Phytoecological Study of Sylvotundra at Small Tree Lake, N.W.T.

Attempts to make a quantitative evaluation of representative plant communities in relation to physiographic features in the central part of North American sylvotundra (the ecotone between treeless tundra and the taiga). Lake shores and hill-bottoms support closed canopy Picea mariana forest, but the exposed slopes are treeless. A Picea glauca parkland forms a transition between forests and treeless slopes. Analysis of the vegetation by strata, viz: ground cover, low herbs and decumbent shrubs, and tall herbs, tall shrubs and arboreal seedlings, showed decrease of cover as level above ground increased. Along a gradient from forests to treeless shapes, the percentage of boreal plants decreased and that of the arctic plants increased. The present forest-tundra boundaries at Small Tree Lake appear semi-permanent.Étude phytoécologique de la toundra forestière à Small Tree Lake, T. du N.-O. Dans l'aire d'étude, les caractères du terrain et les conditions de micro-environnement qui en découlent déterminent divers types de végétation. Les rives du lac e le pied des collines supportent une forêt de Picea mariana à voûte fermée, mais les pentes exposées sont dépourvues d'arbres. Une savane boisée de Picea glauca forme la transition entre les forêts et les pentes. La grande dimension des arbres de la savane, l'absence d'une zone de krumholz et une abrupte limite des arbres liée à la topographie indiquent que l'équilibre entre les types de végétation de cette toundra forestière est délicat. Les frontières actuelles entre la forêt et la toundra à Small Tree Lake semblent semi-permanentes.L'analyse de la stratification a démontré que, pour chaque strate, la couverture diminuait selon l'éloignement au-dessus du sol. Le pourcentage des plantes boréales diminuait et celui des plantes arctiques augmentait selon un gradient entre les forêts et les pentes

Regulating Industrial Risks. An Executive Summary of a Workshop

The issues discussed in this Executive Summary are explored fully in the book "Regulating Industrial Risks", edited by Harry Otway and Malcolm Peltu, published by Butterworths in 1985. An abstract is included under BK-85-903 in this index

Analysis of travelling waves associated with the modelling of aerosolised skin grafts

A previous model developed by the authors investigates the growth patterns of keratinocyte cell colonies after they have been applied to a burn site using a spray technique. In this paper, we investigate a simplified one-dimensional version of the model. This model yields travelling wave solutions and we analyse the behaviour of the travelling waves. Approximations for the rate of healing and maximum values for both the active healing and the healed cell densities are obtained

Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages