Climate projections over the Antarctic Peninsula region to the end of the 21st century. Part ІІ: wet/dry indices

Objective of the study is an assessment of possible climate change in the region of the Antarctic Peninsula from 1986 until the end of the 21st century projected by the RCMs’ ensemble. During the last decades Antarctica has undergone predominantly warming, with the highest rate of surface air temperature increase found over the Antarctic Peninsula, where the Ukrainian Antarctic Akademik Vernadsky station is located. There is a unique ecosystem in the region which is vulnerable and under the growing impact of a changing weather regime due to rapid climate changes with consequent changes in sea ice, land distribution under snow/ice, etc. Thus, an important task for the region is an estimation of climate change trends and definition of possible subregionalization.Мета дослідження — оцінка можливої зміни клімату в регіоні Антарктичного півострова до кінця 21 століття за проекціями ансамблю регіональних кліматичних моделей (РКМ). Впродовж останніх десятиліть на переважаючій території Антарктиди спостерігається потепління, воно найінтенсивніше для Антарктичного півострова, де знаходиться Українська антарктична станція «Академік Вернадський». У регіоні існує унікальна екосистема, яка є вразливою до зміни погодного режиму, що відбувається під впливом швидких змін клімату та їхніх наслідків, зокрема, зміни розподілу морського льоду та суші вкритої снігом / льодом тощо. Отже, для регіону важливим завданням є оцінка проекцій зміни клімату з визначенням окремих районів з подібними тенденціями

Climate projections over the Antarctic Peninsula region to the end of the 21st century. Part 1: cold temperature indices

Objective. This paper deals with an estimation of the climate change at the Antarctic Peninsula region. During last decades, the most significant warming is observed in Polar regions, particularly in the Antarctic Peninsula region, where the Ukrainian Antarctic Akademik Vernadsky station is located. Therefore, the providing of the complex estimation of climate change trend is an important task for the region. These changes are taking place nowadays and will happen in the future. So, the main objective of the study is to estimate changes of climate characteristics in the Antarctic Peninsula region in the 21st century, based on calculation of the relevant climate indices. The projections of the temperature and precipitation characteristics in the Antarctic Peninsula region and Akademik Vernadsky station area for RCP4.5 and RCP8.5 scenarios are the objects of the research.Стаття присвячена оцінці змін, що відбуваються в районі Антарктичного півострова. Впродовж останніх десятиліть найсуттєвіше потепління в кліматичній системі спостерігається в полярних регіонах, зокрема в районі Антарктичного півострова, де розташована Українська антарктична станція «Академік Вернадський». У зв’язку з цим необхідно забезпечити кращу комплексну оцінку тенденцій кліматичних змін, які вже зафіксовані та прогнозуються в майбутньому. Мета дослідження — оцінити зміни кліматичних характеристик в регіоні Антарктичного півострова в ХХІ столітті, на основі обчислення відповідних кліматичних показників. Об’єкт дослідження: проекції характеристик температури повітря та режиму зволоження в районі Антарктичного півострову та Української антарктичної станції «Академік Вернадський» за сценаріями RCP4.5 та RCP8.5 (Representative Concentration Pathway, RCP, Траєкторії репрезентативних концентрацій). Методами дослідження є чисельне моделювання та статистичний аналіз даних регіональних кліматичних моделей

Vulnerability of Ukrainian forests to climate change

Ukraine is a country of the Mid-Latitude ecotone – a transition zone between forest zone and forestless dry lands. Availability of water defines distribution of the country’s forests and decreasing their productivity towards the south. Climate change generates a particular threat for Ukrainian forests and stability of agroforestry landscapes. The paper considers the impacts of expected climate change on vulnerability of Ukrainian forests using ensembles of global and regional climatic models (RCM) based on IPCC Scenarios B1, A2, A1B, and a “dry and warm” scenario A1B+T-P (increasing temperature and decreasing precipitation). The spatially explicit assessment was provided by RCM for the WMO standard period (1961-1990), “recent” (1991-2010) and three future periods – 2011-2030, 2031-2050 and 2081-2100. Forest-climate model by Vorobjov and model of amplitude of flora’s tolerance to climate change by Didukh, as well as a number of specialized climatic indicators, were used in the assessment. Different approaches leads to rather consistent conclusions. Water stress is the major limitation factor of distribution and resilience of flatland Ukrainian forests. Within Scenario A1B, the area with unsuitable growth conditions for major forest forming species will substantially increase by end of the century occupying major part of Ukraine. Scenario A1B+T-P projects even a more dramatic decline of the country’s forests. It is expected that the boundary of conditions that are favorable for forests will shift to north and north-west, and forests of the xeric belt will be the most vulnerable. Consistent policies of adaptation and mitigation might reduce climate-induced risks for Ukrainian forests

Climate projections over the Antarctic Peninsula region to the end of the 21st century. Part III: clouds and extreme precipitation

This paper focuses on the parameters that represent the characteristics of clouds and extreme precipitation events over the Antarctic Peninsula region, where clouds and precipitation play a crucial role in regional climate warming, particularly when a higher fraction of precipitation becomes liquid. In this work, we assess cloud and precipitation properties under climate change over the Antarctic Peninsula region under the Representative Concentrations Pathways (RCP) scenarios using model outputs of the Coordinated Regional Downscaling Experiment for polar regions (Polar CORDEX) for the 21st century. A similar approach was previously applied by authors for estimating projected changes in the temperature regime (Part I) and wet/dry indices (Part II) for the Antarctic Peninsula. We evaluated changes in cloud ice and condensed water contents, spatial distributions of both rain fraction and 95th percentile of total precipitation for the future periods, 2041–2060 and 2081–2100, for RCP4.5, RCP8.5 comparing them to the historical period of 1986–2005. We found that changes in studied parameters have similar tendencies and patterns under both scenarios, with more remarkable changes for the RCP8.5 scenario through the end of the 21st century. Analysis of obtained projections shows that all cloud amounts, liquid content in clouds, the annual fraction of rain in precipitation events, and frequency of extreme precipitation events will increase over the Antarctic Peninsula by the end of the 21st century under both RCP scenarios. The most significant changes are expected for the west coast and over the ocean to the west of the Antarctic Peninsula region, while the lowest changes are projected for the ridge of the Antarctic Peninsula mountains. However, the rates of expected changes vary within the broad Antarctic Peninsula region. While extreme event intensities will increase over the whole area, the changes will be most remarkable over the northwestern slopes of the Antarctic Peninsula, where Akademik Vernadsky station is located

Кліматичні проекції опалювального періоду в Україні до середини ХХІ сторіччя

The paper presents projections for the balanced scenario A1B of specialized climatic indicators of the heating period for the territory of Ukraine for decades until the middle of the 21st century. Prediction of mean temperature, duration and heating degree-days are based on calculations of the previously formed and adapted to Ukraine ensemble of 10 regional climate models from the European project ENSEMBLES. The main and specialized climatic indicators calculated on all nodes of a regular grid of 25×25 km were verified by E-Obs data for the period 2001―2010. A negligible bias in the heating period mean temperature (in average less than 0.01°C) and an acceptable bias in duration (with a mean value of less than 6,4 days or <4 %) were found in the verification that resulted in obtaining an average bias in heating degree-days by about 4 %. Forecasting of specialized indicators of the heating season for future periods was performed with corresponding bias corrections. The spatial and temporal changes of heating period indices for the decades to the middle of the 21st century have been analyzed and averaging values for administrative units of Ukraine have been calculated. Obtained insignificant, within the limits of 0―0,2 °С, increase of the mean heating period temperature for most of the country in the modern decade of 2011―2020 in relation to the base period of 2001―2010, reducing the heating period duration by an average of 3 days and reducing values of heating degree-days by 2―3 %. By the middle of the 21st century the mean heating period temperature will increase significantly with maximum values of 1,5 °С in the northeastern, central and eastern parts of the country, and the least increasing of 0,8 °С to the south, southwest and the Crimea. The heating period duration will be reduced by 15―18 days in average, with a maximum of 20 days to the south. The values of heating degree-days will decrease in most areas by 12―16 %, with maximum by 20 % in the Crimea, and the minimum reduction by 9―12 % in the Carpathians. Results obtained in the study may be used, primarily, for the calculation of heating costs and other needs of the energy sector and other national economy sectors for the overall development of infrastructure and other needs of any settlement in the territory of Ukraine.В работе представлен прогноз по сбалансированному сценарию А1В специализированных климатических показателей отопительного периода для территории Украины по десятилетиям до середины XXI ст. Прогноз средней температуры, продолжительности и величины градусо-дней составлен на расчетах ансамбля 10 региональных климатических моделей Европейского проекта ENSEMBLES, предварительно сформированного и адаптированного для Украины. Рассчитаные во всех узлах регулярной сетки 25₅25 км основные и специализированные климатические показатели были верифицированы данными Е-Оbs для периода 2001―2010 гг. Обнаружены незначительная погрешность средней температуры отопительного периода, усредненное значение которой на всей территории меньше 0,01 °С, и приемлемая погрешность продолжительности с усредненным значением менее 6,4 дня (<4 %), что в результате позволило получить осредненную погрешность градусо-дней около 4 %. Прогнозирование на будущие периоды специализированных показателей отопительного сезона проводилось с учетом полученных в базовом периоде ошибок. Проанализированы пространственно-временные изменения показателей отопительного периода по десятилетиям к середине XXI ст. и рассчитаны усредненные значения для административных единиц Украины. Получен несущественный, в пределах 0―0,2 °С, рост средней температуры отопительного периода на большей части территории страны в современном десятилетии 2011―2020 гг. относительно базового периода 2001―2010 гг., сокращение продолжительности отопительного периода в среднем на 3 дня и уменьшение величины градусо-дней на 2―3 %. К середине XXI ст. существенно возрастут средние температуры отопительного периода с максимальными приростами в 1,5 °С на северо-востоке, в центре и на Левобережье и наименьшими, до 0,8 °С, — на юге, юго-западе и в Крыму. Продолжительность периода будет сокращаться на 15―18 суток, максимально на 20 суток на юге. Величины градусо-дней уменьшатся на большей части территории на 12―16 %, максимально в Крыму на 20 %, а минимальное снижение получено для Карпат — 9―12 %. Полученные в исследовании результаты можно использовать прежде всего для проведения расчетов расходов энергии на отопление и прочие потребности энергетического сектора, а также других отраслей экономики для общего развития инфраструктуры и разнообразных потребностей любого населенного пункта на территории Украины.У роботі представлений прогноз щодо збалансованого сценарієм А1В спеціалізованих кліматичних показників опалювального періоду для території України по десятиліттях до середини XXI ст. Прогноз середньої температури, тривалості та величини градусо-днів складено на розрахунках ансамблю 10 регіональних кліматичних моделей Європейського проекту ENSEMBLES, попередньо сформованого і адаптованого для України. Розраховані в усіх вузлах регулярної сітки 25₅25 км основні та спеціалізовані кліматичні показники були верифіковані даними Е-Оbs для періоду 2001-2010 рр. Виявлено незначна похибка середньої температури опалювального періоду, усереднене значення якої на всій території менше 0,01 ° С, і прийнятна похибка тривалості з середнім значенням менше 6,4 дня (<4%), що в результаті дозволило отримати осредненную похибка градусо-днів близько 4%. Прогнозування на майбутні періоди спеціалізованих показників опалювального сезону проводилося з урахуванням отриманих в базовому періоді помилок. Проаналізовано просторово-часові зміни показників опалювального періоду по десятиліттях до середини XXI ст. і розраховані усереднені значення для адміністративних одиниць України. Отримано несуттєвий, в межах 0-0,2 ° С, зростання середньої температури опалювального періоду на більшій частині території країни в сучасному десятилітті 2011-2020 рр. щодо базового періоду 2001-2010 рр., скорочення тривалості опалювального періоду в середньому на 3 дні і зменшення величини градусо-днів на 2-3%. До середини XXI ст. істотно зростуть середні температури опалювального періоду з максимальними приростами в 1,5 ° С на північному сході, в центрі і на Лівобережжі та найменшими, до 0,8 ° С, - на півдні, південному заході та в Криму. Тривалість періоду буде скорочуватися на 15-18 діб, максимально на 20 діб на півдні. Величини градусо-днів зменшаться на більшій частині території на 12-16%, максимально в Криму на 20%, а мінімальне зниження отримано для Карпат - 9-12%. Отримані в дослідженні результати можна використовувати перш за все для проведення розрахунків витрат енергії на опалення та інші потреби енергетичного сектора, а також інших галузей економіки для загального розвитку інфраструктури та різноманітних потреб будь-якого населеного пункту на території України

Identification of Novel Molecular Targets for Endometrial Cancer Using a Drill-Down LC-MS/MS Approach with iTRAQ

BACKGROUND: The number of patients with endometrial carcinoma (EmCa) with advanced stage or high histological grade is increasing and prognosis has not improved for over the last decade. There is an urgent need for the discovery of novel molecular targets for diagnosis, prognosis and treatment of EmCa, which will have the potential to improve the clinical strategy and outcome of this disease. METHODOLOGY AND RESULTS: We used a "drill-down" proteomics approach to facilitate the identification of novel molecular targets for diagnosis, prognosis and/or therapeutic intervention for EmCa. Based on peptide ions identified and their retention times in the first LC-MS/MS analysis, an exclusion list was generated for subsequent iterations. A total of 1529 proteins have been identified below the Proteinpilot® 5% error threshold from the seven sets of iTRAQ experiments performed. On average, the second iteration added 78% new peptides to those identified after the first run, while the third iteration added 36% additional peptides. Of the 1529 proteins identified, only 40 satisfied our criteria for significant differential expression in EmCa in comparison to normal proliferative tissues. These proteins included metabolic enzymes (pyruvate kinase M2 and lactate dehydrogenase A); calcium binding proteins (S100A6, calcyphosine and calumenin), and proteins involved in regulating inflammation, proliferation and invasion (annexin A1, interleukin enhancer-binding factor 3, alpha-1-antitrypsin, macrophage capping protein and cathepsin B). Network analyses revealed regulation of these molecular targets by c-myc, Her2/neu and TNF alpha, suggesting intervention with these pathways may be a promising strategy for the development of novel molecular targeted therapies for EmCa. CONCLUSIONS: Our analyses revealed the significance of drill-down proteomics approach in combination with iTRAQ to overcome some of the limitations of current proteomics strategies. This study led to the identification of a number of novel molecular targets having therapeutic potential for targeted molecular therapies for endometrial carcinoma

Modelling imperfect adherence to HIV induction therapy

Abstract Background Induction-maintenance therapy is a treatment regime where patients are prescribed an intense course of treatment for a short period of time (the induction phase), followed by a simplified long-term regimen (maintenance). Since induction therapy has a significantly higher chance of pill fatigue than maintenance therapy, patients might take drug holidays during this period. Without guidance, patients who choose to stop therapy will each be making individual decisions, with no scientific basis. Methods We use mathematical modelling to investigate the effect of imperfect adherence during the inductive phase. We address the following research questions: 1. Can we theoretically determine the maximal length of a possible drug holiday and the minimal number of doses that must subsequently be taken while still avoiding resistance? 2. How many drug holidays can be taken during the induction phase? Results For a 180 day therapeutic program, a patient can take several drug holidays, but then has to follow each drug holiday with a strict, but fairly straightforward, drug-taking regimen. Since the results are dependent upon the drug regimen, we calculated the length and number of drug holidays for all fifteen protease-sparing triple-drug cocktails that have been approved by the US Food and Drug Administration. Conclusions Induction therapy with partial adherence is tolerable, but the outcome depends on the drug cocktail. Our theoretical predictions are in line with recent results from pilot studies of short-cycle treatment interruption strategies and may be useful in guiding the design of future clinical trials

A Stochastic Model of Latently Infected Cell Reactivation and Viral Blip Generation in Treated HIV Patients

Motivated by viral persistence in HIV+ patients on long-term anti-retroviral treatment (ART), we present a stochastic model of HIV viral dynamics in the blood stream. We consider the hypothesis that the residual viremia in patients on ART can be explained principally by the activation of cells latently infected by HIV before the initiation of ART and that viral blips (clinically-observed short periods of detectable viral load) represent large deviations from the mean. We model the system as a continuous-time, multi-type branching process. Deriving equations for the probability generating function we use a novel numerical approach to extract the probability distributions for latent reservoir sizes and viral loads. We find that latent reservoir extinction-time distributions underscore the importance of considering reservoir dynamics beyond simply the half-life. We calculate blip amplitudes and frequencies by computing complete viral load probability distributions, and study the duration of viral blips via direct numerical simulation. We find that our model qualitatively reproduces short small-amplitude blips detected in clinical studies of treated HIV infection. Stochastic models of this type provide insight into treatment-outcome variability that cannot be found from deterministic models

Models of general circulation of the atmosphere and oceans in forecasting changes in the regional climate of Ukraine in the 21st century.

For the first time quantitative characteristics of probable climate changes in Ukraine during the 21st century for three SRES emission scenarios B1, A1B and A2 have been obtained from an analysis of 84 runs of 10 Atmosphere-Ocean General Circulation Models (AOGCM) used for AR4 IPCC-2007. The analysis of AOGCM’s results has shown that projected differences of the averaged over the territory of Ukraine surface temperatures of the ending and the first decades of the 21st century will be in limits: B1 - from 0,7 to 3,0 °С with ensemble mean 2,0±0,8 °С; А1В - from 2,4 to 4,2 °С with mean 3,1±0,7 °С; and А2 - from 2,6 to 4,6 °С with mean 3,8±0,8 °С. There is not such an agreement for precipitation variations during the 21st century between AOGCMs, and precipita-tion changes vary from -23,4 to +11,6 % up to the end of the 21st century comparing to 2001-2010. Therefore, more detailed precipitation change projections for the territory of Ukraine could be made only with regional climate models. The most rapid changes of surface temperature and precipita-tion have been obtained in AOGCMs for А2 scenario, the slowest - for В1 respectively. The model ECHAM5/MPI-OM has been determined as the most successful AOGCM in simulation of climate of Ukraine because statistical analysis has shown that differences of its results with ensemble mean were minimal. Results of this model could be recommended as initial and boundary conditions for simulation of climate of Ukraine with regional climate models

Role of moesin in hyaluronan induced cell migration in glioblastoma multiforme

Abstract Background A major barrier to effective treatment of glioblastoma multiforme (GBM) is the invasion of glioma cells into the brain parenchyma rendering local therapies such as surgery and radiation therapy ineffective. GBM patients with such highly invasive and infiltrative tumors have poor prognosis with a median survival time of only about a year. However, the mechanisms leading to increased cell migration, invasion and diffused behavior of glioma cells are still poorly understood. Methods In the current study, we applied quantitative proteomics for the identification of differentially expressed proteins in GBMs as compared to non-malignant brain tissues. Results Our study led to the identification of 23 proteins showing overexpression in GBM; these include membrane proteins, moesin and CD44. The results were verified using Western blotting and immunohistochemistry in independent set of GBM and non-malignant brain tissues. Both GBM tissues and glioma cell lines (U87 / U373) demonstrated membranous expression of moesin and CD44, as revealed by immunohistochemistry and immunofluorescence, respectively. Notably, glioma cells transfected with moesin siRNA displayed reduced migration and invasion on treatment with hyaluronan (HA), an important component of the extracellular matrix in GBM. CD44, a transmembrane glycoprotein, acts as a major receptor for hyaluronan (HA). Using co-immunoprecipitation assays, we further demonstrated that moesin interacts with CD44 in glioma cells only after treatment with HA; this implicates a novel role of moesin in HA-CD44 signaling in gliomas. Conclusions Our results suggest that development of inhibitors which interfere with CD44-moesin interactions may open a new avenue in the future to mitigate cellular migration in gliomas