NMSSM with Lopsided Gauge Mediation

We study a gauge mediated supersymmetry breaking version of the NMSSM in which the soft m_{H_u}^2 and m_{H_d}^2 masses receive extra contributions due to the presence of direct couplings between the Higgs and the messenger sector. We are motivated by the well-known result that minimal gauge mediation is phenomenologically incompatible with the NMSSM due to the small value of the induced effective mu term. The model considered in the present paper solves the aforementioned problem through a modified RG running of the singlet soft mass m_N^2. This effect, which is induced by the dominant m_{H_d}^2 term in the one-loop beta-function of m_N^2, shifts the singlet soft mass towards large negative values at the electroweak scale. That is sufficient to ensure a large VEV for the scalar component of the singlet which in turn translates into a sizeable effective mu term. We also describe a mechanism for generating large soft trilinear terms at the messenger scale. This allows us to make the mass of the lightest Higgs boson compatible with the current LHC bound without relying on exceedingly heavy stops

Aspects of Supersymmetry and Quantum Gravity in the Era of the LHC

This thesis addresses several problems related to low-energy supersymmetry and quantum gravity. The first of those is the gauge coupling unication problem within the Minimal Supersymmetric Standard Model. We derive a so called holomorphic master formula which we use in order to analyze the two-loop problem using one-loop renormalization group equations. In terms of model-building our solution relies on the inclusion of extra vector-like matter at intermediate energies which couples to the two Higgs doublets through Yukawa interactions. We find that the extra Yukawa couplings can ameliorate the two-loop discrepancy, an effect which is encoded in the wave-function renormalization factors of the Higgs superfields. Next we address and solve the so called mu-problem by combining two well-known mechanisms for generating a mu-term in the MSSM superpotential - we add a gauge singlet superfield which acquires a vacuum expectation value in its scalar component, on the one hand, and extra vector-like messenger superfields which couple directly to the Higgs sector, on the other. A key ingredient of our construction is the non-trivial hierarchy between the soft masses in the Higgs sector which puts our model into the class of models known as lopsided gauge mediation. This so called inverted hierarchy modifies the RG running of the soft singlet mass ensuring that the effective mu-term can attain sufficiently large values, i.e. mu > 100 GeV, as required by phenomenology. Finally we discuss an application of the so called functional renormalization group to quantum gravity. We construct a diffeomorphism invariant and gauge-fixing independent flow equation which we use in order to analyze the phase diagram of quantum gravity. We solve this equation in several non-trivial approximations, starting with the usual background field approximation. We confirm the presence of a non-trivial UV fixed point and also analyze the infrared sector of the theory which exhibits an infrared fixed point related to classical gravity

Precision Gauge Unification from Extra Yukawa Couplings

We investigate the impact of extra vector-like GUT multiplets on the predicted value of the strong coupling. We find in particular that Yukawa couplings between such extra multiplets and the MSSM Higgs doublets can resolve the familiar two-loop discrepancy between the SUSY GUT prediction and the measured value of alpha_3. Our analysis highlights the advantages of the holomorphic scheme, where the perturbative running of gauge couplings is saturated at one loop and further corrections are conveniently described in terms of wavefunction renormalization factors. If the gauge couplings as well as the extra Yukawas are of O(1) at the unification scale, the relevant two-loop correction can be obtained analytically. However, the effect persists also in the weakly-coupled domain, where possible non-perturbative corrections at the GUT scale are under better control.Comment: 26 pages, LaTeX. v6: Important early reference adde

Transgenic nematodes as biosensors for metal stress in soil pore water samples

Caenorhabditis elegans strains carrying stress-reporter green fluorescent protein transgenes were used to explore patterns of response to metals. Multiple stress pathways were induced at high doses by most metals tested, including members of the heat shock, oxidative stress, metallothionein (mtl) and xenobiotic response gene families. A mathematical model (to be published separately) of the gene regulatory circuit controlling mtl production predicted that chemically similar divalent metals (classic inducers) should show additive effects on mtl gene induction, whereas chemically dissimilar metals should show interference. These predictions were verified experimentally; thus cadmium and mercury showed additive effects, whereas ferric iron (a weak inducer) significantly reduced the effect of mercury. We applied a similar battery of tests to diluted samples of soil pore water extracted centrifugally after mixing 20% w/w ultrapure water with air-dried soil from an abandoned lead/zinc mine in the Murcia region of Spain. In addition, metal contents of both soil and soil pore water were determined by ICP-MS, and simplified mixtures of soluble metal salts were tested at equivalent final concentrations. The effects of extracted soil pore water (after tenfold dilution) were closely mimicked by mixtures of its principal component ions, and even by the single most prevalent contaminant (zinc) alone, though other metals modulated its effects both positively and negatively. In general, mixtures containing similar (divalent) metal ions exhibited mainly additive effects, whereas admixture of dissimilar (e.g. trivalent) ions often resulted in interference, reducing overall levels of stress-gene induction. These findings were also consistent with model predictions

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Parasites of domestic and wild animals in South Africa. XLVIII . Ticks (Acari: Ixodidae) infesting domestic cats and wild felids in southern Africa

Ticks collected from domestic cats (Felis catus), cheetahs (Acinonyx jubatus),caracals (Caracal caracal), African wild cats (Felis lybica), black-footed cats (Felis nigripes), a serval (Leptailurus serval), lions(Panthera leo), and leopards (Panthera pardus) were identified and counted. Thirteen species of ixodid ticks and one argasid tick were identified from domestic cats and 17 species of ixodid ticks from wild felids. The domestic cats and wild felids harboured 11 ixodid species in common. The adults of Haemaphysalis elliptica, the most abundant tick species infesting cats and wild felids, were most numerous on a domestic cat in late winter and in mid-summer, during 2 consecutive years. The recorded geographic distribution of the recently described Haemaphysalis colesbergensis, a parasite of cats and caracals, was extended by 2 new locality records in the Northern Cape Province,South Africa

Homological properties of quantised Borel-Schur algebras and resolutions of quantised Weyl modules

We continue the development of the homological theory of quan- tum general linear groups previously considered by the first author. The development is used to transfer information to the representation theory of quantised Schur algebras. The acyclicity of induction from some rank-one modules for quantised Borel-Schur subalgebras is de- duced. This is used to prove the exactness of the complexes recently constructed by Boltje and Maisch, giving resolutions of the co-Specht modules for Hecke algebras