Observations on the Nesting of \u3ci\u3eCrabro Tenuis\u3c/i\u3e (Hymenoptera: Sphecidae)

Three nests of Crabro tenuis were studied during June 1971-1972 in Oswego County, New York. Females constructed shallow but lengthy, multicelled nests in sand with the cells being built in clusters, sometimes in series. Females plugged the entrances with damp sand and occupied the burrows during midday. Paralyzed prey were stored head inward at the end of the burrow. The deeper cells in a cluster were excavated and provisioned first and the shallower cells built and stored later, as determined by the developmental stages of the wasps within the cells. From four to seven paralyzed, adult male flies were placed in a fully provisioned cell with their venters toward the center. Such a cell usually held only one species of fly. Provisions consisted of the suborders Brachycera and Cyclorrhapha and comprised the families Rhagionidae, Anthomyiidae and Tachinidae. An egg was affixed about equally to the left or right side of the neck of a fly and this prey was placed against or near the wall of the cell. The nesting traits of C. tenuis were compared with those of other members of the Cribrarius group, C. advena of the Advena, group, C. venator of the Tumidus group and species in the Hilaris group

Range Extensions for Species of Sphecidae (Hymenoptera) in the Northeastern United States

The ranges of 10 Nearctic species of Sphecidae, Spilomena pusilla, Tachytes parvus, Solierella plenoculoides, Pison agile, Entomognathus lenapeorum, Rhopalum clavipes, Crabro hilaris, C. tenuis, Alysson conicus and Lestiphorus cockerelli, are extended in the northeastern U.S. based upon collections made in Pennsylvania and New York. The first prey record for a North American species of Lestiphorus, cockerelli, is included

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The Strength and Metallography of a Bimetallic Friction Stir Bonded Joint between AA6061 and High Hardness Steel

12.7-mm thick plates of 6061-T6511 aluminum alloy and high hardness steel (528 HV) were successfully joined by a friction stir bonding process using a tungsten-rhenium stir tool. Process parameter variation experiments, which included tool design geometry, plunge and traverse rates, tool offset, spindle tilt, and rotation speed, were conducted to develop a parameter set which yielded a defect free joint. Laboratory tensile tests exhibited yield stresses which exceed the strengths of comparable AA6061-to-AA6061 fusion and friction stir weld joints. Scanning electron microscopy and energy dispersive X-ray spectroscopy analysis also show atomic diffusion at the material interface region

On Limitations to the achievable path following performance for linear multivariable plants

In this paper, we consider a problem termed “path following”. This differs from the common problem of reference tracking, in that here we can adjust the speed at which we traverse the reference trajectory. We are interested in ascertaining the degree to which we can track a given trajectory, and in characterizing the class of paths for which we can generate an appropriate temporal specification so that the path can be tracked arbitrarily well in an L2 sense.We give various bounds on the achievable performance, as well as tight results in special cases. In addition, we give a numerical procedure based on convex optimization for computing the achievable performance. The results demonstrate that there are situations where arbitrarily good L2 performance may be achieved even though the origin is not in the convex hull of the positive limit set of the path to be followed

Evidence for O-atom exchange in the O(^1D) + N_2O reaction as the source of mass-independent isotopic fractionation in atmospheric N_2O

Recent experiments have shown that in the oxygen isotopic exchange reaction for O(^1D) + CO_2 the elastic channel is approximately 50% that of the inelastic channel [Perri et al., 2003]. We propose an analogous oxygen atom exchange reaction for the isoelectronic O(^1D) + N_2O system to explain the mass-independent isotopic fractionation (MIF) in atmospheric N_2O. We apply quantum chemical methods to compute the energetics of the potential energy surfaces on which the O(^1D) + N_2O reaction occurs. Preliminary modeling results indicate that oxygen isotopic exchange via O(^1D) + N_2O can account for the MIF oxygen anomaly if the oxygen atom isotopic exchange rate is 30–50% that of the total rate for the reactive channels

Drivers of the Value of the Firm: Profitability, Growth, and Capital Intensity

Value-based management systems focus on wealth and the wealth creation process and promote the generation of value for the shareholders. A valuation model for the firm is extended analytically to focus explicitly on profitability, growth, and capital intensity as drivers of the value of the firm. The extended model provides information about the sensitivities of the value of the firm to changes in the firm\u27s profitability, growth, and capital intensity. These sensitivities are presented in terms of changes per dollar of sales and actual dollar changes. The changes per dollar of sales show the relative sensitivities of the changes in the value of the firm resulting from changes in the measures for profitability, growth, and capital intensity. Each dollar amount shows the total dollar changes in the value of the firm resulting from changes in the profitability, growth, and capital intensity measures. These sensitivities show the impact of changes in the profitability, growth, and capital intensity measures on the value of the firm. This information is valuable in helping managers determine a desired course of action to improve the wealth generating ability of the firm by managing these value drivers more effectively

Setting Goals in Different Roles: Applying Key Results From the Goal-Setting Literature

Decades of research have demonstrated that managers can effect substantial performance improvements by setting challenging and specific performance goals (Locke & Latham, 2002), providing goal-relevant feedback on a regular basis (Karakowsky & Mann, 2008), and, when appropriate, involving subordinates in goal setting (Stansfield & Longenecker, 2006). This article reviews core findings from the goal setting literature, and presents a collaborative exercise in which teams of students apply these findings to address management problems in five fictitious scenarios. Debriefing tips cite additional research evidence to allow for more nuanced classroom discussion of goal setting. A pretest indicated that prior to completing the goal-setting exercise, only a minority of students had a strong intuitive sense of how to set effective goals; a posttest following its completion demonstrated substantial improvement. Students rated the exercise as both challenging and effective in improving their knowledge of goal setting

WILDLIFE CONTRACEPTION: TARGETING THE OOCYTE

The USDA’s National Wildlife Research Center (NWRC) has successfully researched and developed a number of chemical and immunologically-based wildlife contraceptives. Diazacon™ interferes with cholesterol metabolism and disrupts steroidogenesis, while nicarbazin (registered as OvoControl-P® and OvoControl-G®) disrupts the structure of the vitelline membrane of bird eggs. Immunologically-based agents act to stimulate targeted antibody production. GonaCon™ causes the host’s immune system to bind gonadotropin releasing hormone, preventing ovulation, while SpayVac™ prevents fertilization of the postovulatory oocyte. This kind of target specificity can be highly advantageous. A number of oocyte-only control contraceptive strategies are currently being researched at the NWRC. 4-Vinylcyclohexene diepoxide (VCD) is an industrial chemical which is specifically ovotoxic, depleting the ovarian oocyte pool with repeated exposure. Research into VCD efficacy as well as the comparability of a similar diepoxide, ERL 4221, in rats and pigs is in progress. Immunological inhibition of recently discovered oocyte-secreted proteins which regulate follicular development in mammals is also of interest. Two such proteins, growth differentiation factor 9 (GDF9) and bone morphogenic protein 15 (BMP15), are highly specific targets for the suppression or elimination of folliculogenesis. These oocyte-specific strategies may offer new, effective alternatives for wildlife contraception

Reply to comment by Röckmann and Kaiser on "Evidence for O-atom exchange in the O(^1D) + N_2O reaction as the source of mass-independent isotopic fractionation in atmospheric N_2O"

Based upon the authors’ questioning of the existence of the C_(2v) intermediate, we have reviewed our evidence for the existence of this state. It now appears that this state was in fact an artifact of our calculation [Yung et al., 2004], and was a saddle point rather than a true minimum. Our desire to provide a timely response to this criticism has kept us from determining exactly what minimum structure will be obtained by a full minimization at the level of theory employed. However, it is clear that the C_(2v) symmetry of the compound is broken in such a way that the two N-O bonds are no longer equivalent. We are grateful to the authors for helping us resolve this issue