Pheromone production by axenically rearedDendroctonus ponderosae andIps paraconfusus (Coleoptera: Scolytidae)

Mountain pine beetles,Dendroctonus ponderosae Hopkins, and California five-spined ips,Ips paraconfusus Lanier, were reared axenically from surface-sterilized eggs on aseptic pine phloem. After 24 hr in host logs, axenip femaleD. ponderosae and maleI. paraconfusus produced the aggregation pheromones,trans-verbenol (D. ponderosae), and ipsenol and ipsdienol (I. paraconfusus). Emergent, axenically reared maleD. ponderosae contained normal amounts of the pheromoneexo-brevicomin. Axenic femaleD. ponderosae treated with juvenile hormone or exposed to vapors of -pinene, produced the pheromonetrans-verbenol. By 25–35 days after eclosion, axenic females exposed to -pinene vapors produced over six times as muchtrans-verbenol as wild females, suggesting that while microorganisms in wild females may producetrans-verbenol, they may also inhibit production of the pheromone or use it as a substrate.Research supported in part by Natural Sciences and Engineering Research Council, Canada, Operating Grants A3881 and A3706, and H.R. MacMillan Family Fund Fellowships to J.E. Conn and D.W.A. Hunt.     

Input correlation with the a.s.w. storage correlator

By correlating during read-in, we correlate signals of much greater length than could be stored within the device, thereby obtaining a large improvement in t.b. product.     

PKC signalling regulates tight junction membrane assembly in the pre-implantation mouse embryo

Epithelial differentiation including tight junction (TJ) formation occurs exclusively within the trophectoderm (TE) lineage of the mouse blastocyst. Here we examine mechanisms by which TJ protein membrane assembly might be regulated by protein kinase C (PKC) in the embryo. To overcome the inherent staging asynchrony of individual blastomeres within intact embryos, we have used isolated inner cell masses (ICMs) from early blastocysts to induce epithelial differentiation in their outer cells responding to their new cell contact pattern. Two TJ proteins examined retain their order of membrane assembly in isolated ICMs in culture as during normal development (early-assembling ZO-2 and late-assembling ZO-1alpha(+)), but this process is highly accelerated. Using six chemical modulators of PKC activity, we show here that PKC signalling is involved in the regulation of TJ membrane assembly. While indolactam-mediated PKC activation stimulates membrane assembly of both TJ proteins, TPA-mediated PKC activation stimulates only that of ZO-1alpha(+). The PKC inhibitors Ro-31-8220, Ro-31-8425 and G? 6983 suppress the stimulatory effect of both PKC activators on membrane assembly to varying extents according to inhibitor and TJ protein examined. G? 6983 similarly inhibits ZO-2 and ZO-1alpha(+) membrane assembly. PKC inhibition by G? 6976 appeared to stimulate TJ membrane assembly. Despite the broad PKC isotype specificity of the inhibitors used, these data suggest that the two TJ proteins are differently regulated by PKC isotypes or subfamilies. As G? 6983 uniquely affects aPKC (particularly PKCzeta) and we find that both PKCdelta and zeta relocate upon activator treatment to colocalise partially with the TJ proteins in isolated ICMs, we suggest that at least PKCdelta and zeta may play a central role in regulating TJ membrane assembly.     

Simulations of Vortex Evolution and Phase Slip in Oscillatory Potential Flow of the Superfluid Component of 4He Through an Aperture

The evolution of semicircular quantum vortex loops in oscillating potential flow emerging from an aperture is simulated in some highly symmetrical cases. As the frequency of potential flow oscillation increases, vortex loops that are evolving so as eventually to cross all of the streamlines of potential flow are drawn back toward the aperture when the flow reverses. As a result, the escape size of the vortex loops, and hence the net energy transferred from potential flow to vortex flow in such 2π phase-slip events, decreases as the oscillation frequency increases. Above some aperture-dependent and flow-dependent threshold frequency, vortex loops are drawn back into the aperture. Simulations are performed using both radial potential flow and oblate-spheroidal potential flow.     

Studies of freezing–melting hysteresis in cryoporometry scanning loop experiments using NMR diffusometry and relaxometry

Theories of freeze–thaw hysteresis in NMR cryoporometry of disordered mesoporous solids have been rigorously tested using scanning loop experiments together with concurrently obtained (PFG) NMR diffusometry and relaxometry data. PFG-NMR and relaxometry have revealed that the spatial disposition of frozen and molten phases, at a particular point in a loop, depends upon the prior thermal history, as expected from previous work. However, these data have also shown the vital importance of incorporating the advanced melting process in order to adequately interpret cryoporometry data, and thence the ability to distinguish between interpretations arising from structural or thermodynamic considerations. The advanced melting process has been shown to greatly impact the accuracy of pore size distributions derived from the melting curve using the conventional approach that neglects it. Further, it has been shown that the freeze/thaw hysteresis can be progressively expunged using ‘mini-loop’-type experiments. Hence, the potential reversibility of freeze/thaw processes, even in disordered materials, has been demonstrated. This lack of hysteresis is consistent with the axial freezing and melting expected when both heterogeneous nucleation of freezing, and advanced melting, occur.     

The Electric City as a Solution to Sustainable Urban Development

Comprehensive frameworks for sustainable urban development have been advanced by many scholars and global institutions in recent years. These frameworks are broad and overlapping in nature, but each has its own structure and emphasis. We review a cross-section of these frameworks, examining their foundations and general predictions for an urban future. From this review, we cultivate an argument that continued progress toward sustainable urban development hinges on low-carbon electrification. Our position for electric cities is supported by the sustainability literature and by empirical evidence gathered from the world's largest cities, which shows that economy, physical environment, and basic service delivery improve with per capita electricity consumption. We close with an overview of the challenges associated with urban electrification.     

The planning of late colonial village housing in the tropics: Tema Manhean,Ghana

This paper examines the planning, physical development, and housing in Tema New Town, an appendix of the newly created Tema industrial and harbour city, located on the northeastern part of Accra in the Greater Accra Region in Ghana. The city and its appendage were designed and built during the 1950s, as the country was rapidly approaching political independence. Tema, originally an old Ga-fishing village, became a significant part of a much larger and ambitious scheme, known as the Volta River Project proposed as part of Kwame Nkrumah's domestic policy, embracing multifaceted and multidimensional development projects. These projects were to serve as a symbol of ‘progress’ and were part of Ghana's desire for modernization as it emerged from a colonial past. The related schemes were largely funded as a result of the British Colonial Development and Welfare Acts, and this paper investigates the implementation of this policy and the effect that it had on physical planning and provision of architectural solutions in Ghana.     

Hardscrabble Heritage: The Ruined Blackhouse and Crofting Landscape as Heritage from below

Abstract

This article explores a particular materialisation of the relationship between landscape, heritage and identity. Understood as heritage from below, the emphasis is on the role of non-elites in the constitutive processes of landscape and the place/space of the past in the present. The landscape at the heart of this study is that of the ruined blackhouse, an intrinsic part and mnemonic of crofting identity in the Scottish Highlands. These quotidian and mundane spaces are constituted by routine habits which, together with the material ‘left-behinds’ of a past way of life, comprise landmarks to place making from below and within. For members of the crofting community, the blackhouse is understood and experienced as inheritance from the past and source of everyday affectual and sensual entanglements. This rural ruin is thus an intrinsic part of the crofting taskscape, the past drawn into the present as a form of cultural heritage from below.     

The home as enabler of more active lifestyles among older people

Inactive lifestyles have negative health consequences, while time spent sedentary (sitting and lying) is related to morbidity and premature mortality. Older adults often form the most sedentary segment of the population. Much of this behaviour may be practised at home where this group can spend extended periods. Physical activity rates among older adults are particularly low. Even household physical activities can be beneficial for this group, while they can constitute much of an older person's total activity. Despite this context, the home's role in the active and sedentary behaviours of the older population appears critically understudied. Using interview and focus group data collected from 22 older adults (healthy volunteers, stroke survivors and people with dementia), this paper begins to address this issue. Aspects of the home that aid or impede a more active, less sedentary lifestyle are identified with three presenting particular capacity in this respect discussed: steps, space within the home, and the location and form of facilities, fixtures and fittings. The crucial role health status plays in structuring this capacity is identified. Simple design recommendations, devised to support older people to lead more active lives at home, are presented.