Formation of plasma around a small meteoroid: 1. Kinetic theory

This article is a companion to Dimant and Oppenheim [2017] https://doi.org/10.1002/2017JA023963.This paper calculates the spatial distribution of the plasma responsible for radar head echoes by applying the kinetic theory developed in the companion paper. This results in a set of analytic expressions for the plasma density as a function of distance from the meteoroid. It shows that at distances less than a collisional mean free path from the meteoroid surface, the plasma density drops in proportion to 1/R where R is the distance from the meteoroid center; and, at distances much longer than the mean‐free‐path behind the meteoroid, the density diminishes at a rate proportional to 1/R2. The results of this paper should be used for modeling and analysis of radar head echoes.This work was supported by NSF grant AGS-1244842. (AGS-1244842 - NSF

Study of the activity of sunflower honey against a mixed microbial association isolated from bees with signs of dyspepsia in laboratory conditions

Beekeeping is one of the essential branches of agriculture in Ukraine, the main activity of which is aimed at breeding bees and obtaining honey and other products beneficial for human health. Maintaining the physiological state of bee colonies at the proper level is one of the essential tasks of veterinary medicine doctors and beekeepers. Compliance with veterinary and sanitary requirements at bee farms is the basis of preventing infectious pathologies in bee colonies. Since the body of insects has a fast metabolism, any infectious pathology quickly acquires a massive manifestation. One indicative symptom of infectious damage to the “gut” of bees is dyspepsia. Diarrhea, anorexia, and loss of productivity are observed in bees in this condition. The market of means to prevent such pathological manifestations in beekeeping is relatively narrow. The healing and favorable properties of honey, manifested in pain-relieving, antimicrobial and anti-inflammatory effects, have been known since ancient times. Sunflower honey differs from other types in a wide range of components, particularly phytoncides, which inhibit the growth of pathogenic microorganisms. Therefore, the main goal of the experiment was a laboratory study of the effect of different concentrations of sunflower honey sieve on the mixed microbial association isolated from bees with signs of dyspepsia. The activity of sunflower honey in laboratory conditions was studied by the disco-diffusion method in Petri dishes on MPA medium (meat-peptone agar). To obtain syrup from sunflower honey, sunflower honey was diluted with distilled water in a ratio of 1:1, working solutions were prepared from sunflower honey syrup in dilutions of 1:2, 1:4, 1:10, 1:100. The data analysis indicates the bacteriostatic activity of the syrup from sunflower honey in all studied concentrations concerning the mixed microbial association. Moreover, the largest diameter of the growth inhibition zone of the studied microorganisms was noted when the syrup from sunflower honey was diluted in a ratio of 1:10 (19.2 ± 0.42 mm). In turn, the antagonistic effect of the syrup from sunflower honey was observed in all dilutions concerning the mixed microbial association, where the largest diameter of the antagonism was 19.6 ± 0.27 mm when the disc was impregnated with the native working solution. Thus, it is promising to accumulate and identify a pure culture antagonist concerning a mixed culture of bacteria isolated during bee diarrhea to further create a pharmacological agent for preventing infectious pathologies of bees in unhealthy apiaries

Encounter complexes and dimensionality reduction in protein-protein association

An outstanding challenge has been to understand the mechanism whereby proteins associate. We report here the results of exhaustively sampling the conformational space in protein–protein association using a physics-based energy function. The agreement between experimental intermolecular paramagnetic relaxation enhancement (PRE) data and the PRE profiles calculated from the docked structures shows that the method captures both specific and non-specific encounter complexes. To explore the energy landscape in the vicinity of the native structure, the nonlinear manifold describing the relative orientation of two solid bodies is projected onto a Euclidean space in which the shape of low energy regions is studied by principal component analysis. Results show that the energy surface is canyon-like, with a smooth funnel within a two dimensional subspace capturing over 75% of the total motion. Thus, proteins tend to associate along preferred pathways, similar to sliding of a protein along DNA in the process of protein-DNA recognition

МОНІТОРИНГ РЕАКЦІЇ ЯЧМЕНЮ ЯРОГО НА УДОБРЕННЯ ФОСФОАЗОТИНОМ

The influence of fertilizer on the growth and development of spring barley has been studied and the influence of phosphoazotine on the productivity and quality of spring barley grain has been analyzed and the efficiency of using the proposed fertilizer system has been established.One of the conditions for intensive agriculture at the present stage is the optimal management of nutrients and creating their active balance through the use of mineral fertilizers in the implementation of programmed yield levels based on a clear implementation of science-based system (model) measures and technologies for enhanced soil fertility reproduction. regional conditions.The genetic potential of modern varieties of cereals, including spring barley, has crossed the 10 t / ha mark. However, due to insufficient study of the biological characteristics of these varieties, lack of mineral fertilizers and financial resources, as well as changes in weather and climatic conditions, the realization of genetic potential reaches barely 40-50%. One of the important factors that significantly affect the productivity of cereals is the optimal fertilizer system.The agrochemical and economic feasibility of fertilizing spring barley with phosphoazitin has been proved and the optimal doses of fertilizers for this crop on sod-podzolic sandy soils of the Western Polissya of Ukraine have been established.Meat waste can be a valuable fertilizer due to its high protein content. This is one of the promising measures to reduce the amount of nitrogen and phosphorus fertilizers. One ton of this fertilizer is close to 5 tons of manure.The positive effect of this fertilizer must be supplemented with mineral fertilizers. But in conditions of high prices for fertilizers, even partial replacement can give significant savings.Numerous studies show that the productivity of spring barley depends on its growth and development during the growing season. Given this, we were faced with the task of studying the effect of fertilizers on the growth and development of spring barley plants. Structural analysis data show that yield structure indicators also depended on fertilizer systems.Досліджений вплив удобрення на ріст і розвиток ячменю ярого та проаналізований вплив фосфоазотину на продуктивність та якість зерна ячменю ярого і встановлена ефективність використання запропонованої системи удобрення.Доведено агрохімічну та економічну доцільність удобрення ячменю ярого фосфоазитином та встановлені оптимальні дози застосування добрив під дану культуру на дерново-підзолистих супіщаних ґрунтах Західного Полісся України.Генетичний потенціал сучасних сортів зернових культур, у тому числі ярого ячменю, перевищив позначку в 10 т/га. Однак через недостатню вивченість біологічних особливостей цих сортів, нестачу мінеральних добрив і фінансових ресурсів, а також зміну погодно-кліматичних умов реалізація генетичного потенціалу досягає ледве 40–50%. Одним із важливих факторів, що істотно впливають на продуктивність зернових культур, є оптимальна система удобрення.Доведено агрохімічну та економічну доцільність підживлення ярого ячменю фосфоазитином та встановлено оптимальні дози добрив для цієї культури на дерново-підзолистих піщаних ґрунтах Західного Полісся України.М’ясні відходи можуть бути цінним добривом завдяки високому вмісту білка. Це один із перспективних заходів щодо зменшення кількості азотних і фосфорних добрив. Одна тонна цього добрива – це близько 5 тон гною.Позитивну дію цього добрива необхідно доповнити мінеральними добривами. Але в умовах високих цін на добрива навіть часткова заміна може дати значну економію.Численні дослідження показують, що продуктивність ярого ячменю залежить від його росту та розвитку протягом вегетації. З огляду на це перед нами постало завдання вивчення впливу добрив на ріст і розвиток рослин ярого ячменю. Дані структурного аналізу показують, що показники структури врожайності також залежали від систем внесення добрив

Epitaxial growth of Cu on Cu(001): experiments and simulations

A quantitative comparison between experimental and Monte Carlo simulation results for the epitaxial growth of Cu/Cu(001) in the submonolayer regime is presented. The simulations take into account a complete set of hopping processes whose activation energies are derived from semi-empirical calculations using the embedded-atom method. The island separation is measured as a function of the incoming flux and the temperature. A good quantitative agreement between the experiment and simulation is found for the island separation, the activation energies for the dominant processes, and the exponents that characterize the growth. The simulation results are then analyzed at lower coverages, which are not accessible experimentally, providing good agreement with theoretical predictions as well.Comment: Latex document. 7 pages. 3 embedded figures in separate PS files. One bbl fil

Effective Lagrangian for strongly coupled domain wall fermions

We derive the effective Lagrangian for mesons in lattice gauge theory with domain-wall fermions in the strong-coupling and large-N_c limits. We use the formalism of supergroups to deal with the Pauli-Villars fields, needed to regulate the contributions of the heavy fermions. We calculate the spectrum of pseudo-Goldstone bosons and show that domain wall fermions are doubled and massive in this regime. Since we take the extent and lattice spacing of the fifth dimension to infinity and zero respectively, our conclusions apply also to overlap fermions.Comment: 26 pp. RevTeX and 3 figures; corrected error in symmetry breaking scheme and added comments to discussio

Chiral perturbation theory at O(a^2) for lattice QCD

We construct the chiral effective Lagrangian for two lattice theories: one with Wilson fermions and the other with Wilson sea fermions and Ginsparg-Wilson valence fermions. For each of these theories we construct the Symanzik action through order $a^2$. The chiral Lagrangian is then derived, including terms of order $a^2$, which have not been calculated before. We find that there are only few new terms at this order. Corrections to existing coefficients in the continuum chiral Lagrangian are proportional to $a^2$, and appear in the Lagrangian at order $a^2 p^2$ or higher. Similarly, O(4) symmetry breaking terms enter the Symanzik action at order $a^2$, but contribute to the chiral Lagrangian at order $a^2 p^4$ or higher. We calculate the light meson masses in chiral perturbation theory for both lattice theories. At next-to-leading order, we find that there are no order $a^2$ corrections to the valence-valence meson mass in the mixed theory due to the enhanced chiral symmetry of the valence sector.Comment: 25 pages, LaTeX2e; references adde

Vortex State of Tl2_2Ba2_2CuO6+δ_{6+\delta} via 205^{205}Tl NMR at 2 Tesla

We report a $^{205}$Tl NMR study of vortex state for an aligned polycrystalline sample of an overdoped high-$T_c$ superconductor Tl$_2$Ba$_2$CuO$_{6+\delta}$ ($T_{c}\sim$85 K) with magnetic field 2 T along the c axis. We observed an imperfect vortex lattice, so-called Bragg glass at $T$=5 K, coexistence of vortex solid with liquid between 10 and 60 K, and vortex melting between 65 and 85 K. No evidence for local antiferromagnetic ordering at vortex cores was found for our sample.Comment: 4 pages with 5 figure

Religious beliefs and entrepreneurial behaviours in Africa: a case study of the informal sector in Uganda

Religion plays a major role in Africa’s polity and its influence on the business landscape of the continent has been acknowledged in literature. This study contributes to the discourse by investigating and explaining how religious beliefs shape entrepreneurial behaviours in Uganda’s informal sector. Using a qualitative methodology, we explored how entrepreneurs in the context use or adopt religious beliefs in their entrepreneurial activities. By spanning a diverse set of entrepreneurial activities in the informal sector- food vendors, fabricators, hawkers, and recyclers among others, we conducted 49 in-depth interviews. Our findings reveal that the entrepreneurs relied on their religious beliefs in defining and coping with a penurious context. Further to this, we explain how religious beliefs galvanize business behaviours and calibrate the entrepreneurial identities of respondents in the context. To facilitate future work, the study highlights how knowledge gaps in the cultural and social setup of the informal economy will produce new insights in entrepreneurship research. It concludes by guiding policy makers and educators to engage and involve faith based institutions in the entrepreneurship promotion agenda