The three-body problem and the Hannay angle

The Hannay angle has been previously studied for a celestial circular restricted three-body system by means of an adiabatic approach. In the present work, three main results are obtained. Firstly, a formal connection between perturbation theory and the Hamiltonian adiabatic approach shows that both lead to the Hannay angle; it is thus emphasised that this effect is already contained in classical celestial mechanics, although not yet defined nor evaluated separately. Secondly, a more general expression of the Hannay angle, valid for an action-dependent potential is given; such a generalised expression takes into account that the restricted three-body problem is a time-dependent, two degrees of freedom problem even when restricted to the circular motion of the test body. Consequently, (some of) the eccentricity terms cannot be neglected {\it a priori}. Thirdly, we present a new numerical estimate for the Earth adiabatically driven by Jupiter. We also point out errors in a previous derivation of the Hannay angle for the circular restricted three-body problem, with an action-independent potential.Comment: 11 pages. Accepted by Nonlinearit

Geometric phases and anholonomy for a class of chaotic classical systems

Berry's phase may be viewed as arising from the parallel transport of a quantal state around a loop in parameter space. In this Letter, the classical limit of this transport is obtained for a particular class of chaotic systems. It is shown that this ``classical parallel transport'' is anholonomic --- transport around a closed curve in parameter space does not bring a point in phase space back to itself --- and is intimately related to the Robbins-Berry classical two-form.Comment: Revtex, 11 pages, no figures

Natural incidence of egg parasitoids of <i>Edessa meditabunda</i> (F.) (Hemiptera: pentatomidae) on <i>Crotalaria spectabilis</i> in Campo Novo do Parecis, MT, Brazil

Egg parasitoids of the stink bug Edessa meditabunda (F) were studied on rattlepod Crotalaria spectabilis used in soybean crop rotation in Campo Novo do Parecis, Mato Grosso state, central western Brazil. Seven species of parasitoids were found: two Encyrtidae, one Eurytomidae, and four Platygastridae. The occurrence of Trissolcus euchisti (Ashmead) and Trissolcus elimatus Johnson (Platygastridae) on eggs of E. meditabunda is recorded for the first time. Moreover, this is the first record of T. elimatus and T. euchisti from Brazil.Facultad de Ciencias Naturales y Muse

Natural incidence of egg parasitoids of <i>Edessa meditabunda</i> (F.) (Hemiptera: pentatomidae) on <i>Crotalaria spectabilis</i> in Campo Novo do Parecis, MT, Brazil

Egg parasitoids of the stink bug Edessa meditabunda (F) were studied on rattlepod Crotalaria spectabilis used in soybean crop rotation in Campo Novo do Parecis, Mato Grosso state, central western Brazil. Seven species of parasitoids were found: two Encyrtidae, one Eurytomidae, and four Platygastridae. The occurrence of Trissolcus euchisti (Ashmead) and Trissolcus elimatus Johnson (Platygastridae) on eggs of E. meditabunda is recorded for the first time. Moreover, this is the first record of T. elimatus and T. euchisti from Brazil.Facultad de Ciencias Naturales y Muse

An Adiabatic Theorem without a Gap Condition

The basic adiabatic theorems of classical and quantum mechanics are over-viewed and an adiabatic theorem in quantum mechanics without a gap condition is described.Comment: Talk at QMath 7, Prague, 1998. 10 pages, 7 figure

Natural incidence of egg parasitoids of <i>Edessa meditabunda</i> (F.) (Hemiptera: pentatomidae) on <i>Crotalaria spectabilis</i> in Campo Novo do Parecis, MT, Brazil

Egg parasitoids of the stink bug Edessa meditabunda (F) were studied on rattlepod Crotalaria spectabilis used in soybean crop rotation in Campo Novo do Parecis, Mato Grosso state, central western Brazil. Seven species of parasitoids were found: two Encyrtidae, one Eurytomidae, and four Platygastridae. The occurrence of Trissolcus euchisti (Ashmead) and Trissolcus elimatus Johnson (Platygastridae) on eggs of E. meditabunda is recorded for the first time. Moreover, this is the first record of T. elimatus and T. euchisti from Brazil.Facultad de Ciencias Naturales y Muse

The case for prioritizing implementation strategy fidelity measurement: Benefits and challenges

Implementation strategies are systematic approaches to improve the uptake and sustainability of evidence-based interventions. They frequently focus on changing provider behavior through the provision of interventions such as training, coaching, and audit-and-feedback. Implementation strategies often impact intermediate behavioral outcomes like provider guideline adherence, in turn improving patient outcomes. Fidelity of implementation strategy delivery is defined as the extent to which an implementation strategy is carried out as it was designed. Implementation strategy fidelity measurement is under-developed and under-reported, with the quality of reporting decreasing over time. Benefits of fidelity measurement include the exploration of the extent to which observed effects are moderated by fidelity, and critical information about Type-III research errors, or the likelihood that null findings result from implementation strategy fidelity failure. Reviews of implementation strategy efficacy often report wide variation across studies, commonly calling for increased implementation strategy fidelity measurement to help explain variations. Despite the methodological benefits of rigorous fidelity measurement, implementation researchers face multi-level challenges and complexities. Challenges include the measurement of a complex variable, multiple data collection modalities with varying precision and costs, and the need for fidelity measurement to change in-step with adaptations. In this position paper, we weigh these costs and benefits and ultimately contend that implementation strategy fidelity measurement and reporting should be improved in trials of implementation strategies. We offer pragmatic solutions for researchers to make immediate improvements like the use of mixed methods or innovative data collection and analysis techniques, the inclusion of implementation strategy fidelity assessment in reporting guidelines, and the staged development of fidelity tools across the evolution of an implementation strategy. We also call for additional research into the barriers and facilitators of implementation strategy fidelity measurement to further clarify the best path forward

Prediction of Anisotropic Single-Dirac-Cones in Bi1−x{}_{1-x}Sbx{}_{x} Thin Films

The electronic band structures of Bi${}_{1-x}$Sb${}_{x}$ thin films can be varied as a function of temperature, pressure, stoichiometry, film thickness and growth orientation. We here show how different anisotropic single-Dirac-cones can be constructed in a Bi${}_{1-x}$Sb${}_{x}$ thin film for different applications or research purposes. For predicting anisotropic single-Dirac-cones, we have developed an iterative-two-dimensional-two-band model to get a consistent inverse-effective-mass-tensor and band-gap, which can be used in a general two-dimensional system that has a non-parabolic dispersion relation as in a Bi${}_{1-x}$Sb${}_{x}$ thin film system

Quantum Conductance in Semimetallic Bismuth Nanocontacts

Electronic transport properties of bismuth nanocontacts are analyzed by means of a low temperature scanning tunneling microscope. The subquantum steps observed in the conductance versus elongation curves give evidence of atomic rearrangements in the contact. The underlying quantum nature of the conductance reveals itself through peaks in the conductance histograms. The shape of the conductance curves at 77 K is well described by a simple gliding mechanism for the contact evolution during elongation. The strikingly different behaviour at 4 K suggests a charge carrier transition from light to heavy ones as the contact cross section becomes sufficiently small.Comment: 5 pages including 4 figures. Accepted for publication in Phys. Rev. Let

Progress in Classical and Quantum Variational Principles

We review the development and practical uses of a generalized Maupertuis least action principle in classical mechanics, in which the action is varied under the constraint of fixed mean energy for the trial trajectory. The original Maupertuis (Euler-Lagrange) principle constrains the energy at every point along the trajectory. The generalized Maupertuis principle is equivalent to Hamilton's principle. Reciprocal principles are also derived for both the generalized Maupertuis and the Hamilton principles. The Reciprocal Maupertuis Principle is the classical limit of Schr\"{o}dinger's variational principle of wave mechanics, and is also very useful to solve practical problems in both classical and semiclassical mechanics, in complete analogy with the quantum Rayleigh-Ritz method. Classical, semiclassical and quantum variational calculations are carried out for a number of systems, and the results are compared. Pedagogical as well as research problems are used as examples, which include nonconservative as well as relativistic systems