2,592 research outputs found
Inefficient lobbying, populism and oligarchy
This paper analyses the efficiency consequences of lobbying in a production economy with imperfect commitment. We first show that the Pareto efficiency result found for truthful equilibria of common agency games in static exchange economies no longer holds under these more general conditions. We construct a model of pressure groups where the set of e.cient truthful common-agency equilibria has measure zero. Equilibria are generally inefficient as a direct result of the existence of groups with conflicting interests, which allocate real resources to lobbying. If lobbies representing "the poor " and "the rich " have identical organizational capacities, we show that these equilibria are biased towards the poor, who have a comparative advantage in politics, rather than in production. If the pressure groups di.er in their organizational capacity, both pro-rich (oligarchic) and pro-poor (populist) equilibria may arise, all of which are inefficient with respect to the constrained optimum.
Natural Inflation from 5D SUGRA and Low Reheat Temperature
Motivated by recent cosmological observations of a possibly unsuppressed
primordial tensor component of inflationary perturbations, we reanalyse in
detail the 5D conformal SUGRA originated natural inflation model of Ref. [1].
The model is a supersymmetric variant of 5D extra natural inflation, also based
on a shift symmetry, and leads to the potential of natural inflation. Coupling
the bulk fields generating the inflaton potential via a gauge coupling to the
inflaton with brane SM states we necessarily obtain a very slow gauge inflaton
decay rate and a very low reheating temperature ~GeV. Analysis of the required number of e-foldings (from the CMB
observations) leads to values of in the lower range of present Planck
2015 results. Some related theoretical issues of the construction, along with
phenomenological and cosmological implications, are also discussed.Comment: Analysis and discussions updated in light of recent Planck and joint
analysis of BICEP2/Keck and Planck result
SAFT-γ force field for the simulation of molecular fluids: 8. hetero-group coarse-grained models of perfluoroalkylalkanes assessed with new vapour-liquid interfacial tension data
The air-liquid interfacial behaviour of linear perfluoroalkylalkanes (PFAAs) is reported through a combined experimental and computer simulation study. The surface tensions of seven liquid PFAAs (perfluorobutylethane, F4H2; perfluorobutylpentane, F4H5; perfluorobutylhexane, F4H6, perfluorobutyloctane, F4H8; perfluorohexylethane, F6H2; perfluorohexylhexane, F6H6; and perfluorohexyloctane, F6H8) are experimentally determined over a wide temperature range (276 to 350 K). The corresponding surface thermodynamic properties and the critical temperatures of the studied compounds are estimated from the temperature dependence of the surface tension. Experimental density and vapour pressure data are employed to parameterize a generic heteronuclear coarse-grained intermolecular potential of the SAFT- γ family for PFAAs. The resulting force field is used in direct molecular dynamics simulations to predict with quantitative agreement the experimental tensions and to explore the conformations of the molecules in the interfacial region revealing a preferential alignment of the PFAA molecules towards the interface and an enrichment of the perfluoro-groups at the outer interface region
Co-infection with Onchocerca volvulus and Loa loa microfilariae in central Cameroon: are these two species interacting?
Ivermectin treatment may induce severe adverse reactions in some individuals heavily infected with Loa loa. This hampers the implementation of mass ivermectin treatment against onchocerciasis in areas where Onchocerca volvulus and L. loa are co-endemic. In order to identify factors, including co-infections, which may explain the presence of high L. loa microfilaraemia in some individuals, we analysed data collected in 19 villages of central Cameroon. Two standardized skin snips and 30 mul of blood were obtained from each of 3190 participants and the microfilarial (mf) loads of both O. volvulus and L. loa were quantified. The data were analysed using multivariate hierarchical models. Individual-level variables were: age, sex, mf presence, and mf load; village-related variables included the endemicity levels for each infection. The two species show a certain degree of ecological separation in the study area. However, for a given individual host, the presence of microfilariae of one species was positively associated with the presence of microfilariae of the other (OR=1.79, 95% CI [1.43-2.24]). Among individuals harbouring Loa microfilariae, there was a slight positive relationship between the L. loa and O. volvulus mf loads which corresponded to an 11% increase in L. loa mf load per 100 O. volvulus microfilariae. Co-infection with O. volvulus is not sufficient to explain the very high L. loa mf loads harboured by some individuals
Unique Features of Odorant-Binding Proteins of the Parasitoid Wasp Nasonia vitripennis Revealed by Genome Annotation and Comparative Analyses
Insects are the most diverse group of animals on the planet, comprising over 90% of all metazoan life forms, and have adapted to a wide diversity of ecosystems in nearly all environments. They have evolved highly sensitive chemical senses that are central to their interaction with their environment and to communication between individuals. Understanding the molecular bases of insect olfaction is therefore of great importance from both a basic and applied perspective. Odorant binding proteins (OBPs) are some of most abundant proteins found in insect olfactory organs, where they are the first component of the olfactory transduction cascade, carrying odorant molecules to the olfactory receptors. We carried out a search for OBPs in the genome of the parasitoid wasp Nasonia vitripennis and identified 90 sequences encoding putative OBPs. This is the largest OBP family so far reported in insects. We report unique features of the N. vitripennis OBPs, including the presence and evolutionary origin of a new subfamily of double-domain OBPs (consisting of two concatenated OBP domains), the loss of conserved cysteine residues and the expression of pseudogenes. This study also demonstrates the extremely dynamic evolution of the insect OBP family: (i) the number of different OBPs can vary greatly between species; (ii) the sequences are highly diverse, sometimes as a result of positive selection pressure with even the canonical cysteines being lost; (iii) new lineage specific domain arrangements can arise, such as the double domain OBP subfamily of wasps and mosquitoes.Rothamsted Research receives grant-aided support from the BBSRC of the UK. The authors thank Prof. David M. Shuker, University of Edinburgh, UK,
who provided us with N. vitripennis. FGV was supported by a predoctoral fellowship SFRH/BD/22360/2005 from the ‘Fundac¸a˜o para a Cieˆncia e a Tecnologı´a’
(Portugal). This work was funded by grants BFU2007-62927 and BFU2010-15484 from the ‘Direccio´n General de Investigacio´n Cientı´fica y Te´cnica’ (Spain) to JR. JR
was partially supported by ICREA Academia (Generalitat de Catalunya). The funders had no role in study design, data collection and analysis, decision to publish,
or preparation of the manuscript
Multiplexing Biochemical Signals
In this paper we show that living cells can multiplex biochemical signals,
i.e. transmit multiple signals through the same signaling pathway
simultaneously, and yet respond to them very specifically. We demonstrate how
two binary input signals can be encoded in the concentration of a common
signaling protein, which is then decoded such that each of the two output
signals provides reliable information about one corresponding input. Under
biologically relevant conditions the network can reach the maximum amount of
information that can be transmitted, which is 2 bits.Comment: 4 pages, 4 figure
Four dimensional R^4 superinvariants through gauge completion
We fully compute the N=1 supersymmetrization of the fourth power of the Weyl
tensor in d=4 x-space with the auxiliary fields. In a previous paper, we showed
that their elimination requires an infinite number of terms; we explicitely
compute those terms to order \kappa^4 (three loop). We also write, in
superspace notation, all the possible N=1 actions, in four dimensions, that
contain pure R^4 terms (with coupling constants). We explicitely write these
actions in terms of the \theta components of the chiral density \epsilon and
the supergravity superfields R, G_m, W_{ABC}. Using the method of gauge
completion, we compute the necessary \theta components which allow us to write
these actions in x-space. We discuss under which circumstances can these extra
R^4 correction terms be reabsorbed in the pure supergravity action, and their
relevance to the quantum supergravity/string theory effective actions.Comment: 20 pages, no figures. Sec. 3 clarified; typos correcte
- …