Higgs Messengers

We explore the consequences of the Higgs fields acting as messengers of supersymmetry breaking. The hidden-sector paradigm in the gauge mediation framework is relaxed by allowing two types of gauge-invariant, renormalizable operators that are typically discarded: direct coupling between the Higgses and supersymmetry breaking singlets, and Higgs-messenger mixing terms. The most important phenomenological consequence is a flavor-dependent shift in sfermion masses. This is from a one-loop contribution, which we compute for a general set of weak doublet messengers. We also study a couple of explicit models in detail, finding that precision electroweak constraints can be satisfied with a spectrum significantly different from that of gauge mediation.Comment: 20 pages, 5 figure

Mixture models for distance sampling detection functions

Funding: EPSRC DTGWe present a new class of models for the detection function in distance sampling surveys of wildlife populations, based on finite mixtures of simple parametric key functions such as the half-normal. The models share many of the features of the widely-used “key function plus series adjustment” (K+A) formulation: they are flexible, produce plausible shapes with a small number of parameters, allow incorporation of covariates in addition to distance and can be fitted using maximum likelihood. One important advantage over the K+A approach is that the mixtures are automatically monotonic non-increasing and non-negative, so constrained optimization is not required to ensure distance sampling assumptions are honoured. We compare the mixture formulation to the K+A approach using simulations to evaluate its applicability in a wide set of challenging situations. We also re-analyze four previously problematic real-world case studies. We find mixtures outperform K+A methods in many cases, particularly spiked line transect data (i.e., where detectability drops rapidly at small distances) and larger sample sizes. We recommend that current standard model selection methods for distance sampling detection functions are extended to include mixture models in the candidate set.Publisher PDFPeer reviewe

Insights into the Middle Eastern paternal genetic pool in Tunisia: high prevalence of T-M70 haplogroup in an Arab population

To obtain refreshed insights into the paternal lineages of Tunisian populations, Y-chromosome diversity was assessed in two populations belonging to an Arab genealogical lineage, Kairouan and Wesletia, as well as in four Tunisian Andalusian populations, Testour, Slouguia, Qalaat-El-Andalous and El Alia. The Arabs from Kairouan revealed 73.47% of E-M81 and close affinities with Berber groups, indicating they are likely arabized Berbers, clearly differentiated from the Arabs from Wesletia, who harbored the highest frequency (71.8%) of the Middle Eastern component ever observed in North Africa. In the Tunisian Andalusians, the North African component largely prevailed, followed by the Middle Eastern contribution. Global comparative analysis highlighted the heterogeneity of Tunisian populations, among which, as a whole, dominated a set of lineages ascribed to be of autochthonous Berber origin (71.67%), beside a component of essentially Middle Eastern extraction (18.35%), and signatures of Sub-Saharan (5.2%), European (3.45%) and Asiatic (1.33%) contributions. The remarkable frequency of T-M70 in Wesletia (17.4%) prompted to refine its phylogeographic analysis, allowing to confirm its Middle Eastern origin, though signs of local evolution in Northern Africa were also detected. Evidence was clear on the ancient introduction of T lineages into the region, probably since Neolithic times associated to spread of agriculture.This work was partially financed by FEDER-Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020-Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT-Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the projects “Institute for Research and Innovation in Health Sciences (i3S)” (POCI-01-0145-FEDER007274). IPATIMUP integrates the i3S research unit. VG is supported by FCT under the program contract provided in Decree-Law no.57/2016 of August 29

GAFF-IC: realistic viscosities for isocyanate molecules with a GAFF-based force field

Aliphatic diisocyanates and their derivatives are key liquid components in the industrial processing of polyurethane materials. In particular, for the synthesis of crosslinked polyurethane materials, the higher functionality molecules obtained by reacting three -or more- diisocyanates are of interest. However, despite their widespread application, the relation between molecular structure and macroscopic physical properties, in particular viscosity, is poorly understood in these systems. In this work, we introduce a new force field parameter set, GAFF-IC, based on the widely-used and versatile GAFF force field, meant for accurate predictions of physical properties of isocyanate-based molecular liquids. The new parameters allow to predict the vaporization enthalpies and densities of several isocyanate-based molecules, which are found in excellent agreement with the available experimental data. The effectiveness and transferability of the improved parameters is verified by calculating the viscosities of several isocyanates, isocyanate dimers (uretdiones) and isocyanate trimers (isocyanurates), resulting in accurate viscosity predictions in excellent agreement with experimental values.This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sk lodowska-Curie Grant Agreement no. 642890 (http://thelink-project.eu/) and it was partially supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013, and by the project ”Search-ON2: Revitalization of HPC infrastructure of Uminho” (NORTE-07-0162-FEDER-0000869), under the National Strategic Reference Framework, through the European Regional Development Fun

The Second Transmembrane Domain of P2X7 Contributes to Dilated Pore Formation

Activation of the purinergic receptor P2X7 leads to the cellular permeability of low molecular weight cations. To determine which domains of P2X7 are necessary for this permeability, we exchanged either the C-terminus or portions of the second transmembrane domain (TM2) with those in P2X1 or P2X4. Replacement of the C-terminus of P2X7 with either P2X1 or P2X4 prevented surface expression of the chimeric receptor. Similarly, chimeric P2X7 containing TM2 from P2X1 or P2X4 had reduced surface expression and no permeability to cationic dyes. Exchanging the N-terminal 10 residues or C-terminal 14 residues of the P2X7 TM2 with the corresponding region of P2X1 TM2 partially restored surface expression and limited pore permeability. To further probe TM2 structure, we replaced single residues in P2X7 TM2 with those in P2X1 or P2X4. We identified multiple substitutions that drastically changed pore permeability without altering surface expression. Three substitutions (Q332P, Y336T, and Y343L) individually reduced pore formation as indicated by decreased dye uptake and also reduced membrane blebbing in response to ATP exposure. Three others substitutions, V335T, S342G, and S342A each enhanced dye uptake, membrane blebbing and cell death. Our results demonstrate a critical role for the TM2 domain of P2X7 in receptor function, and provide a structural basis for differences between purinergic receptors. © 2013 Sun et al

Direct Mediation and Metastable Supersymmetry Breaking for SO(10)

We examine a metastable $\mathcal{N}=1$ Macroscopic SO(N) SQCD model of Intriligator, Seiberg and Shih (ISS). We introduce various baryon and meson deformations, including multitrace operators and explore embedding an SO(10) parent of the standard model into two weakly gauged flavour sectors. Direct fundamental messengers and the symmetric pseudo-modulus messenger mediate SUSY breaking to the MSSM. Gaugino and sfermion masses are computed and compared for each deformation type. We also explore reducing the rank of the magnetic quark matrix of the ISS model and find an additional fundamental messenger.Comment: 43 pages, Latex. Version to appear in JHEP

A new insight for monitoring ungulates : density surface modelling of roe deer in a Mediterranean habitat

We would like to thank the University of Aveiro (Department of Biology) and FCT/MEC for the financial support to CESAM RU (UID/AMB/50017) through national funds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement. TAM is partially funded by FCT, Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2013.Ungulates are especially difficult to monitor, and population estimates are challenging to obtain; nevertheless, such information is fundamental for effective management. This is particularly important for expanding species such as roe deer (Capreolus capreolus), whose populations dramatically increased in number and geographic distribution over the last decades. In an attempt to follow population trends and assess species ecology, important methodological advances were recently achieved by combining line or point sampling with geographic information systems (GIS). In this study, we combined density surface modelling (DSM) with line transect survey to predict roe deer density in northeastern Portugal. This was based on modelling pellet group counts as a function of environmental factors while taking into account the probability of detecting pellets and conversion factors to relate pellet density to animal density. We estimated a global density of 3.01 animals/100 ha (95 % CI 0.37–3.51) with a 32.82 % CV. Roe deer densities increased with increasing distance to roads as well as with higher percentage of cover areas and decreased with increasing distance to human populations. This recently developed spatial method can be advantageous to predict density over space through the identification of key factors influencing species abundance. Furthermore, surface maps for subset areas will enable to visually depict abundance distribution of wild populations. This will enable the assessment of areas where ungulate impacts should be minimized, allowing an adaptive management through time.PostprintPeer reviewe