Poisson point process models solve the "pseudo-absence problem" for presence-only data in ecology

Presence-only data, point locations where a species has been recorded as being present, are often used in modeling the distribution of a species as a function of a set of explanatory variables---whether to map species occurrence, to understand its association with the environment, or to predict its response to environmental change. Currently, ecologists most commonly analyze presence-only data by adding randomly chosen "pseudo-absences" to the data such that it can be analyzed using logistic regression, an approach which has weaknesses in model specification, in interpretation, and in implementation. To address these issues, we propose Poisson point process modeling of the intensity of presences. We also derive a link between the proposed approach and logistic regression---specifically, we show that as the number of pseudo-absences increases (in a regular or uniform random arrangement), logistic regression slope parameters and their standard errors converge to those of the corresponding Poisson point process model. We discuss the practical implications of these results. In particular, point process modeling offers a framework for choice of the number and location of pseudo-absences, both of which are currently chosen by ad hoc and sometimes ineffective methods in ecology, a point which we illustrate by example.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS331 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

The evolving epidemiology and emerging biomarkers of cancers in the HIV positive populations

Effective and durable HIV treatment and increased longevity of HIV-positive (HIV+) people [1-6] has led to a growing burden of cancers in this population [7-9]. The aims of this thesis were to describe the changing epidemiology of commonly occurring cancers in HIV+ people (with a focus on Europe) and to explore and characterise plasma biomarkers of common cancers in HIV+ people. Results showed that the incidence of infection unrelated cancers are not declining in HIV+ people, primarily driven by aging of the HIV+ population and higher prevalence of cancer risk factors such as smoking. Smoking presents as one of the few modifiable cancer risk factors which can be targeted to reduce burden. Although smoking cessation quickly reduces the incidence of many smoking related cancers, the incidence of lung cancer remains at a similar level to current smokers ≥5 years after cessation. Risk factors for non-Hodgkin (NHL) and Hodgkin lymphoma (HL) differ, with HL primarily driven by low CD4 cell counts, whereas NHL is driven by a combination of immune deficiency and other HIV-mediated immune dysfunction. Furthermore, markers of immune activation are elevated ≥2 years prior to lymphoma diagnosis and are correlated with high level of HIV viremia. Levels of prostate specific antigen (PSA) were raised and increasing many years prior to prostate cancer diagnosis, however, use of the cut off of PSA >4 ng/mL to identify men at high risk of prostate cancer may not be appropriate in HIV+ men due to lower levels of circulating PSA. In conclusion, the results of this thesis provide evidence to advise and improve the care of aging HIV+ people at elevated risk for cancers through the identification and characterisation of risk factors for common cancers, investigating possible mechanisms driving cancer genesis, and assessing the usefulness of commonly used diagnostic practices

Raising awareness of sensory impairment among community nurses: a brief intervention in a remote island setting

Introduction: The prevalence of sensory impairment that includes, sight and/or hearing impairment is projected to rise worldwide given the strong correlation between sensory impairment, older age, and the demographic structure of the global population. Sensory impairment and associated disability is thus a significant global health concern. The prevalence rates for sensory impairment in Scotland are significant as more people live into older age and as the age distribution in rural areas is markedly different with a higher proportion of older people, the extent of sensory impairment in the rural population will increase proportionally.  In rural areas community nurses have a key role in recognising sensory impairment and signposting people to sensory services to reduce the debilitating impact of sensory impairment. However, there is limited evidence about the utility of educational interventions to enhance healthcare professionals’ knowledge, skills and attitudes about sensory impairment and subsequent impact on referral practices. The aim of this study was to evaluate the impact of a brief educational intervention with community nurses. The educational intervention was a training workshop that included simulation practice, information on assessment and referral pathways. The study was conducted in a remote, island community health setting in the Western Isles of Scotland. The study evaluated nurses’ perceptions of the training on their knowledge, attitudes and practice.  Methods: Mixed method, longitudinal design implemented in three phases. Phase 1: Pre and post workshop questionnaire; Phase 2: Postal questionnaire three months post workshop; Phase 3: Qualitative focus group interview six months post workshop. Kirkpatrick’s (1) model of training evaluation provided a framework for data evaluation.  Results: 41 community based healthcare professionals who were mostly nurses participated in the study. Participants described increased awareness of the potential for their patients to have a sensory impairment, greater understanding and empathy with patients who experience sensory impairment, more robust patient assessment to identify impairment, and increased likelihood to inform of, and refer to, sensory services.  Conclusions: Community nurses are often well placed to identity disabilities and patients at risk of injury because of sensory impairment. Participation in simulation training can help to develop greater awareness of the impact of that sensory impairment. Knowledge of specialist services will increase the opportunities for referral to services and impact positively on the lives of older people living in rural settings. Provision of accessible education on sensory impairment for health and social care professionals can enhance care delivery to older people

Smoking and use of primary care services : findings from a population-based cohort study linked with administrative claims data

Background: Available evidence suggests that smokers have a lower propensity than others to use primary care services. But previous studies have incorporated only limited adjustment for confounding and mediating factors such as income, access to services and health status. We used data from a large prospective cohort study (the 45 and Up Study), linked to administrative claims data, to quantify the relationship between smoking status and use of primary care services, including specific preventive services, in a contemporary Australian population. Methods: Baseline questionnaire data from the 45 and Up Study were linked to administrative claims (Medicare) data for the 12-month period following study entry. The main outcome measures were Medicare benefit claimed for unreferred services, out-of-pocket costs (OOPC) paid, and claims for specific preventive services (immunisations, health assessments, chronic disease management services, PSA tests and Pap smears). Rate ratios with 95% confidence intervals were estimated using a hierarchical series of models, adjusted for predisposing, access-and health-related factors. Separate hurdle (two part) regression models were constructed for Medicare benefit and OOPC. Poisson models with robust error variance were used to model use of each specific preventive service. Results: Participants included 254,382 people aged 45 years and over of whom 7.3% were current smokers. After adjustment for predisposing, access-and health-related factors, current smokers were very slightly less likely to have claimed Medicare benefit than never smokers. Among those who claimed benefit, current smokers claimed similar total benefit, but recent quitters claimed significantly greater benefit, compared to never-smokers. Current smokers were around 10% less likely than never smokers to have paid any OOPC. Current smokers were 15-20% less likely than never smokers to use immunisations, Pap smears and prostate specific antigen tests. Conclusions: Current smokers were less likely than others to use primary care services that incurred out of pocket costs, and specific preventive services. This was independent of a wide range of predisposing, access-and health-related factors, suggesting that smokers have a lower propensity to seek health care. Smokers may be missing out on preventive services from which they would differentially benefit

Concert recording 2021-11-18

[Track 1]. Prelude, op. 43, no. 1 / Reinhold Glière -- [Track 2]. Etude in D minor, op. 109, no. 13, The storm / Friedrich Burgmüller -- [Track 3]. Liebestraum no. 3 / Franz Liszt -- [Track 4]. Sonata no. 13 in E-flat major, op. 27, no. 1. III. Adagio con espressione, Presto / Ludwig van Beethoven -- [Track 5]. Moment Musicaux in B minor op. 16, no. 3 ; Prelude in C-sharp minor, op. 3, no. 2 / Sergei Rachmaninov -- [Track 6]. Album Leaf / Claude Debussy ; Autumn leaves / Joseph Kosma, Johnny Mercer, Jacques Prevert ; arranged by Morgan Brown ; Jazz exercise no. 2 / Oscar Peterson -- [Track 7]. Fantasia in C minor, K. 475 / Wolfgang Amadeus Mozart -- [Track 8]. 6 Romanian Folk Dances. I. Stick Dance. II. Sash Dance. III. In One Spot. IV. Horn Dance. V. Romanian Polka. VI. Fast Dance / Béla Bartók

Code Blue! When a Simulation Isn’t a Simulation Anymore

Objectives: • To identify and remediate gaps responding to a medical emergency during a simulated event. • To provide a safe working environment for standardized patients and clinical staff.https://knowledgeconnection.mainehealth.org/lambrew-retreat-2022/1038/thumbnail.jp