Visual parameter optimisation for biomedical image processing

Background: Biomedical image processing methods require users to optimise input parameters to ensure high quality output. This presents two challenges. First, it is difficult to optimise multiple input parameters for multiple input images. Second, it is difficult to achieve an understanding of underlying algorithms, in particular, relationships between input and output. Results: We present a visualisation method that transforms users’ ability to understand algorithm behaviour by integrating input and output, and by supporting exploration of their relationships. We discuss its application to a colour deconvolution technique for stained histology images and show how it enabled a domain expert to identify suitable parameter values for the deconvolution of two types of images, and metrics to quantify deconvolution performance. It also enabled a breakthrough in understanding by invalidating an underlying assumption about the algorithm. Conclusions: The visualisation method presented here provides analysis capability for multiple inputs and outputs in biomedical image processing that is not supported by previous analysis software. The analysis supported by our method is not feasible with conventional trial-and-error approaches

Design of an internet-based health economic evaluation of a preventive group-intervention for children of parents with mental illness or substance use disorders

Background Preventive interventions are developed for children of parents with mental and substance use disorders (COPMI), because these children have a higher risk of developing a psychological or behavioral disorder in the future. Mental health and substance use disorders contribute significantly to the global burden of disease. Although the exact number of parents with a mental illness is unclear, the subject of mentally ill parents is gaining attention. Moreover there is a lack of interventions for COPMI-children, as well of (cost-) effectiveness studies evaluating COPMI interventions. Innovative interventions such as e-health provide a new field for exploration. There is no knowledge about the opportunities for using the internet to prevent problems in children at risk. In the current study we will focus on the (cost-) effectiveness of an online health prevention program for COPMI-children. Methods/Design We designed a randomized controlled trial to examine the (cost-) effectiveness of the Kopstoring intervention. Kopstoring is an online intervention for COPMI-children to strengthen their coping skills and prevent behavioral and psychological problems. We will compare the Kopstoring intervention with (waiting list) care as usual. This trial will be conducted entirely over the internet. An economic evaluation, from a societal perspective will be conducted, to examine the trial's cost-effectiveness. Power calculations show that 214 participants are needed, aged 16-25. Possible participants will be recruited via media announcements and banners on the internet. After screening and completing informed consent procedures, participants will be randomized. The main outcome is internalizing and externalizing symptoms as measured by the Youth Self Report. For the economic evaluation, healthcare costs and costs outside the healthcare sector will be measured at the same time as the clinical measures, at baseline, 3, 6 and 9 months. An extended measure for the intervention group will be provided at 12 months, to examine the long-term effects. In addition, a process evaluation will be conducted. Discussion Recent developments, such as international conferences and policy discussions, show the pressing need to study the (cost-) effectiveness of interventions for vulnerable groups of children. This study will shed light on the (cost-) effectiveness of an online preventive intervention

Validation of Agent-Based Models in Economics and Finance

Since the survey by Windrum et al. (Journal of Artificial Societies and Social Simulation 10:8, 2007), research on empirical validation of agent-based models in economics has made substantial advances, thanks to a constant flow of high-quality contributions. This Chapter attempts to take stock of such recent literature to offer an updated critical review of the existing validation techniques. We sketch a simple theoretical framework that conceptualizes existing validation approaches, which we examine along three different dimensions: (i) comparison between artificial and real-world data; (ii) calibration and estimation of model parameters; and (iii) parameter space exploration. Finally, we discuss open issues in the field of ABM validation and estimation. In particular, we argue that more research efforts should be devoted toward advancing hypothesis testing in ABM, with specific emphasis on model stationarity and ergodicity

Mitral Cells of the Olfactory Bulb Perform Metabolic Sensing and Are Disrupted by Obesity at the Level of the Kv1.3 Ion Channel

Sixty-five percent of Americans are over-weight. While the neuroendocrine controls of energy homeostasis are well known, how sensory systems respond to and are impacted by obesity is scantily understood. The main accepted function of the olfactory system is to provide an internal depiction of our external chemical environment, starting from the detection of chemosensory cues. We hypothesized that the system additionally functions to encode internal chemistry via the detection of chemicals that are important indicators of metabolic state. We here uncovered that the olfactory bulb (OB) subserves as an internal sensor of metabolism via insulin-induced modulation of the potassium channel Kv1.3. Using an adult slice preparation of the olfactory bulb, we found that evoked neural activity in Kv1.3-expressing mitral cells is enhanced following acute insulin application. Insulin mediated changes in mitral cell excitability are predominantly due to the modulation of Kv1.3 channels as evidenced by the lack of effect in slices from Kv1.3-null mice. Moreover, a selective Kv1.3 peptide blocker (ShK186) inhibits more than 80% of the outward current in parallel voltage-clamp studies, whereby insulin significantly decreases the peak current magnitude without altering the kinetics of inactivation or deactivation. Mice that were chronically administered insulin using intranasal delivery approaches exhibited either an elevation in basal firing frequency or fired a single cluster of action potentials. Following chronic administration of the hormone, mitral cells were inhibited by application of acute insulin rather than excited. Mice made obese through a diet of ∼32% fat exhibited prominent changes in mitral cell action potential shape and clustering behavior, whereby the subsequent response to acute insulin stimulation was either attenuated or completely absent. Our results implicate an inappropriate neural function of olfactory sensors following exposure to chronic levels of the hormone insulin (diabetes) or increased body weight (obesity)

Is visual estimation of passive range of motion in the pediatric lower limb valid and reliable

<p>Abstract</p> <p>Background</p> <p>Visual estimation (VE) is an essential tool for evaluation of range of motion. Few papers discussed its validity in children orthopedics' practice. The purpose of our study was to assess validity and reliability of VE for passive range of motions (PROMs) of children's lower limbs.</p> <p>Methods</p> <p>Fifty typically developing children (100 lower limbs) were examined. Visual estimations for PROMs of hip (flexion, adduction, abduction, internal and external rotations), knee (flexion and popliteal angle) and ankle (dorsiflexion and plantarflexion) were made by a pediatric orthopaedic surgeon (POS) and a 5^thyear resident in orthopaedics. A last year medical student did goniometric measurements. Three weeks later, same measurements were performed to assess reliability of visual estimation for each examiner.</p> <p>Results</p> <p>Visual estimations of the POS were highly reliable for hip flexion, hip rotations and popliteal angle (ρ_c≥ 0.8). Reliability was good for hip abduction, knee flexion, ankle dorsiflexion and plantarflexion (ρ_c≥ 0.7) but poor for hip adduction (ρ_c= 0.5). Reproducibility for all PROMs was verified. Resident's VE showed high reliability (ρ_c≥ 0.8) for hip flexion and popliteal angle. Good correlation was found for hip rotations and knee flexion (ρ_c≥ 0.7). Poor results were obtained for ankle PROMs (ρ_c< 0.6) as well as hip adduction and abduction, the results of which not being reproducible. Influence of experience was clearly demonstrated for PROMs of hip rotations, adduction and abduction as well as ankle plantarflexion.</p> <p>Conclusion</p> <p>Accuracy of VE of passive hip flexion and knee PROMs is high regardless of the examiner's experience. Same accuracy can be found for hip rotations and abduction whenever VE is performed by an experienced examiner. Goniometric evaluation is recommended for passive hip adduction and for ankle PROMs.</p

Cell phone-supported cognitive behavioural therapy for anxiety disorders: a protocol for effectiveness studies in frontline settings

The resulting protocol (NCT01205191 at clinicaltrials.gov) for use in frontline clinical practice in which effectiveness, adherence, and the role of the therapists are analyzed, provides evidence for what are truly valuable cell phone-supported CBT treatments and guidance for the broader introduction of CBT in health services.Original Publication:Joakim Ekberg, Toomas Timpka, Magnus Bång, Anders Fröberg, Karin Halje and Henrik Eriksson, Cell phone-supported cognitive behavioural therapy for anxiety disorders: a protocol for effectiveness studies in frontline settings., 2011, BMC medical research methodology, (11), 3.http://dx.doi.org/10.1186/1471-2288-11-3Copyright: BioMed Centralhttp://www.biomedcentral.com

How Phytophthora cinnamomi became associated with the death of Eucalyptus marginata – the early investigations into jarrah dieback

The name jarrah dieback was used in the 1940s to describe a serious economic problem in the jarrah forest in the south west of Western Australia. This was the sudden death of groups of jarrah (Eucalyptus marginata) trees that occurred on previously logged sites that had a tendency to become waterlogged in winter. Although the cause was not determined at the time, from symptoms recorded in early investigations the most likely explanation is that the trees died as the result of waterlogging damage. In the 1960s it was shown that many of these sites were infested by the introduced oomycete Phytophthora cinnamomi and tree deaths, together with the deaths of many mid- and under-storey plants, were attributed to this pathogen. A chronology of the research, based on contemporary unpublished documents, shows that in 1968 the conclusion that P. cinnamomi caused jarrah deaths was not supported by the available evidence, because the work did not satisfy the first and fourth of Koch’s postulates. The evidence that P. cinnamomi killed many mid- and under-storey plants was much stronger. There are two problems that have been confused: the death of groups of jarrah trees (jarrah dieback) that is caused by waterlogging and the death of many mid- and under-storey plants (Phytophthora dieback) caused by P. cinnamomi infection

High-Dimensional Coexistence of Temperate Tree Species: Functional Traits, Demographic Rates, Life-History Stages, and Their Physical Context

Theoretical models indicate that trade-offs between growth and survival strategies of tree species can lead to coexistence across life history stages (ontogeny) and physical conditions experienced by individuals. There exist predicted physiological mechanisms regulating these trade-offs, such as an investment in leaf characters that may increase survival in stressful environments at the expense of investment in bole or root growth. Confirming these mechanisms, however, requires that potential environmental, ontogenetic, and trait influences are analyzed together. Here, we infer growth and mortality of tree species given size, site, and light characteristics from forest inventory data from Wisconsin to test hypotheses about growth-survival trade-offs given species functional trait values under different ontogenetic and environmental states. A series of regression analyses including traits and rates their interactions with environmental and ontogenetic stages supported the relationships between traits and vital rates expected from the expectations from tree physiology. A combined model including interactions between all variables indicated that relationships between demographic rates and functional traits supports growth-survival trade-offs and their differences across species in high-dimensional niche space. The combined model explained 65% of the variation in tree growth and supports a concept of community coexistence similar to Hutchinson's n-dimensional hypervolume and not a low-dimensional niche model or neutral model

Search for rare quark-annihilation decays, B --> Ds(*) Phi

We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and u-bar quarks in the B- meson. Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions BF(B- --> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid Communications

Myocardial perfusion imaging with 99 mTc - tetrofosmin SPECT in breast cancer patients that received postoperative radiotherapy: a case-control study

<p>Abstract</p> <p>Purpose</p> <p>To evaluate the cardiac toxicity of radiotherapy (RT) in breast cancer (BC) patients employing myocardial perfusion imaging (MPI) with Tc-99 m Tetrofosmin - single photon emission computer tomography (T-SPECT).</p> <p>Materials and methods</p> <p>We studied 46 BC female patients (28 patients with left and 18 patients with right BC) treated with postoperative RT compared to a control group of 85 age-matched females. The median time of RT to SPECT was 40 months (6-263).</p> <p>Results</p> <p>Abnormalities in the summed stress score (SSS) were found in 54% of left BC patients, 44.4% of right BC patients, and 32.9% of controls. In left BC patients there were significantly more SSS abnormalities compared to controls (4.0 ± 3.5 vs 2.6 ± 2.0, p = 0.05) and possible trend of increased abnormalities of right BC patients (3.7 ± 3.0 vs 2.6 ± 2.0, p = 0.14). Multiple regression analysis showed more abnormalities in the MPI of left BC patients compared to controls (SSS, p = 0.0001); Marginal toxicity was also noted in right BC patients (SSS, p = 0.045). No additional toxicity was found in patients that received adjuvant cardiotoxic chemotherapy. All T-SPECT abnormalities were clinically silent.</p> <p>Conclusion</p> <p>The study suggests that radiation therapy to BC patients result in MPI abnormalities but without apparent clinical consequences.</p