material. Some lack of reproducibility between labs may have been caused by unspecified differences in individual lab protocols and calculations. A minimum sample activity of 0.1 dpm for both nuclides is recommended for an adequate reproducible sample activity. It is suggested that a consistent set of procedures and calculations be used to optimize future 210 Po and 210 Pb analyses in seawater samples.

The composition and the organization of soil are changing rapidly by the diverged mankind activities, leading to the contamination of environment. Several methods are employed to clean up the environment from these kinds of contaminants, but most of them are costly and ineffective to yield optimum results. Phytoremediation is a natural green technology, which is eco-friendly for the removal of toxic metals from the polluted environment. Phytoremediation is a cost-effective technique through which the cleanup of contaminated soil laced with heavy metals is performed by wild weeds and small herbal plants. The phytoremediation technique provides a promising tool for hyperaccumulation of heavy metals; arsenic, lead, mercury, copper, chromium, and nickel, etc., by the wild weeds and that has been discussed here in detail in case of Cannabissativa, Solanum nigrum and Rorippa globosa. In general, weeds that have the intrinsic capacity to accumulate metals into their shoots and roots, have the ability to form phytochelates and formation of stable compound with ions. This behavior of accumulation along with chelate and stable compound formation is utilized as a tool for phytoremediation activity.

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Suspended particulate matter in the sea is composed of terrestrial material, derived from the upper continental crust, primarily delivered from discharges of rivers and streams and atmospheric deposition, biogenic material (e.g., opal, calcium carbonate, and organics) formed both in the marine and terrestrial environments, and authigenic minerals formed within the sea. The formation, transport, decomposition, dissolution, burial, and ultimate fate of the biogenic particulate matter is primarily controlled by physico-chemical and ecological parameters such as nutrients, light, temperature, upwelling, food chain dynamics, which in turn could be affected by the changing global climate. The biogeochemical dynamics of particulate matter controls scavenging, cycling, and transport of the so-called GEOTRACES particle-reactive Trace Elements and Isotopes (TEIs) in the marine environment. Understanding the behavior of particle-reactive TEIs in the sea requires accurate determination of their dissolved and particulate concentrations.Separation of the particulate matter for the determination of radionuclides concentration (activity) from the seawater involves seawater sampling and filtration through a finite