| 32991. |
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| 32992. |
- Eljammaly, Mahmoud, et al.
(author)
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Evaluation of the Tunability of a New NUMA-Aware Hessenberg Reduction Algorithm
- 2016
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Reports (other academic/artistic)abstract
- The reduction of a general dense and square matrix to Hessenberg form is a well known first step in many standard eigenvalue solvers. Although parallel algorithms exist, the Hessenberg reduction is still one of the bottlenecks in state-of-the-art software for the distributed QR algorithm. We propose a new NUMA-aware algorithm that fits the context of the QR algorithm and evaluate the tunability of its algorithmic parameters. The proposed algorithm can be faster than LAPACK and ScaLAPACK for small problem sizes. In addition, evaluating the algorithmic parameters shows that there is potential for auto-tuning some of the parameters.
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| 32993. |
- Eljammaly, Mahmoud
(author)
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Identification and tuning of algorithmic parameters in parallel matrix computations : Hessenberg reduction and tensor storage format conversion
- 2018
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Licentiate thesis (other academic/artistic)abstract
- This thesis considers two problems in numerical linear algebra and high performance computing (HPC): (i) the parallelization of a new blocked Hessenberg reduction algorithm using Parallel Cache Assignment (PCA) and the tunability of its algorithm parameters, and (ii) storing and manipulating dense tensors on shared memory HPC systems.The Hessenberg reduction appears in the Aggressive Early Deflation (AED) process for identifying converged eigenvalues in the distributed multishift QR algorithm (state-of-the-art algorithm for computing all eigenvalues for dense square matrices). Since the AED process becomes a parallel bottleneck it motivates a further study of AED components. We present a new Hessenberg reduction algorithm based on PCA which is NUMA-aware and targeting relatively small problem sizes on shared memory systems. The tunability of the algorithm parameters are investigated. A simple off-line tuning is presented and the performance of the new Hessenberg reduction algorithm is compared to its counterparts from LAPACK and ScaLAPACK. The new algorithm outperforms LAPACK in all tested cases and outperforms ScaLAPACK in problems smaller than order 1500, which are common problem sizes for AED in the context of the distributed multishift QR algorithm.We also investigate automatic tuning of the algorithm parameters. The parameters span a huge search space and it is impractical to tune them using standard auto-tuning and optimization techniques. We present a modular auto-tuning framework which applies: search space decomposition, binning, and multi-stage search to enable searching the huge search space efficiently. The framework using these techniques exposes the underlying subproblems which allows using standard auto-tuning methods to tune them. In addition, the framework defines an abstract interface, which combined with its modular design, allows testing various tuning algorithms.In the last part of the thesis, the focus is on the problem of storing and manipulating dense tensors. Developing open source tensor algorithms and applications is hard due to the lack of open source software for fundamental tensor operations. We present a software library dten, which includes tools for storing dense tensors in shared memory and converting a tensor storage format from one canonical form to another. The library provides two different ways to perform the conversion in parallel, in-place and out-of-place. The conversion involves moving blocks of contiguous data and are done to maximize the size of the blocks to move. In addition, the library supports tensor matricization for one or two tensors at the same time. The latter case is important in preparing tensors for contraction operations. The library is general purpose and highly flexible.
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| 32994. |
- Eljammaly, Mahmoud, et al.
(author)
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On the Tunability of a New Hessenberg Reduction Algorithm Using Parallel Cache Assignment
- 2018
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In: Parallel Processing and Applied Mathematics. PPAM 2017. - Cham : Springer. - 9783319780238 - 9783319780245 ; , s. 579-589
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Conference paper (peer-reviewed)abstract
- The reduction of a general dense square matrix to Hessenberg form is a well known first step in many standard eigenvalue solvers. Although parallel algorithms exist, the Hessenberg reduction is one of the bottlenecks in AED, a main part in state-of-the-art software for the distributed multishift QR algorithm. We propose a new NUMA-aware algorithm that fits the context of the QR algorithm and evaluate the sensitivity of its algorithmic parameters. The proposed algorithm is faster than LAPACK for all problem sizes and faster than ScaLAPACK for the relatively small problem sizes typical for AED.
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| 32995. |
- Eljas Ahlberg, Eva, et al.
(author)
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End-of-life care in amyotrophic lateral sclerosis : A comparative registry study
- 2021
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In: Acta Neurologica Scandinavica. - : John Wiley & Sons. - 0001-6314 .- 1600-0404. ; 143:5, s. 481-488
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Journal article (peer-reviewed)abstract
- Background: Amyotrophic lateral sclerosis (ALS) is a fatal disease requiring palliative care. End‐of‐life care has been well studied in patients with incurable cancer, but less is known about the quality of such care for patients with ALS.Aim: To study whether the quality of end‐of‐life care the last week in life for patients dying from ALS differed compared to patients with cancer in terms of registered symptoms, symptom management, and communication.Design: This retrospective comparative registry study used data from the Swedish Registry of Palliative Care for 2012–2016. Each patient with ALS (n = 825) was matched to 4 patients with cancer (n = 3,300).Results: Between‐group differences in assessments for pain and other symptoms were significant (p < 0.01), and patients with ALS had fewer as‐needed injection drugs prescribed than patients with cancer. Patients with ALS also had dyspnea and anxiety significantly more often than patients with cancer. There was no significant difference in communication about transition to end‐of‐life care between the two groups. Patients dying from ALS received artificial nutrition on their last day of life significantly more often than patients with cancer.Conclusions: The results indicate that patients with ALS receive poorer end‐of‐life care than patients dying from cancer in terms of validated symptom assessments, prescription of as‐needed drugs, and timely cessation of artificial nutrition. Educational efforts seem needed to facilitate equal care of dying patients, regardless of diagnosis.
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| 32996. |
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| 32997. |
- Ellberg, Lotta, 1959-
(author)
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Postnatal care - outcomes of various care options in Sweden
- 2008
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Doctoral thesis (other academic/artistic)abstract
- Background: In high-income countries, hospital length of stay after a normal birth has gradually decreased correspondingly to length of stay in care of other patients. A short stay provides a greater opportunity for autonomy and an increased sense of participation, but it may involve great challenges satisfying parental guidance as well as on the possibility of preventing, discovering, and treating neonatal medical conditions. Aim: This study evaluates postnatal care based on cost calculations, risk assessments, and parents’ satisfaction with care. Methods: Questionnaires were sent to 1 122 new mothers and her partner during 1998-1999. For the summary of utilization of health care services during the first 28 days postdelivery, the participants were linked with registry data from the hospital administration system for mothers and newborns (n= 773). The answers were also used to describe new parents’ experiences with postnatal care (n = 1 479). The costs for five postnatal care models were estimated, including three care options: Maternity Ward, Family Suite, and Early Discharge. Data about neonatal readmissions and death within 28 days was retrieved from the Swedish Medical Birth Register, the Swedish Hospital Discharge Registry, and the Swedish Cause-of-Death Register between 1999 and 2002 (n = 197 898). This data was related to data about postnatal follow-up practices from all 48 Swedish delivery wards. Results: The readmission rate for the mothers was similar among the various care options, and there was no difference in utilization of health care or breastfeeding outcome due to type of maternity care. As a proxy for morbidity, the readmission rate for the newborns was influenced by postdelivery follow-up routines as routine neonatal examination timing. Depending on the proportion of mothers receiving care at the Maternity Ward, the costs differed significantly between the various care models, while parents’ preferences complied with the cost-minimizing option Family Suite. Most mothers and fathers (70%) were satisfied with the overall impression of the postnatal care, but 72% were dissatisfied with at least one particular topic. A main finding was that the parents experienced a close emotional attachment, an affinity that was not always supported by the staff. The father was not treated as a principal character even though the parents wanted the father’s to be involved and recognized. Conclusions: Since the postnatal care options are not always the most cost minimizing and postnatal routines influence neonatal morbidity and parental satisfaction, the postnatal services need to be improved. Without increasing risks or costs, every postnatal care option ought to meet the families’ need for support, security, autonomy, and attachment with each other.
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| 32998. |
- Ellberg, Lotta, et al.
(author)
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Satisfying parents' preferences with regard to various models of postnatal care is cost-minimizing
- 2006
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In: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 0001-6349 .- 1600-0412. ; 85:2, s. 175-181
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Journal article (peer-reviewed)abstract
- BACKGROUND: This study describes three options for postnatal care in Sweden and contains a cost analysis of the options in various combinations. The aim of the study was to calculate the cost of a postnatal care model according to new parents' preferences. METHODS: Staff costs were calculated for various models of postnatal care, comprising the maternity ward, the family suite, and/or the early discharge program. One of the models was based on answers from 342 parents who specified their preferences with regard to postnatal care in the event of another birth. RESULTS: Comparing costs for five different models of postnatal care showed that the proportion of mothers receiving care at the maternity ward crucially influences the total costs. The staff costs differed significantly between the models, ranging from US$448 000 to US$778 000 per 1500 mother-child dyads. MAIN OUTCOME MEASURES: Cost calculation of various care models and parents' preferences for postnatal care. CONCLUSIONS: Because the parents' preferences with regard to postnatal care created one of the most cost-minimizing care models in the study, it would be possible to better meet parent's desires and, at the same time, reduce costs, without increasing risks in comparison with the early discharge program.
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| 32999. |
- Ellberg, Lotta, et al.
(author)
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“We feel like one, they see us as two” : new parents' discontent with postnatal care
- 2010
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In: Midwifery. - : Elsevier BV. - 0266-6138 .- 1532-3099. ; 26:4, s. 463-468
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Journal article (peer-reviewed)abstract
- Objective postnatal care has gone through remarkable changes, such as reducing the length of hospital stay and increasing the parents’ responsibility. Focusing on dissatisfaction, this study describes how new parents experience postpartum care.Design cross-sectional, population-based study, based on questionnaires.Participants 1474 parents.Measurements and findings the questionnaires, posted six months after childbirth, addressed how parents experienced postnatal care. The data were analysed with descriptive statistics and content analysis.Key conclusions a main finding was that the close emotional attachment between the parents was not always supported by staff. The father was treated as an outsider and the care was described as ‘a woman's world’. The asymmetric encounter between parents and staff was pronounced with respect to decision-making, and some designated this as ‘paternalism’. A great deal of the discontent with health care may be due to organisational failure, and the postnatal care should be more prioritised in the health-care organisation.Implications for practice midwives should acknowledge that parents, irrespective of gender, should have equal opportunities as parents during postpartum care as parenting is a joint project.
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| 33000. |
- Elle, Ida C, et al.
(author)
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Tissue- and paralogue-specific functions of acyl-CoA-binding proteins in lipid metabolism in Caenorhabditis elegans
- 2011
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In: Biochemical Journal. - 0264-6021 .- 1470-8728. ; 437:2, s. 231-241
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Journal article (peer-reviewed)abstract
- ACBP (acyl-CoA-binding protein) is a small primarily cytosolic protein that binds acyl-CoA esters with high specificity and affinity. ACBP has been identified in all eukaryotic species, indicating that it performs a basal cellular function. However, differential tissue expression and the existence of several ACBP paralogues in many eukaryotic species indicate that these proteins serve distinct functions. The nematode Caenorhabditis elegans expresses seven ACBPs: four basal forms and three ACBP domain proteins. We find that each of these paralogues is capable of complementing the growth of ACBP-deficient yeast cells, and that they exhibit distinct temporal and tissue expression patterns in C. elegans. We have obtained loss-of-function mutants for six of these forms. All single mutants display relatively subtle phenotypes; however, we find that functional loss of ACBP-1 leads to reduced triacylglycerol (triglyceride) levels and aberrant lipid droplet morphology and number in the intestine. We also show that worms lacking ACBP-2 show a severe decrease in the β-oxidation of unsaturated fatty acids. A quadruple mutant, lacking all basal ACBPs, is slightly developmentally delayed, displays abnormal intestinal lipid storage, and increased β-oxidation. Collectively, the present results suggest that each of the ACBP paralogues serves a distinct function in C. elegans.
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