Desynchronization of simulation and optimization algorithms in HPC Environment

Need for scalability of an algorithm is essential, when one wants to utilize HPC infrastructure in an efficient and reasonable way. In such infrastructures, synchronization affects the efficiency of the parallel algorithms. However, one can consider introducing certain means of desynchronization in order to increase scalability. Allowing for omitting or delaying certain messages, can be easily accepted in the case of metaheuristics. Furthermore, some simulations can also follow this pattern and handle bigger environments. The paper presents a short survey of desynchronization idea, pointing out already obtained results or sketching out the future work focused on scaling the parallel and distributed computing or simulation algorithms leveraging desynchronization

Longitudinal assessment of renal size and function in extremely low birth weight children at 7 and 11 years of age

BACKGROUND: There are a lack of studies describing a longitudinal association between preterm delivery and renal complications later in life. We assessed renal size and function in preterm infants born with extremely low birth weight (ELBW) during 4 years of follow-up, comparing these parameters to age-matched children born full term (term controls). METHODS: The results of selected renal laboratory tests [levels of cystatin C, creatinine, blood urea nitrogen (BUN)] and of renal ultrasound evaluations were compared between the ELBW group and the term control group at age 7 and 11 years. RESULTS: The study population consisted of 64 children born with ELBW (ELBW children) who had been recruited at birth and 36 children born at term (term children) who took part in both follow-up assessments. Renal ultrasound examination revealed a significantly smaller renal volume in the 7- and 11-year-old ELBW children compared to the term controls [right kidney volume: 50.8 vs. 61.2 ml/m(2), respectively, at 7 years (p <0.01) and 51.4 vs. 58.2 ml/m(2), respectively, at 11 years (p <0.01); left kidney volume: 51.4 vs. 60.3 ml/m(2), respectively, at 7 years (p <0.01) and 55.2 vs. 60.7 ml/m(2), respectively, at 11 years (p = 0.02)]. Renal function in ELBW children was also affected. Serum cystatin C levels were significantly higher in ELBW children than in the controls at 7 years of age, and this difference remained statistically significant at 11 years of age [0.63 vs. 0.59 mg/l, respectively, at 7 years (p = 0.02) and 0.72 vs. 0.61 mg/l, respectively, at 11 years (p = 0.01)]. Six ELBW children also had elevated cystatin C levels (0.97–1.11 mg/l) at 11 years of age. Cystatin C levels were within normal range in the ELBW children at age 7 years and in term children in both follow-up studies. BUN levels were higher in ELBW children at the age of 11 years (4.49 vs. 4.15 mmol/l; p = 0.028). CONCLUSION: Continued follow-up of these patients will reveal whether the observed worsening in renal function will persist into adulthood

Population Diversity in Ant-inspired Optimization Algorithms

Finding a balance between exploration and exploitation is very important in the case of metaheuristics optimization, especially in the systems leveraging population of individuals expressing (as in Evolutionary Algorithms, etc.) or constructing (as in Ant Colony Optimization) solutions. Premature convergence is a real problem and finding means of its automatic detection and counteracting are of great importance. Measuring diversity in Evolutionary Algorithms working in real-value search space is often computationally complex, but feasible while measuring diversity in combinatorial domain is practically impossible (cf. Closest String Problem). Nevertheless, we propose several practical and feasible diversity measurement techniques dedicated to Ant Colony Optimization algorithms, leveraging the fact that even though analysis of the search space is at least an NP problem, we can focus on the pheromone table, where the direct outcomes of the search are expressed and can be analyzed. Besides proposing the measurement techniques, we apply them to assess the diversity of several variants of ACO, and closely analyze their features for the classic ACO. The discussion of the results is the first step towards applying the proposed measurement techniques in auto-adaptation of the parameters affecting directly the exploitation and exploration features in ACO in the future

Glycemic variability in continuous glucose monitoring negatively correlates with gestational age in very low birth weight infants

Introduction: High glycemic variability is commonly observed in intensive care patients, both in pediatrics and adults. The aim of the study was to evaluate the correlation between gestational age and glycemic variability in cohort of very low birth infants. Patients and methods: A prospective, single-center, open cohort study enrolled 74 very low birth weight infants with a mean birth weight of 1066 g. Continuous glucose monitoring system (Guardian Real-Time CGM®, Medtronic, Northridge, CA, USA) was used to measure glucose levels. Spearman’s rank correlation coefficients were calculated for glycemic variability indices and gestational age. Multiple linear regression analyses were used to assess the adjusted effect of multiple glycemic variability variables. Results: The correlations between all calculated glycemic variability indices and gestational age were negative. In multiple regression analysis, all glycemic variability indices negatively correlated with gestational age and positively correlated with mean interstitial fluid glucose concentration. Conclusions: Glycemic variability in very low birth weight infants correlates with gestational age and mean glucose concentrations.</p

Preterm Glycosuria - New Data from a Continuous Glucose Monitoring System

&lt;b&gt;&lt;i&gt;Background:&lt;/i&gt;&lt;/b&gt; Careful control of glucose homeostasis is essential for infants with very low birth weight (VLBW). In clinical practice, blood and urine glucose levels are monitored; however, their correlation has not been fully investigated in VLBW infants. &lt;b&gt;&lt;i&gt;Objectives:&lt;/i&gt;&lt;/b&gt; To evaluate the correlation between interstitial fluid glucose concentration (ISFG), glycosuria, and urine output among VLBW infants through continuous glucose monitoring (CGM). &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; A prospective, single-center, open cohort study enrolled 74 VLBW infants with a mean birth weight of 1,066 g. CGM (Guardian Real-Time CGM®; Medtronic, Northridge, CA, USA) was used to measure glucose. The urine output was calculated using 4-hour intervals. Reagent strips were used for semiquantitative measurement of glycosuria. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; The CGM delivered 102,334 glucose measurements. 2,684 urine samples were checked for glycosuria, of which 92.06% remained negative. Corresponding glycemia in samples without glycosuria remained normoglycemic (median 103 mg/dL; 10–90th percentile 80–144 mg/dL). The median glucose concentrations for samples in ascending glycosuria categories 1+, 2+, 3+, and 4+ were 152, 181, 214, and 222 mg/dL, respectively. A moderate correlation between ISFG and urine output was found for categories ≥1+ (&lt;i&gt;r&lt;/i&gt;&lt;sub&gt;&lt;i&gt;s&lt;/i&gt;&lt;/sub&gt; = 0.56; 95% confidence interval 0.42–0.68; &lt;i&gt;p&lt;/i&gt; &amp;#x3c; 0.001). The urine output was significantly lower when glycosuria was absent (&lt;i&gt;p&lt;/i&gt; &amp;#x3c; 0.05). Polyuria was observed only in glycosuria 4+ (median urine output 9.9; interquartile range 7.4–12.2 mL/kg/h). &lt;b&gt;&lt;i&gt;Conclusions:&lt;/i&gt;&lt;/b&gt; The renal glucose threshold in VLBW infants is between 150 and 180 mg/dL. A negative result for glycosuria is a reliable screening test to exclude hyperglycemia. Occurrence of glycosuria ≥1+ is an indication to test blood glucose.</jats:p