ELPA: A parallel solver for the generalized eigenvalue problem

For symmetric (hermitian) (dense or banded) matrices the computation of eigenvalues and eigenvectors Ax = λBx is an important task, e.g. in electronic structure calculations. If a larger number of eigenvectors are needed, often direct solvers are applied. On parallel architectures the ELPA implementation has proven to be very efficient, also compared to other parallel solvers like EigenExa or MAGMA. The main improvement that allows better parallel efficiency in ELPA is the two-step transformation of dense to band to tridiagonal form. This was the achievement of the ELPA project. The continuation of this project has been targeting at additional improvements like allowing monitoring and autotuning of the ELPA code, optimizing the code for different architectures, developing curtailed algorithms for banded A and B, and applying the improved code to solve typical examples in electronic structure calculations. In this paper we will present the outcome of this project

FEBUKO and MODMEP: Field measurements and modelling of aerosol and cloud multiphase processes

An overview of the two FEBUKO aerosol–cloud interaction field experiments in the Thüringer Wald (Germany) in October 2001 and 2002 and the corresponding modelling project MODMEP is given. Experimentally, a variety of measurement methods were deployed to probe the gas phase, particles and cloud droplets at three sites upwind, downwind and within an orographic cloud with special emphasis on the budgets and interconversions of organic gas and particle phase constituents. Out of a total of 14 sampling periods within 30 cloud events three events (EI, EII and EIII) are selected for detailed analysis. At various occasions an impact of the cloud process on particle chemical composition such as on the organic compounds content, sulphate and nitrate and also on particle size distributions and particle mass is observed. Moreover, direct phase transfer of polar organic compound from the gas phase is found to be very important for the understanding of cloudwater composition. For the modelling side, a main result of the MODMEP project is the development of a cloud model, which combines a complex multiphase chemistry with detailed microphysics. Both components are described in a fine-resolved particle/drop spectrum. New numerical methods are developed for an efficient solution of the entire complex model. A further development of the CAPRAM mechanism has lead to a more detailed description of tropospheric aqueous phase organic chemistry. In parallel, effective tools for the reduction of highly complex reaction schemes are provided. Techniques are provided and tested which allow the description of complex multiphase chemistry and of detailed microphysics in multidimensional chemistry-transport models

An easily made, low-cost phantom for ultrasound airway exam training and assessment

Background: Recent manuscripts have described the use of ultrasound imaging to evaluate airway structures. Ultrasound training tools are necessary for practitioners to become proficient at obtaining and interpreting images. Few training tools exist and those that do can often times be expensive and rendered useless with repeated needle passes. Methods: We utilised inexpensive and easy to obtain materials to create a gel phantom model for ultrasound-guided airway examination training. Results: Following creation of the gel phantom model, images were successfully obtained of the thyroid and cricoid cartilages, cricothyroid membrane and tracheal rings in both the sagittal transverse planes. Conclusion: The gel phantom model mimics human airway anatomy and may be used for ultrasound-guided airway assessment and intervention training. This may have important safety implications as ultrasound imaging is increasingly used for airway assessment

Evaluation of the GlideScope Direct: A New Video Laryngoscope for Teaching Direct Laryngoscopy

Background. Teaching direct laryngoscopy is limited by the inability of the instructor to simultaneously view the airway with the laryngoscopist. Our primary aim is to report our initial use of the GlideScope Direct, a video-enabled, Macintosh laryngoscope intended primarily as a training tool in direct laryngoscopy. Methods. The GlideScope Direct was made available to anyone who planned on performing direct laryngoscopy as the primary technique for intubation. Novices were those who had performed <30 intubations. Results. The GlideScope Direct was used 123 times as primarily a direct laryngoscope while the instructor viewed the intubation on the monitor. It was highly successful as a direct laryngoscope (93% success). Salvage by indirect laryngoscopy occurred in 7/9 remaining patients without changing equipment. Novices performed 28 intubations (overall success rate of 79%). In 6 patients, the instructor took over and successfully intubated the patient. Instructors used the video images to guide the operator in 16 (57%) of those patients. Seven different instructors supervised the 28 novices, all of who subjectively felt advantaged by having the laryngoscopic view available. Conclusions. The GlideScope Direct functions similarly to a Macintosh laryngoscope and provides the instructor subjective reassurance, while providing the ability to guide the trainee laryngoscopist

Validation of the unassisted, gum-elastic bougie-guided, laryngeal mask airway-ProSeal™ placement technique in anaesthetized patients

Aims: The laryngeal mask airway-ProSeal™ can be inserted digitally, by introducer tool, or by railroading it over a bougie placed first in the patient′s oesophagus, which is highly successful, but as originally described, requires an assistant. An unassisted bougie-guided placement technique has also been described, but no data on its effectiveness have been reported. Methods: We reviewed data collected during a randomized, controlled trial comparing the air-Q® Intubating Laryngeal Airway and LMA-Proseal™, in which all LMA-Proseal™ devices were inserted using the unassisted (one-operator), bougie-guided placement technique. Results: Forty-eight devices were placed. All devices were placed successfully. Successful placement was achieved in 47 (98%) patients on first attempt and in one (2%) patient on the third attempt. Mean (SD) time required for insertion establishing ventilation was 28 (11) s. Mean (SD) airway seal pressure was 30 (6) cmH 2 O. Gross blood was found on four (8%) devices upon removal, but no oropharyngeal injuries were noted on oral exam in the recovery unit prior to discharge. The most common complaints in recovery and 24 h post-operatively were sore throat [discharge: mild = 18/48 (38%); 24 h: mild = 9/38 (19%), moderate = 1/38 (3%)] and pain on swallowing [discharge: mild = 7/48 (15%); 24 h: mild = 2/38 (6%)]. Conclusions: Our data confirm that in experienced hands, bougie-guided placement of the LMA-Proseal™ without the aid of an assistant can be accomplished quickly and successfully without affecting the expected clinical performance of the device

Towards an Exascale Enabled Sparse Solver Repository

As we approach the Exascale computing era, disruptive changes in the software landscape are required to tackle the challenges posed by manycore CPUs and accelerators. We discuss the development of a new `Exascale enabled' sparse solver repository (the ESSR) that addresses these challenges---from fundamental design considerations and development processes to actual implementations of some prototypical iterative schemes for computing eigenvalues of sparse matrices. Key features of the ESSR include holistic performance engineering, tight integration between software layers and mechanisms to mitigate hardware failures