The Growth and Survival of Early Instars of \u3ci\u3eBellura Obliqua\u3c/i\u3e (Lepidoptera: Noctuidae) on \u3ci\u3eTypha Latifolia\u3c/i\u3e and \u3ci\u3eTypha Angustifolia\u3c/i\u3e

Larvae of the noctuid moth Bellura obliqua are frequently encountered on Typha latifolia, but less commonly on Typha angustifolia. Experiments were conducted to compare the growth and survivorship of early B. obliqua instars on the two species of cattail. In short-term growth chamber experiments there were no significant differences in the survivorship, relative growth rate (RGR), relative consumption rate (RCR), or the efficiency of conversion of ingested food (ECI) between first-instar larvae reared on leaves of the two species. Third-instar larvae fed stems, however, had a greater RGR and higher ECI when reared on T. lalifolia. Differences in growth are apparently not related to differences in hostplant nitrogen or acid-detergent fiber content. In a long term greenhouse experiment, using transplanted cattails, larvae reared on T. latifolia grew somewhat larger and had a significantly higher survival rate than those reared on T. angustifolia. Host plant structure is postulated to influence larval survivorship. Typha is under consideration for use as a bio-energy crop and planting T. angustifolia may help to reduce infestations in cultivated stands

Becoming a teacher: conceptual and practice development in the learning and skills sector

Drawing on a mixed-methods study of in-service learning and skills sector (LSS) trainees, comprising beginning- and end-of-year surveys and six longitudinal case studies together with literature on trainees’ development in the LSS, schools and higher education sectors, conceptual and practice development continua are proposed. Conceptions become more multi-dimensional and increasingly link teaching and learning whilst initial concern with the practicalities of teaching is followed by recognition of learners’ needs. Next, greater emphasis is placed on learner autonomy and catering for individuals’ needs and finally assessment and evaluation is used systematically to shape practice. The continua offer an understanding of the subtleties and complexities of trainee development allowing for different starting and end points and accommodating varied work contexts. I argue that this provides a more adequate basis for the development of initial teacher education (ITE) than the prescriptive approach embedded within recent LSS ITE policy reforms

Balancing Local Order and Long-Ranged Interactions in the Molecular Theory of Liquid Water

A molecular theory of liquid water is identified and studied on the basis of computer simulation of the TIP3P model of liquid water. This theory would be exact for models of liquid water in which the intermolecular interactions vanish outside a finite spatial range, and therefore provides a precise analysis tool for investigating the effects of longer-ranged intermolecular interactions. We show how local order can be introduced through quasi-chemical theory. Long-ranged interactions are characterized generally by a conditional distribution of binding energies, and this formulation is interpreted as a regularization of the primitive statistical thermodynamic problem. These binding-energy distributions for liquid water are observed to be unimodal. The gaussian approximation proposed is remarkably successful in predicting the Gibbs free energy and the molar entropy of liquid water, as judged by comparison with numerically exact results. The remaining discrepancies are subtle quantitative problems that do have significant consequences for the thermodynamic properties that distinguish water from many other liquids. The basic subtlety of liquid water is found then in the competition of several effects which must be quantitatively balanced for realistic results.Comment: 8 pages, 6 figure

Simulation-based equation of state of the hard disk fluid and prediction of higher-order virial coefficients

We present new molecular dynamics results for the pressure of the pure hard disk fluid up to the hexatic transition (about reduced density 0.9). The data combined with the known virial coefficients (up to $B_{10}$) are used to build an equation of state, to estimate higher-order virial coefficients, and also to obtain a better value of $B_{10}$. Finite size effects are discussed in detail. The ``van der Waals-like'' loop reported in literature in the vicinity of the fluid/hexatic transition is explained by suppressed density fluctuations in the canonical ensemble. The inflection point on the pressure-density dependence is predicted by the equation of state even if the hexatic phase simulation data are not considered.Comment: 9 pages, 3 figures, presented at The Seventh Liblice Conference on the Statistical Mechanics of Liquids (Lednice, Czech Republic, June 11--16, 2006

The free-molecule flow characteristics of concave surfaces

The problem of free molecule flow over concave surfaces is investigated, and general equations formulated for the lift, drag, and heat transfer characteristics of such surfaces. The effect of multiple reflections is taken into account by use of the Clausing integral equation to determine the redistribution of molecular flux over the surface. It is assumed that emission of molecules from the surface is purely diffuse, and that the reflected molecules are perfectly accommodated to the surface conditions. The equations obtained are solved for the cases of (i) an infinitely long circular cylindrical arc and (ii) a section of a spherical surface, at hyperthermal velocities. It is found that under the above conditions the local heat transfer characteristics are the same as those of the corresponding convex surface, the total heat transfer being independent of the geometry of the surface. As drag devices, the concave surfaces examined prove only slightly more effective than a flat plate at similar incidence, and as a generator of lift the cylindrically cambered plate is significantly inferior to the flat plate at similar incidence

The free-molecule flow characteristics of concave surfaces

The problem of free molecule flow over concave surfaces is investigated, and general equations formulated for the lift, drag, and heat transfer characteristics of such surfaces. The effect of multiple reflections is taken into account by use of the Clausing integral equation to determine the redistribution of molecular flux over the surface. It is assumed that emission of molecules from the surface is purely diffuse, and that the reflected molecules are perfectly accommodated to the surface conditions. The equations obtained are solved for the cases of (i) an infinitely long circular cylindrical arc and (ii) a section of a spherical surface, at hyperthermal velocities. It is found that under the above conditions the local heat transfer characteristics are the same as those of the corresponding convex surface, the total heat transfer being independent of the geometry of the surface. As drag devices, the concave surfaces examined prove only slightly more effective than a flat plate at similar incidence, and as a generator of lift the cylindrically cambered plate is significantly inferior to the flat plate at similar incidence

An XMM-Newton observation of the nova-like variable UX UMa: spatially and spectrally resolved two-component X-ray emission

In the optical and ultraviolet regions of the electromagnetic spectrum, UX Ursae Majoris is a deeply eclipsing cataclysmic variable. However, no soft X-ray eclipse was detected in ROSAT observations. We have obtained a 38 ksec XMM-Newton observation to further constrain the origin of the X-rays. The combination of spectral and timing information allows us to identify two components in the X-ray emission of the system. The soft component, dominant below photon energies of 2 keV, can be fitted with a multi-temperature plasma model and is uneclipsed. The hard component, dominant above 3 keV, can be fitted with a kT ~ 5 keV plasma model and appears to be deeply eclipsed. We suggest that the most likely source of the hard X-ray emission in UX UMa, and other systems in high mass transfer states, is the boundary layer.Comment: To appear in MNRAS Letter

Optical and ROSAT X-ray observations of the dwarf nova OY Carinae in superoutburst and quiescence

We present ROSAT X-ray and optical light curves of the 1994 February superoutburst of the eclipsing SU UMa dwarf nova OY Carinae. There is no eclipse of the flux in the ROSAT HRI light curve. Contemporaneous `wide B' band optical light curves show extensive superhump activity and dips at superhump maximum. Eclipse mapping of these optical light curves reveals a disc with a considerable physical flare, even three days into the superoutburst decline. We include a later (1994 July) ROSAT PSPC observation of OY Car that allows us to put constraints on the quiescent X-ray spectrum. We find that while there is little to choose between OY Car and its fellow high inclination systems with regard to the temperature of the emitting gas and the emission measure, we have difficulties reconciling the column density found from our X-ray observation with the column found in HST UV observations by Horne et al. (1994). The obvious option is to invoke time variability.Comment: 16 pages, 14 figures, accepted for publication in MNRA

Oxidized basalts on the surface of Venus: Compositional implications of measured spectral properties

Venera Lander reflectance data are compared with high temperature spectra of the same basaltic materials. The dark, flat unoxidized basalts are still inconsistent with the Venera data in the near-infrared. Basaltic material with a ferric component, however, would satisfy both the increase in reflectance beyond 0.7 microns as well as the dark, relatively colorless character in the visible. Therefore, it is concluded that besaltic surfaces of Venus represented by these measurements either contain minerals with uncommon characteristics, or, more likely, are relatively oxidized