Insect pest - white wax scale

Recent investigations in Western Australia have shown that white wax scale can be very effectively controlled by the application of white oil and of white oil-soda sprays. Wax scales derive their name from the typical waxy covering which covers the female insect. Of the two species, the white wax and the pink wax scale, which have been recorded from Western Australia, only the former has gained a permanent footing and is of interest to the citrus grower. For many years the scale was referred to as the Indian wax scale (C. ceriferus Anderson) but was later identified (O\u27Connor, 1933) as the African white wax scale (C. destructor Newstead)

Glueball plus Pion Production in Photon-Photon Collisions.

We here compute the reaction $\gamma \; \gamma \rightarrow G \; \pi^{0}$ for various glueball candidates $G$ and their assumed quantum states, using a non-relativistic gluon bound-state model for the glueball.Comment: To appear in Zeit. fur Phys. C; Plain Latex file, 16 pages; 5 figures appended as a uuencoded postscript file

Scientific Communication: Reporting on Mental Health Illness (MHI) in Kenya: how well are we doing?

No Abstrac

Provision of straw as a foraging substrate reduces the development of excessive chain and bar manipulation in food restricted sows.

Pregnant sows fed at commercial levels remain highly food motivated for most of the day. The inability to express this behaviour appropriately may, under certain conditions, result in the development of abnormal oral activities such as stereotypic chain and bar manipulation. Ninety-six gilts, all between 1 and 3 weeks post service, were entered into a 2X2 factorial design comparing food level (low, 1.8 kg/23 MJ day(-1) (L); high, 3.2 kg/40 MJ day(-1) (H)) and the provision of a foraging substrate (S, straw; N, no straw). The gilts were loose housed in groups of six with individual stalls. A 70 cm chain loop was attached to the front of each stair. The sows were fed at 09:00 h, during which time S sows received straw (approximately 1.5 kg per sow). Behaviour was recorded over the first two parities, by time sampling for the 2 and 6 h after the start of feeding and over 24 h using video recordings. Activity levels were highest just after feeding, with L sows being more active than H sows (L vs. H, 79% vs. 49% for the second hour after the start of feeding, F-1,F-12 = 41.5, P <0.001). Most of the postprandial activity consisted of manipulating substrates. In LN sows, particularly in Parity 2, this behaviour was mainly directed towards chains and bars, resulting in levels three to four times higher than in other groups (26%, 7%, 4% and 4% for the second hour after feeding for LN, LS, HN and HS respectively; Tukey's HSD, P <0.05). LS sows directed their foraging behaviour mainly towards the straw. It is concluded that in food-restricted pregnant sows, abnormally high levels of chain and bar manipulation can be prevented by providing straw which apparently acts as a foraging substrate

Caretaker mental health and family environment factors are associated with adolescent psychiatric problems in a Vietnamese sample

Little is known about risk factors for adolescent mental health in Vietnam. The present study investigated the relationship between caretaker mental health and adolescent mental health in a cross-sectional Vietnamese sample. Primary caretakers completed measures of their own mental distress and general health status using the Self-Reporting Questionnaire-20 (SRQ-20) as well as reports of adolescent mental health using the parent version of the Strengths and Difficulties Questionnaire (SDQ). Multivariate regression models were used to examine the relationships between the caretaker and adolescent health variables. The demographic factors of age, sex, ethnicity, religious affiliation, and household wealth status demonstrated significant relationships with SDQ subscale scores. Caretaker mental health was positively associated with adolescent mental health, and this association remained significant even after accounting for other relevant demographic variables and caretaker general health status. Understanding correlates of adolescent mental health difficulties may help identify youth and families at risk for developing psychiatric problems and inform mental health interventions in Vietnam

Spin glass transition in a magnetic field: a renormalization group study

We study the transition of short range Ising spin glasses in a magnetic field, within a general replica symmetric field theory, which contains three masses and eight cubic couplings, that is defined in terms of the fields representing the replicon, anomalous and longitudinal modes. We discuss the symmetry of the theory in the limit of replica number n to 0, and consider the regular case where the longitudinal and anomalous masses remain degenerate. The spin glass transitions in zero and non-zero field are analyzed in a common framework. The mean field treatment shows the usual results, that is a transition in zero field, where all the modes become critical, and a transition in non-zero field, at the de Almeida-Thouless (AT) line, with only the replicon mode critical. Renormalization group methods are used to study the critical behavior, to order epsilon = 6-d. In the general theory we find a stable fixed-point associated to the spin glass transition in zero field. This fixed-point becomes unstable in the presence of a small magnetic field, and we calculate crossover exponents, which we relate to zero-field critical exponents. In a finite magnetic field, we find no physical stable fixed-point to describe the AT transition, in agreement with previous results of other authors.Comment: 36 pages with 4 tables. To be published in Phys. Rev.

Plankton lattices and the role of chaos in plankton patchiness

Spatiotemporal and interspecies irregularities in planktonic populations have been widely observed. Much research into the drivers of such plankton patches has been initiated over the past few decades but only recently have the dynamics of the interacting patches themselves been considered. We take a coupled lattice approach to model continuous-in-time plankton patch dynamics, as opposed to the more common continuum type reaction-diffusion-advection model, because it potentially offers a broader scope of application and numerical study with relative ease. We show that nonsynchronous plankton patch dynamics (the discrete analog of spatiotemporal irregularity) arise quite naturally for patches whose underlying dynamics are chaotic. However, we also observe that for parameters in a neighborhood of the chaotic regime, smooth generalized synchronization of nonidentical patches is more readily supported which reduces the incidence of distinct patchiness. We demonstrate that simply associating the coupling strength with measurements of (effective) turbulent diffusivity results in a realistic critical length of the order of 100 km, above which one would expect to observe unsynchronized behavior. It is likely that this estimate of critical length may be reduced by a more exact interpretation of coupling in turbulent flows

The effect of rare regions on a disordered itinerant quantum antiferromagnet with cubic anisotropy

We study the quantum phase transition of an itinerant antiferromagnet with cubic anisotropy in the presence of quenched disorder, paying particular attention to the locally ordered spatial regions that form in the Griffiths region. We derive an effective action where these rare regions are described in terms of static annealed disorder. A one loop renormalization group analysis of the effective action shows that for order parameter dimensions $p<4$ the rare regions destroy the conventional critical behavior. For order parameter dimensions $p>4$ the critical behavior is not influenced by the rare regions, it is described by the conventional dirty cubic fixed point. We also discuss the influence of the rare regions on the fluctuation-driven first-order transition in this system.Comment: 6 pages RevTe

Amplitude measurements of Faraday waves

A light reflection technique is used to measure quantitatively the surface elevation of Faraday waves. The performed measurements cover a wide parameter range of driving frequencies and sample viscosities. In the capillary wave regime the bifurcation diagrams exhibit a frequency independent scaling proportional to the wavelength. We also provide numerical simulations of the full Navier-Stokes equations, which are in quantitative agreement up to supercritical drive amplitudes of 20%. The validity of an existing perturbation analysis is found to be limited to 2.5% overcriticaly.Comment: 7 figure