The sophisticated organization of eusocial insect societies is largely based on the regulation of complex behaviors by hydrocarbon pheromones present on the cuticle. We used electrophysiology to investigate the detection of cuticular hydrocarbons (CHCs) by female-specific olfactory sensilla basiconica on the antenna of Camponotus floridanus ants through the utilization of one of the largest family of odorant receptors characterized so far in insects. These sensilla, each of which contains multiple olfactory receptor neurons, are differentially sensitive to CHCs and allow them to be classified into three broad groups that collectively detect every hydrocarbon tested, including queen and worker-enriched CHCs. This broad-spectrum sensitivity is conserved in a related species, Camponotus laevigatus, allowing these ants to detect CHCs from both nestmates and non-nestmates. Behavioral assays demonstrate that these ants are excellent at discriminating CHCs detected by the antenna, including enantiomers of a candidate queen pheromone that regulates the reproductive division of labor.

Oviposition pheromones specifically influence the females of many insects to lay eggs in the sites resulting in more egg deposition. A previous report describes the principal role of n-heneicosane (C(21)) identified and characterized from the larval cuticle of Aedes aegypti (L.) in attracting the gravid mosquitoes to oviposit in treated substrates among other chemical components. However, the means by which this compound is perceived by the females for oviposition has not been reported. In this study, we have recorded the peripheral olfactory responses from the antenna of Ae. aegypti from 10(-7) g to 10(-3) g doses of n-heneicosane. The EAG response of female mosquitoes increased in a dose-dependent manner with increasing stimulus strength. In the orientation assay using Y-maze olfactometer, female mosquitoes were attracted to the odor plume of 10(-6) g and 10(-5) g dose, while the higher dose of 10(-3) g plume enforced repellency to gravid mosquitoes. The response to oviposition substrates by gravid Ae. aegypti females differed across the range of concentrations of n-heneicosane under multiple choice conditions, larger number of eggs were deposited in 10 ppm (10 mg/l) solutions compared to lower and higher concentrations indicating 10 ppm was most attractive. Application of n-heneicosane at 10 ppm in breeding habitats will be a useful method to attract the gravid mosquitoes using ovitraps for surveillance and monitoring. The possible use of this compound in monitoring of mosquito population in endemic areas in relevance to integrated vector management strategies is discussed in detail.

We studied 45 ASA I/II children aged between 2 and 13 years scheduled for elective strabismus surgery, randomly allocated to receive either a peribulbar block or topical lidocaine 2% combined with general anaesthesia, or general anaesthesia alone. The incidence and severity of the occulocardiac reflex, the requirement for atropine, the occurrence of arrhythmias and incidence of postoperative nausea and vomiting following surgery at 1, 2 and 4 h were studied. We found the incidence and severity of occulocardiac reflex intra-operatively was significantly reduced in children who received a peribulbar block. The incidence of postoperative nausea and vomiting was significantly reduced in patients receiving either peribulbar block or topical local anaesthesia combined with general anaesthesia, compared to general anaesthesia alone (p = 0.008).

Background:Optimal depth of endotracheal tube (ET) placement has been a serious concern because of the complications associated with its malposition.Aims:To find the optimal depth of placement of oral ET in Indian adult patients and its possible determinants viz. height, weight, arm span and vertebral column length.Settings and Design:This study was conducted in 200 ASA I and II patients requiring general anaesthesia and orotracheal intubation.Methods:After placing the ET with the designated black mark at vocal cords, various airway distances were measured from the right angle of mouth using a fibre optic bronchoscope.Statistical Analysis:The power of the study is 0.9. Mean (SD) and median (range) of various parameters and Pearson correlation coefficient was calculated.Results:The mean (SD) lip-carina distance, i.e., total airway length was 24.32 (1.81) cm and 21.62 (1.34) cm in males and females, respectively. With black mark of ET between vocal cords, the mean (SD) ET tip-carina distance of 3.69 (1.65) cm in males and 2.28 (1.55) cm females was found to be considerably less than the recommended safe distance.Conclusions:Fixing the tube at recommended 23 cm in males and 21 cm in females will lead to carinal stimulation or endobronchial placement in many Indian patients. The lip to carina distance best correlates with patient's height. Positioning the ET tip 4 cm above carina as recommended will result in placement of tube cuff inside cricoid ring with currently available tubes. Optimal depth of ET placement can be estimated by the formula “(Height in cm/7)-2.5.”

The phorid fly, Pseudacteon tricuspis Borgmeier, is an introduced parasitoid of imported fire ants, Solenopsis spp., in the USA. Although the assumption that phorid flies use fire ant alarm pheromones for host location is probably true, we demonstrated in a previous study the possible involvement of other ant semiochemicals in the response of P. tricuspis to fire ants. This study was conducted to determine the glandular sources and identity of the semiochemicals mediating this interaction. First, we tested the electroantennogram response of P. tricuspis to extracts of key body parts and glands of workers of the red imported fire ant, S. invicta Buren. The results confirm that the poison (venom) gland/sac is the key source of compounds which elicited strong antennal activity in P. tricuspis. Follow-up studies were conducted by using a combination of bioassay-guided fractionation and behavioral bioassays to test the hypothesis that attraction of this parasitoid to fire ants is mediated by venom alkaloids. The results confirm the response of P. tricuspis to physiologically relevant amounts of the two venom alkaloid fractions (cis and trans alkaloid fractions) of S. invicta. Further analysis by coupled gas chromatography-electroantennogram detection revealed nine venom alkaloid components including two novel 2,6-dialkylpiperideines that elicited significant antennal activity in P. tricuspis. This is the first demonstration of the role of venom alkaloids of ants as attractants for their natural enemies. We propose a semiochemical-mediated host location mechanism for P. tricuspis involving both alarm pheromones and venom alkaloids. The ecological significance of these findings, including the attraction of male P. tricuspis to fire ant venom alkaloids, possibly for mate location, is discussed.

The endoparasitic wasps (Hymenoptera: Braconidae), Microplitis croceipes (specialist), and Cotesia marginiventris (generalist) are parasitoids of lepidopteran larvae that differ in their degree of host specificity. Previous studies by our group have reported key differences in the response of both parasitoids to host-related volatiles. To possibly understand the basis for our results, we compared the abundance of antennal sensilla in both sexes of both parasitoid species using scanning electron microscopy and silver-staining techniques. Males of both species had relatively longer antennae than conspecific females. Five major sensilla types were recorded in both species: sensilla chaetica (nonporous), s. trichodea (nonporous), s. placodea (multiporous), s. basiconica (two types, type 1 with terminal opening and type 2 with wall pores), and s. coeloconica (nonporous). Silver staining confirmed multiple pores on the walls of s. placodea and s. basiconica type 2 and terminal openings on s. basiconica type 1, suggesting chemosensory function. In general, both putative chemosensilla types, s. placodea and s. basiconica, were more abundant in M. croceipes (specialist) than in C. marginiventris (generalist), and this was true for both sexes. Comparing the sexes, s. placodea and s. trichodea were significantly more abundant in M. croceipes males compared to females. In contrast, s. placodea was relatively more abundant in female C. marginiventris than in males. These results may explain the reported differences in the responses of both parasitoid species to host-related volatiles and are discussed in relation to the possible roles of the sensilla types in the behavioral ecology of the parasitoids.

Abstract. In this paper, we describe the kinematical and evolutionary properties of the impulsive cool jets in the solar atmosphere using numerical simulation by Godunov-type PLUTO code at two different quiet-Sun magnetic field strengths (B=56 gauss and B=112 gauss). These types of chromospheric jets originate due to a pressure pulse, which mimics the after-effects of the localized heating in the lower solar atmosphere. These jets may be responsible for the transport of mass and energy in the localized upper atmosphere (i.e. corona). The detection of the height–time profiles for the jets, which were developed by imposing different pressure pulses, exhibit asymmetric near-parabolic behaviour. This infers that the upward motion of the jet occurs under the influence of pressure perturbation. However, its downward motion is not only governed by the gravitational free fall, but also by the complex plasma motions near its base under the effect of counter-propagating pulses. The maximum height and lifetime of the jets with respect to the strength of the pressure pulse show a linear increasing trend. This suggests that if the extent of the heating and, thus, the pressure perturbations are longer, then more longer chromospheric jets can be triggered from the same location in the chromosphere. For a certain amplitude of pressure pulse, the strong magnetic field configuration (B=112 gauss) leads to more longer jets compared with the weaker field (B=56 gauss). This suggests that the strong magnetic field guides the pressure-pulse-driven jets more efficiency towards the higher corona. In conclusion, our model mimics the properties and evolution of the variety of the cool impulsive jets in the chromosphere (e.g. macrospicules, network jets, isolated repeated cool jets, confined and small surges, and so on.).

We perform a 2.5 dimensional magnetohydrodynamic (MHD) simulation to understand a comprehensive view of the formation of spicule-like cool jets due to initial transverse velocity pulses akin to Alfvén pulses in the solar chromosphere. We invoke multiple velocity (Vz) pulses between 1.5 and 2.0 Mm in the solar atmosphere, which create the initial transverse velocity perturbations. These pulses transfer energy non-linearly to the field aligned perturbations due to the ponderomotive force. This physical process further creates the magnetoacoustic shocks followed by quasi-periodic plasma motions in the solar atmosphere. The field aligned magnetoacoustic shocks move upward which subsequently cause quasi-periodic rise and fall of the chromospheric plasma into the overlying corona as a thin and cool spicule-like jets. The magnitude of the initial applied transverse velocity pulses are taken in the range of 50-90 km s−1. These pulses are found to be strong enough to generate the spicule-like jets. We analyse the evolution, kinematics and energetics of these spicule-like jets. We find that the transported mass flux and kinetic energy density are substantial in the localized solar-corona. These mass motions generate in situ quasi-periodic oscillations on the scale of ≃ 4.0 min above the transition region.