Scientific note: varroa mite eradication, the strange case of Gorgona Island

Varroa mites are vectors for several bee viruses contributing also to their diffusion worldwide (Martin 2001; Di Prisco et al. 2011; Cersini et al. 2013). The tripartite relationship among bees, mites, and viruses is thought to be responsible for the loss of a large amount of colonies (Highfield et al. 2009; Berthoud et al. 2010; Francis et al. 2013). Before the arrival of Varroa destructor , virus prevalence was lower (Martin et al. 2012). The mites have contributed to spread the viruses which could be correlated to the high number of mite-infested honey bee colony losses (Berthoud et al. 2010; Francis et al. 2013). Since the varroa mite arrival, control of varroosis has become necessary (Moritz et al. 2010). Such control is focused on the coexistence between honeybees and mites. A trial to eradicate the mite from isolated areas has not been successful. Experiments carried out to eradicate varroa mite by use of several coordinated treatments in Jersey, an island in the English Channel, did not succeed, showing how difficult it is to eradicate this ecto-parasite from an infested area (Sampson and Martin 1999). The aim of this study is to report the disappearance of varroa mite from the island of Gorgona (43° 26′ N; 9° 54′ E) following several treatments in a single apiary kept in complete isolation. Furthermore, after the varroa disappearance, the honeybee viral load has been analyzed. Gorgona Island has been chosen because it provides suitable conditions to guarantee continuous monitoring and isolation to avoid new reintroduction of bee pathogens and pests

Beneficial effect of prolonged heme oxygenase 1 activation in a rat model of chronic heart failure.

SUMMARY We and others have previously demonstrated that heme oxygenase 1 (HO-1) induction by acute hemin administration exerts cardioprotective effects. Here, we developed a rat model of heart failure to investigate whether a long-term induction of HO-1 by chronic hemin administration exerted protective effects. Sprague Dawley rats that underwent permanent ligation of the left coronary artery were closely monitored for survival rate analysis and sacrificed on day 28 post-operation. Administration of hemin (4 mg/kg body weight) every other day for 4 weeks induced a massive increase in HO-1 expression and activity, as shown by the increased levels of the two main metabolic products of heme degradation, bilirubin and carbon monoxide (CO). These effects were associated with significant improvement in survival and reduced the extension of myocardial damage. The ischemic hearts of the hemin-treated animals displayed reduced oxidative stress and apoptosis in comparison with the non-treated rats, as shown by the decreased levels of lipid peroxidation, free-radical-induced DNA damage, caspase-3 activity and Bax expression. Besides, chronic HO-1 activation suppressed the elevated levels of myeloperoxidase (MPO) activity, interleukin 1β (IL-1β) production and tumor necrosis factor-α (TNFα) production that were evoked by the ischemic injury, and increased the plasma level of the anti-inflammatory cytokine IL-10. Interestingly, HO-1 inhibitor zinc protoporphyrin IX (ZnPP-IX; 1 mg/kg) lowered bilirubin and CO concentrations to control values, thus abolishing all the cardioprotective effects of hemin. In conclusion, the results demonstrate that chronic HO-1 activation by prolonged administration of hemin improves survival and exerts protective effects in a rat model of myocardial ischemia by exerting a potent antioxidant activity and disrupting multiple levels of the apoptotic and inflammatory cascade

Holographic approach to a minimal Higgsless model

In this work, following an holographic approach, we carry out a low energy effective study of a minimal Higgsless model based on SU(2) bulk symmetry broken by boundary conditions, both in flat and warped metric. The holographic procedure turns out to be an useful computation technique to achieve an effective four dimensional formulation of the model taking into account the corrections coming from the extra dimensional sector. This technique is used to compute both oblique and direct contributions to the electroweak parameters in presence of fermions delocalized along the fifth dimension.Comment: Latex file, 23 page

Natural Islands for a 125 GeV Higgs in the scale-invariant NMSSM

We study whether a 125 GeV standard model-like Higgs boson can be accommodated within the scale-invariant NMSSM in a way that is natural in all respects, i.e., not only is the stop mass and hence its loop contribution to Higgs mass of natural size, but we do not allow significant tuning of NMSSM parameters as well. We pursue as much as possible an analytic approach which gives clear insights on various ways to accommodate such a Higgs mass, while conducting complementary numerical analyses. We consider both scenarios with singlet-like state being heavier and lighter than SM-like Higgs. With A-terms being small, we find for the NMSSM to be perturbative up to GUT scale, it is not possible to get 125 GeV Higgs mass, which is true even if we tune parameters of NMSSM. If we allow some of the couplings to become non-perturbative below the GUT scale, then the non-tuned option implies that the singlet self-coupling, kappa, is larger than the singlet-Higgs coupling, lambda, which itself is order 1. This leads to a Landau pole for these couplings close to the weak scale, in particular below ~10^4 TeV. In both the perturbative and non-perturbative NMSSM, allowing large A_lambda, A_kappa gives "more room" to accommodate a 125 GeV Higgs, but a tuning of these A-terms may be needed. In our analysis we also conduct a careful study of the constraints on the parameter space from requiring global stability of the desired vacuum fitting a 125 GeV Higgs, which is complementary to existing literature. In particular, as the singlet-Higgs coupling lambda increases, vacuum stability becomes more serious of an issue.Comment: 34 pages, 4 figures, references added, minor corrections to text and figures, version to be published in JHE

A Light Stop with Flavor in Natural SUSY

The discovery of a SM-like Higgs boson near 125 GeV and the flavor texture of the Standard Model motivate the investigation of supersymmetric quiver-like BSM extensions. We study the properties of such a minimal class of models which deals naturally with the SM parameters. Considering experimental bounds as well as constraints from flavor physics and Electro-Weak Precision Data, we find the following. In a self-contained minimal model - including the full dynamics of the Higgs sector - top squarks below a TeV are in tension with b->s{\gamma} constraints. Relaxing the assumption concerning the mass generation of the heavy Higgses, we find that a stop not far from half a TeV is allowed. The models have some unique properties, e.g. an enhancement of the h-> b\bar{b},\tau\bar{{\tau}} decays relative to the h->\gamma{\gamma} one, a gluino about 3 times heavier than the stop, an inverted hierarchy of about 3-20 between the squarks of the first two generations and the stop, relatively light Higgsino neutralino or stau NLSP, as well as heavy Higgses and a W' which may be within reach of the LHC.Comment: LaTeX, 22 pages, 4 figures; V2: references adde

Simplified Models for LHC New Physics Searches

This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the "Topologies for Early LHC Searches" workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first ~50-500 pb-1 of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.Comment: 40 pages, 2 figures. This document is the official summary of results from "Topologies for Early LHC Searches" workshop (SLAC, September 2010). Supplementary material can be found at http://lhcnewphysics.or

Expression of interest for the CODEX-b detector

International audienceThis document presents the physics case and ancillary studies for the proposed CODEX-b long-lived particle (LLP) detector, as well as for a smaller proof-of-concept demonstrator detector, CODEX-$\beta$, to be operated during Run 3 of the LHC. Our development of the CODEX-b physics case synthesizes ‘top-down’ and ‘bottom-up’ theoretical approaches, providing a detailed survey of both minimal and complete models featuring LLPs. Several of these models have not been studied previously, and for some others we amend studies from previous literature: In particular, for gluon and fermion-coupled axion-like particles. We moreover present updated simulations of expected backgrounds in CODEX-b’s actively shielded environment, including the effects of shielding propagation uncertainties, high-energy tails and variation in the shielding design. Initial results are also included from a background measurement and calibration campaign. A design overview is presented for the CODEX-$\beta$ demonstrator detector, which will enable background calibration and detector design studies. Finally, we lay out brief studies of various design drivers of the CODEX-b experiment and potential extensions of the baseline design, including the physics case for a calorimeter element, precision timing, event tagging within LHCb, and precision low-momentum tracking