3,106 research outputs found
The Panopticon under the Light of Politics and Technology
This paper focuses on Foucault's concept of the Panopticon. The Panopticon since time immemorial has been used as a concept in order to control society. Since this is being used as a tool to control society, this then is considered to be a form of technology of which is being used by individuals who hold power
Is There a Negative Thermal Expansion in Supported Metal Nanoparticles? An In-Situ X-ray Absorption Study Coupled with Neural Network Analysis
Interactions with their support, adsorbates and unique structural motifs are responsible for the many intriguing properties and potential applications of supported metal nanoparticles (NPs). At the same time, they complicate the interpretation of experimental data. In fact, the methods and approaches that work well for the ex situ analysis of bulk materials may be inaccurate or introduce artifacts in the in situ analysis of nanomaterials. Here we revisit the controversial topic of negative thermal expansion and anomalies in the Debye temperature reported for oxide-supported metal NPs. In situ X-ray absorption experimental data collected for Pt NPs in ultrahigh vacuum and an advanced data analysis approach based on an artificial neural network demonstrate that Pt NPs do not exhibit intrinsic negative thermal expansion. Similarly as for bulk materials, in the absence of adsorbates the bond lengths in metal NPs increase with temperature. The previously reported anomalies in particle size-dependent Debye temperatures can also be linked to the artifacts in the interpretation of conventional X-ray absorption data of disordered materials such as NPs
Reptile vector-borne diseases of zoonotic concern
Reptile vector-borne diseases (RVBDs) of zoonotic concern are caused by bacteria, protozoa and viruses transmitted by arthropod vectors, which belong to the subclass Acarina (mites and ticks) and the order Diptera (mosquitoes, sand flies and tsetse flies). The phyletic age of reptiles since their origin in the late Carboniferous, has favored vectors and pathogens to co-evolve through millions of years, bridging to the present host-vector-pathogen interactions. The origin of vector-borne diseases is dated to the early cretaceous with Trypanosomatidae species in extinct sand flies, ancestral of modern protozoan hemoparasites of zoonotic concern (e.g., Leishmania and Trypanosoma) associated to reptiles. Bacterial RVBDs are represented by microorganisms also affecting mammals of the genera Aeromonas, Anaplasma, Borrelia, Coxiella, Ehrlichia and Rickettsia, most of them having reptilian clades. Finally, reptiles may play an important role as reservoirs of arborivuses, given the low host specificity of anthropophilic mosquitoes and sand flies. In this review, vector-borne pathogens of zoonotic concern from reptiles are discussed, as well as the interactions between reptiles, arthropod vectors and the zoonotic pathogens they may transmit
Optimal endowments of public investment: an empirical analysis for the Spanish regions
Following Aschauer's (1989) influential contribution, the role of public investment has been stressed as a crucial factor leading to higher private capital productivity, which would lead in turn to higher growth rates. According to this author, the decline in productivity growth experienced by the US economy during the seventies, would explained to a great extent by the decrease in the provision of public infrastructures during that period. In this way, the next years have witnessed the appearance of a great amount of empirical literature that analysed the impact of public investment on economic growth. Although the first empirical studies made use of aggregate time series for countries, this approach has been also extended to a regional framework using panel data, obtaining results that were quantitatively lower than those found with aggregate data. The reason would be the spillover effects related to the regional endowments of public capital, whose effect would extend not only the own region, but also to the neighbouring regions. In any case, public infrastructure seems to play an important role in the growth process of regions that should not be neglected. On the other hand, the issue of the optimal endowments of public infrastructure has been hardly discussed. In a recent paper, Karras (1997) has developed a simple condition to assess whether public capital is optimally provided, namely, whether the marginal productivities of both private and public capital are equal or not. By estimating a simple growth equation for fifteen European countries during the period 1960-1992, he is unable to reject the null hypothesis that the marginal productivities of private and public capital are equal, so that government investment would be neither underprovided nor overprovided in the fifteen countries of his sample. In this paper we try to address this issue (i.e., whether the endowments of public investment are optimal or not) in a regional framework, using Spanish data for the period 1967-91. Unlike Karras (1997), who assumes that the production function exhibits constant returns to scale in all factors, we are able to generalise his condition without the need of this constraint. On the other hand, the Spanish economy can provide an interesting case of study, since it has experienced a sustained period of growth in the last forty years, which has been accompanied by a strong process of structural change. In particular, the establishment of new regional governments after the restoration of democracy in 1977, coupled with the strong increase experienced by public investment since them, are all of them elements that can justify the interest of the Spanish case for the objectives of this paper. Therefore, in this paper we will first derive the theoretical condition under which public capital would be optimally provided, and then we will provide an empirical application of the model, for the case of the Spanish regions during the period 1965-1995.
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