More Visible Effects of the Hidden Sector

There is a growing appreciation that hidden sector dynamics may affect the supersymmetry breaking parameters in the visible sector (supersymmetric standard model), especially when the dynamics is strong and superconformal. We point out that there are effects that have not been previously discussed in the literature. For example, the gaugino masses are suppressed relative to the gravitino mass. We discuss their implications in the context of various mediation mechanisms. The issues discussed include anomaly mediation with singlets, the mu (B mu) problem in gauge and gaugino mediation, and distinct mass spectra for the superparticles that have not been previously considered.Comment: 25 pages; small clarifications and corrections, version to appear in Phys. Rev.

Higgs Boson Decays to Neutralinos in Low-Scale Gauge Mediation

We study the decays of a standard model-like MSSM Higgs boson to pairs of neutralinos, each of which subsequently decays promptly to a photon and a gravitino. Such decays can arise in supersymmetric scenarios where supersymmetry breaking is mediated to us by gauge interactions with a relatively light gauge messenger sector (M_{mess} < 100 TeV). This process gives rise to a collider signal consisting of a pair of photons and missing energy. In the present work we investigate the bounds on this scenario within the minimal supersymmetric standard model from existing collider data. We also study the prospects for discovering the Higgs boson through this decay mode with upcoming data from the Tevatron and the LHC.Comment: 18 pages, 5 figures, added references and discussion of neutralino couplings, same as journal versio

A length-dynamic Tonks gas theory of histone isotherms

We find exact solutions to a new one-dimensional (1D) interacting particle theory and apply the results to the adsorption and wrapping of polymers (such as DNA) around protein particles (such as histones). Each adsorbed protein is represented by a Tonks gas particle. The length of each particle is a degree of freedom that represents the degree of DNA wrapping around each histone. Thermodynamic quantities are computed as functions of wrapping energy, adsorbed histone density, and bulk histone concentration (or chemical potential); their experimental signatures are also discussed. Histone density is found to undergo a two-stage adsorption process as a function of chemical potential, while the mean coverage by high affinity proteins exhibits a maximum as a function of the chemical potential. However, {\it fluctuations} in the coverage are concurrently maximal. Histone-histone correlation functions are also computed and exhibit rich two length scale behavior.Comment: 5 pp, 3 fig

Exons, introns and DNA thermodynamics

The genes of eukaryotes are characterized by protein coding fragments, the exons, interrupted by introns, i.e. stretches of DNA which do not carry any useful information for the protein synthesis. We have analyzed the melting behavior of randomly selected human cDNA sequences obtained from the genomic DNA by removing all introns. A clear correspondence is observed between exons and melting domains. This finding may provide new insights in the physical mechanisms underlying the evolution of genes.Comment: 4 pages, 8 figures - Final version as published. See also Phys. Rev. Focus 15, story 1

Comment on "Why is the DNA denaturation transition first order?"

In this comment we argue that while the conclusions in the original paper (Y. Kafri, D. Mukamel and L. Peliti, Phys. Rev. Lett. 85, 4988 (2000)) are correct for asymptotically long DNA chains, they do not apply to the chains used in typical experiments. In the added last paragraph, we point out that for real DNA the average distance between denatured loops is not of the order of the persistence length of a single-stranded chain but much larger. This corroborates our reasoning that the double helix between loops is quite rigid, and thereby our conclusion.Comment: 1 page, REVTeX. Last paragraph adde

Taking part in the community occupational therapy in dementia UK intervention from the perspective of people with dementia, family carers and occupational therapists: A qualitative study

AIM: Community Occupational Therapy in Dementia (COTiD-UK) is a manualised intervention delivered to the person with dementia and their identified family carer primarily in their own home. The focus is on enabling both the person with dementia and their family carer to engage in personally meaningful activities. This qualitative study examines the experiences of people with mild to moderate dementia, their family carers and occupational therapists, of taking part in the COTiD-UK intervention. METHOD: A purposive sample of 22 pairs of people with dementia and a family carer and seven occupational therapists took part in semi-structured interviews that were audio recorded, transcribed and inductively analysed using thematic analysis. FINDINGS: Themes from the occupational therapist interviews relate to the COTiD-UK intervention philosophy and content, aspects of delivering it in practice and thinking ahead to it becoming usual practice. Themes from the pair interviews relate to the focus of COTiD-UK sessions on meaningful occupation and working together and a sense of being able to plan to live well with dementia in the short- and longer-term as a result of the intervention. CONCLUSION: This person-centred occupation-focussed intervention was highly valued by people with dementia and their family carers and the occupational therapists delivering it

Solving the 3D Ising Model with the Conformal Bootstrap

We study the constraints of crossing symmetry and unitarity in general 3D Conformal Field Theories. In doing so we derive new results for conformal blocks appearing in four-point functions of scalars and present an efficient method for their computation in arbitrary space-time dimension. Comparing the resulting bounds on operator dimensions and OPE coefficients in 3D to known results, we find that the 3D Ising model lies at a corner point on the boundary of the allowed parameter space. We also derive general upper bounds on the dimensions of higher spin operators, relevant in the context of theories with weakly broken higher spin symmetries.Comment: 32 pages, 11 figures; v2: refs added, small changes in Section 5.3, Fig. 7 replaced; v3: ref added, fits redone in Section 5.

Why is the DNA Denaturation Transition First Order?

We study a model for the denaturation transition of DNA in which the molecules are considered as composed of a sequence of alternating bound segments and denaturated loops. We take into account the excluded-volume interactions between denaturated loops and the rest of the chain by exploiting recent results on scaling properties of polymer networks of arbitrary topology. The phase transition is found to be first order in d=2 dimensions and above, in agreement with experiments and at variance with previous theoretical results, in which only excluded-volume interactions within denaturated loops were taken into account. Our results agree with recent numerical simulations.Comment: Revised version. To appear in Phys. Rev. Let

“Everyone needs to understand each other’s systems”: Stakeholder views on the acceptability and viability of a Pharmacist Independent Prescriber role in care homes for older people in the UK

The role of an innovative Pharmacist Independent Prescriber (PIP) for care homes to optimise medications has not been examined. We explored stakeholders’ views on issues and barriers that the PIP might address to inform a service specification for the PIP intervention in older people's care homes. Focus groups (n = 72 participants) and semi‐structured interviews (n = 13) undertaken in 2015 across four sites in the United Kingdom captured the views of doctors, pharmacists, care‐home managers and staff, residents and relatives. Stakeholders identified their expectations of what service should be provided by PIPs, what might affect their support for the role, and barriers and enablers to providing the service. Transcripts were analysed using the Theoretical Domains Framework to identify key components, which were reviewed by stakeholders in 2016. A PIP service was envisaged offering benefits for residents, care homes and doctors but stakeholders raised challenges including agreement on areas where PIPs might prescribe, contextual barriers in chronic disease management, PIPs’ knowledge of older people's medicine, and implementation barriers in integrated team‐working and ensuring role clarity. Introducing a PIP was welcomed in principle but conditional on: a clearly defined PIP role communicated to stakeholders; collaboration across doctors, PIPs and care‐home staff; dialogue about developing the service with residents and relatives, based on trust and effective communication. To embed a PIP service within increasingly complex care‐homes provision, the overarching theme from this research was that everyone must “understand each other's systems”

Dynamical scaling of the DNA unzipping transition

We report studies of the equilibrium and the dynamics of a general set of lattice models which capture the essence of the force-induced or mechanical DNA unzipping transition. Besides yielding the whole equilibrium phase diagram in the force vs temperature plane, which reveals the presence of an interesting re-entrant unzipping transition for low T, these models enable us to characterize the dynamics of the process starting from a non-equilibrium initial condition. The thermal melting of the DNA strands displays a model dependent time evolution. On the contrary, our results suggest that the dynamical mechanism for the unzipping by force is very robust and the scaling behaviour does not depend on the details of the description we adopt.Comment: 6 pages, 4 figures, A shorter version of this paper appeared in Phys. Rev. Lett. 88, 028102 (2002