543 research outputs found
Unobtrusive Maintenance: Temporal Complexity, Latent Category Control and the Stalled Emergence of the Cleantech Sector
© 2018 John Wiley & Sons Ltd and Society for the Advancement of Management Studies Disruptive innovation changes the basis of competition within an industry and poses substantial threats for market incumbents. While researchers have focused on whether incumbents can successfully adapt, we know little about how potentially disruptive innovation may be avoided. Studying clean technology in Canada, we examine incumbent resistance when potentially disruptive technologies are seen as socially beneficial. We identify actions taken by incumbents and other socio-technical regime actors to respond to the issue while simultaneously enacting legitimate stabilizing mechanisms within the regime’s institutional infrastructure. Specifically, temporal and resource-based actions led to temporal complexity for disruptive cleantech entrepreneurs, and evaluation structuring work led to latent control of the cleantech category, privileging incumbents and resulting in unobtrusive maintenance. Our findings contribute to the disruptive innovation and institutional theory literatures by showing how disruption may be stalled by the enactment of legitimate elements of the institutional infrastructure rather than direct institutional defence
Density Dependence Drives Habitat Production and Survivorship of Acropora cervicornis Used for Restoration on a Caribbean Coral Reef
Coral restoration is gaining traction as a viable strategy to help restore degraded reefs. While the nascent field of coral restoration has rapidly progressed in the past decade, significant knowledge gaps remain regarding the drivers of restoration success that may impede our ability to effectively restore coral reef communities. Here, we conducted a field experiment to investigate the influence of coral density on the growth, habitat production, and survival of corals outplanted for restoration. We used nursery-raised colonies of Acropora cervicornis to experimentally establish populations of corals with either 3, 6, 12, or 24 corals within 4m2 plots, generating a gradient of coral densities ranging from 0.75 corals m−2 to 12 corals m−2. After 13 months we found that density had a significant effect on the growth, habitat production, and survivorship of restored corals. We found that coral survivorship increased as colony density decreased. Importantly, the signal of density dependent effects was context dependent. Our data suggest that positive density dependent effects influenced habitat production at densities of 3 corals m−2, but further increases in density resulted in negative density dependent effects with decreasing growth and survivorship of corals. These findings highlight the importance of density dependence for coral restoration planning and demonstrate the need to evaluate the influence of density for other coral species used for restoration. Further work focused on the mechanisms causing density dependence such as increased herbivory, rapid disease transmission, or altered predation rates are important next steps to advance our ability to effectively restore coral reefs
Contributions from DMS and ship emissions to CCN observed over the summertime North Pacific
Measurements of cloud condensation nuclei (CCN) made over the North Pacific Ocean in July 2002 are analysed with concurrent measurements of aerosol number, mass and composition. Overall the CCN are controlled by the sulphate, including one case that suggests particle nucleation and growth resulting from dimethyl sulphide oxidation that enhanced CCN concentrations. Hourly CCN concentrations are correlated with concentrations of sulphate plus methanesulphonic acid (MSA) over the entire study period (<i>r</i><sup>2</sup>=0.43 and 0.52 for supersaturations of 0.34% and 0.19%, respectively), and are not well correlated with other organics (<i>r</i><sup>2</sup>&lt;0.2). One case study reveals elevated mass and number concentrations of ultrafine and fine organic particles due to regional ship emissions, identified through quadrupole aerosol mass spectrometer (Q-AMS) measurements, during which organic mass concentrations are correlated with CCN values (<i>r</i><sup>2</sup>=0.39 and 0.46 for supersaturations of 0.19% and 0.34%, respectively). The evolution of the time series and mass distributions of organics, sulphate and MSA over this timeframe indicate that the regional distribution of small, diffuse ship-sourced organic particles act as condensation sites for sulphur species, resulting in a subsequent increase in number concentrations of CCN. We conclude that, where present, direct emissions of anthropogenic organic particles may exert a strong control on marine CCN concentrations once diffused into the marine atmosphere, by acting as condensation sites for biogenic and anthropogenic sulphur species
The effect of organic compounds on the growth rate of cloud droplets in marine and forest settings
International audienceOrganic matter represents an important fraction of the fine particle aerosol, yet our knowledge of the roles of organics in the activation of aerosol particles into cloud droplets is poor. A cloud condensation nucleus (CCN) counter is used to examine the relative growth rates of cloud droplets for case studies from field measurements on the North Pacific Ocean and in a coniferous forest. A model of the condensational growth of water droplets, on particles dissolving according to their solubility in water, is used to simulate the initial scattering of the droplets as they grow in the CCN counter. Simulations of the growth rates of fine particles sampled in the marine boundary layer of the North Pacific Ocean indicate that the main influence of the marine organic material on the water uptake rate is from its effect on the size distribution of the sulphate. Simulations of the observations of water uptake on biogenic organic aerosol particles sampled in a coniferous forest indicate an impact of the organic on the water uptake rates, but one that is still smaller than that of pure sulphate. The solubility of the organic becomes an important factor in determining the water uptake as the organic mass increases relative to sulphate. The values of the organic component of the hygroscopicity parameter ? that describes the CCN activity were found to be negligible for the marine particles and 0.02?0.05 for the forest particles
Is a community still a community? Reviewing definitions of key terms in community ecology
Community ecology is an inherently complicated field, confounded by the conflicting use of fundamental terms. Nearly two decades ago, Fauth etal. (1996) demonstrated that imprecise language led to the virtual synonymy of important terms and so attempted to clearly define four keywords in community ecology; community, assemblage, guild, and ensemble. We revisit Fauth etal.\u27s conclusion and discuss how the use of these terms has changed over time since their review. An updated analysis of term definition from a selection of popular ecological textbooks suggests that definitions have drifted away from those encountered pre-1996, and slightly disagreed with results from a survey of 100 ecology professionals (comprising of academic professors, nonacademic PhDs, graduate and undergraduate biology students). Results suggest that confusion about these terms is still widespread in ecology. We conclude with clear suggestions for definitions of each term to be adopted hereafter to provide greater cohesion among research groups
The management of volunteers – what can human resources do? A review and research agenda
There is an increasing interest from scholars and practitioners in understanding how non-profit organizations can design and implement human resources (HR) practices to enhance desirable volunteer attitudes and behaviors. This paper presents a comprehensive overview of existing studies on the relationship between HR practices and volunteering outcomes. We use the ability-motivation-opportunity model (AMO) as a guiding framework to systematically integrate current knowledge on this topic. We identify gaps in existing research and offer detailed suggestions on how scholars can further enhance knowledge on how HR practices can lead to beneficial outcomes for both volunteers and non-profit organizations
Mechanical tuning of the evaporation rate of liquid on crossed fibers
We investigate experimentally the drying of a small volume of perfectly
wetting liquid on two crossed fibers. We characterize the drying dynamics for
the three liquid morphologies that are encountered in this geometry: drop,
column and a mixed morphology, in which a drop and a column coexist. For each
morphology, we rationalize our findings with theoretical models that capture
the drying kinetics. We find that the evaporation rate depends significantly on
the liquid morphology and that the drying of liquid column is faster than the
evaporation of the drop and the mixed morphology for a given liquid volume.
Finally, we illustrate that shearing a network of fibers reduces the angle
between them, changes the morphology towards the column state, and so enhances
the drying rate of a volatile liquid deposited on it
Beyond capitalism and liberal democracy: on the relevance of GDH Cole’s sociological critique and alternative
This article argues for a return to the social thought of the often ignored early 20th-century English thinker GDH Cole. The authors contend that Cole combined a sociological critique of capitalism and liberal democracy with a well-developed alternative in his work on guild socialism bearing particular relevance to advanced capitalist societies. Both of these, with their focus on the limitations on ‘free communal service’ in associations and the inability of capitalism to yield emancipation in either production or consumption, are relevant to social theorists looking to understand, critique and contribute to the subversion of neoliberalism. Therefore, the authors suggest that Cole’s associational sociology, and the invitation it provides to think of formations beyond capitalism and liberal democracy, is a timely and valuable resource which should be returned to
Impact of Controlling the Site Distribution of Al Atoms on Catalytic Properties in Ferrierite-Type Zeolites
Zeolites with the ferrierite (FER) topology are synthesized using a combination of tetramethylammonium
(TMA) cations with differently sized cyclic amines (pyrrolidine (Pyr), hexamethyleneimine (HMI), and 1,4-
diazabicyclo[2.2.2]octane (DAB)). Using these organic structure-directing agents (SDAs), low Si/Al ratios
and concentrated synthesis mixtures favor the crystallization of FER materials. Increasing the size of the
cyclic amine or decreasing the aluminum content leads to the crystallization of other phases or the creation
of excessive amounts of connectivity defects. TMA cations play a decisive role in the synthesis of the FER
materials, and their presence allows the use of HMI to synthesize FER. Proton MAS NMR is used to quantify
the accessibility of pyridine to acid sites in these FER samples, where it is found that the FER + HMI + TMA
sample contains only 27% acid sites in the 8-MR channels, whereas FER + Pyr and FER + Pyr + TMA
contain 89% and 84%, respectively. The constraint index (CI) test and the carbonylation of dimethyl ether
(DME) with carbon monoxide are used as probe reactions to evaluate how changes in the aluminum distribution
in these FER samples affect their catalytic behavior. Results show that the use of Pyr as an SDA results in
the selective population of acid sites in the 8-MR channels, whereas the use of HMI generates FER zeolites
with an increased concentration of acid sites in the 10-MR channels
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