Some results on Kolmogorov-Loveland randomness

Whether Kolmogorov-Loveland randomness is equal to the Martin-Löf randomness is a well known open question in the field of algorithmic information theory. Randomness of infinite binary sequences can be defined in terms of betting strategies, a string is non-random if a computable betting strategy wins unbounded capital by successive betting on the sequence. For Martin-Löf randomness, a betting strategy makes a bet by splitting a set of sequences into any two clopen sets, and placing a portion of capital on one of them as a wager. Kolmogorov-Loveland betting strategies are more restricted, they bet on a value of the bit at some position they choose, which splits a set of sequences into two clopen sets, the sequences that have 0 at the chosen position and the sequences that have 1. In this thesis we consider betting strategies that when making a bet are restricted to split a set of sequences into two sets of equal uniform Lebesgue measure. We call this generalization of Kolmogorov-Loveland betting strategies the half-betting strategies. We show that there is a pair of such betting strategies such that for every non-Martin-Löf random sequence one of them wins unbounded capital (the pair is universal). Next, we define a finite betting game where the betting strategies bet on finite binary strings, and show that in this game Kolmogorov-Loveland betting strategies cannot increase capital by more than an arbitrary small amount on all strings on which the unrestricted betting strategy achieves arbitrary large capital. We also look at another relaxation of Kolmogorov-Loveland betting, where a betting strategy is allowed to access bits of the sequence within a set of positions a bounded number of times. We show that if this bound is less than ℓ - log ℓ for the first ℓ positions then a pair of such betting strategies cannot be universal. Furthermore, we show that, at least for some universal betting strategies, this bound is exponential

Acute kidney damage in pregnancy: Etiopathogenesis, diagnostics and basic principles of treatment

© 2020, University of Kragujevac, Faculty of Science. All rights reserved. Acute kidney damage associated with pregnancy occurs in 1/20.000 pregnancies. In developing countries, the main cause of the development of acute kidney damage is septic abortion, and preeclampsia in the developed countries of the world. Preeclamp-sia is defined as newly developed hypertension, proteinuria and swelling in pregnant women after the 20th week of gestation. It occurs due to disorders in the development of placenta and sys-temic disorders of the function of the endothelium of the mother. It is treated with methyldopa, magnesium sulfate and timely deliv-ery. Urgent delivery is indicated if the age of gestation is ≥ 34 weeks. HELLP syndrome is a difficult form of preeclampsia. Its main characteristics are decreased platelet count, microangio-pathic hemolysis anemia, increased concentration of aminotrans-ferase in the serum and acute kidney damage. Severe HELLP syndrome is treated with emergency delivery, antihypertensives, magnesium sulfate, and in some cases plasmapheresis and hemo-dialysis. Acute fatty liver in pregnancy occurs because of decreased activity of the LCHAD enzyme of the fetus. Due to the reduced beta oxidation of fatty acids in the hepatocytes of the fetus, long chain fatty acids that cause damage to the mother's hepato-cytes are released. Swansea criteria are used for diagnosis, and the difficult form of the disease is treated with plasmapheresis and extracorporeal liver support. Atypical HUS is due to a reduced protein activity that regulates the activity of the alternative pathway of the complement system. Its main features are thrombocy-topenia, microangiopathic hemolytic anemia and acute kidney damage. It is treated with plasmapheresis, and in case of resistance with eculizumab. Thrombotic thrombocytopenic purpura is due to decreased activity of the ADAMTS13 enzyme. It is char-acterized by thrombocytopenia, microangiopathic hemolytic ane-mia, high temperature, nervous system disorders and acute kidney damage. It is treated with plasmapheresis, and severe form of disease with corticosteroids and azathioprine. Early detection and timely treatment of acute kidney damage provides a good outcome for the mother and fetus

Median arcuate ligament syndrome with post stenotic pancreaticoduodenal aneurysm: case report

Background: Median arcuate ligament syndrome (celiac artery compression syndrome, Dunbar syndrome) is an infrequent form of chronic mesenterial ischemia. The culprit for a sub optimal celiac blood flow is a lowpositioned median arcuate ligament which is an arch of fibrous tissue connecting the diaphragmatic crura. Symptomatic patients complain of postprandial pain situated in the epigastrium. Still, most of the individuals proven to have some form of celiac artery compressions report no complaints at all. The gold standard for diagnosis is a CT angiography and treatment is surgical. The median arcuate ligament is transacted with or without additional endovascular treatment. Case study: We present the case of a 50-year-old male patient with a radiologically confirmed diagnosis of median arcuate ligament syndrome treated surgically at our institution. An open approach was used since the patient had a previous median laparotomy scar. Due to a post stenotic pancreaticoduodenal aneurysm coil embolization was additionally performed. On follow up the patient had no further complaints. Conclusion: Patients with chronic postprandial pain require a systematic approach. In the differential diagnosis of abdominal angina, although uncommon, median arcuate ligament syndrome is to be remembered. The diagnosis is rather straightforward once clinical suspicion is established and treatment-wise minimally invasive surgery is performed whenever possible

Miniaturized push-button rotational energy harvesting generator

This work presents a development and miniaturization of a rotational electromagnetic energy harvesting (EH) generator. The energy harvesting generator is driven mechanically by pushing the button. The energy harvester system has an integrated mechanism for movement conversion. This mechanism converts the linear movement of the button into rotation with a rotational speed of 1000 rpm. An electromagnetically part of harvester consists of in FR-4 embedded multilayer planar coils and of multipole NdFeB hard magnets. The miniaturized energy harvester generates a maximum open circuit output voltage of about 500 mV with duration of about 2 s and a maximum short circuit output current higher than 40 mA

Poređenje efikasnosti uklanjanja uremijskih toksina srednje molekulske mase između visokopropusne hemodijalize i postdilucione online hemodijafiltracije

Introduction. Conventional high-flux hemodialysis effectively removes uremic toxins of medium molecular weight of 0.5-15 (20) kDa, while postdilution online hemodiafiltration effectively removes uremic toxins of medium molecular weight in the range of 0.5-60 kDa. AIM. The aim of the study was to compare the efficacy of b2-microglobulin removal from the patient serum during a single session of conventional high-flux hemodialysis and postdilution online hemodiafiltration. METHOD. Eighty-five patients treated with conventional high-flux hemodialysis and thirty patients treated with postdilution online hemodiafiltration were examined. The main parameter for assessing the removal efficiency of medium molecular weight uremic toxins was serum b2microglobulin concentration before and after a single session of conventional high-flux hemodialysis and postdilution online hemodiafiltration. The following were used for statistical analysis: Kolmogorov-Smirnov test, Student's T test and Mann-Whitney U test. RESULTS. In patients treated with postdilution online hemodiafiltration, the average total convective volume was 21.38 ± 2.97 liters per session. The b2-microglobulin reduction index for the FX CorDiax 600 dialysis membrane was 61.76 ± 7.32%, while for the FX CorDiax 800 dialysis membrane it was 74.69 ± 6.51%. The albumin reduction index for the FX CorDiax 600 membrane was 3.48 ± 1.28%, and for the FX CorDiax 800 dialysis membrane it was 6.01 ± 2.97%. There is a highly statistically significant difference between the reduction index of b2-microglobulin and albumin, for two different dialysis modalities and two different dialysis membranes (p < 0.01). CONCLUSION. Postdilution online hemodiafiltration is more efficient in removing b2-microglobulin from patient serum, compared to conventional high-flux hemodialysis. Albumin loss during a single session of high-flux hemodialysis is lower compared to a single session of postdilution online hemodiafiltration. With both dialysis modalities, albumin loss is less than 4.0 g/4h. High-flux hemodialysis effectively prevents the development of dialysis-related amyloidosis, while postdilution online hemodiafiltration effectively prevents not only the development of dialysis-related amyloidosis, but also the development of resistance to erythropoietin and atherosclerotic cardiovascular diseases in the population treated with regular dialysis

pROCeNA UTICAjA pROšIReNe hemODIjAlIze NA sTepeN UklANjANjA URemIjskIh TOksINA sReDNje mOlekUlske mAse

Objective. The aim of this study was to examine the effect of expanded hemodialysis on the degree of b2-microglobulin removal. Methods. Sixteen patients treated with extended MCO hemodialysis were examined. The main parameter for assessing the efficiency of removal of uremic toxins of middle molecular weight is the concentration of b2-microglobulin in the serum before and after a single session of extended MCO hemodialysis. The following were used for statistical analysis: Kolmogorov-Smirnov test, Student's T test for bound samples and Wilcoxon test. Results. Extended MCO hemodialysis effectively removes uremic toxins of middle molecular weight. The reduction index of b2-microglobulin during a single session of extended MCO hemodialysis is 70.60 ± 5.88%. The average loss of albumin during a single session of extended MCO hemodialysis is 1.88 ± 1.02 g/4h, and the index of albumin reduction is 4.94 ± 2.49%. Conclusion. Extended MCO hemodialysis effectively removes b2-microglobulin. The b2-microglobulin reduction index is ~ 71% and the albumin loss is less than 4.0 g/4h. This dialysis modality prevents the development of amyloidosis, atherosclerosis and atherosclerotic cardiovascular diseases in the population of patients treated with regular hemodialysis.Publishe

Expanded hemodialysis: Basic principles and clinical significance

Expanded hemodialysis is a method of treatment to replace kidney function, which effectively removes uremic toxins of middle molecular weight from the blood of the patients with the end stage of chronic kidney disease. Two basic principles of removing uremic toxins during an expanded hemodialysis session are diffusion and convection. The basis of diffusion is the concentration gradient, and the basis of convection is internal filtration (covective transport). Increased MCO membrane sieving capacity and high internal filtration provide high clearance of middle molecular weight uremic toxins. Expanded hemodialysis prevents the development of microinflammation, malnutrition, resistance to the action of erythropoietin, amyloidosis, accelerated atherosclerosis and atherosclerotic cardiovascular diseases in the population of patients treated with regular dialysis. The task of the nephrologist is to evaluate different dialysis modalities that are available and to select the optimal dialysis modality for the treatment of each patient individually, i.e., the individualization of dialysis treatment.Publishe

International evidence-based recommendations for point-of-care lung ultrasound

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International consensus conference recommendations on ultrasound education for undergraduate medical students

Objectives: The purpose of this study is to provide expert consensus recommendations to establish a global ultrasound curriculum for undergraduate medical students. Methods: 64 multi-disciplinary ultrasound experts from 16 countries, 50 multi-disciplinary ultrasound consultants, and 21 medical students and residents contributed to these recommendations. A modified Delphi consensus method was used that included a systematic literature search, evaluation of the quality of literature by the GRADE system, and the RAND appropriateness method for panel judgment and consensus decisions. The process included four in-person international discussion sessions and two rounds of online voting. Results: A total of 332 consensus conference statements in four curricular domains were considered: (1) curricular scope (4 statements), (2) curricular rationale (10 statements), (3) curricular characteristics (14 statements), and (4) curricular content (304 statements). Of these 332 statements, 145 were recommended, 126 were strongly recommended, and 61 were not recommended. Important aspects of an undergraduate ultrasound curriculum identified include curricular integration across the basic and clinical sciences and a competency and entrustable professional activity-based model. The curriculum should form the foundation of a life-long continuum of ultrasound education that prepares students for advanced training and patient care. In addition, the curriculum should complement and support the medical school curriculum as a whole with enhanced understanding of anatomy, physiology, pathophysiological processes and clinical practice without displacing other important undergraduate learning. The content of the curriculum should be appropriate for the medical student level of training, evidence and expert opinion based, and include ongoing collaborative research and development to ensure optimum educational value and patient care. Conclusions: The international consensus conference has provided the first comprehensive document of recommendations for a basic ultrasound curriculum. The document reflects the opinion of a diverse and representative group of international expert ultrasound practitioners, educators, and learners. These recommendations can standardize undergraduate medical student ultrasound education while serving as a basis for additional research in medical education and the application of ultrasound in clinical practice