On the Matthew effect on Individual Investments into Skills in Arts, Sports and Science

The paper describes the process of capital accumulation subject to the following characteristics: (i) convex returns to (human) capital; (ii) the need to self _nance the investment. This set up is applicable to explain some peculiarities in arts, sports and science, inter alia, the \Matthew effect" coined in Merton (1968) to explain why prominent researchers get disproportional credit for their work. The potential young artist's (or sportsman's or even scientist's) optimal strategies include quitting, or continuing and even expanding one's human capital in a profession. Both outcomes are separated by a threshold level in human capital. In addition, it can be optimal to stay in business although consumption falls and stays at the subsistence level (we call this outcome a \Sisyphus point")

On the matthew effect on individual investments in skills in arts, sports and science

This paper describes the process of capital accumulation subject to the following characteristics: (i) convex returns to (human) capital and (ii) the need to self-finance investments. Our setup is applicable to some peculiarities in the arts, sports and science, inter alia, coined the Matthew effect in Merton (1968) and explains, e.g., why prominent researchers get disproportional credit for their work. The potential young artist’s (athlete’s or scientist’s) optimal strategies include quitting, or continuing and even expanding one’s human capital in the respective profession. Both outcomes are separated by a threshold level in human capital. In addition, we find that it can be optimal to stay in business although consumption falls and stays at the subsistence level forever (we call this outcome a Sisyphus point). This possibility is also interesting from a theoretical point-of-view, as the optimal control problem may turn abnormal, i.e., the objective does not enter the Hamiltonian

Варианты создания гетеротопических и ортотопических PDX-моделей колоректального рака человека

Aim. To create heterotopic and orthotopic patient-derived xenograft (PDX) models of colorectal cancer (CRC) by transplantation of patient’s tumor samples into immunodeficient BALB / c Nude mice.Materials and methods. The study was performed on 15 female BALB / c Nude mice aged 6–8 weeks weighing 21–25 g. All animals underwent transplantation of the tumor material obtained from CRC patients into the following sites: heterotopic transplantation (under the skin of the thigh and into the omentum), orthotopic transplantation (into the descending and ascending colon and into the cecum). Weight and general condition of the animals and the size of the tumor nodule had been monitored for 80 days. The success of each model was assessed by the degree of engraftment, the dynamics of tumor growth, and the reproducibility of histopathologic characteristics. At the end of the experiment, the animals were euthanized by cervical dislocation.Results. 100% survival of the animals and similar tumor growth dynamics in the xenograft models were observed throughout the experiment. The analysis of histologic specimens obtained from the xenografts and patient’s tumor showed their correspondence to moderately differentiated intestinal adenocarcinoma. The main advantages and disadvantages of different variants of PDX models were described.Conclusion. Heterotopic and orthotopic PDX models reproduce the morpho-histologic characteristics of human tumors and demonstrate stable growth dynamics. Therefore, they are a suitable tool for the development, testing, and validation of potential anticancer drugs.Цель. Создание гетеротопических и ортотопических моделей ксенографтов колоректального рака (КРР), полученных от пациентов (Patient-derived xenograft, PDX-модель), путем трансплантации образцов опухоли пациента иммунодефицитным мышам линии Balb/c nude.Материалы и методы. Проведено исследование на 15 самках мышей линии Balb/c nude, возраст 6–8 нед, масса тела 21–25 г. Всем животным проведена трансплантация опухолевого материала, взятого от пациентов с КРР, в следующие сайты: гетеротопические (под кожу бедра, в сальник); ортотопические (в нисходящий и восходящий отделы толстой кишки, в слепую кишку). В течение 80 сут у животных контролировали следующие параметры: массу тела, общее состояние, объем опухолевого узла. Успешность каждой из моделей оценивали по степени приживления, динамике опухолевого роста и воспроизводимости гистопатологических характеристик. По завершению эксперимента животным выполнена эвтаназия методом цервикальной дислокации.Результаты. На протяжении всего эксперимента наблюдалась 100%-я выживаемость животных и схожая динамика роста ксенографтов. Анализ гистологических препаратов ксенографтов и опухоли пациентов показал их соответствие умеренно дифференцированной аденокарциноме кишки. Описаны основные преимущества и недостатки создания различных вариантов PDX-моделей.Заключение. Гетеротопические и ортотопические PDX-модели воспроизводят морфогистологические признаки человеческой опухоли и обладают устойчивой динамикой роста, следовательно, являются подходящим инструментом для разработки, тестирования и валидации потенциальных лекарственных препаратов против рака

New early Triassic Lingulidae (Brachiopoda) genera and species from South China

Two new genera, Sinolingularia gen. nov. and Sinoglottidia gen. nov., together with three new species, Sinolingularia huananensis gen. et sp. nov., Sinolingularia yini gen. et sp. nov. and Sinoglottidia archboldi gen. et sp. nov., are described on the basis of a large collection of well-preserved specimens from several sections straddling the Permian - Triassic boundary in South China. <br /

Growth and Collapse of Empires: A Dynamic Optimization Model

This paper addresses the spatial evolution of countries accounting for economics, geography and (military) force. Economic activity is spatially distributed following the AK model with the output being split into consumption, investment, transport costs and military (for defense and expansion). The emperor controls the military force subject to the constraints imposed by the economy but also the geography (transport costs, border length) and the necessity to satisfy the needs of the population. The border changes depending on how much pressure the emperor can muster to counter the pressure of neighboring countries. The resulting dynamic process determines a country’s size over time. The model leads to multiple steady states, large empires and small countries being separated by a threshold and collapse. The resulting patterns can be linked to historical observations

Pitavastatin – A New Inhibitor of the HMG-CoA Reductase: Peculiarities of Clinical Pharmacology and Perspectives of Its Usage in Treatment of Cardiovascular Diseases.

Cardiovascular mortality makes up 66.3 % of the total mortality in Ukraine. Myocardial infarction, stroke, atherosclerosis of peripheral arteries are the diseases caused by atherosclerosis and are prevalent in the mortality structure. One of the most effective means of successful prevention of cardiovascular disease are drugs that reduce the content of atherogenic lipids in the blood. Statins are the first line drugs for the treatment of patients with dyslipidemia and atherosclerosis in accordance with national and International guidelines. The article presents the features of the pharmacokinetics and pharmacodynamics, results of clinical trials and data on the efficacy and safety of a new inhibitor of the HMG-CoA reductase – pitavastatin (Livazo © (Recordati, Italy). Data from several multicenter randomized studies indicate that pitavastatin significantly reduces the level of cholesterol low-density lipoproteins and triglycerides, significantly increases the level of cholesterol high-density lipoproteins after 12 weeks of observation, and contributes to a significant regression of atherosclerotic plaques. It was shown that pitavastatin has a high level of safety and is well tolerated regardless of patients' age and racial origin. Pitavastatin is a new effective inhibitor of HMG -CoA reductase, which has been successfully used in many countries for the dyslipidemia treatment in patients with cardiovascular disease, diabetes, kidney diseases and other comorbid conditions