The stability of decelerating shocks revisited

We present a new method for analyzing the global stability of the Sedov-von Neumann-Taylor self-similar solutions, describing the asymptotic behavior of spherical decelerating shock waves, expanding into ideal gas with density \propto r^{-\omega}. Our method allows to overcome the difficulties associated with the non-physical divergences of the solutions at the origin. We show that while the growth rates of global modes derived by previous analyses are accurate in the large wave number (small wavelength) limit, they do not correctly describe the small wave number behavior for small values of the adiabatic index \gamma. Our method furthermore allows to analyze the stability properties of the flow at early times, when the flow deviates significantly from the asymptotic self-similar behavior. We find that at this stage the perturbation growth rates are larger than those obtained for unstable asymptotic solutions at similar [\gamma,\omega]. Our results reduce the discrepancy that exists between theoretical predictions and experimental results.Comment: 10 pages, 9 figures. Accepted to ApJ; Expanded discussion of boundary condition

Student’s Learning Profile as a Tool of Personal Learning Logistics

Increase of complexity and uncertainty as well as demand for personalization (including in education) urges universities to pay attention to educational subjectivity and its development; to transfer towards individual / collective-individual educational navigation and flexible systems of educational programs management (including formation of temporary learning groups, supply of required educational resources in due time, protocols of appraisal and mutual offset of educational results), what determines the relevance of the research. Usage of logistic approach enables to distinguish the pedagogical and management objectives of educational activity organization as well as to facilitate personalization of education. The article considers an educational profile as an instrument of personal educational logistics in digital educational environment, presents the preliminary terms “digital track”, “portfolio”, “profile”. The authors also dwell on the requirements to educational profiles development and scenarios of handling them in digital educational environment taking into account domestic and global experience of educational profiles’ implementation

A CLINICAL CASE OF CROHN’S DISEASE

The article demonstrates a clinical case of Crohn’s disease. The clinical manifestation of the disease, a diagnostic approach based on laboratory and instrumental methods with discussion of obtained results, and the up-to-date methods of investigation based on the literature data are shown. The significance of lifestyle modification, optimal drug treatment and regular check-ups for improvement of prognosis is emphasized

ДОСЛІДЖЕННЯ КОРМІВ НА НАЯВНІСТЬ КОМПОНЕНТІВ ТВАРИННОГО ПОХОДЖЕННЯ ТА БІЛКІВ ЖУЙНИХ ТВАРИН

A significant number of infectious diseases are transmitted from sick animals to humans, which causes a danger to their lives and health. Therefore, of great importance is continuous epizootological monitoring of the dynamics of the appearance and spread of infectious animal diseases and the analysis of the risks of introducing pathogens of particularly dangerous animal diseases into the territory of Ukraine. Diseases of prion etiology are currently the most dangerous for human health. In view of this, the main attention during the fight against prion diseases is paid to preventive measures, in particular the ban on the use of meat-and-bone or bone meal made from sheep that died and were sick with scrapie in livestock feed, as well as the slaughter of prion-infected ruminants. Since 2017, Ukraine has been implementing the Program for determining the status of Ukraine as a country with a controlled risk of bovine spongiform encephalopathy (BSE), approved by the Order of the State Production and Consumer Service № 258 dated April 14, 2017. One of the basic elements of the program is the monitoring of feeds. In accordance with the Plan for State Monitoring of Fodder for Ruminant Animals in 2023, research was conducted on 120 samples of fodder from different regions of Ukraine. In accordance with Commission Regulation (EU) № 51/2013 and Commission Regulation № 1560/2020, the determination of ingredients of animal origin in feed is carried out using a combination of light microscopy and real-time polymerase chain reaction (PCR-RT). The presence of components of animal origin (meat and bone, bone, meat meal, etc.) was not detected during the examination of fodder by light microscopy. When examining feed by the PCR method, the presence of ruminant DNA was detected in only two samples. When examining feed by the PCR method, the presence of ruminant DNA was detected in two samples. However, when reviewing the accompanying documents, it was established that the manufacturer declared the introduction of dry milk into the feed. By the EU Regulation and Instruction № 180 dated 04.09.2008, approved by the order of the State Veterinary Medicine Committee of Ukraine, ruminants are allowed to feed such fodder.Значна кількість інфекційних захворювань передається від хворих тварин до людини, що становить загрозу її життю та здоров’ю. Тому проведення безперервного епізоотологічного нагляду за динамікою прояву і розповсюдженням інфекційних хвороб тварин, аналізу ризиків занесення збудників особливо небезпечних хвороб тварин на територію України має велике значення. Найнебезпечнішими для здоров’я людства нині є захворювання пріонної етіології. З огляду на це, основна увага під час боротьби з пріонними захворюваннями акцентується на запобіжних заходах, зокрема забороні використання у годівлі худоби м’ясо-кісткового чи кісткового борошна, виготовленого із загиблих, які хворіли на скрепі овець, а також забій заражених пріонами жуйних тварин. З 2017 року в Україні реалізується Програма визначення статусу України, як країни з контрольованим ризиком щодо губчастоподібної енцефалопатії великої рогатої худоби, затверджена наказом Держпродспоживслужби від 14.04.2017 р. № 258. Одним з базових елементів Програми є проведення моніторингу кормів. Відповідно до Плану державного моніторингу кормів для жуйних тварин у 2023 році було проведено дослідження 120 зразків кормів з різних регіонів України. Відповідно до Регламенту Комісії (ЄС) № 51/2013 та імплементованого Регламенту Комісії № 1560/2020, визначення інгредієнтів тваринного походження в кормах здійснюється на поєднанні методу світлової мікроскопії та полімеразної ланцюгової реакції в реальному часі (ПЛР-РЧ). При дослідженні кормів методом світлової мікроскопії наявність компонентів тваринного походження (м'ясо-кісткове, кісткове, м'ясне борошно тощо) не виявлено. При дослідженні кормів методом ПЛР у двох зразках виявлено наявність ДНК жуйних. Однак, при ознайомленні із супровідними документами, встановили, що виробник декларує внесення у корм сухого молока. Відповідно до Регламенту ЄС та Інструкції № 180 від 04.09.2008 р., затвердженою наказом Державного комітету ветеринарної медицини України жуйним тваринам дозволяється згодовувати такі корми

Hydroclimate Variability and Change in the Prairie Pothole Region, the “Duck Factory” of North America

The Prairie Pothole Region (PPR) of the northern Great Plains is a vital ecosystem responsible each year for producing 50%–80% of new recruits to the North American duck population. Climate variability and change can impact the hydrology and ecology of the region with implications for waterfowl populations. The historical relationship between PPR wetlands, duck populations, and seasonal hydroclimate are explored. Model experiments from phase 5 of the Coupled Model Intercomparison Project are used to determine whether a recent wetting trend is due to natural variability or changing climate and how PPR hydroclimate will change into the future. Year-to-year variations in May duck populations, pond numbers, and the Palmer drought severity index are well correlated over past decades. Pond and duck numbers tend to increase in spring following La Niña events, but the correlation is not strong. Model simulations suggest that the strengthening of the precipitation gradient across the PPR over the past century is predominantly due to natural variability and therefore could reverse. Model projections of future climate indicate precipitation will increase across the PPR in all seasons except summer, but this gain for surface moisture is largely offset by increased evapotranspiration because of higher temperatures and increased atmospheric evaporative demand. In summer, the combined effects of warming and precipitation changes indicate seasonal surface drying in the future. The presented hydroclimate analyses produce potential inputs to ecological and hydrological simulations of PPR wetlands to inform risk analysis of how this North American waterfowl habitat will evolve in the future, providing guidance to land managers facing conservation decisions

Mesoscopic scattering of spin s particles

Quantum effects in weakly disordered systems are governed by the properties of the elementary interaction between propagating particles and impurities. Long range mesoscopic effects due to multiple scattering are derived by iterating the single scattering vertex, which has to be appropriately diagonalized. In the present contribution, we present a systematic and detailed diagonalisation of the diffuson and cooperon vertices responsible for weak localisation effects. We obtain general expressions for eigenvalues and projectors onto eigenmodes, for any spin and arbitrary elementary interaction with impurities. This description provides a common frame for a unified theory of mesoscopic spin physics for electrons, photons, and other quantum particles. We treat in detail the case of spin-flip scattering of electrons by freely orientable magnetic impurities and briefly review the case of photon scattering from degenerate dipole transitions in cold atomic gases.Comment: published version, with a new figure and new section

Changes in the reactivity of the vertebrobasilar arteries when using glucose-electrolyte drink with antioxidant plant extracts during submaximal exercise test

The aim. To assess the effect of glucose-electrolyte composition with plant extracts having antioxidant activity on the hemodynamic parameters of vertebrobasilar system during the incrementally increasing submaximal exercise test.Materials and methods. The study included 12 athletes (6 candidates for master of sports and 6 masters of sports) aged 18–22, who have been engaged in orienteering for 10 years and more. Time of aerobic exercise – 2 hours a day, five days a week. The study subjects performed an incrementally increasing submaximal exercise test and also submaximal exercise test with the preventive intake of a glucose-electrolyte composition with plant extracts having antioxidant properties. To assess the hemodynamic parameters in all study subjects we used Doppler ultrasound of the cerebral vessels, evaluating vertebrobasilar system blood flow, exercise gas test in the modification of hypo- and hyperventilation, and also positional test.Results. A single intake of glucose-electrolyte drink under conditions of incrementally increasing exercise test contributed to the manifestation of a homeostatic effect in hemodynamic parameters of the vertebrobasilar arteries. It is evidenced by the approximation to the pre-exercise level of maximum systolic velocity and average blood velocity in the breath-holding test, of the diastolic blood velocity in the hyperventilation test, and of the pulsatility index in the torsion test, as compared to the isolated submaximal exercise test which caused the change in both velocity indicators and calculated indices during the functional tests.The article considers the main mechanisms underlying the change in arterial hemodynamic parameters caused by incrementally increasing load, as well as describes the proposed mechanisms arising from the combined effect of an incrementally increasing load and the intake of a glucose-electrolyte composition with plant extracts having antioxidant activity.Conclusion. It was shown that using glucose-electrolyte drink contributed to the restoration of hemodynamic parameters of the vertebrobasilar arteries after an incrementally increasing submaximal exercise test

Терапевтический потенциал куркумина для лечения мультиформной глиобластомы

Glioblastoma multiforme (GBM), a grade IV astrocytoma, is the most common and deadly type of primary malignant brain tumor, with a patien’s median survival rate ranging from 12 to 15 months. Over the last fifteen years, the treatment for GBM has included maximal safe surgical resection with combination radiotherapy and adjuvant temozolomide chemotherapy. The low efficacy of mentioned therapies has forced researchers to explore an appropriate alternative or complementary treatment for GBM. It has been shown that curcumin has therapeutic potentials to fight against GBM via affecting on cell proliferation, apoptosis, cell cycle, invasion and angiogenesis pathways. In addition, curcumin possess a synergistic impact with chemotherapeutic agents. Herein, we summarized the current findings on curcumin as potential therapeutic agent in the treatment of GBM.Мультиформная глиобластома (МГБ), астроцитома IV степени, является наиболее распространенным и смертельно опасным типом первичной злокачественной опухоли головного мозга с медианой выживаемости 12–15 мес. Последние 15 лет терапия МГБ включает максимально безопасную хирургическую резекцию в комбинации с лучевой терапией и адъювантной химиотерапией темозоломидом. Низкая эффективность упомянутых методов лечения вынуждает исследователей искать подходящее альтернативное или дополнительное лечение МГБ. Было показано, что куркумин имеет терапевтический потенциал для борьбы с МГБ, воздействуя на пролиферацию клеток, апоптоз, клеточный цикл, инвазию и ангиогенные сигнальные пути. Кроме этого, куркумин обладает синергическим эффектом с химиотерапевтическими препаратами. Здесь мы суммировали текущие данные о курку мине как потенциальном терапевтическом агенте для лечения МГБ