Sterol composition of the phytolaccaceae and closely related families

Total sterols were analyzed from 28 species of Phytolaccaceae and from 29 species of closely related families—Basellaceae, Portulaccaceae, Molluginaceae, and Stegnospermataceae. Eighteen of twenty-eight species of Phytolaccaceae contained dominant Δ⁷-sterols while six species had dominant Δ⁵-sterols. Three species had dominant Δ⁰-sterols. Sterol composition strongly reflected taxonomic position. Nineteen of twenty-nine species from Basellaceae, Portulaccaceae, Molluginaceae, and Stegnospermataceae contained dominant Δ⁷-sterols while ten species contained dominant Δ⁵-sterols. Until recently Δ⁷-sterols were considered rare in higher plants. It appears that a large number of species in the order Caryophyllales contain primarily Δ⁷-sterols.     

Characterization of tributyrin hydrolysis by immobilized lipase on woolen cloth using conventional batch and novel spinning cloth disc reactors

Optimal loading and operating conditions for a new, superior immobilization of amano lipase from Pseudomonas fluorescens on woolen cloth were determined. The optimal enzyme loading was 46.8 mg g dry cloth⁻¹ with activity of 200 U. A batch reactor was used to characterize process conditions important to industrial application of the wool immobilized lipase. The optimal pH for immobilized lipase in tributyrin hydrolysis was 7, slightly lower than that of free lipase (pH 8). The optimal temperature for both free and immobilized lipase was 45 °C. The immobilized lipase was more stable to reuse than some other lipase immobilizations, maintaining 85% of its activity after 6 long term runs and 75.8% of the original activity after storage of 40 weeks at 4 °C. The thermal stability of lipase was improved by 2.4 times after immobilization. The thermal deactivation rate of immobilized lipase followed the Arrhenius law with E_d = 199 kJ mol⁻¹. The Michaelis–Menten constant (K_m) of the lipase increased from 1.63 mM to 4.48 mM after immobilization. The immobilized lipase was also successfully applied for tributyrin hydrolysis in a novel enzyme process intensification technology – the spinning cloth disc reactor (SCDR): conversion increased by around 13% under similar conditions compared to a conventional batch stirred tank reactor. The SCDR is therefore key to exploiting the advantages of the wool immobilized lipase developed in this work.     

Degradation of Thermal Barrier Coatings by Fuel Impurities and CMAS: Thermochemical Interactions and Mitigation Approaches

Degradation of free-standing yttria-stabilized zirconia (YSZ) and CoNiCrAlY coatings (300 μm) due to V₂O₅ and a laboratory-synthesized CMAS was investigated at temperatures up to 1400 °C. Reactions, phase transformations, and microstructural development in coatings were examined by using x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The molten deposits destabilized the YSZ and reacted with the thermally grown oxide with various phase transformations and reaction product formation. A dense, continuous environmental barrier overlay, based on oxides, applied by electrophoretic deposition was effective in mitigating the molten deposit attack. Enriching CMAS composition with Al promoted the crystallization of anorthite platelets and MgAl₂O₄ spinel, and mitigated CMAS ingression. EPD MgO overlay was also effective in protection against V₂O₅ melt by formation of magnesium vanadates. EPD alumina overlay deposited on thermal barrier coatings with APS 8YSZ and bond-coated IN939 superalloy retained its adhesion and structural integrity after prolonged furnace thermal cycle test at 1100 °C.     

Fish intake and serum levels of organochlorines among Japanese women

This study evaluates background serum levels of selected organochlorine compounds among Japanese women of reproductive age and investigates whether lifestyle factors, especially dietary factors, may be associated with these levels. A cross-sectional study was performed on 80 Japanese women, aged 26-43 years, who complained of infertility and were confirmed not to have endometriosis. The serum levels of total toxic equivalency (TEQ), 18 polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs), 4 coplanar polychlorinated biphenyls (cPCBs), 36 ortho-substituted polychlorinated biphenyls (PCBs), and 13 chlorinated pesticides or their metabolites were measured and data were collected on the women's age, residence, occupation, body mass index (BMI), smoking and alcohol habit and 6 dietary intakes (fish, meats, rice, vegetables, fruits and dairy products). The serum median level of total TEQ was 25.1 pg TEQ/g lipid, that of PCDDs/PCDFs/cPCBs was 11.5 pmol/g lipid, that of PCBs was 0.46 nmol/g lipid, and that of total pesticides was 1.32 nmol/g lipid. The serum levels of total TEQ, PCDDs/PCDFs/cPCBs, PCBs and pesticides were positively associated with age (P for trend=0.003, 0.01, 0.005 and 0.01, respectively) and frequent fish consumption (P for trend=0.002, 0.003, 0.0003 and 0.006, respectively). Other lifestyle factors were not associated with serum organochlorine levels. The present study suggests that Japanese women who consume fish frequently in their reproductive period tend to accumulate organochlorines in their bodies.     

Metabolism of DL-methionine and methionine analogs by rumen microorganisms

Rates of degradation of DL-methionine and a number of methionine derivatives by rumen microorganisms were studied in vitro. Methionine hydroxy analog, the ammonium salt, and the amide derivative of methionine hydroxy analog were degraded more slowly than was methionine. Methyl and ethyl esters of methionine hydroxy analog were rapidly converted to methionine hydroxy analog, which was then degraded. Whole rumen contents were separated into protozoal and bacterial fractions, and rates of disappearance of [14C]carboxyl-labeled methionine and methionine hydroxy analog were determined. Disappearance of the label tended to be slower in the bacterial fraction; however, incorporation into cellular material tended to be higher for the bacterial than for the protozoal fraction. Disappearance of labeled methionine hydroxy analog was slower than labeled methionine in all fractions. Addition of unlabeled methionine inhibited disappearance of labeled methionine hydroxy analog, but unlabeled methionine hydroxy analog did not affect disappearance of labeled methionine. The effect of either Na2SO4, methionine, or methionine hydroxy analog on neutral detergent fiber digestion was related to amount of sulfur in the medium and not source of sulfur.     

Community energy planning in Canada: The role of renewable energy

An emerging trend in Canada is the creation of community energy plans, where decisions that used to be left to regional level energy agencies or private individuals are now being considered at the community level. A desire to reduce greenhouse gas emissions and to become more energy self-sufficient is driving this change. Theoretically, local level management is desirable because it achieves these goals through improvements in the three areas of energy efficiency, energy conservation and switching to renewable energy sources. The analysis of 10 of the first community energy plans in Canadian communities, ranging in population size from 500 to one million, finds that communities are choosing policies and programs centred on increasing energy efficiency and conservation while renewable energy receives much less attention. Municipal operations were called upon to set higher targets than the general community. Communities that recognized the substantial potential of renewable energy often focused on technologies that the municipal sector could implement, such as bio-fuels for their transportation fleet. Wind, passive solar design, solar photovoltaics and solar thermal options were only recommended in a few cases. Overall, only one of the five larger communities (Calgary) recommended implementing multiple renewable energy technologies while three of the five smaller communities proposed multiple renewable energy sources. The implication is that smaller and more remote communities may be the most willing to lead in the planned introduction of renewable energy systems.     

Robust Empirical Predictions of Residual Performance of Damaged Composites with Quantified Uncertainties

Robust predictions with estimated uncertainties were made for the residual strength of impact-damaged composite laminates based on simple non-destructive measurements of the size of the damage from ultrasound C-scans. Experimental data was acquired for two sets of composite coupons, one with a crossply and the other with a quasi-isotropic layup. The laminates were subject to drop-weight impacts, non-destructively evaluated using ultrasound and then loaded to failure in bending. An empirical model of the residual strength of each laminate layup, as a function of the ultrasound measurements, was generated by fitting a Bayesian linear regression model to the normalised measured data. Bayesian linear regression was demonstrated to provide conservative estimates when only minimal data is available. Unlike classical regression, this technique provides a robust treatment of outliers, which avoids underestimation of residual strength. The Leave-One-Out-Cross-Validation (LOOCV) metric was used to assess the performance of models allowing for the quantitative comparison of the predictive power of regression models as well as being consistent in the presence of outliers in the data. The LOOCV metric indicated that predictions of residual strength are up to 25% more accurate when based on damage area than when using measurements of the damage width or length. The proposed approach provides a robust methodology for performing damage assessments in safety critical composite components based on reliable predictions with quantified uncertainties.     

Visible emission of hydrogen flames

The common misconception that hydrogen flames are not visible is examined. Examples are presented of clearly visible emissions from typical hydrogen flames. It is shown that while visible emissions from these flames are considerably weaker than those from comparable hydrocarbon flames, they are indeed visible, albeit at reduced light levels in most cases. Detailed flame spectra are presented to characterize flame emission bands in the ultraviolet, visible and infrared regions of the spectrum that result in a visible hydrogen flame. The visible blue emission is emphasized, and recorded spectra indicate that fine spectral structure is superimposed on a broadband continuum extending from the ultraviolet into the visible region. Tests were performed to show that this emission does not arise from carbon or nitrogen chemistry resulting from carbon-containing impurities (hydrocarbons) in the hydrogen fuel or from CO₂ or N₂ entrainment from the surrounding air. The spectral structure, however, is also observed in methane flames. The magnitude of the broadband emission increases with flame temperature in a highly nonlinear manner while the finer spectral structure is insensitive to temperature. A comparison of diffusion and premixed H₂ flames shows that the fine scale structure is comparable in both flames.     

Pain, depression, and physical functioning following burn injury.

Objective: Little is known about how pain and depression after burn injury may influence long-term outcomes such as physical functioning. This prospective study examined associations between pain, depression, and physical functioning in a sample of burn injury survivors. Design and Participants: Questionnaires assessing pain, depression, and physical functioning were completed by 64 (52% of original sample) adult burn survivors shortly after discharge from burn care and at 1- and 2-year follow-ups. Results: Pain and physical functioning improved over the 2 years of the study, whereas depression levels were stable. Pain and depression were associated with poorer physical functioning over time, but associations varied according to the time span under consideration. Also, the association between pain and physical functioning was strongest among persons with higher depression scores. Conclusions: Pain and depression may contribute independently to compromises in physical functioning. The co-occurrence of pain and depression represents even greater risk for reduced physical functioning over time among burn survivors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)