The effectiveness of dieldrin for control of the Argentine ant in Western Australia

The results of three experiments to compare insecticides for the eradication of Argentine ants are reported. The areas used for the tests were typical household allotments in Shenton Park, a suburb of Perth, Western Australia. The methods of application of sprays and evaluation of results were the same as described in a previous paper. (Forte & Greaves 1953.

New insecticides for the control of the Argentine ant in Western Australia

The Argentine Ant (Iridomyrmex humilis Mayr), has been the subject of much investigation in Western Australia. Jenkins (1943), Jenkins and Forte (1946, 1951), Jenkins (1948) and Forte (1949) have reported results of extensive work on the control of this pest. The results of the investigations have shown that effective control can be obtained by the use of DDT sprays but that large scale eradication was not possible with DDT

Ground-based detection of a cloud of methanol from Enceladus: When is a biomarker not a biomarker?

Saturn's moon Enceladus has vents emerging from a sub-surface ocean, offering unique probes into the liquid environment. These vents drain into the larger neutral torus in orbit around Saturn. We present a methanol (CH3OH) detection observed with IRAM 30-m from 2008 along the line-of-sight through Saturn's E-ring. Additionally, we also present supporting observations from the Herschel public archive of water (ortho-H2O; 1669.9 GHz) from 2012 at a similar elongation and line-of-sight. The CH3OH 5(1,1)-4(1,1) transition was detected at 5.9 sigma confidence. The line has 0.43 km/s width and is offset by +8.1 km/s in the moon's reference frame. Radiative transfer models allow for gas cloud dimensions from 1750 km up to the telescope beam diameter ~73000 km. Taking into account the CH3OH lifetime against solar photodissociation and the redshifted line velocity, there are two possible explanations for the CH3OH emission: methanol is primarily a secondary product of chemical interactions within the neutral torus that (1) spreads outward throughout the E-ring or (2) originates from a compact, confined gas cloud lagging Enceladus by several km/s. We find either scenario to be consistent with significant redshifted H2O emission (4 sigma) measured from the Herschel public archive. The measured CH3OH:H2O abundance (> 0.5 per cent) significantly exceeds the observed abundance in the direct vicinity of the vents (~0.01 per cent), suggesting CH3OH is likely chemically processed within the gas cloud with methane (CH4) as its parent species.Comment: 16 pages, 4 figures, accepted for publication in the International Journal of Astrobiology (IJA

Matrix controlled channel diffusion of sodium in amorphous silica

To find the origin of the diffusion channels observed in sodium-silicate glasses, we have performed classical molecular dynamics simulations of Na$_2$O--4SiO$_2$ during which the mass of the Si and O atoms has been multiplied by a tuning coefficient. We observe that the channels disappear and that the diffusive motion of the sodium atoms vanishes if this coefficient is larger than a threshold value. Above this threshold the vibrational states of the matrix are not compatible with those of the sodium ions. We interpret hence the decrease of the diffusion by the absence of resonance conditions.Comment: 5 pages, 4 figure

Coplanar Circumbinary Debris Disks

We present resolved Herschel images of circumbinary debris disks in the alpha CrB (HD139006) and beta Tri (HD13161) systems. We find that both disks are consistent with being aligned with the binary orbital planes. Though secular perturbations from the binary can align the disk, in both cases the alignment time at the distances at which the disk is resolved is greater than the stellar age, so we conclude that the coplanarity was primordial. Neither disk can be modelled as a narrow ring, requiring extended radial distributions. To satisfy both the Herschel and mid-IR images of the alpha CrB disk, we construct a model that extends from 1-300AU, whose radial profile is broadly consistent with a picture where planetesimal collisions are excited by secular perturbations from the binary. However, this model is also consistent with stirring by other mechanisms, such as the formation of Pluto-sized objects. The beta Tri disk model extends from 50-400AU. A model with depleted (rather than empty) inner regions also reproduces the observations and is consistent with binary and other stirring mechanisms. As part of the modelling process, we find that the Herschel PACS beam varies by as much as 10% at 70um and a few % at 100um. The 70um variation can therefore hinder image interpretation, particularly for poorly resolved objects. The number of systems in which circumbinary debris disk orientations have been compared with the binary plane is now four. More systems are needed, but a picture in which disks around very close binaries (alpha CrB, beta Tri, and HD 98800, with periods of a few weeks to a year) are aligned, and disks around wider binaries (99 Her, with a 50 yr period) are misaligned, may be emerging. This picture is qualitatively consistent with the expectation that the protoplanetary disks from which the debris emerged are more likely to be aligned if their binaries have shorter periods.Comment: accepted to MNRA

Channel diffusion of sodium in a silicate glass

We use classical molecular dynamics simulations to study the dynamics of sodium atoms in amorphous Na$_2$O-4SiO$_2$. We find that the sodium trajectories form a well connected network of pockets and channels. Inside these channels the motion of the atoms is not cooperative but rather given by independent thermally activated hops of individual atoms between the pockets. By determining the probability that an atom returns to a given starting site, we show that such events are not important for the dynamics of this system.Comment: 10 pages of Latex, 5 figures, one figure added, text expande

Atomic environments in iron meteorites using EXAFS

Extended x ray absorption fine structure (EXAFS) is observed as a modulation on the high energy side of an x ray absorption edge. It occurs when the photo-ejected electron wave is scattered by neighboring atoms in a solid, and interference occurs between the outgoing and scattered waves. The result is that the absorption spectrum carries a signature that is characteristic of the identity and disposition of scattering atoms around the absorbing atom. Therefore, it may be shown that the Fourier transform of the normalized EXAFS can provide detailed information about the immediate environment of specific atoms in a solid and is ideally suited to the study of cosmic dusts. A study of cosmic dust was initiated using EXAFS and other techniques. The simplest type of cosmic material, namely iron meteorites, was investigated

Feasibility Randomized Controlled Trial of ImpulsePal: Smartphone App–Based Weight Management Intervention to Reduce Impulsive Eating in Overweight Adults

This is the final version. Available from JMIR Publications via the DOI in this record.Background: ImpulsePal is a theory-driven (dual-process), evidence-informed, and person-centered smartphone app intervention designed to help people manage impulsive processes that prompt unhealthy eating to facilitate dietary change and weight loss. Objective: The aims of this study were to (1) assess the feasibility of trial procedures for evaluation of the ImpulsePal intervention, (2) estimate standard deviations of outcomes, and (3) assess usability of, and satisfaction with, ImpulsePal. Methods: We conducted an individually randomized parallel two-arm nonblinded feasibility trial. The eligibility criteria included being aged ≥16 years, having a body mass index of ≥25 kg/m2, and having access to an Android-based device. Weight was measured (as the proposed primary outcome for a full-scale trial) at baseline, 1 month, and 3 months of follow-up. Participants were randomized in a 2:1 allocation ratio to the ImpulsePal intervention or a waiting list control group. A nested action-research study allowed for data-driven refinement of the intervention across 2 cycles of feedback. Results: We screened 179 participants for eligibility, and 58 were randomized to the intervention group and 30 to the control group. Data were available for 74 (84%, 74/88) participants at 1 month and 67 (76%, 67/88) participants at 3 months. The intervention group (n=43) lost 1.03 kg (95% CI 0.33 to 1.74) more than controls (n=26) at 1 month and 1.01 kg (95% CI −0.45 to 2.47) more than controls (n=43 and n=24, respectively) at 3 months. Feedback suggested changes to intervention design were required to (1) improve receipt and understanding of instructions and (2) facilitate further engagement with the app and its strategies. Conclusions: The evaluation methods and delivery of the ImpulsePal app intervention are feasible, and the trial procedures, measures, and intervention are acceptable and satisfactory to the participants. Trial Registration: International Standard Randomized Controlled Trial Number (ISRCTN): 14886370; http://www.isrctn.com/ISRCTN14886370 (Archived by WebCite at http://www.webcitation.org/76WcEpZ51)University of ExeterNational Institute for Health Research (NIHR