Cardanol Polymerization Under Acid Conditions By Addition And Condensation Reactions

Cashew nut shell liquid (CNSL) is a byproduct of the cashew nut industry and consists predominantly of phenolic compounds that have an side chain with different degrees of unsaturation. Cardanol, one of these components, is biodegradable and widely available. Studies have revealed several polymerization reactions involving cardanol. However, the mechanisms and detailed structures of polymerization reactions have not been explored, although the final product shows different applications. In this work, we evaluated the mechanism and the products structure of the reaction of cardanol with: (i) boron trifluoride diethyl etherate (BF₃O(CH₂CH₃)₂), and (ii) formaldehyde. The characterizations were performed by FTIR, ¹H NMR, SEC and TGA. The results show that the reaction of cardanol with aldehyde produces the expected like-comb structure with a long hydrocarbon pendent chain. Nevertheless, the reaction of cardanol with BF₃O(CH₂CH₃)₂ can exhibits a more complex structure since it was identified aromatic ring linkages, besides the expected polymerization through C=C.     

Fluorescent in situ hybridization (FISH): A new application in the delineation of true vs. pseudomosaicism in prenatal diagnosis

Metaphase chromosomes and interphase nuclei from nine amniotic fluid cultures were studied with fluorescence in situ hybridization (FISH). The samples were initially analyzed with routine G-banding and were diagnosed as having true mosaicism (five patients) or pseudomosaicism (four patients). In our study, FISH analysis could provide additional information to distinguish pseudo– from true mosaicism by allowing interphase studies and analysis of an increased number of metaphase spreads. These results suggest a multilinear origin of ‘in situ’ colonies of cells.     

Immunity in a Social Insect

 Although pathogens appear to have exerted significant selective pressure on various aspects of sociality, mechanisms of disease resistance in the social insects are poorly understood. We report here on an immune response to infection by the dampwood termite, Zootermopsis angusticollis. Nymphs immunized with an injection of 7.6×10⁷, 7.6×10⁵, or 7.6×10⁴ cells/ml glutaraldehyde-killed solution of the bacterium Pseudomonas aeruginosa had significantly higher survivorship than controls following a challenge with a lethal concentration of active bacteria. Similarly, nymphs exposed to a 9×10^–1 spores/ml suspension of the fungus Metarhizium anisopliae had higher survivorship than controls after a challenge with a lethal concentration of spores. Prior exposure to a pathogen thus conferred upon termites a degree of protection during a subsequent encounter with the same pathogen. This represents the first demonstration of immune function in vivo in a social insect. Received: 18 May 1999 / Accepted in revised form: 26 August 1999     

Variability of the frequency of male neoteny in Ostrea puelchana (Mollusca: Bivalvia)

Ostrea puelchana (D'Orbigny), a larviparous oyster from the Atlantic coast of South America, comprises two types of individuals: (1) adults which live for several years and become sexually developed after one year, these show a rhythmic successive hermaphroditism with male, hermaphroditic and female phases; (2) neotenic individuals settled on the adults, which live for only about one year and function exclusively as males. Adult oysters were collected in February 1982 from a natural bed in the San Matias Gulf, Argentina, and were transferred to two sites 200 km to the south of their original habitat, where they were maintained under culture conditions. At the beginning of the study, 17% of adult oysters were observed bearing neotenic individuals. After two years, the number of adults in the female phase had decreased, and neotenic individuals had entirely disappeared. The presence of female-phase adults would seem to be necessary for the existence of neotenic males. Further analysis of the results revealed high adult density to be directly associated with greatly decreased numbers of adults in the female phase; this may play a role in the decrease of neotenic individuals.     

Gametogenesis and spawning periodicity in the fan worm <Emphasis Type="Italic">Sabellastarte spectabilis</Emphasis> (Polychaeta: Sabellidae)

The sabellid polychaete Sabellastarte spectabilis (Grube 1878) was collected at approximately monthly intervals from January 2002 to December 2003 from intertidal and subtidal reefs near the Hawaii Institute of Marine Biology in Kane’ohe Bay, Hawaii, USA (21°N, 157°W). Gametogenesis and spawning periodicity were investigated using histological techniques and induction of spawning trials. Worms were characterized into four discrete reproductive stages based on histological evidence: (1) No evidence of reproductive activity in the coelom (sex cannot be determined), (2) Only coelomocytes present in the coelom (sex cannot be determined), (3) Some gametes present in the coelom (sex can be determined) and (4) Coelom densely packed with gametes (sex can be determined). The small hermaphroditic portion of the population was not used in this study. Stage 4 worms were present over an extended period of time (females, March–December and males, March–November) indicating a potentially broad reproductive season. No correlation between day length and maturation stages in S. spectabilis was detected. However, the statistical model Y = ([394.26 × X] − [7.793 × X ²]) − 4960.781 where Y the % frequency of Stage 4 worms and X the mean monthly water temperature explained 44% of the variation between water temperature and % frequency of Stage 4 worms. Maturation appeared to coincide with water temperatures of 24–25°C (March–September) after which there is a reduction in the % frequency of stage 4 individuals. Induction of spawning trials conducted between May and January showed the month of October with a significantly higher percent success than any other month investigated. According to all available information (e.g., natural spawning in water tables, histological data, induction of spawning trials, correlation of maturation stages with observed changes in average monthly water temperature.), there is an apparent peak in reproductive activity (spawning) within a broad maturational season, which may be influenced by water temperature.     

Effects of reactive hydrocarbons and hydrogen peroxide on antioxidant activity in cherry leaves

One-year-old cherry trees were fumigated with propene and gas-phase hydrogen peroxide, singly and in combination, in controlled-environment chambers for an 8-week period during the summer season. A UV light source was included with the combined propene and hydrogen peroxide regime to provide a source of hydroxyl radicals and ozone, and thus all the constituents of a photochemical smog. Measurements were made of soluble protein concentration and of glutathione reductase activity in leaf extracts from two or three leaf classes in plants from each treatment regime at the end of each fumigation period. Significant increases in soluble protein concentration with respect to the controls were found in plants fumigated with propene and hydrogen peroxide. The occurrence and extent of these differences depended on the leaf class and on the timing of the fumigation period over the summer with respect to bud break. The activity of glutathione reductase was found to be significantly increased in mature lower leaves of plants which had been fumigated with hydrogen peroxide. This effect was independent of the timing of fumigation with respect to bud break. Enzyme activity was also increased in propene and in propene plus hydrogen peroxide treatments, but only when plants were fumigated early in the growth season.     

Field method comparison between passive air samplers and continuous monitors for Vocs and NO2 in El Paso, Texas

This study evaluates the performance of Model 3300 Ogawa Passive Nitrogen Dioxide (NO2) Samplers and 3M 3520 Organic Vapor Monitors (OVMs) by comparing integrated passive sampling concentrations to averaged hourly NO2 and volatile organic compound (VOC) measurements at two sites in El Paso, TX. Sampling periods were three time intervals (3-day weekend, 4-day weekday, and 7-day weekly) for three consecutive weeks. OVM concentrations were corrected for ambient pressure to account for higher elevation. Precise results (< 5% relative standard deviation, RSD) were found for NO2 measurements from collocated Ogawa samplers. Reproducibility was lower from duplicate OVMs for BTEX (benzene, toluene, ethylbenzene, and xylene isomers) VOCs (> or = 77% RSD for 2-day samples) with better precision for longer sampling periods. Comparison of Ogawa NO2 samplers with chemiluminescence measurements averaged over the same time period suggested potential calibration problems with the chemiluminescence analyzer. For BTEX species, generally good agreement was obtained between OVMs and automated-gas chromatograph (auto-GC) measurements. The OVMs successfully tracked increasing levels of VOCs recorded by the auto-GCs. However, except for toluene, OVM BTEX measurements generally exceeded their continuous counterparts with a mean bias of 5-10%. Although interpretation of the study results was limited due to small sample sizes, diffusion barrier influences caused by shelters that housed OVMs and differences in sampling heights between OVMs and auto-GC inlet may explain the overestimation.     

The effects of prior exposure to sulphur dioxide and nitrogen dioxide on the water relations of timothy grass (Phleum pratense) under drought conditions

Studies of the growth and water relations of the grass Phleum pratense L. (Timothy) were made after simultaneous exposure to SO(2) and NO(2) at concentrations ranging from 80 + 57.4 microg m(-3) to 240 + 172.2 microg m(-3) (SO(2) + NO(2)). Decreased partitioning to the roots was evident during exposure to the pollutants, but when the plants were returned to clean air restrictions in root growth did not persist. Shoot to root partitioning was, however, complicated by the additional factor of changes in the nutritional status of the soil after additional columns of fresh soil were attached to the original tubes. The rate of use of soil water was nevertheless substantially increased by the pollution treatment and after a period of 23 days in which water was withheld, a clear pollution x water stress interaction was seen. The ability of polluted leaves to conserve water under severe water stress was tested by excising the leaves and measuring their water loss over time. The results from this second experiment showed that conservation of water by the leaves was appreciably affected after exposure to 80 + 57.4 microg m(-3) or 133.3 + 95.6 microg m(-3) SO(2) + NO(2). It seems likely that damage to the cells in the epidermal layer, leading to malfunctioning of stomata, is mainly responsible for the reduced ability to conserve water under conditions of extreme stress.     

Simulation of atmospheric PAH emissions from diesel engines

Simulation of atmospheric PAH emissions in a typical European passenger car diesel engine at steady conditions or under a certification cycle is made using in-house software. It is based on neural fitting of experimental data from eight different fuels tested under five operating steady conditions (reproducing modes of the European transient urban/extraurban certification cycle). The software allows the determination of PAH emissions as a function of the fuel composition parameters (aromatic content, cetane index, gross heat power, nitrogen and sulphur content) and operation conditions (torque and engine speed). The mathematical model reproduces experimental data with a maximum error of 20%. This tool is very useful, since changes in parameters can be made without experimental cost and the trend in modifications in PAH emissions is immediately obvious.     

Comparison of the method of diffusive gels in thin films with conventional extraction techniques for evaluating zinc accumulation in plants and isopods

The measurement of diffusive gels in thin films (DGT) has recently been developed to assess metal bioavailability in soils. The DGT-method is based on diffusion in a porous matrix. To test the predictive capabilities of the method with regard to metal bioavailability, a study was set up with 28 soils having a variety of textures and amounts of zinc salts added. Correlation and regression analyses were performed to compare DGT-extracted zinc levels to zinc concentrations obtained by extraction with 0.01 M CaCl(2) and 0.43 M HNO(3), digestion with aqua regia and the zinc concentration in pore water. The amount of zinc extracted with CaCl(2) correlated well with DGT-extracted zinc levels in all soils spiked with different amounts of ZnCl(2). A similar correlation was not found for zinc concentrations in soil samples collected in the field. Experiments were performed to compare zinc content in organisms and in soils. The organisms tested were plants (grass, lettuce and lupine) and the hard bodied soil dwelling isopod Oniscus asellus. Good correlations were found between zinc accumulation in grass and lettuce and the C(E) (effective concentration) measured by a DGT-device, CaCl(2) extracted zinc and the zinc content in the pore water of all soils. The correlation with C(E) was not significant for lupine, neither for spiked soils, nor for field soils (p< or =0.001). Zinc levels in the isopods were not significantly related to any set of zinc measurements. From a synthesis of all results obtained it is concluded that the DGT-methodology does not have an additional value in predicting bioavailability of zinc in terrestrial ecosystems as compared to conventional extraction methods.