Effects of changes of land use on some animal populations

Two examples are considered: (1) The effects-of organotin agricultural fungicides on soil Acarina; (2) The effects of reclamation of intertidal land on overwintering shorebirds at Seal Sands, Teesmouth, The effect of triphenyltin acetate and triphenyltin hydroxide was examined by field experiments and the results are discussed in relation to the dose level, regime and season of treatment. Numbers of soil Acarina were reduced by both clianicals when applied in autumn at recctmended doses. The Mesostigmata and an abundant Prostigmatid, Ttarsonemus floricolus. were particularly affected and the magnitude of reductions was related to the quantity of chemical applied. Not all species of mites were affected and treatment of half the recommended dose resulted in an increase in seme families, of Prostigmata, Seasonal changes in the abundance of mites are described and compared with the results of studies elsewhere in Britain, Suitable laboratory culturing techniques were devised for small Prostigmatid mites. Reclamation of Seal Sands between 1972-74 resulted in a loss of feeding area and reduced feeding time. The effects of reclamation are considered in relation to the overwintering numbers of five waders: Grey Plover (Pluvialis squatarola), Curlew (Numenius arauata). Godwit (Limosa lapponica). Redshank (Trinqa tetanus) and Dunlin (Calidris alpina) and to the Shelduck (Tadorna tadorna). Monthly counts of each species are described and compared with counts in previous winters. Changes in numbers are discussed in relation to progressive reclamation. The relative importance of the reduction in feeding area and feeding time in determining the overwintering numbers after reclamation is considered by examination of: (a) the time spent feeding, and (b) the foraging behaviour and diet. The waders overwintered in lower numbers than previously but Shelduck numbers were unchanged. To satisfy their food requirements. Grey Plovers adapted by feeding at night while the other waders fed on adjacent fields in mid-winter. Shorebirds did not change their diet or foraging behaviour. Reduction in numbers was related to the reduced feeding area and food resources available, but for Dunlins loss in feeding tine was more important

On the action of alum in bread-making

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Guest Editors' introduction: philosophical contributions to leadership ethics

This article introduces the first of two special issues on philosophical approaches to leadership ethics. In it, we show some of the ways that philosophy contributes to the study of leadership and leadership ethics. We begin with an overview of how philosophers have treated some of the ethical aspects and challenges of leadership. These include discussions of self interest, the problem of dirty hands, responsibility, moral luck, power, gender and diversity, and spirituality. The articles in this issue draw on philosophy to explore a variety of ethical questions related to leadership and the relationships that leaders have with followers and others

Impurity-free seeded crystallization of amorphous silicon by nanoindentation

We demonstrate that nanoindents formed in amorphous Si films, with dimensions as small as ∼20 nm, provide a means to seed solid phase crystallization. During post-indentation annealing at ∼600 °C, solid phase crystallization initiates from the indented sites, effectively removing the incubation time for random nucleation in the absence of seeds. The seeded crystallization is studied by optical microscopy, cross-sectional transmission electron microscopy, and electrical characterization via Hall measurements. Full crystallization can be achieved, with improved electrical characteristics attributed to the improved microstructure, using a lower thermal budget. The process is metal contaminant free and allows for selective area crystallization.The authors gratefully acknowledge financial support from the Australian Research Council and the Natural Sciences and Engineering Research Council of Canada

Electrical conduction of silicon oxide containing silicon quantum dots

Current-voltage measurements have been made at room temperature on a Si-rich silicon oxide film deposited via Electron-Cyclotron Resonance Plasma Enhanced Chemical Vapor Deposition (ECR-PECVD) and annealed at 750 - 1000$^\circ$C. The thickness of oxide between Si quantum dots embedded in the film increases with the increase of annealing temperature. This leads to the decrease of current density as the annealing temperature is increased. Assuming the Fowler-Nordheim tunneling mechanism in large electric fields, we obtain an effective barrier height $\phi_{eff}$ of $\sim$ 0.7 $\pm$ 0.1 eV for an electron tunnelling through an oxide layer between Si quantum dots. The Frenkel-Poole effect can also be used to adequately explain the electrical conduction of the film under the influence of large electric fields. We suggest that at room temperature Si quantum dots can be regarded as traps that capture and emit electrons by means of tunneling.Comment: 14 pages, 5 figures, submitted to J. Phys. Conden. Mat

Why does early childhood deprivation increase the risk for depression and anxiety in adulthood? A developmental cascade model

Abstract Background: Using data from the English & Romanian Adoptees (ERA) study we recently reported that early time-lmited exposure to severe institutional deprivation is associated with early onset and persistent neurodevelopmental problems and later onset emotional problems. Here we examine possible reasons for the late emergence of emotional problems in this cohort. Our main focus is on testing a developmental cascade mediated via the functional impact of early-appearing neurodevelopmental problems on late adolescent functioning. We also explore a second putative pathway via sensitization to stress. Methods: The ERA study includes 165 Romanian individuals who spent their early lives in grossly depriving institutions and were subsequently adopted into UK families, along with 52 UK adoptees with no history of deprivation. Age six years symptoms of neurodevelopmental problems and age 15 anxiety/depression symptoms were assessed via parental reports. Young adult symptoms of depression and anxiety were assessed by both parent and self-reports; young adults also completed measures of stress reactivity , exposure to adverse life events and functioning in work and interpersonal relationships. Results: The path between early institutional deprivation and adult emotional problems was mediated via the impact of early neurodevelopmental problems on unemployment and poor friendship functioning during the transition to adulthood. The findings with regard to early deprivation, later life stress reactivity and emotional problems were inconclusive. Conclusions: Our analysis suggests that the risk for adult depression and anxiety following extreme institutional deprivation is explained through the effects of early neurodevelopmental problems on later social and vocational functioning. Future research should more fully examine the role of stress susceptibility in this model

Technique for producing highly planar Si/SiO0.64Ge0.36/Si metal–oxide–semiconductor field effect transistor channels

Si/Si0.64Ge0.36/Si heterostructures have been grown at low temperature (450 °C) to avoid the strain-induced roughening observed for growth temperatures of 550 °C and above. The electrical properties of these structures are poor, and thought to be associated with grown-in point defects as indicated in positron annihilation spectroscopy. However, after an in situ annealing procedure (800 °C for 30 min) the electrical properties dramatically improve, giving an optimum 4 K mobility of 2500 cm2 V – 1 s – 1 for a sheet density of 6.2 × 1011 cm – 2. The low temperature growth yields highly planar interfaces, which are maintained after anneal as evidenced from transmission electron microscopy. This and secondary ion mass spectroscopy measurements demonstrate that the metastably strained alloy layer can endure the in situ anneal procedure necessary for enhanced electrical properties. Further studies have shown that the layers can also withstand a 120 min thermal oxidation at 800 °C, commensurate with metal–oxide–semiconductor device fabrication

The golden circle: A way of arguing and acting about technology in the London ambulance service

This paper analyses the way in which the London Ambulance Service recovered from the events of October 1992, when it implemented a computer-aided despatch system (LASCAD) that remained in service for less than two weeks. It examines the enactment of a programme of long-term organizational change, focusing on the implementation of an alternative computer system in 1996. The analysis in this paper is informed by actor-network theory, both by an early statement of this approach developed by Callon in the sociology of translation, and also by concepts and ideas from Latour’s more recent restatement of his own position. The paper examines how alternative interests emerged and were stabilized over time, in a way of arguing and acting among key players in the change programme, christened the Golden Circle. The story traces four years in the history of the London Ambulance Service, from the aftermath of October 1992 through the birth of the Golden Circle to the achievement of National Health Service (NHS) trust status. LASCAD was the beginning of the story, this is the middle, an end lies in the future, when the remaining elements of the change programme are enacted beyond the Golden Circle