Isolation and characterization of Treponema phagedenis-like spirochetes from digital dermatitis lesions in Swedish dairy cattle

© 2008 Pringle et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Plasma in a monopole background does not have a twisted Poisson structure

For a particle in the magnetic field of a cloud of monopoles, the naturally associated 2-form on phase space is not closed, and so the corresponding bracket operation on functions does not satisfy the Jacobi identity. Thus, it is not a Poisson bracket; however, it is twisted Poisson in the sense that the Jacobiator comes from a closed 3-form. The space D of densities on phase space is the state space of a plasma. The twisted Poisson bracket on phase-space functions gives rise to a bracket on functions on D. In the absence of monopoles, this is again a Poisson bracket. It has recently been shown by Heninger and Morrison that this bracket is not Poisson when monopoles are present. In this note, we give an example where it is not even twisted Poisson

Reviewing the geometric Hamilton-Jacobi theory concerning Jacobi and Leibniz identities

In this survey, we review the classical Hamilton-Jacobi theory from a geometric point of view in different geometric backgrounds. We propose a Hamilton-Jacobi equation for different geometric structures attending to one particular characterization: whether they fulfill the Jacobi and Leibniz identities simultaneously, or if at least they satisfy one of them. This property reviews the work of the present authors in such a way that it is presented according to a hierarchy of nested brackets. This is a new outlook in which we do not only present the geometric structures themselves, but their hierarchical relations and how they affect their dynamic through the Hamilton-Jacobi equation. In this regard, we review the case of time-dependent (t-dependent in the sequel) and dissipative physical systems as systems that fulfill the Jacobi identity but not the Leibnitz identity, as instances of cosymplectic and contact mechanical problems. Let us remark that dissipative here means dissipation provided by a dissipation parameter included in the Hamiltonian function, for instance, the entropy in some thermodynamical systems. Furthermore, we review the contact-evolution Hamilton-Jacobi theory as a split off the regular contact geometry, and that actually satisfies the Leibniz rule instead of Jacobi. Furthermore, we include a novel result, which is the Hamilton-Jacobi equation for conformal Hamiltonian vector fields as a generalization of the well-known Hamilton-Jacobi on a symplectic manifold, that is retrieved in the case of a zero conformal factor. The interest of a geometric Hamilton-Jacobi equation is the primordial observation that if a Hamiltonian vector field X H can be projected into a configuration manifold by means of a one-form dW, then the integral curves of the projected vector field XHdW can be transformed into integral curves of X H provided that W is a solution of the Hamilton-Jacobi equation. Geometrically, the solution of the Hamilton-Jacobi equation plays the role of a Lagrangian submanifold of a certain bundle. Exploiting these features in different geometric scenarios we propose a geometric theory for multiple physical systems depending on the fundamental identities that their dynamic satisfies. Different examples are pictured to reflect the results provided, being all of them new, except for one that is reassessment of a previously considered example. Finally, let us mention that an important issue in the study of the Hamilton-Jacobi equation is separability, relevant for finding conserved quantities. However, we will not deal with this subject in this survey, although we refer the reader to papers [16, 17, 136].Manuel de León acknowledges financial support from the Spanish Ministry of Science and Innovation (MICINN), under Grants PID2019-106715GB-C21, EIN2020-11210, and "Severo Ochoa Programme for Centres of Excellence in R&D" (CEX2019-000904-S)

Use of Eight Major National Data Systems

US-born across the life course. Survival and logistic regression, prevalence, and age-adjusted death rates were used to examine differentials. Although these data systems vary considerably in their coverage of health and behavioral characteristics, ethnic-immigrant groups, and time periods, they all serve as important research databases for understanding the health of US immigrants. The NVSS and NHIS, the two most important data systems, include a wide range of health variables and many racial/ethnic and immigrant groups. Immigrants live 3.4 years longer than the US-born, with a life expectancy ranging from 83.0 years for Asian/Pacific Islander immigrants to 69.2 years for US-born blacks. Overall, immigrants have better infant, child, and adult health and lower disability and mortality rates than the US-born, with immigrant health patterns varying across racial/ethnic groups. Immigrant children and adults, however, fare substantially worse than the US-born in health insurance coverage and access to preventive health services. Suggestions and new directions are offered for improvements in health monitoring and for strengthening and developing databases for immigrant health assessment in the USA