Simultaneous PIV/LIF measurements of a transitional buoyant plume above a horizontal cylinder

Results from an experimental investigation of the simultaneous temperature and velocity fields above an evenly heated horizontal cylinder with a Rayleigh number of 9.4E7 is presented. Ensemble averaged two-dimensional velocity and temperature fields, velocity fluctuations, temperature variance, and velocity–temperature correlations are computed from 2700 instantaneous data sets from simultaneous laser-induced fluorescence (LIF) and particle image velocimetry (PIV). The vertical velocity and temperature field in the plume are compared with similarity solutions from turbulent planar plumes. The production of turbulent kinetic energy (TKE) due to mean shear and buoyancy is evaluated and shows that the production of TKE is dominated by velocity shear.     

Anti-oxidant capacities of flavonoid compounds isolated from acai pulp (Euterpe oleracea Mart.)

Acai fruit (Euterpe oleracea Mart.) has been demonstrated to exhibit extremely high anti-oxidant capacity. Seven major flavonoids were isolated from freeze-dried acai pulp by various chromatographic methods. Their structures were elucidated as orientin (1), homoorientin (2), vitexin (3), luteolin (4), chrysoeriol (5), quercetin (6), and dihydrokaempferol (7) by NMR, MS and compared with the reported literature. Compounds 3 and 6 were reported from acai pulp for the first time. Anti-oxidant capacities of these flavonoids were evaluated by oxygen radical absorbance capacity (ORAC) assay, cell-based anti-oxidant protection (CAP-e) assay and reactive oxygen species (ROS) formation in polymorphonuclear (PMN) cells (ROS PMN assay). ORAC values varied distinctly (1420–14,800 μmol TE/g) among the seven compounds based on numbers and positions of hydroxyl groups and/or other substitute groups. The ORAC values of aglycones are generally higher than that of glycosides. CAP-e results indicated that only three compounds (4, 6 and 7) could enter the cytosol and contribute to the reduction of oxidative damage within the cell. The ROS PMN assay showed that five compounds (2–3 and 5–7) demonstrated exceptional effects by reducing ROS formation in PMN cells, which produced high amounts of ROS under oxidative stress. In evaluating the anti-oxidant capacity of natural products, combining both chemical and cell-based assays will provide more comprehensive understanding of anti-oxidant effects and potential biological relevance.     

Towards a More Robust Evaluation of Climate Model and Hydrological Impact Uncertainties

Water Resources Management - The uncertainty of climate model projections is recognized as being large. This represents a challenge for decision makers as the simulation spread of a climate model...     

Information-Theoretic Registration with Explicit Reorientation of Diffusion-Weighted Images

Journal of Mathematical Imaging and Vision - We present an information-theoretic approach to the registration of images with directional information, especially for diffusion-weighted images...     

Testing for cross-subsidisation in the combined heat and power generation sector: A comparison of three tests

In this paper we examine cross-subsidisation among combined heat and power producers in Denmark. Information on stand-alone costs for heat generation allows us to empirically compare the Faulhaber tests, tests with an upper bound on stand-alone costs (the Palmer tests) and the fully distributed cost test (FDC). All tests indicate a substantial amount of cross-subsidisation from heat generation to power generation. It is shown that the FDC test is closer to that of the Faulhaber tests in its results than the Palmer tests. Thus as the Faulhaber tests are considered in the literature to be the theoretically correct tests, the FDC test is shown to be the best approximation for tests of cross-subsidisation for this specific sector.     

Antagonistic Interactions Mediated by Marine Bacteria: The Role of Small Molecules

Marine bacteria are known to produce a wide variety of structurally diverse and biologically active secondary metabolites. Considerably less is known about the ecological functions of these compounds, in part due to methodological challenges associated with this field of research. Here, we review the antagonistic activities mediated by marine bacteria with a focus on activities linked to structurally defined secondary metabolites. Bacterial antagonism has been documented against other marine bacteria as well as eukaryotes, and includes antibiosis, the inhibition of quorum sensing, larval settlement deterrence, and defense against predation. These compounds likely play important ecological roles that ultimately affect ecosystem structure and function, however, much remains to be learned before these roles can be fully appreciated. Recent technological advances coupled with a better understanding of the diverse processes mediated by secondary metabolites provide new opportunities to expand our understanding of the chemical ecology of bacterial antagonism in the marine environment.     

Expanded ethanol production: Implications for agriculture,water demand,and water quality

Feedstock production for large scale development of the U.S. ethanol industry and introduction of cellulose-to-ethanol technology will require extensive changes in land use and field management. Hence, this production will likely have significant impact on water demand and quality. This study compares two ‘what if’ scenarios for attaining a 227.1 hm³ of ethanol by 2030 and 3.8 hm³ of biodiesel by 2012. In the first scenario cellulose-to-ethanol technology is introduced in 2012, while in the second scenario the technology is delayed until 2015. Results show that the timing of introduction of cellulose-to-ethanol technology will affect the water use and water quality related input use in primarily in the eastern part of the nation. Results also suggest policy emphasis on reduced and no-till practices needs to be complementary to increased crop residue use.     

Modeling, chemistry, and biology of the benzolactam analogues of indolactam V (ILV). 2. Identification of the binding site of the benzolactams in the CRD2 activator-binding domain of PKCdelta and discovery of an ILV analogue of improved isozyme selectivity

Protein kinase C (PKC) is a complex enzyme system comprised of at least 11 isozymes that serves to mediate numerous extracellular signals which generate lipid second messengers. The discovery of isozyme-selective activators and inhibitors (modulators) of PKC is crucial to ascertaining the role of the individual isozymes in physiological and pathophysiological processes and to manipulating their function. The discovery of such small molecule modulators of PKC is at present a largely unmet pharmacological need. Herein we detail our modeling studies which reveal how the natural product indolactam V (ILV) and its 8-membered ring analogue, the benzolactam 15, bind to the CRD2 activator domain of PKC. These modeling studies reveal that not all PKC ligands possess a common pharmacophore, and further suggest an important role of specific hydrophobic contacts in the PKC-ligand interaction. The modeling studies find strong experimental support from mutagenesis studies on PKC alpha that reveal the crucial role played by the residues proline 11, leucine 20, leucine 24, and glycine 27. Next, we describe the synthesis of two 8-substituted benzolactams starting from L-phenylalanine and characterize their isozyme selectivity; one of the two benzolactams exhibits improved isozyme selectivity relative to the n-octyl-ILV. Lastly, we report inhibition of cellular proliferation of two different breast carcinoma cell lines by the benzolactam 5 and show that the compound preferentially down-regulates PKCbeta in both cell lines.