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The double-gyre circulation, formulated in terms of the quasigeostrophic equations, has a symmetry about the basin midlatitude (y → −y, ψ → −ψ), which is absent in a formulation based on the shallow-water equations. As a result, the shallow-water model does not have the pitchfork bifurcation structures that, in the case of the quasigeostrophic model, connect together multiple solution branches with elongated and contracted recirculation gyres. For the shallow-water model, solution branches with elongated recirculation gyres are disconnected, and a one-parameter bifurcation analysis is unable to detect their existence. The deeply penetrating jet solution branches do, however, continue to exist, and can be found using a bifurcation analysis couched in terms of two parameters. An effective pair of parameters is the viscosity and a parameter controlling the symmetry of the wind stress profile. A bifurcation analysis with these parameters reveals the existence of new solution branches that were not found in previous bifurcation analyses of the shallow-water model. The new solutions have a jet extension that penetrates farther eastward and that is more stable than the jet-up and jet-down solutions found in previous studies. Furthermore, the origin of the low-frequency variability at low viscosities is associated with a sequence of bifurcations originating from one of the new steady-state solution branches. In particular, the eigenmode analysis of the new branch reveals that a so-called gyre mode is at the origin of the model’s low-frequency variability at decadal time scales.

The steady state bifurcation structure of the double-gyre wind-driven ocean circulation is examined in a shallow water model where the upper layer is allowed to outcrop at the sea surface. In addition to the classical jet-up and jet-down multiple equilibria, we find a new regime in which one of the equilibrium solutions has a large outcropping region in the subpolar gyre. Time dependent simulations show that the outcropping solution equilibrates to a stable periodic orbit with a period of 8 months. Co-existing with the periodic solution is a stable steady state solution without outcropping.A numerical scheme that has the unique advantage of being differentiable while still allowing layers to outcrop at the sea surface is used for the analysis. In contrast, standard schemes for solving layered models with outcropping are non-differentiable and have an ill-defined Jacobian making them unsuitable for solution using Newton’s method. As such, our new scheme expands the applicability of numerical bifurcation techniques to an important class of ocean models whose bifurcation structure had hitherto remained unexplored.

A growing body of research has focused on distinguishing general forms of gratitude from gratitude to God. We contributed to this area of research by examining correlates of personality traits and meaning in life in a cross-sectional study (N = 1,398). General gratitude was more strongly positively related to honesty-humility, extraversion, conscientiousness, agreeableness, openness, and meaning in life than gratitude to God. Moreover, gratitude to God moderated the positive relationship between general gratitude and meaning in life such that the relationship was stronger at lower than higher levels of gratitude to God. The results suggest that general forms of gratitude may be more important for well-being and positive traits than gratitude to God. General forms of gratitude may be particularly beneficial among less religious people, while gratitude to God may be particularly beneficial for people's well-being among those who are less grateful in general. [ABSTRACT FROM AUTHOR]

The purpose of this article is to inform researchers about and encourage the use of longitudinal designs to further understanding of human resource development and organizational theory. This article presents information about a variety of longitudinal research designs, related statistical procedures, and an overview of general data collecting approaches, covering their strengths and weaknesses. The article also serves as a reminder of the importance of alignment between the research purpose, questions and methodology while highlighting the benefits of using multiple methods. Finally, importance of research replicability in the context of longitudinal inquiry is stressed.

This document is an editorial from the journal Frontiers in Marine Science titled "The discovery, identification and application of marine microorganisms derived natural products." It discusses the importance of natural products as a source of small molecule drugs and the challenges in studying them. It highlights the potential of marine microorganisms to produce novel bioactive natural products and their significance in the development of new drugs. The editorial also mentions specific research topics covered in the journal, including the use of secondary metabolites from mangrove soil bacteria for anthracnose treatment, bioactive compounds from deep-sea fungi, natural products from marine mudflat actinomycetes, and the potential of microorganisms associated with marine sponges to yield new bioactive compounds. The document concludes by emphasizing the need for further research on marine microorganisms and their potential applications in various fields. [Extracted from the article]