Abstract. Electrical Impedance Tomography (EIT) is an attractive method for clinically monitoring patients during mechanical ventilation, because it can provide a non-invasive continuous image of pulmonary impedance which indicates the distribution of ventilation. However, most clinical and physiological research in lung EIT is done using older and proprietary algorithms; this is an obstacle to interpretation of EIT images because the reconstructed images are not well characterized. To address this issue, we are developing a consensus linear reconstruction algorithm for lung EIT, called GREIT (Graz consensus Reconstruction algorithm for EIT). This paper describes the unified approach to linear image reconstruction developed for GREIT. The framework for the linear reconstruction algorithm consists of: 1) detailed finite element models of a representative adult and neonatal thorax; 2) consensus on the performance figures of merit for EIT image reconstruction; and 3) a systematic approach to optimize a linear reconstruction matrix to desired performance measures. Consensus figures of merit, in order of importance, are: a) uniform amplitude response, GREIT: linear EIT image reconstruction 2 b) small and uniform position error, c) small ringing artefacts, d) uniform resolution, e) limited shape deformation, and f) high resolution. Such figures of merit must be attained while maintaining small noise amplification and small sensitivity to electrode and boundary movement. This approach represents the consensus of a large and representative group of experts in EIT algorithm design and clinical applications for pulmonary monitoring. All software and data to implement and test the algorithm has been made available under an open source license which allows free research and commercial use.
Objective
To investigate the potential of Mindfulness-Based Stress Reduction (MBSR) as a treatment for chronic primary insomnia.
Design
Randomized controlled trial.
Setting
University health center.
Patients
30 adults with primary chronic insomnia based on DSM-IV-TR criteria were randomized 2:1 to MBSR or pharmacotherapy (PCT).
Interventions
MBSR, a program of mindfulness meditation training consisting of 8 weekly 2.5 hour classes and a day-long retreat, with ongoing home meditation practice expectations during 3 month follow-up; PCT, consisting of 3 mg of eszopiclone (LUNESTA™) nightly for 8 weeks, followed by 3 months of use as needed. A 10-minute sleep hygiene presentation was included in both interventions.
Main Outcomes
The Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), sleep diaries and wrist actigraphy collected pre-treatment, post-treatment (8 weeks), and at 5 months (self-reports only).
Results
Between baseline and 8-weeks, sleep onset latency measured by actigraphy decreased 8.9 minutes in the MBSR arm (P<.05). Large, significant improvements were found on the ISI, PSQI, and diary-measured total sleep time, sleep onset latency and sleep efficiency (Ps<.01, all) from baseline to 5 month follow-up in the MBSR arm. Changes of comparable magnitude were found in the PCT arm. 27 out of 30 patients completed their assigned treatment. This study provides initial evidence for the efficacy of MBSR as a viable treatment for chronic insomnia as measured by: sleep diary, actigraphy, well-validated sleep scales and measures of remission and clinical recovery.
Rainfall is seldom sufficient to meet the evaporative and transpirational demands of a soybean crop [Glycine max (L.) Merr.] in the southeastern USA. Development of new drought‐tolerant cultivars would thus seem an effective way in which to address the problem of moisture stress. Unfortunately, few drought‐tolerant genotypes have been identified for use as breeding stock. The objective of this study was to compare the relative droughtolerance of plant introduction PI 416937, a visually slow‐wilting accession, with that of ‘Forrest’, a popular cultivar of similar maturity. Leaf water potential (Ψw), solute potential (Ψs), and relative water content (RWC) these genotypes were measured under two levels of soil water adjustment (well‐watered and water‐stressed at early pod‐fill) during 2 yr in the field (on a Varina loamy sand, a clayey, kaolinitic, thermic Plinthic Paleudult). Although water stress reduced Ψw equally for both genotypes, PI 416937 maintained lower levels of Ψs and. higher levels of pressure potential and RWC than Forrest. A comparison of the relationship between RWC and Ψs for the two genotypes indicated that the PI may accumulate more solutes in leaf tissue under stress than Forrest. That is, at a normalized leaf pressure potential of zero, the Ψs of the PI was estimated to be 0.3 MPa lower than that of Forrest. Seed yields of Forrest and the unadapted PI were comparable under stress. However, stress reduced the yield of Forrest by more than half while reducing yield of the PI by only a third. The superior turgor maintenance and competitive yielding ability of the unadapted PI under stress indicated that the PI may be an important source of drought tolerance for breeding programs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.