Решение оптимизационных задач для систем массового обслуживання с отказами в условиях неопределенности

Построены математические модели расчета показателей качества функционирования вычислительных сетей, которые можно представить в виде сетей массового обслуживания с отказами. Сформулированы задачи оптимизации показателей качества функционирования таких сетей при заданных ограничениях на максимальную пропускную способность каналов связи и на выделяемые для модернизации сети ресурсы. Построены алгоритмы, которые позволяют решать поставленные оптимизационные задачи в рамках оговоренных ограничений

The Yin and Yang of Yeast Transcription: Elements of a Global Feedback System between Metabolism and Chromatin

When grown in continuous culture, budding yeast cells tend to synchronize their respiratory activity to form a stable oscillation that percolates throughout cellular physiology and involves the majority of the protein-coding transcriptome. Oscillations in batch culture and at single cell level support the idea that these dynamics constitute a general growth principle. The precise molecular mechanisms and biological functions of the oscillation remain elusive. Fourier analysis of transcriptome time series datasets from two different oscillation periods (0.7 h and 5 h) reveals seven distinct co-expression clusters common to both systems (34% of all yeast ORF), which consolidate into two superclusters when correlated with a compilation of 1,327 unrelated transcriptome datasets. These superclusters encode for cell growth and anabolism during the phase of high, and mitochondrial growth, catabolism and stress response during the phase of low oxygen uptake. The promoters of each cluster are characterized by different nucleotide contents, promoter nucleosome configurations, and dependence on ATP-dependent nucleosome remodeling complexes. We show that the ATP:ADP ratio oscillates, compatible with alternating metabolic activity of the two superclusters and differential feedback on their transcription via activating (RSC) and repressive (Isw2) types of promoter structure remodeling. We propose a novel feedback mechanism, where the energetic state of the cell, reflected in the ATP:ADP ratio, gates the transcription of large, but functionally coherent groups of genes via differential effects of ATP-dependent nucleosome remodeling machineries. Besides providing a mechanistic hypothesis for the delayed negative feedback that results in the oscillatory phenotype, this mechanism may underpin the continuous adaptation of growth to environmental conditions

Galectin-3 alters the lateral mobility and clustering of beta 1-integrin receptors

Glycoprotein receptors are influenced by myriad intermolecular interactions at the cell surface. Specific glycan structures may interact with endogenous lectins that enforce or disrupt receptor-receptor interactions. Glycoproteins bound by multivalent lectins may form extended oligomers or lattices, altering the lateral mobility of the receptor and influencing its function through endocytosis or changes in activation. In this study, we have examined the interaction of Galectin-3 (Gal-3), a human lectin, with adhesion receptors. We measured the effect of recombinant Gal-3 added exogenously on the lateral mobility of the alpha 5 beta 1 integrin on HeLa cells. Using single-particle tracking (SPT) we detected increased lateral mobility of the integrin in the presence of Gal-3, while its truncated C-terminal domain (Gal-3C) showed only minor reductions in lateral mobility. Treatment of cells with Gal-3 increased beta 1-integrin mediated migration with no apparent changes in viability. In contrast, Gal-3C decreased both cell migration and viability. Fluorescence microscopy allowed us to confirm that exogenous Gal-3 resulted in reorganization of the integrin into larger clusters. We used a proteomics analysis to confirm that cells expressed endogenous Gal-3, and found that addition of competitive oligosaccharide ligands for the lectin altered the lateral mobility of the integrin. Together, our results are consistent with a Gal-3-integrin lattice model of binding and confirm that the lateral mobility of integrins is natively regulated, in part, by galectins

Health outcomes measurement and organizational readiness support quality improvement: a systematic review

Contains fulltext : 200145.pdf (publisher's version ) (Open Access)BACKGROUND: Using outcome measures to advance healthcare continues to be of widespread interest. The goal is to summarize the results of studies which use outcome measures from clinical registries to implement and monitor QI initiatives. The second objective is to identify a) facilitators and/or barriers that contribute to the realization of QI efforts, and b) how outcomes are being used as a catalyst to change outcomes over time. METHODS: We searched the PubMed, EMBASE and Cochrane databases for relevant articles published between January 1995 and March 2017. We used a standardized data abstraction form. Studies were included when the following three criteria were fulfilled: 1) they relied on structural data collection, 2) when a structural and comprehensive QI intervention had been implemented and evaluated, and 3) impact on improving clinical and/or patient-reported outcomes was described. Data on QI strategies, QI initiatives and the impact on outcomes was extracted using standardized assessment tools. RESULTS: We included 21 articles, of which eight showed statistically significant improvements on outcomes using data from clinical registries. Out of these eight studies, the Chronic Care Model, IT application as feedback, benchmarking and the Collaborative Care Model were used as QI methods. Encouraging trends in realizing improved outcomes through QI initiatives were observed, ranging from improving teamwork, implementation of clinical guidelines, implementation of physician alerts and development of a decision support system. Facilitators for implementing QI initiatives included a high quality database, audits, frequent reporting and feedback, patient involvement, communication, standardization, engagement, and leadership. CONCLUSION: This review suggests that outcomes collected in clinical registries are supportive to realize QI initiatives. Organizational readiness and an active approach are key in achieving improved outcomes

Outcomes in pulmonary sarcoidosis: results of a newly implemented prednisone protocol.

Background and aim Prednisone is used as first-line therapy for patients with pulmonary sarcoidosis. There is however no clear association between prednisone dose and FVC change in patients with pulmonary sarcoidosis. In order to improve our standard of care we introduced a more conservative prednisone protocol. Methods This study is a single centre observational study, applying value-based healthcare (VBHC) and quality improvement (QI) principles. Prednisone intake was reduced from a starting dose of 40 mg to a starting dose of 20 mg. Primary outcomes evaluated were FVC, FEV1 and DLCO % predicted. The secondary outcome measure was BMI. Results 369 patients were included in the old-cohort and 215 in the new-cohort. In the old-cohort, 182 (49.0%) of the patients were treated with prednisone. In total, 114 patients (62.6%) were treated according to the old protocol with a mean initial prednisone dose of 32.1 ±14.2 mg. In the new-cohort, 93 patients (45.0%) were treated with prednisone of which 53 patients (57.0%) received prednisone according to the new protocol. The mean initial prednisone dose in the new-cohort was 21.4 ±9.8 mg. Changes in FVC and FEV1 % predicted did not vary. Change in % predicted DLCO was 2.4 ±9.3 for the old-cohort and -1.3 ±11.4 for the new-cohort (p = 0.01). No statistically significant changes in BMI were observed. Conclusions Our results indicate that in more than half of the patients the new protocol was followed. Data support the observation that a more conservative prednisone regimen might be equally effective, looking at changes in pulmonary function and BMI