Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.     

Reduction of rodent fertility by plant consumption

The present study investigates the possibility that plants used in traditional medicine for birth control may also reduce reproduction in their natural herbivores. Ten species of plants utilized by Bedouins for birth control were selected. These were dried, ground, and mixed with the standard diet and offered to female laboratory rats. Six plant species (60%) were found to reduce reproduction rate in white female rats, and the shoots and fruit of one of the effective species,Ziziphus spina-christi, when offered to its natural herbivore,Meriones tristrami, at the level of 35% of the standard diet, postponed female puberty and significantly reduced offspring survival. Plants that are known to be an effective factor in human birth control may have similar effects on their natural mammalian herbivores. In such cases, when the seeds of the plant are part of the herbivore diet, a certain percentage of the seeds will be dispersed and germinate, while the resulting population control of the animal achieved by its consumption of the seeds will prevent overgrazing, thus maintaining a mutual balance. It is suggested that ethnopharmacological data may assist in uncovering plants that, under the following conditions, have the potential to regulate reproduction in mammalian herbivores (with implications for human reproduction): (1) the plant is an important component of the animal's diet and (2) the active secondary metabolites of the plant directly interact with the physiological systems governing reproduction in the herbivore.     

Modified dynamic matrix control

DMC (Dynamic Matrix Control) has been used successfully in industry for the last decade. It can deal with constraints and unusual dynamic behavior directly. It also shows a good control performance for the servo problem. Relatively, it can’t reject disturbances systematically. We propose a modified DMC method to control the regulatory process more efficiently. The proposed DMC method makes the control output by subtracting the estimated disturbance from the control output of the original DMC. Here, the disturbance is estimated by a new disturbance estimator. It shows better control performances than the original DMC.     

Aphid semiochemicals — A review,and recent advances on the sex pheromone

The alarm pheromones are known for many species of aphids, and methods of using the synthetic pheromone to improve control of aphids by contact insecticides and biological agents have been devised. Highly active analogs have been prepared and plant-derived synergists identified. Laboratory studies on compounds obtained by chemical modification of the alarm pheromone and antifeedants derived from non-host plants have led to successful field trials against aphid-borne virus diseases in crops. Strategies for biotechnological production of aphid semiochemicals are described. The sex pheromones for a number of aphids have recently been identified. Further studies on the production, perception, and interspecific attraction of the pheromone components are described and possible uses for the sex pheromone are discussed.     

Time-optimal control of mmama copolymerization in a CSTR for grade change

The time-optimal control of MMA-MA copolymerization in a CSTR is treated for a grade-change operation. The control objective is to bring system specifications, such as polymer production rate and polymer composition, to desired values in minimum time. The initiator concentration is chosen as a manipulated variable. Two cases are considered: One is to get the time optimal control for both a desired polymer production rate and a desired weight composition of MA in dead copolymer; the other is only for a desired polymer production rate. In numerical calculation, the final t(ⁱ)_f is chosen at each iteration as the time at which the system reached steady-state. This allows us to use a more easily manipulatable form of the performance index and at the same time not directly use the free final time boundary condition.     

Influence of mustelid semiochemicals on population dynamics of the deer mouse (Peromyscus maniculatus)

The influence of mustelid anal-gland compounds on population dynamics of the deer mouse (Peromyscus maniculatus) was investigated. Densities of deer mice were not found to be significantly different between treated and control areas. However, on average, numbers of deer mice were lower on treated areas following the July treatments of 1991 and 1992. Survival rates appeared to be lower and more erratic on treated than control areas in 1991; however, there were no statistically significant differences. Reproduction appeared to be unaffected by the odors. We concluded that deer mice did not display a behavioral response to weasel odors. We speculated that decreases in densities were owing to predation by weasels, which were attracted to the odors on treated sites. We also concluded that the use of weasel odors as a biological control method for voles (Microtus spp.) would likely have little impact on deer mice (a nontarget species).     

Intra- and interspecific avoidance of areas marked with skin extract from brook sticklebacks (Culaea inconstans) in a natural habitat

The detection of a chemical alarm pheromone may allow receivers to avoid areas where a predator has captured the prey's conspecifics. We marked minnow traps with either brook stickleback (Culaea inconstans) skin extract or a control of distilled water and tested whether sticklebacks avoided the skin extract marked traps in a natural habitat. Significantly more sticklebacks were captured in traps marked with control water, thereby demonstrating avoidance of conspecific skin extract. The stickleback captured in traps marked with conspecific extract were significantly smaller than those captured in traps marked with control water, implicating ontogenetic factors (i.e., experience or physiological development) in the development of the response. We also captured significantly fewer finescale dace (Chrosomus neogaeus) and fathead minnows (Pimephales promelas) in traps marked with skin extract. These data suggest that dace and minnows may benefit by avoiding areas where predators have recently captured sticklebacks.     

Importance of bacterial decomposition and carrion substrate to foraging brown treesnakes

Brown treesnakes are an invasive species to the island of Guam that have caused extensive ecological and economic damage. Efforts to control the snake population have included trapping using live mouse lures, but for logistical and economic reasons a synthetic lure is needed. When searching for live food, brown treesnakes use both visual and odor cues. However, when searching for carrion, odor cues are sufficient. Attempts to develop synthetic lures based on chemical reconstruction of the complex carrion odor have not succeeded. We provide evidence that a microbial–substrate interaction is important for bait take by brown treesnakes. Microbial cultures taken from mouse carrion indicate that Enterobacter agglomerans is the predominant bacterium, and field tests suggest that this organism may be important to odor production that attracts brown treesnakes. This information may prove useful in the development of microbial-based biological reactors that could be formulated to produce a continuous stream of odor of sufficient complexity so as to be attractive to foraging snakes.     

Changing the hydroisomerization to hydrocracking ratio of long chain alkanes by varying the level of delamination in zeolitic (ITQ-6) materials

Several delaminated ITQ-6 acid samples have been synthesized and tested in the isomerization of n-hexadecane. It has been found that the swelling time is a decisive parameter to prepare ITQ-6 catalytic materials with different ratios of micro to mesoporous surface area. n-Hexadecane hydroisomerization results indicate that the appropriate control of the delamination conditions can drive to obtain optimized ITQ-6 materials highly active for the hydroisomerization/hydrocracking of long chain alkanes to produce lube oils, diesels or gasolines.     

Biological Functions and Metabolism of Oleoylethanolamide

The present review is focused on the metabolism and the emerging roles of oleoylethanolamide (OEA) with emphasis on its effects on food intake control and lipid metabolism. The biological mechanism of action, including a non-genomic effect mediated through peroxisome proliferator-activated receptor alpha (PPAR-alpha) and transient receptor potential vanilloid type 1 (TRPV1) receptor, is discussed. The research related to fatty acid ethanolamides has been focused until recently on anandamide and its interaction with cannabinoid receptor subtype 1. The roles of other N-acyl ethanolamine fatty acid derivatives have been neglected until it was demonstrated that OEA can modulate food intake control through interaction with PPAR-alpha. Further investigations demonstrated that OEA modulates lipid and glucose metabolism, and recent study confirmed that OEA is an antagonist of TRVP1. It has been demonstrated that OEA has beneficial effects on health by inducing food intake control, lipid beta-oxidation, body weight loss and analgesic effects. The investigation of the mechanism of action revealed that OEA activates PPAR-alpha and stimulates the vagal nerve through the capsaicin receptor TRPV1. Pre-clinical studies showed that OEA remains active when administered orally.     

Responses by domestic cats (Felis catus) to snake scent gland secretions

The scent gland secretions of snakes are thought to repel predators, but few predator species have been tested for responses to these exudates. Domestic cats (Felis catus) were tested for responses to scent gland secretions of the gray rat snake (Elaphe obsoleta), or to choloroform extracts of them, applied to filter paper or food. More cats salivated or rubbed on filter papers treated with scent gland secretions than on control papers. Scent gland exudates elicited rubbing and pawing in cats more frequently than did chemicals from a shed snake skin. Cats offered food pieces treated either with water or with scent gland secretions ate fewer of the latter; this result is consistent with the hypothesis that scent gland secretions deter feeding.     

Plant defenses: Chlorogenic acid and polyphenol oxidase enhance toxicity ofBacillus thuringiensis subsp.kurstaki toHeliothis zea

Two chemicals implicated in resistance of the tomato plant, chlorogenic acid and polyphenol oxidase, are known to form orthoquinones in damaged plant tissue. Orthoquinones have been reported to alkylate –NH₂ and –SH groups of proteins and amino acids, altering solubility, digestibility, and, for some pathogenic viruses, infectivity. Here we explore effects of quinone alkylation on toxicity of an important microbial insecticide,Bacillus thuringiensis subsp.kurstaki (BTk), to larvalHeliothis zea. BTk incubated with these phytochemicals and fed to larvae was more toxic than untreated BTk. Similar but less dramatic results arose when BTk was incubated with polyphenol oxidase alone. Digestibility experiments suggest that alkylation enhanced the solubilization and/or proteolysis of crystal protein in vivo. Implications of our results for compatibility of BTk with host-plant resistance and biological control are discussed.     

Influence of the olfactory sense upon smolt transformation in salmonid fishes

The effect of olfactory deprivation on the process of smolt transformation in Atlantic salmon (Salmo salar L.) was investigated. Salmon parr were rendered anosmic by heat-cauterizing in November, and, together with controls, size, purine deposition (silvering), and mortality were monitored throughout spring in individuals within sibling groups. In May the fish were exposed to seawater (3.2% salinity) to determine levels of smoking in anosmic fish compared with control fish. Olfactory deprivation was found to induce a negative effect on survival in both anosmic fish as well as controls when reared within the same rearing tank. A 54% survival was metered in anosmic fish as opposed to only 26% survival in control fish during the experimental period. The low survival rates observed are suggested to result from abnormal behavior in anosmic fish due to lack of proper olfactory stimuli. Within each strain, the anosmic fish were found shorter and displayed less-silvering than their control fish at the end of the experimental period. Further, since control fish could withstand salinity exposure longer than anosmic fish, smolting is suggested to have been retarded among the anosmic fish. Olfactory influence on smolt transformation may be caused by conspecific pheromones secreted for the purpose of mediating effects of life-history patterns in salmonid fishes.     

Effects of predator chemical cues and behavioral biorhythms on foraging activity of terrestrial salamanders

Red-backed salamanders, Plethodon cinereus, show a variety of alarm responses to chemical cues from eastern garter snakes, Thamnophis sirtalis. We measured the foraging activity of red-backed salamanders exposed to water soiled by a garter snake (fed P. cinereus) or to unsoiled water. Salamanders exposed to snake-soiled water showed less foraging activity than salamanders exposed to unsoiled water; therefore, predators could have nonlethal effects on salamander populations. Our results also show additional factors influenced salamander foraging activity. Salamander foraging activity and responsiveness to chemical cues do not appear to have been affected by sex or food deprivation. Salamander foraging activity does appear to have been influenced by activity biorhythms. Foraging activity of animals in both treatments showed a bimodal periodicity that is consistent with natural activity patterns controlled by internal biorhythms. Exposure to snake-soiled water significantly reduced foraging activity during periods of peak foraging activity, but had a subtler effect0 on foraging activity during natural lulls in activity. We suggest that both activity biorhythms and exposure to chemical cues are important factors affecting salamander foraging behavior.     

Influence Of Diet-Related Chemical Cues from Predators on the Hatching of Egg-Carrying Spiders

Previous studies have shown that animals may make adaptive adjustments in response to chemical cues from predators, but hatching responses to diet-related chemical cues from predators have not been previously demonstrated. In the system studied here, the predator is an araneophagic jumping spider (Salticidae), Portia labiata, and the prey organism is a subsocial spitting spider, Scytodes pallida (Scytodidae). The spitting spider carries its eggs in its chelicerae, and carrying eggs is known to make it more vulnerable to predators. It is also known from an earlier study that the prior diet of the predator alters how dangerous the individual predator is to the spitting spider. In the experiments reported here, incubation time was shorter when volatile cues from the predator were present and longer in control tests when no chemical cues from the predator were present. The previous predators diet also influenced incubation time: when in the presence of volatile cues from individuals of P. labiata that had previously fed on individuals of S. pallida, incubation time was shorter than when in the presence of volatile cues from individuals of P. labiatathat had been feeding instead on house flies.     

Responses to prey chemicals by a lacertid lizard,Podarcis muralis: Prey chemical discrimination and poststrike elevation in tongue-flick rate

The ability to discriminate prey chemicals from control substances and the presence of a poststrike elevation in tongue-flicking (PETF) rate are experimentally demonstrated in the lacertid lizard,Podarcis muralis, The tongue-flick attack score, a composite index of response strength, was significantly higher in response to integumental chemicals from cricket than to cologne or distilled water. The cricket chemicals additionally elicited a significantly greater rate of tongue-flicking and higher proportion of attacks by the lizards than did control stimuli. PETF combined with apparent searching movements strongly suggest the presence of strike-induced chemosensory searching (SICS). Experimental evidence indicates that both PETF and SICS occur in insectivorous representatives of three families of actively foraging autarchoglossan lizards, suggesting their widespread occurrence in such lizards. The adaptive roles of chemosensory behavior in the foraging behavior of P.Muralis are discussed. It is proposed that these lizards may form chemical search images and that PETF and SICS may have been present in the lacertilian ancestors of snakes.     

Jasmonic Acid-Induced Changes in <Emphasis Type="BoldItalic">Brassica oleracea</Emphasis> Affect Oviposition Preference of Two Specialist Herbivores

Jasmonic acid (JA) is a key hormone involved in plant defense responses. The effect of JA treatment of cabbage plants on their acceptability for oviposition by two species of cabbage white butterflies, Pieris rapae and P. brassicae, was investigated. Both butterfly species laid fewer eggs on leaves of JA-treated plants compared to control plants. We show that this is due to processes in the plant after JA treatment rather than an effect of JA itself. The oviposition preference for control plants is adaptive, as development time from larval hatch until pupation of P. rapae caterpillars was longer on JA-treated plants. Total glucosinolate content in leaf surface extracts was similar for control and treated plants; however, two of the five glucosinolates were present in lower amounts in leaf surface extracts of JA-treated plants. When the butterflies were offered a choice between the purified glucosinolate fraction isolated from leaf surface extracts of JA-treated plants and that from control plants, they did not discriminate. Changes in leaf surface glucosinolate profile, therefore, do not seem to explain the change in oviposition preference of the butterflies after JA treatment, suggesting that as yet unknown infochemicals are involved.     

Weed control using allelopathic crop plants

The concept that some crop plants may be allelopathic to common weeds of agricultural lands is receiving greater attention as an alternative weed control strategy. Several crops showing promise are: grain and forage species such as barley (Hordeum), oat (A vena), fescue (Festuca), and sorghum (Sorghum), and the agronomic species of corn (Zea) and sunflower (Helianthus). Among the problems that hinder the conclusive demonstration of allelopathic effects of crop plants are the loss of that capacity through selection and the variability among cultivars. Recent studies to evaluate the allelopathic potential of crop plants have shown that several sunflower varieties inhibit the germination and growth of associated weeds and to a greater extent than found in several biotypes of native sunflower. Aqueous extracts of dried sunflower and rape tissue inhibited or stimulated germination and growth of weeds, and the response depended upon the source of extract, the extract concentration, and the weed species tested. The validity of bioassay results was tested in a 5-year field study with sunflower and oat grown in rotation. Weed density increased in all plots but the extent of increase was significantly less in plots of sunflower than in control plots. The use of crop plants with increased allelochemical production could limit the need for conventional herbicides to early season application with late season control provided by the crop.     

Ontogeny and Environment as Determinants of the Secondary Chemistry of Three Species of White Birch

This study investigates variation in the secondary chemistry of the bark of three closely related, winter-dormant species of white birch (Betula resinifera, B. pendula, and B. platyphylla) at different ontogenetic stages by using different plant parts (top and base). The experimental birches were grown for 4 years in two growing conditions (pot and field) at different nutrient levels. There was considerable species-specific quantitative and qualitative variation in the secondary chemicals in bark, but this was also affected by fertilization and the age of the plant. In general, there was greater chemical diversity in saplings than in seedlings. The study revealed three new components, secoisolariciresinol 9-O-β-glucopyranoside and two of its derivatives, that have not been reported previously for the bark of white birches. Principal component analysis showed that the species studied had a similar chemical composition at the juvenile stage, but as the plants grew, they became more clearly differentiated, which indicates that the species of older plants can be identified by chemotaxonomy. Evidently, the secondary chemistry of birches is under genetic control, but it is affected by properties of growing conditions and ontogeny. Electronic Supplementary Material Supplementary material to this paper is available in electronic form at     

Release of ethylene from pruned olive logs: Influence on attack by bark beetles (Coleoptera,Scolytidae)

In recently pruned olive logs, an increase in ethylene release has been observed between 48 and 72 hr after pruning. The values reached, as well as the duration of ethylene release, varied greatly from one log to another. PioneerPhloeotribus scarabaeoides females have shown a preference for logs in which ethylene emission was higher. In logs treated with ethrel, a significant increase in ethylene emission was observed, together with a greater period of release. Therefore, the use of logs treated with ethrel could be of great importance in the control of this pest of olive trees.