Desperately Seeking Selznick: Cooptation and the Dark Side of Public Management in Networks

Most literature on public-sector networks focuses on how to build and manage systems and ignores the political problems that networks can create for organizations. This article argues that individual network nodes can work to bias the organization's actions in ways that benefit the organization's more advantaged clientele. The argument is supported by an analysis of performance data from 500 organizations over a five-year period. A classic theoretical point is supported in a systematic empirical investigation. While networks can greatly benefit the organization, they have a dark side that managers and scholars need to consider more seriously

Bubbles emerging from a submerged granular bed

This paper explores the phenomena associated with the emergence of gas bubbles from a submerged granular bed. While there are many natural and industrial applications, we focus on the particular circumstances and consequences associated with the emergence of methane bubbles from the beds of lakes and reservoirs since there are significant implications for the dynamics of lakes and reservoirs and for global warming. This paper describes an experimental study of the processes of bubble emergence from a granular bed. Two distinct emergence modes are identified, mode 1 being simply the percolation of small bubbles through the interstices of the bed, while mode 2 involves the cumulative growth of a larger bubble until its buoyancy overcomes the surface tension effects. We demonstrate the conditions dividing the two modes (primarily the grain size) and show that this accords with simple analytical evaluations. These observations are consistent with previous studies of the dynamics of bubbles within porous beds. The two emergence modes also induce quite different particle fluidization levels. The latter are measured and correlated with a diffusion model similar to that originally employed in river sedimentation models by Vanoni and others. Both the particle diffusivity and the particle flux at the surface of the granular bed are measured and compared with a simple analytical model. These mixing processes can be consider applicable not only to the grains themselves, but also to the nutrients and/or contaminants within the bed. In this respect they are shown to be much more powerful than other mixing processes (such as the turbulence in the benthic boundary layer) and could, therefore, play a dominant role in the dynamics of lakes and reservoirs

Intraspecific Variation in Taxonomic Characteristics of the Mayfly \u3ci\u3ePotamanthus Myops\u3c/i\u3e (Walsh)

Data collected from an ecological study of the mayfly Potamanthus rnyops (Walsh) in Michigan showed intraspecific variability in taxonomic characteristics that have been employed by previous investigators for species separation. Nymphal dorsal maculation patterns varied considerably within a single population. Also, the ratio of mandibular tusk length to head length increased with successive nymphal instars. Certain adult taxonomic characteristics, particularly relative male imago eye size and distance of separation, were either too poorly defined or too variable to be conclusive in species identification

Effects of Hyperbaric Hypoxia on Some Enzyme Systems in the Mammalian Liver

The metabolic effects of hypobaric hypoxic stress on the mammalian liver were studied. The lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) activity of mouse liver homogenates were measured after exposure to an equivalent altitude of 36,000 feet and compared to controls kept at zero altitude. After six and twelve hour incubation periods, the altitude exposed samples demonstrated a significantly higher LDH activity than controls. SDH activity remained unchanged from controls after six hours but was significantly lower than controls after a 12 hour exposure to altitude. It is concluded that the changes in enzyme activity reflect a metabolic control mechanism attempting to maintain adequate energy production during periods of exposure to hypobaric hypoxic stress

Fleshing out the monetary transmission mechanism: output composition and the role of financial frictions

Financial frictions affect the way in which different components of GDP respond to a monetary policy shock. We embed the financial accelerator of Bernanke, Gertler and Gilchrist (1999) into a medium-scale Dynamic General Equilibrium model and evaluate the relative importance of financial frictions in explaining monetary transmission. Specifically, we match the impulse responses generated by the model with empirical impulse response functions obtained from a vector autoregression on US time series data. This allows us to provide estimates for the structural parameters of our model and judge the relevance of different model features. In addition, we propose a set of simple and instructive specification tests that can be used to assess the relative fit of various restricted models. Although our point estimates suggest some role for financial accelerator effects, they are actually of minor importance for the descriptive success of the model. JEL Classification: E32, E44, E51Financial Frictions, Minimum Distance Estimation, monetary policy, Output Composition

An Interim Assessment of the U.S. Trade Policy of “Competitive Liberalization”

Since taking office the Administration of George W. Bush has pursued a trade policy known as Competitive Liberalization. This policy envisages a series of mutually-reinforcing steps to open markets abroad to U.S. companies, to strengthen market-oriented laws and regulations overseas, and to place the U.S. at the centre of the world trading system. Foreign and security policy considerations have influenced U.S. trade policymaking, perhaps more so than in the 1990s. To date the principal outcome of this policy has been the negotiation by the U.S. of numerous free trade agreements, mainly with developing countries individually or in subregional groupings. In addition to characterising this policy in detail, the principal purpose of this paper is to assess the logic underlying this approach to trade policymaking and whether Competitive Liberalization has begun to fulfil the promise spelt out for it at the beginning of this decade.United States, trade policy, commercial policy, Competitive Liberalization, WTO, regional trade agreements

Comparison of different methods for estimating snowcover in forested, mountainous basins using LANDSAT (ERTS) images

Snow-covered areas on LANDSAT (ERTS) images of the Santiam River basin, Oregon, and other basins in Washington were measured using several operators and methods. Seven methods were used: (1) Snowline tracing followed by measurement with planimeter, (2) mean snowline altitudes determined from many locations, (3) estimates in 2.5 x 2.5 km boxes of snow-covered area with reference to snow-free images, (4) single radiance-threshold level for entire basin, (5) radiance-threshold setting locally edited by reference to altitude contours and other images, (6) two-band color-sensitive extraction locally edited as in (5), and (7) digital (spectral) pattern recognition techniques. The seven methods are compared in regard to speed of measurement, precision, the ability to recognize snow in deep shadow or in trees, relative cost, and whether useful supplemental data are produced

Controlling the effective mass of quantum well states in Pb/Si(111) by interface engineering

The in-plane effective mass of quantum well states in thin Pb films on a Bi reconstructed Si(111) surface is studied by angle-resolved photoemission spectroscopy. It is found that this effective mass is a factor of three lower than the unusually high values reported for Pb films grown on a Pb reconstructed Si(111) surface. Through a quantitative low-energy electron diffraction analysis the change in effective mass as a function of coverage and for the different interfaces is linked to a change of around 2% in the in-plane lattice constant. To corroborate this correlation, density functional theory calculations were performed on freestanding Pb slabs with different in-plane lattice constants. These calculations show an anomalous dependence of the effective mass on the lattice constant including a change of sign for values close to the lattice constant of Si(111). This unexpected relation is due to a combination of reduced orbital overlap of the 6p_z states and altered hybridization between the 6p_z and 6p_xy derived quantum well states. Furthermore it is shown by core level spectroscopy that the Pb films are structurally and temporally stable at temperatures below 100 K.Comment: 7 pages, 6 figure