The Effects of Boric Acid Sugar Bait on \u3ci\u3eWolbachia\u3c/i\u3e Trans-Infected Male \u3ci\u3eAedes albopictus\u3c/i\u3e (ZAP Males\u3csup\u3e®\u3c/sup\u3e) in Laboratory Conditions

The field release of Wolbachia trans-infected male mosquitoes, as well as the use of toxic sugar baits, is a novel and promising candidate technique for integrated mosquito management programs. However, the methods of action of the two techniques may not be complementary, because the Wolbachia method releases mosquitoes into the environment expecting a wild population reduction in subsequent generations while the toxic baits are intended to reduce the wild population by killing mosquitoes. This laboratory study was conducted to evaluate the effectiveness of boric acid toxic sugar baits on Wolbachia trans-infected male Aedes albopictus, relative to wild-type Ae. albopictus males. Wolbachia trans-infected (ZAP male®) and the wild-type Ae. albopictus males were exposed separately to 1% boric acid in a 10% sucrose solution in BugDorms. In the control test, the two groups were exposed to 10% sucrose solution without boric acid. Percent mortalities were counted for 24 h, 48 h and 72 h post exposure periods. The results show that 1% boric acid toxic sugar bait can effectively kill ZAP males under laboratory conditions, and the effectiveness was significantly higher after 24 h and 48 h, compared to wild-type male Ae. albopictus. This finding will help in planning and coordinating integrated mosquito management programs, including both Wolbachia trans-infected mosquito releases and the use of toxic sugar baits against Ae. albopictus

Pupil mobility, attainment and progress in secondary school

This paper is the second of two articles arising from a study of the association between pupil mobility and attainment in national tests and examinations in an inner London borough. The first article (Strand & Demie, 2006) examined the association of pupil mobility with attainment and progress during primary school. It concluded that pupil mobility had little impact on performance in national tests at age 11, once pupils’ prior attainment at age 7 and other pupil background factors such as age, sex, special educational needs, stage of fluency in English and socio-economic disadvantage were taken into account. The present article reports the results for secondary schools (age 11-16). The results indicate that pupil mobility continues to have a significant negative association with performance in public examinations at age 16, even after including statistical controls for prior attainment at age 11 and other pupil background factors. Possible reasons for the contrasting results across school phases are explored. The implications for policy and further research are discussed

Cloning and characterization of a gene encoding the major surface protein of the bacterial endosymbiont Wolbachia pipientis

The maternally inherited intracellular symbiont Wolbachia pipientis is well known for inducing a variety of reproductive abnormalities in the diverse arthropod hosts it infects. It has been implicated in causing cytoplasmic incompatibility, parthenogenesis, and the feminization of genetic males in different hosts. The molecular mechanisms by which this fastidious intracellular bacterium causes these reproductive and developmental abnormalities have not yet been determined. In this paper, we report on (i) the purification of one of the most abundantly expressed Wolbachia proteins from infected Drosophila eggs and (ii) the subsequent cloning and characterization of the gene (wsp) that encodes it. The functionality of the wsp promoter region was also successfully tested in Escherichia coli. Comparison of sequences of this gene from different strains of Wolbachia revealed a high level of variability. This sequence variation correlated with the ability of certain Wolbachia strains to induce or rescue the cytoplasmic incompatibility phenotype in infected insects. As such, this gene will be a very useful tool for Wolbachia strain typing and phylogenetic analysis, as well as understanding the molecular basis of the interaction of Wolbachia with its host

Determinants of Male Aedes aegypti and Aedes polynesiensis (Diptera: Culicidae) Response to Sound: Efficacy and Considerations for Use of Sound Traps in the Field

Understanding the mating competitiveness of male mosquitoes in field settings is essential to programs relying on the mass release of modified male mosquitoes, yet studies on male ecology have been hampered by the lack of a convenient trapping method. An existing promising method makes use of the innate attraction of males to female flight tones. Here, we present laboratory, greenhouse, and field experiments on the efficacy of sound traps for the collection of Aedes aegypti (L.) and Aedes polynesiensis Marks, and laboratory experiments with Ae. aegypti on the effects of male age, size, and mating status on responsiveness to a range of frequencies. Age and mating status influenced the overall responsiveness to sound, whereas male size did not. There were no interactions between these factors and sound frequency. A Centers for Disease Control and Prevention miniature light trap modified to produce a tone of 465 Hz collected 76.2% of Ae. aegypti males in laboratory cages, and 49.7% of males in a greenhouse enclosure. In two sets of experiments in laboratory cages, 50.8 and 46.5% of male Ae. polynesiensis were captured with a trap producing a tone of 440 Hz. In the field, CDC miniature light traps or BG-Sentinel traps fitted with a portable speaker producing tones of 440 or 465 Hz captured significantly more male Ae. polynesiensis when placed near a male swarm than did traps that did not produce sound. When the trap was placed at a distance of 16.5 m from the nearest swarm, there was no significant difference in the number of males caught between control and sound-producing traps. The numbers of Ae. aegypti males captured were low under all circumstances in the fiel

Swarming Behavior of Aedes polynesiensis (Diptera: Culicidae) and Characterization of Swarm Markers in American Samoa

We characterize the swarming behavior of male Aedes polynesiensis (Marks) in American Samoa. Instead of swarming around a blood host, males used the base of certain trees as a marker. Repeated sampling proved nondestructive and allowed us to investigate the impact of static (e.g., tree species) and dynamic (e.g., barometric pressure) characters on the likelihood of swarm presence and intensity. Tree circumference and oviposition activity (number of Ae. polynesiensis reared from oviposition cups) were significant positive predictors of the number of males in a swarm. Tree circumference and diameter were significantly positively associated, and canopy height was significantly negatively associated, with swarm occurrence. Comparisons between males swarming early and late during the swarming period allowed for insight into swarm composition in terms of male size and the amount of putative fluid (e.g., nectar) in the crop, indicators of energetic reserves. Males collected during the late period had significantly larger wings and less crop contents than did males of the early cohort. Because the ecology of male Ae. polynesiensis remains understudied, we consider how the current results could facilitate further studies related to applied autocidal strategies as well as the evolution of host-based mating behavio

Collisionless hydrodynamics for 1D motion of inhomogeneous degenerate electron gases: equivalence of two recent descriptions

Recently I. Tokatly and O. Pankratov (''TP'', Phys. Rev. B 60, 15550 (1999)) used velocity moments of a semiclassical kinetic equation to derive a hydrodynamic description of electron motion in a degenerate electron gas. Independently, the present authors (Theochem 501-502, 327 (2000)) used considerations arising from the Harmonic Potential Theorem (Phys. Rev. Lett. 73, 2244 (1994)) to generate a new form of high-frequency hydrodynamics for inhomogeneous degenerate electron gases (HPT-N3 hydrodynamics). We show here that TP hydrodynamics yields HPT-N3 hydrodynamics when linearized about a Thomas-Fermi groundstate with one-dimensional spatial inhomnogeneity.Comment: 17p

Asymptotically exact dispersion relations for collective modes in a confined charged Fermi liquid

Using general local conservations laws we derive dispersion relations for edge modes in a slab of electron liquid confined by a symmetric potential. The dispersion relations are exact up to $\lambda^{2} q^{2}$, where $q$ is a wave vector and $\lambda$ is an effective screening length. For a harmonic external potential the dispersion relations are expressed in terms of the {\em exact} static pressure and dynamic shear modulus of a homogeneous liquid with the density taken at the slab core. We also derive a simple expression for the frequency shift of the dipole (Kohn) modes in nearly parabolic quantum dots in a magnetic field.Comment: RevTeX4, 4 pages. Revised version with new results on quantum qots and wires. Published in Phys.Rev.

Exchange and Correlation Kernels at the Resonance Frequency -- Implications for Excitation Energies in Density-Functional Theory

Specific matrix elements of exchange and correlation kernels in time-dependent density-functional theory are computed. The knowledge of these matrix elements not only constraints approximate time-dependent functionals, but also allows to link different practical approaches to excited states, either based on density-functional theory, or on many-body perturbation theory, despite the approximations that have been performed to derive them.Comment: Submitted to Phys. Rev. Lett. (February 4, 1999). Other related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

Time-dependent density functional theory beyond the adiabatic local density approximation

In the current density functional theory of linear and nonlinear time-dependent phenomena, the treatment of exchange and correlation beyond the level of the adiabatic local density approximation is shown to lead to the appearance of viscoelastic stresses in the electron fluid. Complex and frequency-dependent viscosity/elasticity coefficients are microscopically derived and expressed in terms of properties of the homogeneous electron gas. As a first consequence of this formalism, we provide an explicit formula for the linewidths of collective excitations in electronic systems.Comment: RevTeX, 4 page