Studies on the biology of some species of British corixidae

The life history of the water-bug, Corixa germari (Fieb.) was studied quantitatively in a Derbyshire reservoir and observations on the biology of the species were also made. The eggs of C.germari are firmly attached to stones and are laid chiefly on the undersides or in crevices. The oviposition rate and egg mortality during 1958 were estimated by direct counts of eggs in the field, the abundance of the adults and nymphs was measured in terms of a Standard Net Sweep and the number of eggs laid per female per season was calculated from these data. By means of these methods, it was found that in I958 the breeding adults gave mean catches of 10 per Standard Net Sweep (43% of the adults were females) and that these adults produced 916 eggs. About 530 hatched and, of the nymphs produced, about 80 survived to become adults in the autumn. About 20 of these survived to breed in 1959. Estimates of the density of eggs laid per m(^2) of substratum in 1958 show that the catch per Standard Net Sweep represents about 1/38 of the number of C.germari per m(^2) of substratum. By weighing the various stages in the life history it was shown that the standing crop of C.germari gives a biomass value of2about 20 g. dry weight per m of substratum in the autumn. This is the highest value reached in the course of the season. C.germari has been shown to live at greater depths than most other British species and this may be a means of avoiding the the effects of wave action. Its ability to exploit deep water is coupled with the fact that it visits the surface less often and swims more rapidly than certain shallow water species

Deuterium on Venus: Observations from Earth

In view of the importance of the deuterium-to-hydrogen ratio in understanding the evolutionary scenario of planetary atmospheres and its relationship to understanding the evolution of our own Earth, we undertook a series of observations designed to resolve previous observational conflicts. We observed the dark side of Venus in the 2.3 micron spectral region in search of both H2O and HDO, which would provide us with the D/H ratio in Venus' atmosphere. We identified a large number of molecular lines in the region, belonging to both molecules, and, using synthetic spectral techniques, obtained mixing ratios of 34 plus or minus 10 ppm and 1.3 plus or minus 0.2 ppm for H2O and HDO, respectively. These mixing ratios yield a D/H ratio for Venus of D/H equals 1.9 plus or minus 0.6 times 10 (exp 12) and 120 plus or minus 40 times the telluric ratio. Although the detailed interpretation is difficult, our observations confirm that the Pioneer Venus Orbiter results and establish that indeed Venus had a period in its early history in which it was very wet, perhaps not unlike the early wet period that seems to have been present on Mars, and that, in contrast to Earth, lost much of its water over geologic time

First year student expectations: Results from a university-wide student survey

Although much has been written on the first-year experience of students at higher education institutions, less attention has been directed to the expectations of students when they enter an institution for the first time. This paper provides additional insights into the expectations of students at an Australian university and highlights areas in which students’ expectations may not necessarily align with the realities of common university practices. By providing opportunities for students to articulate their expectations, staff are able to use the responses for a constructive dialogue and work towards a more positive alignment between perceived expectations and levels of student satisfaction with their experience.Geoffrey Crisp, Edward Palmer, Deborah Turnbull, Ted Nettelbeck, Lynn Ward, Amanda LeCouteur, Aspa Sarris, Peter Strelan, and Luke Schneide

Direct patterning of organic conductors on knitted textiles for long-term electrocardiography.

Wearable sensors are receiving a great deal of attention as they offer the potential to become a key technological tool for healthcare. In order for this potential to come to fruition, new electroactive materials endowing high performance need to be integrated with textiles. Here we present a simple and reliable technique that allows the patterning of conducting polymers on textiles. Electrodes fabricated using this technique showed a low impedance contact with human skin, were able to record high quality electrocardiograms at rest, and determine heart rate even when the wearer was in motion. This work paves the way towards imperceptible electrophysiology sensors for human health monitoring

Extreme alpha-clustering in the 18O nucleus

The structure of the 18O nucleus at excitation energies above the alpha decay threshold was studied using 14C+alpha resonance elastic scattering. A number of states with large alpha reduced widths have been observed, indicating that the alpha-cluster degree of freedom plays an important role in this N not equal Z nucleus. However, the alpha-cluster structure of this nucleus is very different from the relatively simple pattern of strong alpha-cluster quasi-rotational bands in the neighboring 16O and 20Ne nuclei. A 0+ state with an alpha reduced width exceeding the single particle limit was identified at an excitation energy of 9.9+/-0.3 MeV. We discuss evidence that states of this kind are common in light nuclei and give possible explanations of this feature.Comment: 4 pages, 2 figures, 1 table. Resubmission with minor changes for clarity, including removal of one figur