4,494 research outputs found

    Issues for the Next Generation of Galaxy Surveys

    Get PDF
    I argue that the weight of the available evidence favours the conclusions that galaxies are unbiased tracers of mass, the mean mass density (excluding a cosmological constant or its equivalent) is less than the critical Einstein-de Sitter value, and an isocurvature model for structure formation offers a viable and arguably attractive model for the early assembly of galaxies. If valid these conclusions complicate our work of adding structure formation to the standard model for cosmology, but it seems sensible to pay attention to evidence.Comment: 14 pages, 3 postscript figures, uses rspublic.st

    Constraining Large Scale Structure Theories with the Cosmic Background Radiation

    Full text link
    We review the relevant 10+ parameters associated with inflation and matter content; the relation between LSS and primary and secondary CMB anisotropy probes; COBE constraints on energy injection; current anisotropy band-powers which strongly support the gravitational instability theory and suggest the universe could not have reionized too early. We use Bayesian analysis methods to determine what current CMB and CMB+LSS data imply for inflation-based Gaussian fluctuations in tilted Λ\LambdaCDM, Λ\LambdahCDM and oCDM model sequences with age 11-15 Gyr, consisting of mixtures of baryons, cold (and possibly hot) dark matter, vacuum energy, and curvature energy in open cosmologies. For example, we find the slope of the initial spectrum is within about 5% of the (preferred) scale invariant form when just the CMB data is used, and for Λ\LambdaCDM when LSS data is combined with CMB; with both, a nonzero value of ΩΛ\Omega_\Lambda is strongly preferred (≈2/3\approx 2/3 for a 13 Gyr sequence, similar to the value from SNIa). The ooCDM sequence prefers Ωtot<1\Omega_{tot}<1 , but is overall much less likely than the flat ΩΛ≠0\Omega_\Lambda \ne 0 sequence with CMB+LSS. We also review the rosy forecasts of angular power spectra and parameter estimates from future balloon and satellite experiments when foreground and systematic effects are ignored.Comment: 20 pages, LaTeX, 5 figures, 2 tables, uses rspublic.sty To appear in Philosophical Transactions of the Royal Society of London A, 1998. "Discussion Meeting on Large Scale Structure in the Universe," Royal Society, London, March 1998. Text and colour figures also available at ftp://ftp.cita.utoronto.ca/bond/roysoc9

    Embedding effective depression care: using theory for primary care organisational and systems change

    Get PDF
    Background: depression and related disorders represent a significant part of general practitioners (GPs) daily work. Implementing the evidence about what works for depression care into routine practice presents a challenge for researchers and service designers. The emerging consensus is that the transfer of efficacious interventions into routine practice is strongly linked to how well the interventions are based upon theory and take into account the contextual factors of the setting into which they are to be transferred. We set out to develop a conceptual framework to guide change and the implementation of best practice depression care in the primary care setting.Methods: we used a mixed method, observational approach to gather data about routine depression care in a range of primary care settings via: audit of electronic health records; observation of routine clinical care; and structured, facilitated whole of organisation meetings. Audit data were summarised using simple descriptive statistics. Observational data were collected using field notes. Organisational meetings were audio taped and transcribed. All the data sets were grouped, by organisation, and considered as a whole case. Normalisation Process Theory (NPT) was identified as an analytical theory to guide the conceptual framework development.Results: five privately owned primary care organisations (general practices) and one community health centre took part over the course of 18 months. We successfully developed a conceptual framework for implementing an effective model of depression care based on the four constructs of NPT: coherence, which proposes that depression work requires the conceptualisation of boundaries of who is depressed and who is not depressed and techniques for dealing with diffuseness; cognitive participation, which proposes that depression work requires engagement with a shared set of techniques that deal with depression as a health problem; collective action, which proposes that agreement is reached about how care is organised; and reflexive monitoring, which proposes that depression work requires agreement about how depression work will be monitored at the patient and practice level. We describe how these constructs can be used to guide the design and implementation of effective depression care in a way that can take account of contextual differences.Conclusions: ideas about what is required for an effective model and system of depression care in primary care need to be accompanied by theoretically informed frameworks that consider how these can be implemented. The conceptual framework we have presented can be used to guide organisational and system change to develop common language around each construct between policy makers, service users, professionals, and researchers. This shared understanding across groups is fundamental to the effective implementation of change in primary care for depressio

    The Unanticipated Benefits of Behavioral Assessments and Interviews on Anxiety, Self-Esteem and Depression Among Women Engaging in Transactional Sex

    Get PDF
    Women engaging in transactional sex have disproportional mental health co-morbidity and face substantial barriers to accessing social services. We hypothesized that participation in a longitudinal research study, with no overt intervention, would lead to short-term mental health improvements. For 4-weeks, 24 women disclosed information about their lives via twice daily cell-phone diaries and weekly interviews. We used t tests to compare self-esteem, anxiety, and depression at baseline and exit. Tests were repeated for hypothesized effect modifiers (e.g., substance abuse severity; age of sex work debut). For particularly vulnerable women (e.g., less educated, histories of abuse, younger initiation of sex work) participation in research conferred unanticipated mental health benefits. Positive interactions with researchers, as well as discussing lived experiences, may explain these effects. Additional studies are needed to confirm findings and identify mechanisms of change. This work contributes to the growing body of literature documenting that study participation improves mental health

    Kinetic decoupling of neutralino dark matter

    Get PDF
    After neutralinos cease annihilating in the early Universe, they may still scatter elastically from other particles in the primordial plasma. At some point in time, however, they will eventually stop scattering. We calculate the cross sections for neutralino elastic scattering from standard-model particles to determine the time at which this kinetic decoupling occurs. We show that kinetic decoupling occurs above a temperature T∌T\sim MeV. Thereafter, neutralinos act as collisionless cold dark matter.Comment: Replaced with revised version, new references adde

    ‘I Got it off my Chest’: An Examination of how Research Participation Improved the Mental Health of Women Engaging in Transactional Sex

    Get PDF
    Ecologic momentary assessment (EMA) is a form of close-ended diary writing. While it has been shown that participating in a study that incorporates EMA improves mental health of participants, no study to date has examined the pathways through which benefits may occur. For 4-weeks, twice-daily EMAs and weekly interviews captured mood, daily activities and HIV risk behavior of 25 women who engage in transactional sex. Qualitative analysis of exit interviews was performed to examine how participation impacted women's mental health. The majority of participants felt that EMAs heightened awareness of emotions and behavior. Most reported experiencing catharsis from the interviews; specifically, from having a non-judgmental, trusting listener. Participants felt responsible for completing tasks, a sense of accomplishment for completing the study, and altruism. This study demonstrates there are direct benefits associated with participation in an EMA and interview study

    Using a Diverse Seed Mix to Establish Native Plants on a Sonoran Desert Burn

    Full text link
    Revegetating burned areas is a formidable challenge facing resource managers in southwestern United States arid lands. Natural revegetation of desert burns by native species may be slow, or dominated by exotic annual grasses that perpetuate a frequent-fire regime. Resource managers may have several reasons for actively revegetating burns with native species, such as for providing competition with exotic species, minimizing soil erosion and dust pollution, and improving aesthetics. The use of native species in revegetation has been limited by a lack of available seed and by findings that native desert species are difficult to establish (e.g., Bainbridge and Virginia 1990, Banjerjee et al. 2006). Seeding may be one of only a few feasible options for reintroducing propagules to large desert burns covering thousands of hectares. Our objective was to assess the outcome of a 28-species (all native) operational seeding project for revegetating a 2005 burn in the Arizona Upland Subdivision of the Sonoran Desert

    The velocity peaks in the cold dark matter spectrum on Earth

    Full text link
    The cold dark matter spectrum on earth is expected to have peaks in velocity space. We obtain estimates for the sizes and locations of these peaks. To this end we have generalized the secondary infall model of galactic halo formation to include angular momentum of the dark matter particles. This new model is still spherically symmetric and it has self-similar solutions. Our results are relevant to direct dark matter search experiments.Comment: 12 pages including 1 table and 4 figures, LaTeX, REVTEX 3.0 versio
    • 

    corecore