Well-tempered n-plet dark matter

We study simple effective models of fermionic WIMP dark matter, where the dark matter candidate is a mixture of a Standard Model singlet and an n-plet of SU(2) with n >= 3, stabilized by a discrete symmetry. The dark matter mass is assumed to be around the electroweak scale, and the mixing is generated by higher-dimensional operators, with a cutoff scale > 1 TeV. For appropriate values of the mass parameters and the mixing we find that the observed dark matter relic density can be generated by coannihilation. Direct detection experiments have already excluded large parts of the parameter space, and the next-generation experiments will further constrain these models.Comment: 25 pages, 7 figures; v2: references and plots updated, minor corrections, conclusions unchange

Spatial market integration in the EU beef and veal sector: policy decoupling and export bans

The 2003 reforms of the Common Agricultural Policy of the Euro-pean Union allowed for discretionary implementation among member states. Discretion was allowed with respect to the timing and the degree of decoupling of policy support. Differences among member states were particularly apparent in the European beef and veal sector. Using weekly data from 2003 to 2009, we assess the consequences of different national implementation strategies of the reforms on market integration for young calves, which are intensively traded in the European Union. Time series properties are analyzed with a range unit-root test after which a multivariate cointegration model is estimated. We find that the calf markets in Germany, France, the Netherlands and Spain are integrated and tightly interrelated as evidenced by both short and long-run price transmis-sion. We also find strong statistical support for the hypothesis that decoupling reduced calf price levels. Additionally, we ascertain that the outbreak of the Blue Tongue disease induced a structural change in parts of the EU calf market. Using counterfactual scenarios, we provide an indication of the cost involved with granting member states such a high degree of discretion in implementation. We conclude that the national markets studied here belong to a common market. --2003 CAP reform,calf market,decoupling,EU,market integration,price transmission

Temporal Control of the TGF-β Signaling Network by Mouse ESC MicroRNA Targets of Different Affinities.

Although microRNAs (miRNAs) function in the control of embryonic stem cell (ESC) pluripotency, a systems-level understanding is still being developed. Through the analysis of progressive Argonaute (Ago)-miRNA depletion and rescue, including stable Ago knockout mouse ESCs, we uncover transforming growth factor beta (TGF-β) pathway activation as a direct and early response to ESC miRNA reduction. Mechanistically, we link the derepression of weaker miRNA targets, including TGF-β receptor 1 (Tgfbr1), to the sensitive TGF-β pathway activation. In contrast, stronger miRNA targets impart a more robust repression, which dampens concurrent transcriptional activation. We verify such dampened induction for TGF-β antagonist Lefty. We find that TGF-β pathway activation contributes to the G1 cell-cycle accumulation of miRNA-deficient ESCs. We propose that miRNA target affinity is a determinant of the temporal response to miRNA changes, which enables the coordination of gene network responses

How people know their risk preference

People differ in their willingness to take risks. Recent work found that revealed preference tasks (e.g., laboratory lotteries)—a dominant class of measures—are outperformed by survey-based stated preferences, which are more stable and predict real-world risk taking across different domains. How can stated preferences, often criticised as inconsequential “cheap talk,” be more valid and predictive than controlled, incentivized lotteries? In our multimethod study, over 3,000 respondents from population samples answered a single widely used and predictive risk-preference question. Respondents then explained the reasoning behind their answer. They tended to recount diagnostic behaviours and experiences, focusing on voluntary, consequential acts and experiences from which they seemed to infer their risk preference. We found that third-party readers of respondents’ brief memories and explanations reached similar inferences about respondents’ preferences, indicating the intersubjective validity of this information. Our results help unpack the self perception behind stated risk preferences that permits people to draw upon their own understanding of what constitutes diagnostic behaviours and experiences, as revealed in high-stakes situations in the real world

A natural renormalizable model of metastable SUSY breaking

We propose a model of metastable dynamical supersymmetry breaking in which all scales are generated dynamically. Our construction is a simple variant of the Intriligator-Seiberg-Shih model, with quark masses induced by renormalizable couplings to an auxiliary supersymmetric QCD sector. Since all scales arise from dimensional transmutation, the model has no fundamental dimensionful parameters. It also does not rely on higher-dimensional operators.Comment: 9 pages; v2: typos correcte

On SUSY GUTs with a degenerate Higgs mass matrix

Certain supersymmetric grand unified models predict that the coefficients of the quadratic terms in the MSSM Higgs potential should be degenerate at the GUT scale. We discuss some examples for such models, and we analyse the implications of this peculiar condition of a GUT-scale degenerate Higgs mass matrix for low-scale MSSM phenomenology. To this end we explore the parameter space which is consistent with existing experimental constraints by means of a Markov Chain Monte Carlo analysis.Comment: 31 pages, 27 figures; v2: typos correcte

Online Signature Verification: Improving Performance through Pre-classification Based on Global Features

In this paper, a pre-classification stage based on global features is incorporated to an online signature verification system for the purposes of improving its performance. The pre-classifier makes use of the discriminative power of some global features to discard (by declaring them as forgeries) those signatures for which the associated global feature is far away from its respective mean. For the remaining signatures, features based on a wavelet approximation of the time functions associated with the signing process, are extracted, and a Random Forest based classification is performed. The experimental results show that the proposed pre-classification approach, when based on the apppropriate global feature, is capable of getting error rate improvements with respect to the case where no pre-classification is performed. The approach also has the advantages of simplifying and speeding up the verification process.Fil: Parodi, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y Sistemas; ArgentinaFil: Gómez, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y Sistemas; Argentin

Holographic metastability

We show how supersymmetric QCD in a slice of AdS can naturally acquire metastable vacua. The formulation closely follows that of Intriligator, Seiberg and Shih (ISS), with an "electric" sector on the UV brane and a "magnetic" sector on the IR brane. However the 't Hooft anomaly matching that constrains the Seiberg duality central to ISS is replaced by anomaly inflow and cancellation, and the source of strong coupling is the CFT to which the theory couples rather than the gauge groups. The theory contains an anomaly free R-symmetry that, when broken by UV effects, leads to an O'Raifeartaigh model on the IR brane. In contrast to ISS, the R-symmetry breaking in the UV can be maximal, and yet the R-symmetry breaking in the IR theory remains under strict control: there is no need for retrofitting of small parameters.Comment: 20 pages, 2 figure

gas phase vibrational spectroscopy of V3O6-8+

We present gas phase vibrational spectra of the trinuclear vanadium oxide cations V3O6+·He1–4, V3O7+·Ar0,1, and V3O8+·Ar0,2 between 350 and 1200 cm−1. Cluster structures are assigned based on a comparison of the experimental and simulated IR spectra. The latter are derived from B3LYP/TZVP calculations on energetically low-lying isomers identified in a rigorous search of the respective configurational space, using higher level calculations when necessary. V3O7+ has a cage-like structure of C3v symmetry. Removal or addition of an O-atom results in a substantial increase in the number of energetically low-lying structural isomers. V3O8+ also exhibits the cage motif, but with an O2 unit replacing one of the vanadyl oxygen atoms. A chain isomer is found to be most stable for V3O6+. The binding of the rare gas atoms to V3O6–8+ clusters is found to be strong, up to 55 kJ/mol for Ar, and markedly isomer-dependent, resulting in two interesting effects. First, for V3O7+·Ar and V3O8+·Ar an energetic reordering of the isomers compared to the bare ion is observed, making the ring motif the most stable one. Second, different isomers bind different number of rare gas atoms. We demonstrate how both effects can be exploited to isolate and assign the contributions from multiple isomers to the vibrational spectrum. The present results exemplify the structural variability of vanadium oxide clusters, in particular, the sensitivity of their structure on small perturbations in their environment