Brain activation in response to personalized behavioral and physiological feedback from self-monitoring technology: pilot study

Background: The recent surge in commercially available wearable technology has allowed real-time self-monitoring of behavior (eg, physical activity) and physiology (eg, glucose levels). However, there is limited neuroimaging work (ie, functional magnetic resonance imaging [fMRI]) to identify how people’s brains respond to receiving this personalized health feedback and how this impacts subsequent behavior. Objective: Identify regions of the brain activated and examine associations between activation and behavior. Methods: This was a pilot study to assess physical activity, sedentary time, and glucose levels over 14 days in 33 adults (aged 30 to 60 years). Extracted accelerometry, inclinometry, and interstitial glucose data informed the construction of personalized feedback messages (eg, average number of steps per day). These messages were subsequently presented visually to participants during fMRI. Participant physical activity levels and sedentary time were assessed again for 8 days following exposure to this personalized feedback. Results: Independent tests identified significant activations within the prefrontal cortex in response to glucose feedback compared with behavioral feedback (P<.001). Reductions in mean sedentary time (589.0 vs 560.0 minutes per day, P=.014) were observed. Activation in the subgyral area had a moderate correlation with minutes of moderate-to-vigorous physical activity (r=0.392, P=.043). Conclusion: Presenting personalized glucose feedback resulted in significantly more brain activation when compared with behavior. Participants reduced time spent sedentary at follow-up. Research on deploying behavioral and physiological feedback warrants further investigation

Metadata correction: Brain activation in response to personalized behavioral and physiological feedback from self-monitoring technology: pilot study

[This corrects the article DOI: 10.2196/jmir.8890.]

Discovery of the progenitor of the type Ia supernova 2007on

Type Ia supernovae are exploding stars that are used to measure the accelerated expansion of the Universe and are responsible for most of the iron ever produced. Although there is general agreement that the exploding star is a white dwarf in a binary system, the exact configuration and trigger of the explosion is unclear, which could hamper their use for precision cosmology. Two families of progenitor models have been proposed. In the first, a white dwarf accretes material from a companion until it exceeds the Chandrasekhar mass, collapses and explodes. Alternatively, two white dwarfs merge, again causing catastrophic collapse and an explosion. It has hitherto been impossible to determine if either model is correct. Here we report the discovery of an object in pre-supernova archival X-ray images at the position of the recent type Ia supernova (2007on) in the elliptical galaxy NGC 1404. Deep optical images (also archival) show no sign of this object. From this we conclude that the X-ray source is the progenitor of the supernova, which favours the accretion model for this supernova, although the host galaxy is older (6-9 Gyr) than the age at which the explosions are predicted in the accreting models.Comment: Published in Nature See also the two follow-up papers: Roelofs, Bassa, Voss, Nelemans Nelemans, Voss, Roelofs, Bassa both on astro-ph 02/15/0

A digital lifestyle behaviour change intervention for the prevention of type 2 diabetes: a qualitative study exploring intuitive engagement with real-time glucose and physical activity feedback.

Background Mobile health technologies have advanced to now allow monitoring of the acute physiological responses to lifestyle behaviours. Our aim was to explore how people engaged with real-time feedback on their physical activity and glucose levels over several weeks. Methods Semi-structured interviews with 26 participants (61.5% female, 56.6 years) at moderate-to-high risk of developing type 2 diabetes were conducted. Interviews were completed after participants took part in an intervention comprising a flash glucose monitor (Freestyle Libre) and a physical activity monitor (Fitbit Charge 2). Purposive sampling ensured representation of ages, genders and group allocations. Results Inductive thematic analysis revealed how individuals intuitively used, interpreted and acted on feedback from wearable technologies. Six key themes emerged: triggers of engagement with the technologies, links between behaviour and health, lack of confidence, changes to movement behaviours, changes to diet and barriers to lifestyle behaviour change. Conclusions Our findings demonstrate that accessing behavioural and physiological feedback can increase self-awareness of how lifestyle impacts short-term health. Some participants noticed a link between the feedback presented by the two devices and changed their behaviour but many did not. Training and educational support, as well as efforts to optimize how feedback is presented to users, are needed to sustain engagement and behaviour change. Extensions of this work to involve people with diabetes are also warranted to explore whether behavioural and physiological feedback in parallel can encourage better diabetes self-management

An Emerging Infectious Disease Triggering Large-Scale Hyperpredation

Hyperpredation refers to an enhanced predation pressure on a secondary prey due to either an increase in the abundance of a predator population or a sudden drop in the abundance of the main prey. This scarcely documented mechanism has been previously studied in scenarios in which the introduction of a feral prey caused overexploitation of native prey. Here we provide evidence of a previously unreported link between Emergent Infectious Diseases (EIDs) and hyperpredation on a predator-prey community. We show how a viral outbreak caused the population collapse of a host prey at a large spatial scale, which subsequently promoted higher-than-normal predation intensity on a second prey from shared predators. Thus, the disease left a population dynamic fingerprint both in the primary host prey, through direct mortality from the disease, and indirectly in the secondary prey, through hyperpredation. This resulted in synchronized prey population dynamics at a large spatio-temporal scale. We therefore provide evidence for a novel mechanism by which EIDs can disrupt a predator-prey interaction from the individual behavior to the population dynamics. This mechanism can pose a further threat to biodiversity through the human-aided disruption of ecological interactions at large spatial and temporal scales.MM and JASZ were partially supported by a project of the Spanish Ministerio de Educación y Ciencia (reference CGL-2006-10689/BOS)

Moderate alcohol consumption is associated with better endothelial function: a cross sectional study

<p>Abstract</p> <p>Background</p> <p>Moderate alcohol consumption is protective against coronary artery disease. Endothelial dysfunction contributes to atherosclerosis and the pathogenesis of cardiovascular disease. The effects of alcohol consumption on endothelial function may be relevant to these cardiovascular outcomes, but very few studies have examined the effect of alcohol consumption on endothelial function assessed by flow-mediated dilation (FMD) of the brachial artery in humans.</p> <p>Methods</p> <p>In the population-based Northern Manhattan Study (NOMAS), we performed a cross-sectional analysis of lifetime alcohol intake and brachial artery FMD during reactive hyperemia using high-resolution B-mode ultrasound images among 884 stroke-free participants (mean age 66.8 years, women 56.6%, Hispanic 67.4%, black 17.4%, and white 15.2%).</p> <p>Results</p> <p>The mean brachial FMD was 5.7% and the median was 5.5%. Compared to non-drinkers, those who drank >1 drink/month to 2 drinks/day were more likely to have FMD above the median FMD (5.5%) (unadjusted OR 1.7, 95% CI 1.2–2.4, p = 0.005). In multivariate analysis, the relationship between moderate alcohol consumption and FMD remained significant after adjusting for multiple traditional cardiovascular risk factors, including sex, race-ethnicity, body mass index, diabetes mellitus, coronary artery disease, Framingham risk score, medication use (adjusted OR 1.8, 95%CI 1.1–3.0, p = 0.03). No beneficial effect on FMD was seen for those who drank more than 2 drinks/day.</p> <p>Conclusion</p> <p>In conclusion, consumption of up to 2 alcoholic beverages per day was independently associated with better FMD compared to no alcohol consumption in this multiethnic population. This effect on FMD may represent an important mechanism in explaining the protective effect of alcohol intake on cardiovascular disease.</p

Stochastic Gravity: Theory and Applications

Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel.In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime: we compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a quasi-static black hole.Comment: 75 pages, no figures, submitted to Living Reviews in Relativit

Stochastic Gravity: Theory and Applications

Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime, compute the two-point correlation functions of these perturbations and prove that Minkowski spacetime is a stable solution of semiclassical gravity. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a black hole and describe the metric fluctuations near the event horizon of an evaporating black holeComment: 100 pages, no figures; an update of the 2003 review in Living Reviews in Relativity gr-qc/0307032 ; it includes new sections on the Validity of Semiclassical Gravity, the Stability of Minkowski Spacetime, and the Metric Fluctuations of an Evaporating Black Hol

Adjuvant whole abdominal intensity modulated radiotherapy (IMRT) for high risk stage FIGO III patients with ovarian cancer (OVAR-IMRT-01) – Pilot trial of a phase I/II study: study protocol

<p>Abstract</p> <p>Background</p> <p>The prognosis for patients with advanced epithelial ovarian cancer remains poor despite aggressive surgical resection and platinum-based chemotherapy. More than 60% of patients will develop recurrent disease, principally intraperitoneal, and die within 5 years. The use of whole abdominal irradiation (WAI) as consolidation therapy would appear to be a logical strategy given its ability to sterilize small tumour volumes. Despite the clinically proven efficacy of whole abdominal irradiation, the use of radiotherapy in ovarian cancer has profoundly decreased mainly due to high treatment-related toxicity. Modern intensity-modulated radiation therapy (IMRT) could allow to spare kidneys, liver, and bone marrow while still adequately covering the peritoneal cavity with a homogenous dose.</p> <p>Methods/Design</p> <p>The OVAR-IMRT-01 study is a single center pilot trial of a phase I/II study. Patients with advanced ovarian cancer stage FIGO III (R1 or R2< 1 cm) after surgical resection and platinum-based chemotherapy will be treated with whole abdomen irradiation as consolidation therapy using intensity modulated radiation therapy (IMRT) to a total dose of 30 Gy in 1.5 Gy fractions. A total of 8 patients will be included in this trial. For treatment planning bone marrow, kidneys, liver, spinal cord, vertebral bodies and pelvic bones are defined as organs at risk. The planning target volume includes the entire peritoneal cavity plus pelvic and para-aortic node regions.</p> <p>Discussion</p> <p>The primary endpoint of the study is the evaluation of the feasibility of intensity-modulated WAI and the evaluation of the study protocol. Secondary endpoint is evaluation of the toxicity of intensity modulated WAI before continuing with the phase I/II study. The aim is to explore the potential of IMRT as a new method for WAI to decrease the dose to kidneys, liver, bone marrow while covering the peritoneal cavity with a homogenous dose, and to implement whole abdominal intensity-modulated radiotherapy into the adjuvant multimodal treatment concept of advanced ovarian cancer FIGO stage III.</p