Risk Factors of Portal Vein Thrombosis in Patients with Different Child-Pugh Classes Liver Cirrhosis

Aim: to evaluate the frequency of portal vein thrombosis (PVT) and build predictive models of the development of PVT for patients with liver cirrhosis (LC) of A and B/C classes by Child-Pugh.Materials and methods. Research design is a case-control. The Case group included 130 patients with newly diagnosed PVT not caused by invasive hepatocellular carcinoma (HCC); 29 patients were assigned to class A, 101 patients were assigned to class B/C. From the database of cirrhotic patients without PVT 60 Controls for class A and 205 for B/C were selected using sratified randomization by sex, age and etiology of cirrhosis. The Mann-Whitney U-test and Pearson's chi-squared test were used to compare the groups. Odds ratios (OR) and 95 % confidence intervals (95 % CI) were calculated. Logistic regression models are constructed with the separation of the sample into training and test (0.7; 0.3). The operational characteristics of the models were calculated on the test sample; ROC analysis was carried out, the area under the ROC curve (AUC) was calculated.Results. The overall frequency of PVT was 4.1 % (95 % CI 2.7-5.8 %) in class A and 10.4 % (95 % CI 8.5-12.5 %) class B/C. Patients with class A and B/C PVT differed from the corresponding controls by more severe portal hypertension: the frequency of bleeding / number of interventions on varices compared with the control were 41/45 % vs. 7/8 % (p < 0.001) for class A and 25.7/30.7 % vs. 16.1/16.1 % (p < 0.05) for class B/C, ascites frequency was 24 % vs. 8 % (p < 0.05) for class A and 89.1 % vs. 68.3 % (p < 0.001) for class B/C. The cutoff by the portal vein diameter was the same for both classes — 13.4 mm; the spleen length was similar and amounted 17.5 mm for class A, 17.1 mm for class B/C. Patients with PVT differed from the corresponding controls by neutrophil-to-lymphocyte ratio: class A 2.33 (1.82; 3.61) vs. 1.76 (1.37; 2.20), p < 0.01, class B/C 2.49 (1.93; 3.34) vs. 2.15 (1.49; 3.26), p < 0.05. Patients of class B/C had a higher incidence of newly diagnosed malignant tumors - 23.8% (primarily HCC that does not invade the portal vein), compared with control and cases of class A - 6.3 % and 3 % (p < 0.05), respectively. The best model for class A included variceal bleeding, ascites, portal vein diameter, absolute number of neutrophils, for class B — ascites, spleen length, portal vein diameter, malignant tumors / local factors; sensitivity, specificity, accuracy and AUC were 79.3 %, 90 %, 86.5 %, 0.897 and 73.3 %, 68.3 %, 69.9 %, 0.789, respectively.Conclusion. Independently of the Child-Pugh class of LC, the main risk factor for PVT is severe portal hypertension

Thresholds for adding degraded tropical forest to the conservation estate

Logged and disturbed forests are often viewed as degraded and depauperate environments compared with primary forest. However, they are dynamic ecosystems1 that provide refugia for large amounts of biodiversity2,3, so we cannot afford to underestimate their conservation value4. Here we present empirically defined thresholds for categorizing the conservation value of logged forests, using one of the most comprehensive assessments of taxon responses to habitat degradation in any tropical forest environment. We analysed the impact of logging intensity on the individual occurrence patterns of 1,681 taxa belonging to 86 taxonomic orders and 126 functional groups in Sabah, Malaysia. Our results demonstrate the existence of two conservation-relevant thresholds. First, lightly logged forests (68%) of their biomass removed, and these are likely to require more expensive measures to recover their biodiversity value. Overall, our data confirm that primary forests are irreplaceable5, but they also reinforce the message that logged forests retain considerable conservation value that should not be overlooked

Математическая модель успешной игры на фондовой бирже

Татьяна Александровна Верещагина, кандидат экономических наук, доцент, заведующий кафедрой экономической теории и менеджмента, ФГБОУ ВПО «Челябинский государственный педагогический университет> (Челябинск, Российская Федерация), [email protected]. Максут Масновиевич Якупов, кандидат физико-математических наук, доцент, доцент кафедры математического анализа, ФГБОУ ВПО «Челябинский государственный университет> (Челябинск, Российская Федерация), [email protected]. Вера Константиновна Хен, аспирант кафедры экономической теории и менеджмента, ФГБОУ ВПО «Челябинский государственный педагогический университет (Челябинск, Российская Федерация), [email protected]. T.A. Vereschagina, Chelyabinsk State Pedagogical University, Chelyabinsk, Russian Federation, [email protected], M.M. Yakupov, Chelyabinsk State University, Chelyabinsk, Russian Federation, [email protected], V.K. Khen, Chelyabinsk State Pedagogical University, Chelyabinsk, Russian Federation, [email protected]Все известные прогностические модели биржевых спекуляций (такие как например, регрессионный или статистический анализ) основаны на изучении колебаний курсов ценных бумаг. В статье предложена новая модель успешной игры на фондовой бирже, основанная на изучении поведения крупнейших удачливых игроков. Суть предлагаемой модели заключается в том, что относительно слабый игрок повторяет действия сильного игрока подобно тому, как в спортивной «гонке за лидером» велосипедист, укрываясь за мотоциклистом, развивает большую скорость. Мы под «лидером» понимаем вектор в неотрицательном ортанте R™, который строится в зависимости от наиболее удачливых биржевых спекулянтов (хедж-фондов). Вектор собственных ресурсов путем купли-продажи ценных бумаг всегда следует держать коллинеарным «лидеру». Такая стратегия не приведет к значительному выигрышу, но и не позволит случиться значительному проигрышу. All available predictive models of stock market trade (like regression or statistical analysis, for instance) are based on studying of price uctuation. This article proposes a new model of a successful stock market strategy based on studying of the behavior of the largest successful players. The main point of this model is that a relatively weak player repeats the actions of stronger players in the same fashion as in a race after leader a cyclist following a motorbike reaches greater velocity. We represent the leader as a vector in the nonnegative orthant Rn + depending on the most successful traders (hedge funds). When buying and selling stocks, we should always keep the vector of own resources collinear to the leader's. This strategy will not yield signi cant pro t, but it prevents considerable loss

Evaluation and management of recurrent urinary tract infections in children: state of the art

Urinary tract infections (UTIs) represent an important cause of febrile illness in young children and can lead to renal scarring and kidney failure. However, diagnosis and treatment of recurrent UTI in children is an area of some controversy. Guidelines from the American Academy of Pediatrics, National Institute for Health and Clinical Excellence and European Society of Paediatric Radiology differ from each other in terms of the diagnostic algorithm to be followed. Treatment of vesicoureteral reflux and antibiotic prophylaxis for prevention of recurrent UTI are also areas of considerable debate. In this review, we collate and appraise recently published literature in order to formulate evidence-based guidance for the diagnosis and treatment of recurrent UTI in children