Oklahoma State University–Stillwater

About: Oklahoma State University–Stillwater is a education organization based out in Stillwater, Oklahoma, United States. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 18267 authors who have published 36743 publications receiving 1107500 citations. The organization is also known as: Oklahoma State University & OKState.

Lower Bounds for an Integral Involving Fractional Laplacians and the Generalized Navier-Stokes Equations in Besov Spaces

Abstract: When estimating solutions of dissipative partial differential equations in L p -related spaces, we often need lower bounds for an integral involving the dissipative term. If the dissipative term is given by the usual Laplacian −Δ, lower bounds can be derived through integration by parts and embedding inequalities. However, when the Laplacian is replaced by the fractional Laplacian (−Δ) α , the approach of integration by parts no longer applies. In this paper, we obtain lower bounds for the integral involving (−Δ) α by combining pointwise inequalities for (−Δ) α with Bernstein's inequalities for fractional derivatives. As an application of these lower bounds, we establish the existence and uniqueness of solutions to the generalized Navier-Stokes equations in Besov spaces. The generalized Navier-Stokes equations are the equations resulting from replacing −Δ in the Navier-Stokes equations by (−Δ) α .

Validating a Comprehensive Model of Environmental Concern Cross‐Nationally: A U.S.‐Canadian Comparison*

Abstract: Objective. The dimensionality of ‘‘environmental concern’’ remains ambiguous despite decades of research on environmental attitudes and beliefs. We attempt to provide insight into this issue by using the belief systems perspective and confirmatory factor analysis (CFA) to test a comprehensive conceptualization of environmental concern. Methods. The study employs a comparative design by using national probability samples of citizens from Canada and the United States, and a comprehensive conceptualization model to maximize content validity. We utilize CFA and structural equation modeling techniques to avoid well-known measurement error problems in survey research. Results. Eight key facets of environmental concern have moderate to high factor loadings on one underlying construct, and all but perception of community problems and national problems have high loadings. Further analyses provide construct validation for our measurement model. Conclusion. Our results suggest that even among the general public, attitudes toward environmental issues are relatively well organized into a broad and coherent sense of ‘‘concern for the environment.’’ The similarity in the U.S. and Canadian results increases our faith in the validity of our comprehensive conceptualization of environmental concern, as well as the utility of the belief systems perspective and CFA modeling for future studies of environmental attitudes and beliefs. In the vast literature on environmental attitudes and behavior, the dimensionality of ‘‘environmental concern’’ has long been the center of attention and debate, for both theoretical and methodological reasons. Methodologically, an examination of the dimensionality of environmental concern is necessary for developing valid and reliable measures. Theoretically, the dimensionality issue is directly tied to the fundamental question of the meaningfulness of environmental concern. As Dunlap and Jones (2002:511) put it: ‘‘Is it appropriate to consider environmental concern as a single construct, or is it inherently multidimensional?’’ In short, the issue is

Formation of a new buried charge drives a large-amplitude protein quake in photoreceptor activation.

Abstract: Photoactive yellow protein (PYP) is a eubacterial photoreceptor and a structural prototype of the PAS domain superfamily of receptor and regulatory proteins. We investigate the activation mechanism of PYP using time-resolved Fourier transform infrared (FTIR) spectroscopy. Our data provide structural, kinetic, and energetic evidence that the putative signaling state of PYP is formed during a large-amplitude protein quake that is driven by the formation of a new buried charge, COO(-) of the conserved Glu46, in a highly hydrophobic pocket at the active site. A protein quake is a process consisting of global conformational changes that are triggered and driven by a local structural "fault". We show that large, global structural changes take place after Glu46 ionization via intramolecular proton transfer to the anionic p-coumarate chromophore, and are suppressed by the absence of COO(-) formation in the E46Q mutant. Our results demonstrate the significance of buried charge formation in photoreceptor activation. This mechanism may serve as one of the general themes in activation of a range of receptor proteins. In addition, we report the results of time-resolved FTIR spectroscopy of PYP crystals. The direct comparison of time-resolved FTIR spectroscopic data of PYP in aqueous solution and in crystals reveals that the structure of the putative signaling state is not developed in P6(3) crystals. Therefore, when the structural developments during the functional process of a protein are experimentally determined to be very different in crystals and solutions, one must be cautious in drawing conclusions regarding the functional mechanism of proteins based on time-resolved X-ray crystallography.