University of Arkansas

About: University of Arkansas is a education organization based out in Fayetteville, Arkansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17225 authors who have published 33329 publications receiving 941102 citations. The organization is also known as: Arkansas & UA.

Fit, Equifinality, and Organizational Effectiveness: A Test of Two Configurational Theories

Abstract: Mintzberg's and Miles and Snow's configurational theories have both received widespread attention. Most researchers, however, have interpreted these theories in terms of categories of organizations rather than organizational configurations based on ideal types. We explicated the logical structure of configurational theories and developed a set of configurational fit models that are congruent with alternative assumptions of equifinality, which is the premise that multiple organizational forms are equally effective. Then the two theories were formalized with these models and tested empirically. Contrary to our expectations, the results do not support Mintzberg's theory that organizations will be more effective to the extent that they resemble his five ideal types. In contrast with these null results, configurational fit based on Miles and Snow's theory predicted 24 percent of the variance in overall organizational effectiveness.

Size Control of Gold Nanocrystals in Citrate Reduction: The Third Role of Citrate

Abstract: Growth kinetics and temporal size/shape evolution of gold nanocrystals by citrate reduction in boiling water were studied systematically and quantitatively. Results reveal that the size variation and overall reaction mechanism were mostly determined by the solution pH that was in turn controlled by the concentration of sodium citrate (Na3Ct) in the traditional Frens's synthesis. This conclusion was further confirmed by the reactions with variable pH but fixed concentrations of the two reactants, HAuCl4 and Na3Ct. Two substantially different reaction pathways were identified, with the switching point at pH = 6.2−6.5. The first pathway is for the low pH range and consists of three overlapping steps: nucleation, random attachment to polycrystalline nanowires, and smoothing of the nanowires via intra-particle ripening to dots. The second pathway that occurred above the pH switching point is consistent with the commonly known nucleation-growth route. Using the second pathway, we demonstrated a new synthetic r...

Drought Reconstructions for the Continental United States

Abstract: The development of a 2° lat × 3° long grid of summer drought reconstructions for the continental United States estimated from a dense network of annual tree-ring chronologies is described. The drought metric used is the Palmer Drought Severity Index (PDSI). The number of grid points is 154 and the reconstructions cover the common period 1700–1978. In producing this grid, an automated gridpoint regression method called “point-by-point regression” was developed and tested. In so doing, a near-optimal global solution was found for its implementation. The reconstructions have been thoroughly tested for validity using PDSI data not used in regression modeling. In general, most of the gridpoint estimates of drought pass the verification tests used. In addition, the spatial features of drought in the United States have been faithfully recorded in the reconstructions even though the method of reconstruction is not explicitly spatial in its design. The drought reconstructions show that the 1930s “Dust Bow...

Classifying drivers of global forest loss

Abstract: Global maps of forest loss depict the scale and magnitude of forest disturbance, yet companies, governments, and nongovernmental organizations need to distinguish permanent conversion (ie, deforestation) from temporary loss from forestry or wildfire Using satellite imagery, we developed a forest loss classification model to determine a spatial attribution of forest disturbance to the dominant drivers of land cover and land use change over the period 2001 to 2015 Our results indicate that 27% of global forest loss can be attributed to deforestation through permanent land use change for commodity production The remaining areas maintained the same land use over 15 years; in those areas, loss was attributed to forestry (26%), shifting agriculture (24%), and wildfire (23%) Despite corporate commitments, the rate of commodity-driven deforestation has not declined To end deforestation, companies must eliminate 5 million hectares of conversion from supply chains each year