Cosmology in the Solar System: Pioneer effect is not cosmological

Does the Solar System and, more generally, a gravitationally bound system follow the cosmic expansion law ? Is there a cosmological influence on the dynamics or optics in such systems ? The general relativity theory provides an unique and unambiguous answer, as a solution of Einstein equations with a local source in addition to the cosmic fluid, and obeying the correct (cosmological) limiting conditions. This solution has no analytic expression. A Taylor development of its metric allows a complete treatment of dynamics and optics in gravitationally bound systems, up to the size of galaxy clusters, taking into account both local and cosmological effects. In the solar System, this provides an estimation of the (non zero) cosmological influence on the Pioneer probe: it fails to account for the " Pioneer effect " by about 10 orders of magnitude. We criticize contradictory claims on this topic

The effects of a kappa-distribution in the heliosheath on the global heliosphere and ENA flux at 1 AU

We investigate heliosheath energetic neutral atom (ENA) fluxes at keV energies, by assuming that the heliosheath proton distribution can be approximated by a kappa-distribution. The choice of the kappa parameter derives from observational data of the solar wind (SW). This has direct applications to the upcoming IBEX mission. We will look at all-sky ENA maps within the IBEX energy range (10 eV to 6 keV), as well as ENA energy spectra in several directions. We find that the use of kappa, as opposed to a Maxwellian, gives rise to greatly increased ENA fluxes above 1 keV, while medium energy fluxes are somewhat reduced. We show how IBEX data can be used to estimate the spectral slope in the heliosheath, and that the use of kappa reduces the differences between ENA maps at different energies. We also investigate the effect introducing a kappa-distribution has on the global interaction between the SW and the local interstellar medium (LISM), and find that there is generally an increase in energy transport from the heliosphere into the LISM, due to the modified profile of ENA's energies. This results in a termination shock that moves out by 4 AU, a heliopause that moves in by 9 AU and a bow shock 25 AU farther out, in the nose direction

Orbital evolution under action of fast interstellar gas flow

Orbital evolution of an interplanetary dust particle under action of an interstellar gas flow is investigated. Secular time derivatives of the particle orbital elements, for arbitrary orbit orientation, are presented. An important result concerns secular evolution of semi-major axis. Secular semi-major axis of the particle on a bound orbit decreases under the action of fast interstellar gas flow. Possible types of evolution of other Keplerian orbital elements are discussed. The paper compares influences of the Poynting-Robertson effect, the radial solar wind and the interstellar gas flow on dynamics of the dust particle in outer planetary region of the Solar System and beyond it, up to 100 AU. Evolution of putative dust ring in the zone of the Edgeworth-Kuiper belt is studied. Also non-radial solar wind and gravitational effect of major planets may play an important role. Low inclination orbits of micron-sized dust particles in the belt are not stable due to fast increase of eccentricity caused by the interstellar gas flow and subsequent planetary perturbations - the increase of eccentricity leads to planet crossing orbits of the particles. Gravitational and non-gravitational effects are treated in a way which fully respects physics. As a consequence, some of the published results turned out to be incorrect. Moreover, the paper treats the problem in a more general way than it has been presented up to now. The influence of the fast interstellar neutral gas flow might not be ignored in modeling of evolution of dust particles beyond planets.Comment: 12 pages, 7 figure

Cosmological spacetimes balanced by a scale covariant scalar field

A scale invariant, Weyl geometric, Lagrangian approach to cosmology is explored, with a a scalar field phi of (scale) weight -1 as a crucial ingredient besides classical matter \cite{Tann:Diss,Drechsler:Higgs}. For a particularly simple class of Weyl geometric models (called {\em Einstein-Weyl universes}) the Klein-Gordon equation for phi is explicitly solvable. In this case the energy-stress tensor of the scalar field consists of a vacuum-like term Lambda g_{mu nu} with variable coefficient Lambda, depending on matter density and spacetime geometry, and of a dark matter like term. Under certain assumptions on parameter constellations, the energy-stress tensor of the phi-field keeps Einstein-Weyl universes in locally stable equilibrium. A short glance at observational data, in particular supernovae Ia (Riess ea 2007), shows interesting empirical properties of these models.Comment: 28 pages, 1 figure, accepted by Foundations of Physic

Astrophysical Constraints on Modifying Gravity at Large Distances

Recently, several interesting proposals were made modifying the law of gravity on large scales, within a sensible relativistic formulation. This allows a precise formulation of the idea that such a modification might account for galaxy rotation curves, instead of the usual interpretation of these curves as evidence for dark matter. We here summarize several observational constraints which any such modification must satisfy, and which we believe make more challenging any interpretation of galaxy rotation curves in terms of new gravitational physics.Comment: References added, submitted to Classical & Quantum Gravit

A framework for the study of zoonotic disease emergence and its drivers: spillover of bat pathogens as a case study

Many serious emerging zoonotic infections have recently arisen from bats, including Ebola, Marburg, SARS-coronavirus, Hendra, Nipah, and a number of rabies and rabies-related viruses, consistent with the overall observation that wildlife are an important source of emerging zoonoses for the human population. Mechanisms underlying the recognized association between ecosystem health and human health remain poorly understood and responding appropriately to the ecological, social and economic conditions that facilitate disease emergence and transmission represents a substantial societal challenge. In the context of disease emergence from wildlife, wildlife and habitat should be conserved, which in turn will preserve vital ecosystem structure and function, which has broader implications for human wellbeing and environmental sustainability, while simultaneously minimizing the spillover of pathogens from wild animals into human beings. In this review, we propose a novel framework for the holistic and interdisciplinary investigation of zoonotic disease emergence and its drivers, using the spillover of bat pathogens as a case study. This study has been developed to gain a detailed interdisciplinary understanding, and it combines cutting-edge perspectives from both natural and social sciences, linked to policy impacts on public health, land use and conservation

A framework for the study of zoonotic disease emergence and its drivers: spillover of bat pathogens as a case study

Many serious emerging zoonotic infections have recently arisen from bats, including Ebola, Marburg, SARS-coronavirus, Hendra, Nipah, and a number of rabies and rabies-related viruses, consistent with the overall observation that wildlife are an important source of emerging zoonoses for the human population. Mechanisms underlying the recognized association between ecosystem health and human health remain poorly understood and responding appropriately to the ecological, social and economic conditions that facilitate disease emergence and transmission represents a substantial societal challenge. In the context of disease emergence from wildlife, wildlife and habitat should be conserved, which in turn will preserve vital ecosystem structure and function, which has broader implications for human wellbeing and environmental sustainability, while simultaneously minimizing the spillover of pathogens from wild animals into human beings. In this review, we propose a novel framework for the holistic and interdisciplinary investigation of zoonotic disease emergence and its drivers, using the spillover of bat pathogens as a case study. This study has been developed to gain a detailed interdisciplinary understanding, and it combines cutting-edge perspectives from both natural and social sciences, linked to policy impacts on public health, land use and conservation

Heliolatitude and time variations of solar wind structure from in situ measurements and interplanetary scintillation observations

The 3D structure of solar wind and its evolution in time is needed for heliospheric modeling and interpretation of energetic neutral atoms observations. We present a model to retrieve the solar wind structure in heliolatitude and time using all available and complementary data sources. We determine the heliolatitude structure of solar wind speed on a yearly time grid over the past 1.5 solar cycles based on remote-sensing observations of interplanetary scintillations, in situ out-of-ecliptic measurements from Ulysses, and in situ in-ecliptic measurements from the OMNI-2 database. Since the in situ information on the solar wind density structure out of ecliptic is not available apart from the Ulysses data, we derive correlation formulae between solar wind speed and density and use the information on the solar wind speed from interplanetary scintillation observations to retrieve the 3D structure of solar wind density. With the variations of solar wind density and speed in time and heliolatitude available we calculate variations in solar wind flux, dynamic pressure and charge exchange rate in the approximation of stationary H atoms.Comment: Accepted for publication in Solar Physic

Laws for the Right to Work of Disabled People: The Italian Experience

This scholarly handbook covers all aspects of people with disabilities entering the workplace, including the legal aspects, transitions, types, and levels of employments, the impact of different disabilities, and the consideration of the intersection of disability with other identities such as gender and ethnicity. Comprehensive in scope, chapters look beyond organizational strategies that accommodate an employee’s disability and use case studies to highlight important issues and the individual’s perspective. The handbook concludes with a reflection on the work included in the book, what was not included and why, and makes recommendations for future disability research. Marking a major contribution to the study of workplace diversity and bringing together academics from various disciplines and global regions, this handbook covers a truly broad and diverse mix of approaches, theories, and models