Incorporation of laurate and hydroxylaurate into phosphatidylcholines and acylglycerols in castor microsomes

Because castor produces oil with a high content of hydroxyl FA (90% ricinoleate), we were interested in determining the flexibility of castor seed microsomes in incorporating other hydroxyl FA into castor oil. To this end, we incubated the [¹⁴C]-labeled 12:0 FA laurate (La), 11-hydroxylaurate, and 12-hydroxylaurate with castor microsomes that were capable of synthesizing castor oil. The molecular species of PC and acylglycerols (AG) incorporating these nonendogenous FA of castor were identified by reversed-phase C₈ and C₁₈ HPLC, respectively. [¹⁴C]Laurate was incorporated into the molecular species of PC and AG at levels of 10 and 4%, respectively, that of [¹⁴C]ricinoleate. Similar to those from the incorporation of six [¹⁴C]FA reported previously [ricinoleate (R), oleate (O), linoleate (L), linolenate (Ln), stearate (S), and palmitate (P)], the molecular species of PC incorporating [¹⁴C]laureate were LLa-PC>PLa-PC>OLa-PC>LnLa-PC>SLa-PC>RLa-PC. The molecular species of AG incorporating [¹⁴C]laurate were RRLa>LaLa>RLa>RLLa>ROLa>LOLa>LLLa>LLa>LLnLa>RSLa>OOLa. The retention times for lipids incorporating laurate were similar to those of lipids incorporating linolenate, because the equivalent carbon numbers of laurate and linolenate are the same. Relative retention times of the molecular species of PC and AG containing laurate are also reported here. The incorporation of 11-hydroxylaurate and 12-hydroxylaurate into PC and AG was not detected.     

Modeling the Impact of Microbial Intrusion on Secondary Disinfection in a Drinking Water Distribution System

The purpose of this study was to quantify the potential level of protection that secondary disinfection may provide in response to an intrusion event. Although several uncertainties exist regarding intrusion events, this study presents an analysis of the inactivation provided by disinfectant residuals by using a distribution system model, inactivation and disinfectant decay models, and conservative assumptions based on available data. A variety of conditions were modeled, including a range of water quality parameters (pH, temperature); inactivation of two microorganisms, Giardia and E. coli O157:H7; and intrusion water dilution ratios. Despite the assumptions inherent in the model, several generalizations were derived from the study. A free chlorine residual of 0.5?mg/L may be insufficient to provide adequate control of disinfectant-resistant Giardia even at low pH (6.5) and high temperature (25°C) conditions that enhance chlorine effectiveness. For E. coli, an organism of “average” disinfectant resistance relative to others, a residual of 0.5?mg/L may provide ample protection against intrusion even assuming that the chlorine residual is reduced within several minutes, such as would be predicted to occur with sewage intrusion at levels below 1% of the total flow. Importantly, chloramines may have a negligible benefit in terms of protecting against intrusion for even relatively susceptible organisms such as E. coli. Consequently, systems should consider protection against intrusion when choosing their secondary disinfectant.     

Edge-region-based segmentation of range images

In this correspondence, we present a new computationally efficient three-dimensional (3-D) object segmentation technique. The technique is based on the detection of edges in the image. The edges can be classified as belonging to one of the three categories: fold edges, semistep edges (defined here), and secondary edges. The 3-D image is sliced to create equidepth contours (EDCs). Three types of critical points are extracted from the EDCs. A subset of the edge pixels is extracted first using these critical points. The edges are grown from these pixels through the application of some masks proposed in this correspondence. The constraints of the masks can be adjusted depending on the noise present in the image. The total computational effort is small since the masks are applied only over a small neighborhood of critical points (edge regions). Furthermore, the algorithm can be implemented in parallel, as edge growing from different regions can be carried out independently of each other     

Information rates of pre/post-filtered dithered quantizers

We consider encoding of a source with pre-specified second-order statistics, but otherwise arbitrary, by entropy-coded dithered (lattice) quantization (ECDQ) incorporating linear pre- and post-filters. In the design and analysis of this scheme we utilize the equivalent additive-noise channel model of the ECDQ. For Gaussian sources and a square error distortion measure, the coding performance of the pre/post filtered ECDQ approaches the rate-distortion function, as the dimension of the (optimal) lattice quantizer becomes large; actually, in this case the proposed coding scheme simulates the optimal forward channel realization of the rate-distortion function. For non-Gaussian sources and finite-dimensional lattice quantizers, the coding rate exceeds the rate-distortion function by at most the sum of two terms: the “information divergence of the source from Gaussianity” and the “information divergence of the quantization noise from Gaussianity”. Additional bounds on the excess rate of the scheme from the rate-distortion function are also provided     

Microstructure of GaN grown by lateral confined epitaxy 2. GaN on patterned sapphire

Transmission electron microscopy (TEM), atomic force microscopy (AFM), and photoluminescence (PL) spectroscopy were used in order to study the microstructure and optical properties of GaN films grown by metal-organic chemical vapor deposition (MOCVD) on c-plane sapphire by lateral confined epitaxy (LCE). In this method, the substrate is etched prior to growth to form uniform mesas separated by trenches for laterally restricting growth area. As previously observed for LCE GaN on Si(111), the density of threading dislocations was significantly reduced in the areas close to the edge of mesas due to the lateral propagation of the dislocations. Hence, the overall material quality improves with decreasing mesa size, which is consistent with the observed increase in photoluminescence band edge peak intensity. Electron diffraction indicated ∼1° rotation about the [ ] axis between the mesa and trench material, which was also observed in the image contrast of these two regions with g= . Additionally, LCE samples prepared in [ ] and [ ] cross sections were used for comparing the growth rates in these two perpendicular directions. As theoretically expected, growth in the [ ] direction appears to proceed considerably faster than that in the [% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9qqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaGymaiaaig% daceaIYaGbaebacaaIWaaaaa!38D1!\[11\bar 20\]] direction.     

Dynamics of complex shells of revolution with arbitrary stiffness and density distributions

A general analytical and numerical procedure, based on the linear theory, is outlined for the elastic stress and deflection analysis of complex shells of revolution with arbitrary stiffness and density distributions, under arbitrary static and dynamic loads. The equations of motion admit shear deformation and rotary inertia. A numerical solution is obtained by recourse to Fourier expansion for the circumferential direction, to finite differences for the meridonial direction, and to Houbolt's method for the time domain. Numerical results are presented.