L\'evy-like behavior in deterministic models of intelligent agents exploring heterogeneous environments

Many studies on animal and human movement patterns report the existence of scaling laws and power-law distributions. Whereas a number of random walk models have been proposed to explain observations, in many situations individuals actually rely on mental maps to explore strongly heterogeneous environments. In this work we study a model of a deterministic walker, visiting sites randomly distributed on the plane and with varying weight or attractiveness. At each step, the walker minimizes a function that depends on the distance to the next unvisited target (cost) and on the weight of that target (gain). If the target weight distribution is a power-law, $p(k)\sim k^{-\beta}$, in some range of the exponent $\beta$, the foraging medium induces movements that are similar to L\'evy flights and are characterized by non-trivial exponents. We explore variations of the choice rule in order to test the robustness of the model and argue that the addition of noise has a limited impact on the dynamics in strongly disordered media.Comment: 15 pages, 7 figures. One section adde

Trabalho assalariado na agricultura paulista: evolução e importância no período 2004?2014.

Em 2014, do total de 702 mil pessoas com mais de 10 anos de idade e ocupadas em atividades agrícolas no estado de São Paulo, 460 mil eram empregados (permanentes e temporários). Também vale ressaltar que, no período 2004?2014, a população economicamente ativa (PEA) agrícola paulista ocupada sofreu fortíssima redução de 328 mil pessoas (taxa de -3,7% ao ano). E deste total, 187 mil (ou 57,1%) eram empregados. Em virtude disso, o objetivo do artigo é analisar a evolução e a importância desta categoria de trabalhadores na agricultura paulista no período 2004?2014, tendo como base de informações os dados primários da Pesquisa Nacional por Amostra de Domicílios (PNAD), realizada pelo Instituto Brasileiro de Geografia e Estatística (IBGE). Especial ênfase será dada para os seguintes aspectos do mercado de trabalho agrícola no período em questão: a queda contínua das ocupações na agropecuária; a masculinização da população economicamente ativa (PEA) ocupada nas atividades agrícolas; e o predomínio das relações de trabalho assalariado.Título em inglês: Wage labor force in the State of São Paulo?s agriculture: evolution and importance in the 2004-2014 period

Assessment of the biochemical methane potential of in-house and outdoor stored pig and dairy cow manure by evaluating chemical composition and storage conditions

Biogas production is a suitable option for producing energy from dairy and pig manure types. During manure storage, organic matter degradation results in methane emissions decreasing the potential biogas yield. The present research advances the understanding of the biochemical methane potential (BMP) and the chemical characteristics of manure collected year-round from sequential stages of the liquid manure management chain of commercial dairy cow and pig farms. To this end, manure samples from six livestock farms in Germany were analyzed. The results showed that changes in chemical composition during storage led to a 20.5% decrease in the BMP of dairy manure from the barn to outdoor storage. For fattening pig manure samples, there was a 39.5% decrease in the BMP from intermediate to outdoor storage. An analysis of BMP according to manure age showed that pig manure degrades faster than dairy manure; the importance of promptly feeding manure to the biogas plant in order to avoid significant CH4 emission losses and reduction in energy producing capacity was highlighted. The best BMP predictors for dairy manure were the contents of dry matter, volatile solids and lignin, whereas best BMP predictors for pig manure were dry matter and volatile fatty acid (VFA) content. Prediction models performed well for samples from outdoor storages; refinements for predicting BMP of less aged samples presenting lower chemical variability would be necessary

Antiferrodistortive phase transition in EuTiO3

X-ray diffraction, dynamical mechanical analysis and infrared reflectivity studies revealed an antiferrodistortive phase transition in EuTiO3 ceramics. Near 300K the perovskite structure changes from cubic Pm-3m to tetragonal I4/mcm due to antiphase tilting of oxygen octahedra along the c axis (a0a0c- in Glazer notation). The phase transition is analogous to SrTiO3. However, some ceramics as well as single crystals of EuTiO3 show different infrared reflectivity spectra bringing evidence of a different crystal structure. In such samples electron diffraction revealed an incommensurate tetragonal structure with modulation wavevector q ~ 0.38 a*. Extra phonons in samples with modulated structure are activated in the IR spectra due to folding of the Brillouin zone. We propose that defects like Eu3+ and oxygen vacancies strongly influence the temperature of the phase transition to antiferrodistortive phase as well as the tendency to incommensurate modulation in EuTiO3.Comment: PRB, in pres

Methane Emissions from Livestock Slurry: Effects of Storage Temperature and Changes in Chemical Composition

Livestock production contributes to releasing methane into the atmosphere. Liquid manure management offers significant opportunities to reduce these emissions. A better understanding of the factors controlling methane emissions from manure is necessary to select effective mitigation strategies. Our study aimed to identify the influence of storage temperature and the associated change in chemical composition on methane emissions from dairy and fattening pig manure. Storage temperature affects microbial activity and induces changes in chemical composition that are key influences in methane emissions. Dairy and fattening pig manure samples were stored at five different temperatures (5–25 °C) for 90 days in a laboratory-scale experiment to measure the methane production. The chemical composition of the slurry samples was analyzed, and the biochemical methane potential (BMP) tests were performed before and after storage. For pig manure stored at 25 °C and 20 °C, methane emissions accounted for 69.3% and 50.3% of the BMP, respectively. Maximum methane emissions for dairy slurry were observed at 25 °C but remained at a low level. Analyses of the accumulation of volatile fatty acids (VFAs) during storage are presented in few studies, this work revealed a potential inhibition of methane production, where the accumulation of VFAs was most elevated in samples stored at 20 °C and 25 °C. This partly counteracted the increase in methane emissions expected from the higher temperatures. The degree of VFA and dissociated fatty acids accumulation in dairy cattle slurry should be assessed for more accurate estimations of methane emissions from slurry stores

Вплив густих екстрактів лопуха великого на перебіг модельної гіперплазії передміхурової залози у щурів

Benign prostatic hyperplasia (BPHP) is one of the most common diseases in middle-aged and elderly men. In this regard, the search and study of new effective and safe medicines with the prostatoprotective effect is important and topical. For today, the nomenclature of domestic protostatotectors of the plant origin is limited.Aim. To study experimentally the protoprotective properties of thick extracts of roots and leaves of common burdock on the model of sulpiride-induced prostatic hyperplasia in rats.Materials and methods. The BPHP model reproduced the intraperitoneal administration of sulpiride to male rats in the dose of 40 mg/kg for 30 days. Thick burdock extracts in the dose of 75 mg/kg and the reference drug Prostaplant Forte in the dose of 35 mg/kg were administered intraperitoneally in the therapeutic regimen from day 31 to day 52 of the study.Results. It has been proven that thick extracts of roots and leaves of burdock on the model of sulpiride-induced benign prostatic hyperplasia in rats reduce development of inflammatory processes, inhibit the processes of LPO, normalize the antioxidant / prooxidant balance in the animal’s body. Under the influence of these extracts the level of androgenic saturation of the body and the testosterone/estradiol ratio increase, indicating a positive effect of drugs on spermatogenesis. Thick extracts of burdock roots and leaves reduce the level of estradiol and dihydrotestosterone in the blood serum of the experimental animals, and it impedes development of proliferative processes in the prostate and inhibits development of the disease.Conclusions. By the intensity of the prostatoprotective action thick extracts of roots and leaves of common burdock are not inferior to the reference drug Prostaplant Forte.Доброкачественная гиперплазия предстательной железы (ДГПЖ) является одним из наиболее распространенных заболеваний у мужчин среднего и пожилого возраста. В связи с этим поиск и изучение новых эффективных и безопасных препаратов для лечения ДГПЖ являются важными и актуальными. На сегодня номенклатура отечественных простатопротекторов растительного происхождения ограничена.Цель работы. Экспериментальное изучение простатопротекторных свойств густых экстрактов корней и листьев лопуха большого на модели сульпирид-индуцированной гиперплазиии предстательной железы у крыс.Материалы и методы. Модель ДГПЖ воспроизводила внутрибрюшинное введение самцам крыс сульпирида в дозе 40 мг/кг в течение 30 дней. Экстракт лопуха в дозе 75 мг/кг и референс-препарат Простаплант форте, 35 мг/кг вводили внутрибрюшинно в лечебном режиме с 31 по 52 день.Результаты. Доказано, что густые экстракты корней и листьев лопуха на модели сульпирид-индуцированной доброкачественной гиперплазии предстательной железы у крыс уменьшают развитие воспалительных процессов, тормозят процессы ПОЛ, нормализуют антиоксидантно/прооксидантный баланс в организме животных. Под влиянием исследуемых экстрактов растет уровень андрогенной насыщенности организма и соотношение тестостерон/эстрадиол, что свидетельствует о положительном влиянии препаратов на сперматогенез. Густые экстракты корней и листьев лопуха снижают уровень эстрадиола и дигидротестостерона в сыворотке крови экспериментальных животных, что препятствует развитию пролиферативных процессов в простате и тормозит развитие заболевания.Выводы. По выраженности простатопротекторного действия густые экстракты корней и листьев лопуха большого не уступают референс-препарату Простаплант форте.Доброякісна гіперплазія передміхурової залози (ДГПЗ) є одним з найбільш поширених захворювань у чоловіків середнього та похилого віку. У зв’язку з цим пошук і вивчення нових ефективних і безпечних препаратів для лікування ДГПЗ є важливим і актуальним. На теперішній час номенклатура вітчизняних простатопротек-торів рослинного походження обмежена.Мета роботи. Експериментальне вивчення простатопротекторних властивостей густих екстрактів коренів і листя лопуха великого на моделі сульпірид-індукованої гіперплазії передміхурової залози у щурів.Матеріали та методи. Модельну ДГПЗ відтворювали за допомогою внутрішньоочеревинного введення щурам-самцям cульпіриду в дозі 40 мг/кг впродовж 30 днів. Густі екстракти листя та коренів лопуха в дозі 75 мг/кг і референс-препарат Простаплант форте в дозі 35 мг/кг вводили внутрішньошлунково в лікувальному режимі з 31 по 52 день дослідження.Результати. Визначено, що густі екстракти коренів і листя лопуха на моделі сульпірид-індукованої доброякісної гіперплазії передміхурової залози у щурів зменшують розвиток запальних процесів, гальмують процеси ПОЛ, нормалізують антиоксидантно/прооксидантний баланс в організмі тварин. Під впливом досліджуваних екстрактів зростає рівень андрогенної насиченості організму і співвідношення тестостерон/ естрадіол, що свідчить про позитивний вплив препаратів на сперматогенез. Густі екстракти коренів і листя лопуха знижують рівень естрадіолу і дигідротестостерону в сироватці крові експериментальних тварин, що перешкоджає розвитку проліферативних процесів у простаті і гальмує розвиток захворювання.Висновки. За вираженістю простатопротекторної дії густі екстракти коренів і листя лопуха великого не поступаються референс-препарату Простаплант форте

ROLE OF PERIVASCULAR ADIPOSE TISSUE IN THE DEVELOPMENT OF ATHEROSCLEROTIC AND NONATHEROSCLEROTIC DISEASES

Perivascular adipose tissue surrounds most large blood vessels and plays an important role in vascular homeostasis. Recent studies have shown that perivascular adipose tissue effects vasodilation and vasoconstriction, which indicates that the perivascular adipose tissue regulates tone and diameter of the vessels. Adipocytokines and chemokines, secreted from the perivascular adipose tissue, apparently have direct access to the adjacent arterial wall by diffusion, or through vasa vasorum. The present data indicate that perivascular adipose tissue plays an important role in atherosclerosis, hypertension. Recently, some studies were performed that examined the role of perivascular adipose tissue in non-atherosclerotic vascular diseases, such as neointimal formation, aortic aneurysm, arterial stiffness and vasculitis. The present review will discuss a role of perivascular adipose tissue in pathogenesis of atherosclerosis, hypertension and non-atherosclerotic vascular diseases

Low carbon global economy: Scenarios of sustainable development, power consumption and greenhouse gas emission control

This paper is devoted to problems of a gradual transfer to renewable energy sources and decarbonization of power systems. It presents the analysis of the structure and the trend in global power consumption, greenhouse gas emissions, and target values of decreased emissions by the largest greenhouse gas emitters. A trend in renewable energy sources in total global power consumption is analyzed. The authors study a potential for carbon capture and storage as an instrument of CO2 emission neutralization in power and industrial processes. The paper contains indicators to evaluate efficiency of power resource utilization and greenhouse gas emission control. © 2019 IOP Publishing Ltd. All rights reserved

Адипонектин и инсулин: молекулярные механизмы реализации метаболических нарушений

Adiponectin, the most common plasma adipocytokine, plays a crucial metabolic and anti-inflammatory role. With insulin resistance associated with obesity, an increase of adiponectin concentration, which leads to the activation of signaling pathways involved in the regulation of metabolism, occurs. Currently, adiponectin is being investigated as a potential therapeutic target for metabolic syndrome, although more research is required to understand the underlying mechanisms controlling its levels. In this review, we will examine the main mechanisms that control adiponectin levels in blood serum and its role in insulin-sensitizing effect, as well as evaluate the potential use of adiponectin and its receptors as a potential therapeutic target.Адипонектин – самый распространенный адипоцитокин в плазме крови, который играет критическую метаболическую и противовоспалительную роль. При инсулинорезистентности, связанной с ожирением, происходит увеличение концентрации адипонектина, что приводит к активации сигнальных путей, участвующих в регуляции метаболизма. В настоящее время  адипонектин исследуется в качестве потенциальной терапевтической мишени для метаболического синдрома, хотя необходимы дополнительные исследования, чтобы понять основные механизмы, контролирующие уровень адипонектина в крови. В этом обзоре мы представим основные механизмы, контролирующие уровень адипонектина в сыворотке крови, и его роль в инсулин-сенсибилизирующем действии, а также оценим потенциальное использование адипонектина и его рецепторов в качестве потенциальной терапевтической мишени