Controllability and observabiliy of an artificial advection-diffusion problem

In this paper we study the controllability of an artificial advection-diffusion system through the boundary. Suitable Carleman estimates give us the observability on the adjoint system in the one dimensional case. We also study some basic properties of our problem such as backward uniqueness and we get an intuitive result on the control cost for vanishing viscosity.Comment: 20 pages, accepted for publication in MCSS. DOI: 10.1007/s00498-012-0076-

That lung cancer incidence falls in ex-smokers: misconceptions 2

Misconceptions and ill-founded theories can arise in all areas of science. However, the apparent accessibility of many epidemiology findings and popular interest in the subject can lead to additional misunderstandings. The article below continues an occasional series of short editorials highlighting some current misinterpretations of epidemiological findings. Invited authors will be given wide scope in judging the prevalence of the misconception under discussion. We hope that this series will prove instructive to cancer researchers in other disciplines as well as to students of epidemiology. Adrian L Harris and Leo Kinle

COVID-19 and vision impairment: Constraints negotiation, participation, and well-being during lockdown in the United Kingdom

In response to the Coronavirus disease, the United Kingdom (UK) government introduced lockdown measures requiring people to isolate and adhere to social distancing. This article uses Constraints Negotiation Theory to examine effects of the lockdown on people with vision impairment (PwVI). The research is based on an online survey of 639 PwVI in the UK. The analysis was conducted using partial least squares structural equation modelling in SmartPLS. The findings show that the lockdown had a negative effect on the participation and well-being of PwVI. However, they also show that the negative effects could be negotiated by adapting activities. This emphasises the need for a more inclusive response to current or future pandemics that recognises the vulnerabilities of PwVI and helps them to overcome the challenges associated with any measures that are introduced

Travelling with a Guide Dog: Experiences of People with Vision Impairment

There is considerable research on people with vision impairment (PwVI) in the transport, travel and tourism sectors, which highlights the significance of real-time information and consistency in services to accessibility. Based on interviews with guide dog owners in the United Kingdom, this paper contributes an additional dimension to our understanding of transport accessibility for PwVI by focusing specifically on guide dog owners’ experiences in the travel and tourism sector. A guide dog is more than a mobility tool, but a human–dog partnership that improves the quality of life for PwVI; however, it also introduces constraints related to the dog’s welfare and safety. Further, lack of understanding of guide dog owners’ rights to reasonable accommodation leads to discrimination through service refusals and challenges to service access. This paper concludes that the limited and inconsistent public knowledge of disability diversity has serious ramifications for transport accessibility and suggests specific industry and legislative interventions in response

Ecological and methodological drivers of species' distribution and phenology responses to climate change

Climate change is shifting species’ distribution and phenology. Ecological traits, such as mobility or reproductive mode, explain variation in observed rates of shift for some taxa. However, estimates of relationships between traits and climate responses could be influenced by how responses are measured. We compiled a global data set of 651 published marine species’ responses to climate change, from 47 papers on distribution shifts and 32 papers on phenology change. We assessed the relative importance of two classes of predictors of the rate of change, ecological traits of the responding taxa and methodological approaches for quantifying biological responses. Methodological differences explained 22% of the variation in range shifts, more than the 7.8% of the variation explained by ecological traits. For phenology change, methodological approaches accounted for 4% of the variation in measurements, whereas 8% of the variation was explained by ecological traits. Our ability to predict responses from traits was hindered by poor representation of species from the tropics, where temperature isotherms are moving most rapidly. Thus, the mean rate of distribution change may be underestimated by this and other global syntheses. Our analyses indicate that methodological approaches should be explicitly considered when designing, analysing and comparing results among studies. To improve climate impact studies, we recommend that (1) reanalyses of existing time series state how the existing data sets may limit the inferences about possible climate responses; (2) qualitative comparisons of species’ responses across different studies be limited to studies with similar methodological approaches; (3) meta-analyses of climate responses include methodological attributes as covariates; and (4) that new time series be designed to include the detection of early warnings of change or ecologically relevant change. Greater consideration of methodological attributes will improve the accuracy of analyses that seek to quantify the role of climate change in species’ distribution and phenology changes

Multifrequency Strategies for the Identification of Gamma-Ray Sources

More than half the sources in the Third EGRET (3EG) catalog have no firmly established counterparts at other wavelengths and are unidentified. Some of these unidentified sources have remained a mystery since the first surveys of the gamma-ray sky with the COS-B satellite. The unidentified sources generally have large error circles, and finding counterparts has often been a challenging job. A multiwavelength approach, using X-ray, optical, and radio data, is often needed to understand the nature of these sources. This chapter reviews the technique of identification of EGRET sources using multiwavelength studies of the gamma-ray fields.Comment: 35 pages, 22 figures. Chapter prepared for the book "Cosmic Gamma-ray Sources", edited by K.S. Cheng and G.E. Romero, to be published by Kluwer Academic Press, 2004. For complete article and higher resolution figures, go to: http://www.astro.columbia.edu/~muk/mukherjee_multiwave.pd

Strengthening confidence in climate change impact science

Aim: To assess confidence in conclusions about climate-driven biological change through time, and identify approaches for strengthening confidence scientific conclusions about ecological impacts of climate change. Location: Global. Methods: We outlined a framework for strengthening confidence in inferences drawn from biological climate impact studies through the systematic integration of prior expectations, long-term data and quantitative statistical procedures. We then developed a numerical confidence index (Cindex) and used it to evaluate current practices in 208 studies of marine climate impacts comprising 1735 biological time series. Results: Confidence scores for inferred climate impacts varied widely from 1 to 16 (very low to high confidence). Approximately 35% of analyses were not associated with clearly stated prior expectations and 65% of analyses did not test putative non-climate drivers of biological change. Among the highest-scoring studies, 91% tested prior expectations, 86% formulated expectations for alternative drivers but only 63% statistically tested them. Higher confidence scores observed in studies that did not detect a change or tracked multiple species suggest publication bias favouring impact studies that are consistent with climate change. The number of time series showing climate impacts was a poor predictor of average confidence scores for a given group, reinforcing that vote-counting methodology is not appropriate for determining overall confidence in inferences. Main conclusions: Climate impacts research is expected to attribute biological change to climate change with measurable confidence. Studies with long-term, high-resolution data, appropriate statistics and tests of alternative drivers earn higher Cindex scores, suggesting these should be given greater weight in impact assessments. Together with our proposed framework, the results of our Cindex analysis indicate how the science of detecting and attributing biological impacts to climate change can be strengthened through the use of evidence-based prior expectations and thorough statistical analyses, even when data are limited, maximizing the impact of the diverse and growing climate change ecology literature

'I'm sorry to hear that'-Empathy and Empathic Dissonance : the Perspectives of PA Students

Context: Our understanding of clinical empathy could be enhanced through qualitative research-research currently under-represented in the field. Physician associates within the UK undergo an intensive 2-year postgraduate medical education. As a new group of health professionals, they represent a fresh pair of eyes through which to examine clinical empathy, its nature and teaching. Methods: Working with a constructivist paradigm, utilising grounded theory methodology, researchers studied 19 purposively sampled physician associate students in two UK medical schools. One-to-one semi-structured interviews were transcribed verbatim. Data were analysed using a grounded theory approach. Results: The global themes were the pathways to empathy, empathy modifiers and empathic dissonance a novel term to describe the discomfort students experience when pressurised into making empathic statements they don't sincerely feel. Students preferred using non-verbal over verbal expressions of empathy. A conceptual model is proposed. The more substantial empathic pathway, affective empathy, involves input from the heart. An alternative empathy, more constrained, comes from the head: cognitive empathy was considered a solution to time pressure and emotional burden. Formal teaching establishes empathic dissonance, a problem which stems from over-reliance on the empathic statement as the means to deliver clinical empathy. Conclusions: This study furthers our understanding of the construct and teaching of empathy. It identifies empathic barriers, especially time pressure. It proposes a novel concept-empathic dissonance-a concept that challenges medical educationalists to reframe future empathy teaching

Increasing condom use in heterosexual men: development of a theory-based interactive digital intervention

Increasing condom use to prevent sexually transmitted infections is a key public health goal. Interventions are more likely to be effective if they are theory- and evidence-based. The Behaviour Change Wheel (BCW) provides a framework for intervention development. To provide an example of how the BCW was used to develop an intervention to increase condom use in heterosexual men (the MenSS website), the steps of the BCW intervention development process were followed, incorporating evidence from the research literature and views of experts and the target population. Capability (e.g. knowledge) and motivation (e.g. beliefs about pleasure) were identified as important targets of the intervention. We devised ways to address each intervention target, including selecting interactive features and behaviour change techniques. The BCW provides a useful framework for integrating sources of evidence to inform intervention content and deciding which influences on behaviour to target

Transient pulsed radio emission from a magnetar

Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very bright and highly variable X-ray emission that are believed to be powered by ultra-strong magnetic fields of >1e14 G, according to the 'magnetar' model. The radio pulsations that have been observed from more than 1,700 neutron stars with weaker magnetic fields have never been detected from any of the dozen known magnetars. The X-ray pulsar XTE J1810-197 was revealed (in 2003) as the first AXP with transient emission when its luminosity increased 100-fold from the quiescent level; a coincident radio source of unknown origin was detected one year later. Here we show that XTE J1810-197 emits bright, narrow, highly linearly polarized radio pulses, observed at every rotation, thereby establishing that magnetars can be radio pulsars. There is no evidence of radio emission before the 2003 X-ray outburst (unlike ordinary pulsars, which emit radio pulses all the time), and the flux varies from day to day. The flux at all radio frequencies is approximately equal -- and at >20 GHz XTE J1810-197 is currently the brightest neutron star known. These observations link magnetars to ordinary radio pulsars, rule out alternative accretion models for AXPs, and provide a new window into the coronae of magnetars.Comment: accepted by Nature; some new data and significantly revised discussio