Interaction of apolipoprotein AII with the putative high-density lipoprotein receptor

There is strong evidence to indicate that binding of HDL by cells is due to recognition of apoproteins residing on the surface of the lipoprotein by the putative HDL receptor(s). Although both of the major HDL apoproteins, AI and AII, are recognized by the putative receptor, the nature of the binding interaction and the domains of the apoproteins involved are largely unknown. Previous data from this laboratory led to the proposal of a model to explain how HDL particles containing AII interacted with the HDL receptor in a different manner as compared to HDL particles which contain apoAI but not apoAII [Vadiveloo, P. K., & Fidge, N. H. (1992) Biochem. J. 284, 145-151]. The model predicted that each chain of the apoAII homodimer contained a binding domain capable of interacting with the HDL receptor. This model was tested in the current study by preparing apoAII monomers, complexing them with phospholipid, and determining the ability of these complexes to bind to putative HDL receptors in rat liver plasma membranes (RLPM) and bovine aortic endothelial cell membranes (BAECM) by ligand blotting. The data showed that these complexes were bound by HB1 and HB2 from RLPM, and to the 110-kDa HDL binding protein from BAECM, providing critical evidence to support the model. Further investigation into the binding interaction revealed that apoAII complexed with phospholipid (apoAII-PC) bound more than delipidated apoAII, which bound more than delipidated apoAII monomers. Thus, optimum binding required the presence of lipid.(ABSTRACT TRUNCATED AT 250 WORDS)     

Poisson wavelets applied to model identification

A novel wavelet transform is introduced based on the backward difference of the Poisson probability density function. This family of wavelets is a function of one discrete and two continuous variables. The Poisson wavelet transform is useful for system identification, parameter estimation and model validation. In particular, it is well-suited for linear time-invariant systems that are modelled as combinations of decaying exponentials with a single time delay. A fast computational algorithm for computing the Poisson wavelet transform is developed using cascaded first-order filters. The concepts are demonstrated on a three-tank process and a simplified heat exchanger.     

Synthesis and characterization of a low stress photosensitive polyimide

Use of polyimides with thermal coefficients of expansion comparable to that of the underlying substrate is critical to achieving low stress in microelectronic packaging applications. Photosensitive polyimides are finding increased use because of their significant reduction in device processing steps. A negative working photosensitive polyimide, based on the BPDA/PPD backbone, has been synthesized that incorporates these key features. The polyimide exhibits excellent photosensitivity and lithographic behavior, while retaining many thermal and physical properties of the polymer framework.     

Larval rearing water and preexisting eggs influence oviposition by Aedes aegypti and Ae. albopictus (Diptera: Culicidae)

Two-choice laboratory bioassays were used to evaluate oviposition responses of gravid Aedes aegypti (L.) and Ae. albopictus (Skuse) to larval rearing water and eggs from prior egg deposition. Oviposition responses by female Ae. aegypti were similar between larval water from Ae. aegypti and water controls but significantly greater to larval water from Ae. albopictus (12.2%) compared with water controls. Oviposition by Ae. albopictus females increased significantly in response to larval water from either species compared with water controls with increases of 15.1% to Ae. aegypti larval water and 17.6% to Ae. albopictus larval water. Oviposition responses of gravid Ae. aegypti and Ae. albopictus were evaluated in the presence of preexisting conspecific and heterospecific eggs on strips of oviposition paper. Significantly more eggs were laid by gravid Ae. aegypti females on oviposition paper containing either Ae. aegypti or Ae. albopictus eggs than on oviposition paper without eggs. In contrast, oviposition responses of gravid Ae. albopictus females were unaffected by the presence of eggs of either species.     

Cyclodextrin enhanced biodegradation of polycyclic aromatic hydrocarbons and phenols in contaminated soil slurries

This work aimed to evaluate the relative contribution of soil catabolic activity, contaminant bioaccessibility, and nutrient levels on the biodegradation of field-aged polycyclic aromatic hydrocarbons and phenolic compounds in three municipal gas plant site soils. Extents of biodegradation achieved, in 6 week-long soil slurry assays, under the following conditions were compared: (i) with inoculation of catabolically active PAH and phenol-degrading microorganisms, (ii) with and without hydroxypropyl-beta-cyclodextrin supplementation (HPCD; 100 g L(-1)), and finally (iii) with the provision of additional inorganic nutrients in combination with HPCD. Results indicated no significant (p < 0.05) differences between biodegradation endpoints attained in treatments inoculated with catabolically active microorganisms as compared with the uninoculated control. Amendments with HPCD significantly (p < 0.05) lowered biodegradation endpoints for most PAHs and phenolic compounds. Only in one soil did the combination of HPCD and nutrients consistently achieve better bioremediation endpoints with respect to the HPCD-only treatments. Thus, for most compounds, biodegradation was not limited by the catabolic activity of the indigenous microorganisms but rather by processes resulting in limited availability of contaminants to degraders. It is therefore suggested that the bioremediation of PAH and phenol impacted soils could be enhanced through HPCD amendments. In addition, the biodegradability of in situ and spiked (deuterated analogues) PAHs following 120 days aging of the soils suggested that this contact time was not sufficient to obtain similar partitions to that observed for field-aged contaminants; with the spiked compounds being significantly (p < 0.05) more available for biodegradation.     

Bioactive glass granules: a suitable bone substitute material in the operative treatment of depressed lateral tibial plateau fractures: a prospective, randomized 1 year follow-up study

Purpose of this study was to compare bioactive glass and autogenous bone as a bone substitute material in tibial plateau fractures. We designed a prospective, randomized study consisting of 25 consecutive operatively treated patients with depressed unilateral tibial comminuted plateau fracture (AO classification 41 B2 and B3).14 patients (7 females, 7 males, mean age 57 years, range 25–82) were randomized in the bioglass group (BG) and 11 patients (6 females, 5 males, mean age 50 years, range 31–82) served as autogenous bone control group (AB). Clinical examination of the patients was performed at 3 and 12 months, patients’ subjective and functional results were evaluated at 12 months. Radiological analysis was performed preoperatively, immediately postoperatively and at 3 and 12 months. The postoperative redepression for both studied groups was 1 mm until 3 months and remained unchanged at 12 months. No differences were identified in the subjective evaluation, functional tests and clinical examination between the two groups during 1 year follow-up. We conclude that bioactive glass granules can be clinically used as filler material instead of autogenous bone in the lateral tibial plateau compression fractures.     

Plant stress physiology: opportunities and challenges for the food industry

We review and analyze the possible advantages and disadvantages of plant-stress-related metabolic and structural changes on applications in the fruit and vegetable processing industry. Knowledge of the cellular and tissue transformations that result from environmental conditions or industrial manipulation is a powerful means for food engineers to gain a better understanding of biological systems in order to avoid potential side effects. Our aim is to provide an overview of the understanding and implementation of physiological and biochemical principles in the industrial processing of fruits and vegetables.     

Surface material, temperature, and soil effects on the survival of selected foodborne pathogens in the presence of condensate

The effects of surface type (stainless steel, acetal resin, and fiberglass reinforced plastic wall paneling [FRP]), soil, and temperature on the survival of Listeria monocytogenes, Salmonella spp., and Yersinia enterocolitica, in the presence of condensate were evaluated. Surface coupons--half soiled with sterile porcine serum--were exposed to cell suspensions made from individual five-strain cocktails composed of organisms from the same genus (10(7) CFU/ml) in Butterfield's phosphate buffer and incubated for 2 h at 25 degrees C allowing attachment of cells to coupon surfaces. Coupons were rinsed to remove unattached cells, incubated at either 4 or 10 degrees C under condensate-forming conditions, and sampled at six time intervals over a 15-day period. For enumeration, cells were removed from the coupons by vigorous shaking in 100 ml of Butterfield's phosphate buffer with 3 g of glass beads and plated on tryptic soy agar with 0.6% yeast extract. Stainless steel did not support the survival of Listeria as well as acetal resin or FRP. Acetal resin and stainless steel were less supportive of Salmonella than FRP. All surfaces supported the survival of Yersinia over the 15-day trial equally. Temperature had little effect on survival of all organisms across all surfaces with one exception. However, Yersinia displayed growth on FRP at 10 degrees C. but death at 4 degrees C. Serum had a protective effect on L. monocytogenes on all surfaces, with populations sustained at significantly (P < or = 0.05) higher numbers over time than unsoiled coupons. Serum didnot effect survival of Salmonella or Yersinia on stainless steel, acetal resin, or FRP.     

Measurement of electrical conductivity of La0.2Sr0.8Cr0.2Fe0.8O3-�� using gas-tight electrochemical cells

The oxygen partial pressure (pO₂) dependence of the electrical conductivity of La_0.2Sr_0.8Cr_0.2Fe_0.8O_3-?? (LSCrF) was obtained at T?=?750?C1060°C and pO₂?=?10^?18?0.5 atm. The slope of the plot of log ?? vs. log pO₂ is ??1/5 in the p?Ctype region, pO₂?=?10^?5?10^?1 atm. The p-n transition pO₂ increases with increasing temperature. The activation energy for ionic conduction was estimated to be 0.86 eV from an Arrhenius plot of the minimum conductivity vs. reciprocal temperature. At temperatures below 942°C, a plateau in the conductivity isotherm suggests the presence of a two-phase region. Most likely, phase separation occurs to form a mixture of a perovskite phase and an oxygen vacancy ordered phase related to brownmillerite.