Differences in the relationship between sensory adaptation of antennae and concentration of aerial pheromone in the oriental fruit moth and obliquebanded leafroller (Lepidoptera: Tortricidae): implications for the role of adaptation in sex pheromone-mediated mating disruption of these species.

The antennae of Grapholita molesta (Busck) are more susceptible to sex pheromone-induced sensory adaptation than the antennae of Choristoneura rosaceana (Harris). Adaptation is detectable in G. molesta at 1/1,000th the aerial concentration of pheromone (i.e., 5.0 x 10(-7) ng Z8-12:OAc/ml air) that is required to induce detectable adaptation in C. rosaceana (i.e., 5.0 x 10(-4) ng Z11-14:OAc/ml air). In addition, the predicted concentration of pheromone required to induce 50% adaptation in G. molesta (i.e., 1.2 x 10(-3) ng Z8-12:OAc/ml air) after 15 min of exposure is only one sixth the estimated aerial concentration required to induce the same level of adaptation in C. rosaceana (i.e., 7.5 x 10(-3) ng Z11-14:OAc/ml air) after 15 min of exposure. Sixteen percent and 28% adaptation of G. molesta antennae is predicted after 15 and 30 min of exposure to the equivalent of 1 ng Z8-12:OAc/m(3) air (i.e., 1 x 10(-6) ng Z8-12:OAc/ml air). The predicted level of adaptation in C. rosaceana antennae, however, is only 1.5 and 9.9% after 15 and 30 min of exposure, respectively, to the equivalent of 1 ng Z11-14:OAc/m(3) air (i.e., 1 x 10(-6) ng Z11-14:OAc/ml air). The approximately three-fold greater level of sensory adaptation in G. molesta antennae after 30 min of exposure to a pheromone concentration measured in pheromone-treated orchards (i.e., 1 ng/m(3)) may be one reason why this species is more readily controlled than C. rosaceana using mating disruption.

Relative attractiveness of incomplete and complete blends of synthetic pheromone to male obliquebanded leafroller (Lepidoptera: Tortricidae) moths in a flight tunnel and in apple orchards: implications for sex pheromone-mediated mating disruption of this species.

The relative attractiveness of synthetic Choristoneura rosaceana (Harris) pheromone consisting of the major compound Z-11-tetradecenyl acetate (Z11-14:OAc), or the major compound plus one, two, or all three of the minor compounds E-11-tetradecenyl acetate (E11-14:OAc), Z-11-tetradecenol (Z11-14:OH), and Z-11-tetradecenal (Z11-14:Ald), in amounts similar to those in the natural pheromone, was compared in a flight tunnel and in apple orchards. In the flight tunnel, there was an increase in the proportion of moths that were activated when E11-14:OAc was combined with the main compound, but no detectible additional increases in response with the addition of Z11-14:OH and Z11-14:Ald. The time required for activation was twice as long when using the major compound than when using the major compound and one or more of the minor compounds. There was a trend of increase in the proportion of males initiating the take-off, lock-on, close-in, and touchdown phases of upwind flight when progressively more complete blends were used. The time required for the initiation of these behavioral phases was statistically similar for each treatment. The proportion of moths landing at the pheromone source was 10 times greater when using the complete blend than when using the main compound alone. Similar results were obtained in apple orchards, where the four-compound blend was 17-55 times more attractive than the main compound. The superior attractiveness of the four-compound pheromone compared with the major compound, or to the major compound plus the minor compound E11-14:OAc, suggests that it would be the most effective synthetic pheromone if competitive attraction were an important mechanism of disruption in this species.

The effect of fathers or father figures on child behavioral problems in families referred to child protective services.

This study examines some possible effects of the presence and quality of parent-child interaction of fathers and father figures on the behavior of young children in a sample of families reported to child protective services. Whereas the presence or absence of a father or father figure seemed to make little difference in child behavioral problems at age 4, lower levels of aggression and depression were observed for children by age 6 if an adult male in some form of father-like relationship was present in the child's life. When controlling for mother's ethnicity, child's gender, the number of referrals to child protective services, and the presence of domestic violence, the direct effect of a father/father figure was no longer significant but remained in the multivariate models as a significant interaction term.

Neural network modeling of risk assessment in child protective services.

The advantages of using neural network methodology for the modeling of complex social science data are demonstrated, and neural network analysis is applied to Washington State Child Protective Services risk assessment data. Neural network modeling of the association between social worker overall assessment of risk and the 37 separate risk factors from the State of Washington Risk Assessment Matrix is shown to provide case classification results superior to linear or logistic multiple regression. The improvement in case prediction and classification accuracy is attributed to the superiority of neural networks for modeling nonlinear relationships between interacting variables; in this respect the mathematical framework of neural networks is a better approximation to the actual process of human decision making than linear, main effects regression. The implications of this modeling advantage for evaluating social science data within the framework of ecological theories are discussed.

Assessment of Amblyseius fallacis (Acari: Phytoseiidae) for biological control of tetranychid mites in an Ontario peach orchard.

We introduced a mass-reared pyrethroid-resistant strain of the predatory phytoseiid mite Amblyseius fallacis (Garman) into an Ontario peach orchard in an attempt to control populations of the phytophagous mites Panonychus ulmi Koch and Tetranychus urticae Koch (Acari: Tetranychidae). Releases of 1,000 and 2,000 mites per tree were made, at three different times. The release of 2,000 mites per tree in June and in July resulted in significantly higher phytoseiid densities than was observed on control trees. However, densities of P. ulmi or T. urticae were not significantly affected by any release rate or by timing. The release of 1,000 A. fallacis per tree, or of any density in August, did not significantly increase phytoseiid abundance. In the following year, population dynamics of both phytoseiid and phytophagous mites were not significantly affected by the previous year's release. Amblyseius fallacis can be a useful predator in some fruit orchards. However, further research is necessary into the timing and rate of release, modified spray programmes, and with different crops, in order to clarify the role of this species for biological control in Ontario peach orchards.

Molecular interactions at octadecylated chromatographic surfaces.

Interactions between fluorescent solutes and an octadecylated silica surface are investigated using fluorescence emission spectra and quenching techniques under conditions similar to those found in high-performance liquid chromatography. Pyrene, benzo[a]pyrene, fluorene, biphenyl, propyldansylamide, and decyldansylamide are used as the fluorescent probes, and potassium iodide and N,N-dimethylaniline are used as quenchers. N,N-Dimethylaniline is a moderately retained quencher thought to probe deeper into the octadecylated surface than the ionic iodide salt. Solvent-dependent fluorescence emission maxima, solvent-dependent fluorescence vibronic band intensities, and quencher access to the probes are investigated using aqueous methanol mobile phase compositions ranging from 60 to 100% methanol. The resulting information is used to interpret differences in interfacial probe environments and to determine the location of the probes within the bonded phase layer. The data indicate that biphenyl and pyrene may remain in very nonpolar interfacial probe environments deep in the bonded phase layer over the mobile phase composition range tested. The fluorophore portion of both propyldansylamide and decyldansylamide may reside in an interfacial environment, which becomes more polar as the water content in the mobile phase is increased. Benzo[a]pyrene apparently becomes exposed to the mobile phase as the water content in the mobile phase increases. This is thought to be due to the relatively large size of the solute molecule and the collapse of the octadecyl chains with increased solvent polarity. Fluorene appears to interact strongly with silanol groups. The results are interpreted in light of the surface convolution and chain cluster octadecylated chromatography surface models and are found to be more constant with the chain cluster model. Implications of the results to reversed phase high-performance liquid chromatography separations are also discussed.

Mapping leaf surface landscapes.

Leaf surfaces provide the ecologically relevant landscapes to those organisms that encounter or colonize the leaf surface. Leaf surface topography directly affects microhabitat availability for colonizing microbes, microhabitat quality and acceptability for insects, and the efficacy of agricultural spray applications. Prior detailed mechanistic studies that examined particular fungi-plant and pollinator-plant interactions have demonstrated the importance of plant surface topography or roughness in determining the outcome of the interactions. Until now, however, it has not been possible to measure accurately the topography--i.e., the three-dimensional structure--of such leaf surfaces or to record precise changes in patterns of leaf surface elevation over time. Using contact mode atomic force microscopy, we measured three-dimensional coordinates of upper leaf surfaces of Vaccinium macrocarpon (cranberry), a perennial plant, on leaves of two age classes. We then produced topographic maps of these leaf surfaces, which revealed striking differences between age classes of leaves: old leaves have much rougher surfaces than those of young leaves. Atomic force microscope measurements were analyzed by lag (1) autocorrelation estimates of leaf surfaces by age class. We suggest that the changes in topography result from removal of epicuticular lipids and that the changes in leaf surface topography influence phylloplane ecology. Visualizing and mapping leaf surfaces permit detailed investigations into leaf surface-mediated phenomena, improving our understanding of phylloplane interactions.

Equine post-anesthetic lameness. A retrospective study.

The incidence of post-anesthetic lameness in 655 horses undergoing 733 anesthetic episodes over a 3 year period was 6.4%. Nineteen factors previously reported or proposed to play a role in the development of post-anesthetic lameness were evaluated statistically. Only hypotension and the duration of the anesthetic period were significant factors.

Indentation Fractography: A Measure of Brittleness.

Indentation constitutes one of the most powerful test techniques for the systematic investigation of deformation and fracture responses in brittle materials. Indentations can be used to evaluate critical mechanical parameters (toughness, hardness, elastic modulus) with great simplicity and high accuracy.

A survey of the use of on-line computer-based scientific search services by academic libraries.

To explore their use of on-line computer-based bibliographic search services, a one-page questionnaire was sent to 100 academic libraries in the United States having separate departmental chemistry or science libraries. An attempt was made to determine the background training of the persons performing the searches, who the end users were, the growth trend, the funding, the data bases used, and the value to the users. Of the 73 replies, 49.3% indicated use of such services, while 24.6% were planning to use them primarily by faculty and graduate students. Of those reporting, 83.3% used searchers with a background in library or information science; 47.2% had a background in scientific discipline. Two or more on-line services were used by 72.2%. A majority of respondents stated that the user paid all expenses or a portion of the expenses. The searches met the needs of the user most of the time in 83.3% of the cases, and all of the time in 5.4%.