Public Relations, Law, and Environmental Pollution

In public relations, however, the relationship is a complementary one, in which the law acts as the formulator of the rules of society and public relations serves as the interpreter of them to the people. Beyond that, public relations often can support the law by creating an atmosphere in which the law can more effectively perform its function of protecting the people and preserving the health of society. Perhaps nowhere is this more evident than in the area of air and water pollution control

Evaluation of microscopic techniques to observe iron precipitation in a natural microbial biofilm

Iron biomineralization in a microbial biofilm consortium from Canadian Shield groundwaters has been investigated with different microscopic techniques. The advantages and disadvantages of the different methods of observing a biofilm growing on an opaque mineral surface are discussed. Scanning electron microscopy was able to show the initial attachment and dispersion of bacteria on the mineral surfaces, whereas transmission electron microscopy gave greater detail and revealed the precise location of the iron precipitation on cell surfaces, including S-layers, and also throughout the extrapolymeric slime of the biofilm. Episcopic Nomarski differential interference contrast microscopy allowed direct observation of biofilm dynamics and confirmed the precipitation of iron directly onto certain bacteria, which were then specifically ingested by protozoa. This novel ingestion of iron-coated bacteria by protozoans essentially eliminated iron from solution and trapped it within the biofilm. Over time in the natural environment, this iron, enmeshed within a biofilm, may become incorporated into iron-rich sediments

Erratum to: Correlations between [superscript 11]B NMR parameters and structural characters in borate and borosilicate minerals investigated by high-resolution MAS NMR and ab initio calculations

Unfortunately, four authors were inadvertently not included in the author group/affiliation of the original publication. The complete authors group should read as:Natural Sciences and Engineering Research Council of Canada (Post-graduate Scholarship

¹¹B MAS NMR and First-Principles Study of the [OBO₃] Pyramids in Borates

Borates are built from the [Bϕ₃] planar triangles and the [Bϕ₄] tetrahedral groups, where ϕ denotes O or OH. However, the [Bϕ₄] groups in some borates are highly distorted to include three normal B–O bonds and one anomalously long B–O bond and, therefore, are best described as the [OBO₃] pyramids. Four synthetic borates of the boracite-type structures (Mg₃B₇O₁₃Br, Cu₃B₇O₁₃Br, Zn₃B₇O₁₃Cl, and Mg₃B₇O₁₃Cl) containing a range of [OBO₃] pyramids were investigated by multifield (7.05, 14.1, and 21.1 T) ¹¹B magic-angle spinning nuclear magnetic resonance (MAS NMR), triple quantum (3Q) MAS NMR experiments, as well as density functional theory calculations. The high-resolution ¹¹B MAS NMR spectra supported by theoretical predictions show that the [OBO₃] pyramids are characterized by isotropic chemical shifts δ_iso(¹¹B) from 1.4(1) to 4.9(1) ppm and nuclear quadrupole parameters <i>C</i>_Q(¹¹B) up to 1.3(1) MHz, both significantly different from those of the [BO₄] and [BO₃] groups in borates. These δ_iso(¹¹B) and <i>C</i>_Q(¹¹B) values indicate that the [OBO₃] pyramids represent an intermediate state between the [BO₄] tetrahedra and [BO₃] triangles and demonstrate that the ¹¹B NMR parameters of four-coordinate boron oxyanions are sensitive to local structural environments. The orientation of the calculated unique electronic field gradient tensor element <i>V</i>_<i>zz</i> of the [OBO₃] pyramids is aligned approximately along the direction of the anomalously long B–O bond, corresponding to B-2p_<i>z</i> with the lowest electron density