Consideration of the bioavailability of metal/metalloid species in freshwaters: experiences regarding the implementation of biotic ligand model-based approaches in risk assessment frameworks

After the scientific development of Biotic Ligand Models (BLMs) in recent decades these models are now considered suitable for implementation in regulatory risk assessment of metals in freshwater bodies. The approach has been developed over several years and has been described in many peer-reviewed publications. The original complex BLMs have been applied in prospective risk assessment reports for metals and metal compounds and are also recommended as suitable concepts for the evaluation of monitoring data in the context of the European Water Framework Directive. Currently, several user-friendly BLM-based bioavailability software tools are available for assessing the aquatic toxicity of a limited number of metals (mainly copper, nickel, and zinc). These tools need only a basic set of water parameters as input (e.g., pH, hardness, dissolved organic matter and dissolved metal concentration). Such tools seem appropriate to foster the implementation in routine water quality assessments. This work aims to review the existing bioavailability-based regulatory approaches and the application of available BLM-based bioavailability tools for this purpose. Advantages and possible drawbacks of these tools (e.g., feasibility, boundaries of validity) are discussed, and recommendations for further implementation are given

Global occurrence, chemical properties, and ecological impacts of e-wastes (IUPAC technical report)

The waste stream of obsolete electronic equipment grows exponentially, creating a worldwide pollution and resource problem. Electrical and electronic waste (e-waste) comprises a heterogeneous mix of glass, plastics (including flame retardants and other additives), metals (including rare earth elements) and metalloids. The e-waste issue is complex and multi-faceted. In examining the different aspects of e-waste, informal recycling in developing countries has been identified as a primary concern due to widespread illegal shipments, weak environmental as well as health and safety regulations, lack of technology and inadequate waste treatment structure. For example, Nigeria, Ghana, India, Pakistan and China have all been identified as hotspots for the disposal of e-waste. This article presents a critical examination on the chemical nature of e-waste and the resulting environmental impacts on, for example, microbial biodiversity, flora and fauna in e-waste recycling sites around the world. It highlights the different types of risk assessment approaches required when evaluating the ecological impact of e-waste. Additionally, it presents examples of chemistry playing a role in potential solutions. The information presented here will be informative to relevant stakeholders to devise integrated management strategies to tackle this global environmental concern

Consideration of the bioavailability of metal/metalloid species in freshwaters: experiences regarding the implementation of biotic ligand model-based approaches in risk assessment frameworks

After the scientific development of Biotic Ligand Models (BLMs) in recent decades these models are now considered suitable for implementation in regulatory risk assessment of metals in freshwater bodies. The approach has been developed over several years and has been described in many peer-reviewed publications. The original complex BLMs have been applied in prospective risk assessment reports for metals and metal compounds and are also recommended as suitable concepts for the evaluation of monitoring data in the context of the European Water Framework Directive. Currently, several user-friendly BLM-based bioavailability software tools are available for assessing the aquatic toxicity of a limited number of metals (mainly copper, nickel, and zinc). These tools need only a basic set of water parameters as input (e.g., pH, hardness, dissolved organic matter and dissolved metal concentration). Such tools seem appropriate to foster the implementation in routine water quality assessments. This work aims to review the existing bioavailability-based regulatory approaches and the application of available BLM-based bioavailability tools for this purpose. Advantages and possible drawbacks of these tools (e.g., feasibility, boundaries of validity) are discussed, and recommendations for further implementation are given

Dream On, Amber

https://stars.library.ucf.edu/diversefamilies/1970/thumbnail.jp

Dara Palmer\u27s Major Drama

https://stars.library.ucf.edu/diversefamilies/1679/thumbnail.jp

Patients with Laron syndrome are protected from development of cancer even if treated with IGF-I

In accordance with the link between increased GH and IGF-I secretion and cancer, we found that homozygous patients with Laron syndrome (severe GH insensitivity) and low to undetectable serum IGF-I are protected from developing cancer even if treated with IGF-I to enhance linear growth

Biochemical characterization of TGÃ1, a plant heterotrimeric G-protein à subunit homologue

grantor: University of TorontoA cDNA encoding an $\alpha$ subunit homologue of a heterotrimeric G-protein in tomato (TGA1) was overexpressed in Escherichia coli as a GST fusion protein and purified by glutathione affinity. The molecular weight of the purified protein (TG$\alpha$1), after thrombin proteolysis to release the GST fragment, was 45 kDa. Assays using ($\gamma$-\sp{32}P) -GTP determined the K\sb{cat} value of GTP hydrolysis (0.075-0.125 min\sp{-1}) while no hydrolysis was detected when ($\gamma$-\sp{32}P) -ATP was used as an alternative nucleotide. A conserved glutamine residue in position 223 was shown to regulate GTP hydrolysis by the enzyme. A point mutation in Q223 $\to$ L resulted in a GTPase-deficient enzyme, capable of binding GTP but with an extremely slow rate of hydrolysis. Polyclonal antibodies were raised using TG$\alpha$1 as an antigen and used for its subcellular localization. Immunoblot analysis using the affinity-purified anti-TG$\alpha$1 antibody detected a 45 kDa protein most abundantly in the plasma membrane and endoplasmic reticulum. The stimulation of the plasma membrane H\sp+-ATPase in response to mastoparan was inhibited by the use of synthetic peptides corresponding to the C-terminus of TG$\alpha$1. This suggests the coupling of TG$\alpha$1 to a seven-transmembrane spanning receptor in plants with its C-terminus as a receptor-G-protein contact. An immunologically-based interactive cloning screen identified an interaction between TG$\alpha$1 and a DnaJ-like protein. This interaction may represent a role for TG$\alpha$1 in regulation of polypeptide translocation into the ER; a mechanism for its processing and targeting; or a mechanism for its stabilization under stress responses.M.Sc