Looking into the shadow: The eugenics argument in debates on reproductive technologies and practices

Eugenics is often referred to in debates on the ethics of reproductive technologies and practices, in relation to the creation of moral boundaries between acceptable and unacceptable technologies, and acceptable and unacceptable uses of these technologies. Historians have argued that twentieth century eugenics cannot be reduced to a uniform set of practices, and that no simple lessons can be drawn from this complex history. Some authors stress the similarities between past eugenics and present reproductive technologies and practices (what I define throughout the paper as ‘the continuity view’) in order to condemn the latter. Others focus on the differences between past and present practices (what I define throughout the paper as ‘the discontinuity view’) in order to defend contemporary reproductive technologies. In this paper, I explore the meanings of the word ‘eugenics’ and the relationship between its past and present uses in terms of contemporary debates on reproductive technologies and practices. I argue that moral disagreement about present technologies originate in divergent views of condemnable and justifiable features of the past

Marine Fungi of Iceland: A Preliminary Account of Ascomycetes

This paper reports, for the first time, 25 species of marine pyrenomycetes from Icelandic waters. Taxonomic notes are included for certain species. Surtsey, a submarine volcanic upthrust off the south coast of Iceland (Thorarinsson, 1967), is a current center for cooperative geophysical, geochemical, and biological investigations on an international scale. The mycological portion of the total biological research effort of the Surtsey project has emphasized a survey of the marine and freshwater mycoflora on the mainland of Iceland itself as a necessary prerequisite to ecological studies on Surtsey. With the exception of two reports on aquatic phycomycetes (Larsen, 1931, and Johnson, 1966), the aquatic mycoflora of Iceland is unknown. Thus Iceland, rather than Surtsey, has become the immediate focal point for mycological investigations

Privatization and Efficiency: from Principals and Agents to Political Economy

We survey the theoretical literature on privatization and efficiency by tracing its evolution from the applications of agency theory to recent contributions in the field of political economy. The first ones extend the theory of regulation with incomplete information to address privatization issues, comparing State Owned Entreprises (SOEs) with private regulated firms. The benefits of privatization may either derive from the constraints it places on malevolent agents or to the impossibility of commitment by a benevolent government because of incomplete contracts. Contributions dealing with political economy issues separate privatization from restructuring decisions. They either explore bargaining between managers and politicians or analyze the impact of privatization shaped by political preferences on efficiency. The theoretical results regarding the relation between privatization and efficiency do not lead to any definitive conclusion. Privatization may increase productive efficiency when restructuring takes place whereas its effects on allocative efficiency still remain uncertain.Regulation, Imperfect Information, Political Preferences

Limited time series with a unit root

This paper develops an asymptotic theory for integrated and near-integrated time series whose range is constrained in some ways. Such a framework arises when integration and cointegration analysis are applied to persistent series which are bounded either by construction or because they are subject to control. The asymptotic properties of some commonly used integration tests are discussed; the bounded unit root distribution is introduced to describe the limiting distribution of the first-order autoregressive coefficient of a random walk under range constraints. The theoretical results show that the presence of such constraints can lead to drastically different asymptotics. Since deviations from the standard unit root theory are measured through noncentrality parameters, simple measures of the impact of range constraints on the asymptotic distributions are obtained. Finally, the proposed asymptotic framework provides an extremely adequate approximation of the finite sample properties of the unit root statistics under range constraints.

A Rescaled Range Statistics Approach to Unit Root Tests

In the framework of integrated processes, the problem of testing the presence of unknown boundaries which constrain the sample path to lie within a closed interval is considered. To discuss this inferential problem, the concept of nearly-bounded integrated process is introduced, thus allowing to define formally the concept of boundary conditions within I(1) processes. When used to detect unknown boundaries, standard unit root tests do not maintain the usual power properties and new methods need developing. Therefore a new class of tests, which are based on the rescaled range of the process, are introduced. The limiting distribution of the proposed tests can be expressed in terms of the distribution of the range of particular Brownian functionals, while the power properties are obtained through the derivation of the limiting Brownian functional of a I(1) process with boundary conditions, which is done by referring to a new invariance principles for nonstationary time series with limited sample paths. Both theoretical and simulation exercises show that range-based tests outperform standard unit root tests significantly when used to detect the presence of boundary conditions.

The History of Cosmic Baryons: X-ray Emission vs. Star Formation Rate

We relate the star formation from cold baryons in virialized structures to the X-ray properties of the associated diffuse, hot baryonic component. Our computations use the standard ``semi-analytic'' models to describe i) the evolution of dark matter halos through merging after the hierarchical clustering, ii) the star formation governed by radiative cooling and by supernova feedback, iii) the hydro- and thermodynamics of the hot gas, rendered with our Punctuated Equilibria model. So we relate the X-ray observables concerning the intra-cluster medium to the thermal energy of the gas pre-heated and expelled by supernovae following star formation, and then accreted during the subsequent merging events. We show that at fluxes fainter than $F_X\approx 10^{-15}$ erg/cm$^2$ s (well within the reach of next generation X-ray observatories) the X-ray counts of extended extragalactic sources (as well as the faint end of the luminosity function, the contribution to the soft X-ray background, and the $L_X-T$ correlation at the group scales) increase considerably when the star formation rate is enhanced for z>1 as indicated by growing optical/infrared evidence. Specifically, the counts in the range 0.5-2 keV are increased by factors $\sim 4$ when the the feedback is decreased and star formation is enhanced as to yield a flat shape of the star formation rate for 2<z<4.Comment: 11 pages, 8 figures, accepted for publication in MNRA

Dark Matter Halos: The Dynamical Basis of Effective Empirical Models

We investigate the dynamical basis of the classic empirical models (specifically, Sersic-Einasto and generalized NFW) that are widely used to describe the distributions of collisionless matter in galaxies. We submit that such a basis is provided by our \alpha-profiles, shown to constitute solutions of the Jeans dynamical equilibrium with physical boundary conditions. We show how to set the parameters of the empirical in terms of the dynamical models; we find the empirical models, and specifically Sersic-Einasto, to constitute a simple and close approximation to the dynamical models. Finally, we discuss how these provide an useful baseline for assessing the impact of the small-scale dynamics that may modulate the density slope in the central galaxy regions.Comment: 11 pages, 2 figures, Accepted by Advances in Astronom

The SZ Effect as a Probe of Non-Gravitational Entropy in Groups and Clusters of Galaxies

We investigate how strongly and at what scales the Sunyaev- Zel'dovich effect reflects the shifting balance between the two processes that compete for governing the density and the thermodynamic state of the hot intra-cluster medium pervading clusters and groups of galaxies: the hierarchical clustering of the DM; the non-gravitational energy and momentum fed back into the ICM by the condensing baryons. We base on a SAM of galaxy formation and clustering to describe how the baryons are partitioned among the hot, the cool and the stellar phase; the partition shifts as the galaxies cluster hierarchically, and as the feedback by stellar winds and SN explosions follows the star formation. Their impact is amplified by the same large scale accretion shocks that thermalize the gravitational energy of gas falling into the growing potential wells. We compute the Compton parameter $y$, and find a relation of $y$ with the ICM temperature, the $y-T$ relation, which departs from the self-similar scaling and bends down at temperatures typical of galaxy groups. We model-independently relate this with the analogous behaviour of the L_x - T relation, and discuss to what extent our results are generic of the hierarchical models of galaxy formation and clustering.Comment: 24 pages, 6 figures, submitted to MNRAS; typos correcte