Edge Effect: Growth and Morphogenetic Features of Scots Pine Trees in Forest Parks and Natural Stands

The degree of development and depth of edge effect are studied in some fragments of forest-park stands under long-term urbanization impact (in the city of Yekaterinburg, Russia) and in natural forests using the method of transect investigation. The method of quantitative assessment of tree stem and crown growth features by a set of morphological characteristics was used. The objects of the research included the edges of Scots pine stands. The edge effect was determined by two of the five studied characteristics: foliation and branchiness, which characterize the level of the development of the tree assimilation apparatus. The general trends indicate an increase in the development of these characters in natural stands and decrease in the forest park at increased distance from the edge. The nonlinear development of morphological characteristics along the transects is due to different types of tree responses on the impact of determining morphogenesis factors. Four statistically significant different zones were identified in the natural stands at distances of 0-75, 100-125, 150-175, and 200-225 m from the forest edge and only two zones were differentiated in the forest park. The unified approach to data analysis suggests the edge effect in both habitats at a distance of 75-100 m from the forest edge according to branchiness and 100-125 m according to foliation. Several types of morphogenetic tree responses, distinguished by the degree of foliation and branchiness variation under edge effect impact, are revealed.This study was supported by the Integrated Program of the Ural Branch of the Russian Academy of Sciences for 2018-2020 (grant no. 18-4-4-10) and performed under the State Assignment of the Botanical Garden, Ural Branch, Russian Academy of Sciences

Dynamics of Branch and Stem Apical Growth in the Progenies of Plus Pine Trees (Pinus sylvestris L.)

The relationship between the characteristics of the linear growth of branches and stems was studied, as well as the possibility of distinguishing between various Scots pine (Pinus sylvestris L.) genotypes. The objects of research were experimental plantations of the half-sib progenies of pine plus trees aged 10–11 years. The annual increments of the stem and differently oriented branches were measured. Correlation, regression and data analysis methods developed by the authors were used. The time dynamics of the obtained values were studied by comparing the regression line slopes describing the interrelation of axial increments and by analysis of the frequency spectra of the Integral Parameter of Characters Sequence applied earlier. The analysisof the obtained results has shown the existence of a significant relationship between auxiblast linear growth within the two adjacent years and a weak interrelation of the characteristics of branch and stem morphogenesis. The possibility of distinguishing Scots pine half-sib families by comparing the dynamics of branches and stem apical growth is described. Keywords: Scots pine, apical growth of branches and stems, genotypic and phenotypic variability, impact of environmental factors on growth, morphogenesis of woody plants, growth modelin

Seasonal changes in chlorophyll and carotenoid content in needles of scots pines (pinus sylvestris l.) Exposed to the thermal field of a gas flare

Seasonal changes in chlorophyll (Chl) and carotenoid (Car) content were analyzed in needle samples from young Scots pines (Pinus sylvestris L.) growing in the thermal field zone at various distances from the petroleum gas flare. Experiments were performed in Khanty Mansi Autonomous Area (Yugra) of Russia throughout the autumn–winter–spring period. Two hypotheses were subject to verification: (1) the thermal field of petroleum gas combustion flame imitates the influence of climate warming on plants, thus affecting the pigment complex of the photosynthetic apparatus (PSA) in pine needles; (2) transformations of PSA pigment complex in pine needles throughout the autumn–winter–spring period are sensitive to a long-term rise in ambient temperature by 1–2°С. In the winter period, the seasonal dynamics of certain PSA parameters comprised maxima and minima that are supposedly due to the regulation of Chl and Car content upon changes in air temperature. In trees growing under divergent thermal conditions, seasonal changes of these parameters were not synchronous. Analysis of seasonal changes revealed that winter-related transformations of the PSA structural–functional condition in needles are subject to consistent variations at different distances from the gas flame. The PSA activity of needles throughout the studied period was higher near the flame and decreased with the distance from the gas flare. When Chl content in needles decreased in autumn–winter, the smallest reduction was observed in the location near the gas flare (site I) where temperature was 1–2°C higher than the background level. The intermediate decrease in pigment content was noted at a moderate distance from the flame (site III), while the most pronounced decrease occurred at the largest distance from the gas flare (site VII). At the same time, the Chl a/b content ratio in needles was consistently lower for trees located at site I than at site VII. Hence, the amount of light-harvesting complexes in chloroplasts from trees grown at site I was higher than the amount of photosystems in the same chloroplasts. The Chl (a + b)/Car ratio in needles of trees grown near the gas flare (site I) was higher than in locations III and VII. This ratio displayed two significant peaks in the winter dynamics, which was supposedly due to the sufficient preservation of green pigments. Divergent seasonal changes in Chl and Car content and their dissimilar correlations with air temperature indicate that the pools of these pigments are controlled by different mechanisms. The actual Chl content, determined by the balance of pigment degradation and synthesis, should depend on the environmentally modified Chl synthesis and on the protective function of Car. Photosynthesizing cells produce additional amounts of carotenoids during autumn–winter, thus preventing the photodegradation of Chl in the period from autumn to late spring. © 2021, Pleiades Publishing, Ltd.This work was supported by the Comprehensive Program of the Ural Branch of the Russian Academy of Sciences for 2018–2020 (project no. 18-4-4-10) and by a state assignment to the Institute Botanic Garden of the Ural Branch of the Russian Academy of Sciences

On the superfluidity of classical liquid in nanotubes

In 2001, the author proposed the ultra second quantization method. The ultra second quantization of the Schr\"odinger equation, as well as its ordinary second quantization, is a representation of the N-particle Schr\"odinger equation, and this means that basically the ultra second quantization of the equation is the same as the original N-particle equation: they coincide in 3N-dimensional space. We consider a short action pairwise potential V(x_i -x_j). This means that as the number of particles tends to infinity, $N\to\infty$, interaction is possible for only a finite number of particles. Therefore, the potential depends on N in the following way: $V_N=V((x_i-x_j)N^{1/3})$. If V(y) is finite with support $\Omega_V$, then as $N\to\infty$ the support engulfs a finite number of particles, and this number does not depend on N. As a result, it turns out that the superfluidity occurs for velocities less than $\min(\lambda_{\text{crit}}, \frac{h}{2mR})$, where $\lambda_{\text{crit}}$ is the critical Landau velocity and R is the radius of the nanotube.Comment: Latex, 20p. The text is presented for the International Workshop "Idempotent and tropical mathematics and problems of mathematical physics", Independent University of Moscow, Moscow, August 25--30, 2007 and to be published in the Russian Journal of Mathematical Physics, 2007, vol. 15, #

Sn delta-doping in GaAs

We have prepared a number of GaAs structures delta-doped by Sn using the well-known molecular beam epitaxy growth technique. The samples obtained for a wide range of Sn doping densities were characterised by magnetotransport experiments at low temperatures and in high magnetic fields up to 38 T. Hall-effect and Shubnikov-de Haas measurements show that the electron densities reached are higher than for other delta-dopants, like Si and Be. The maximum carrier density determined by the Hall effect equals 8.4x10^13 cm^-2. For all samples several Shubnikov-de Haas frequencies were observed, indicating the population of multiple subbands. The depopulation fields of the subbands were determined by measuring the magnetoresistance with the magnetic field in the plane of the delta-layer. The experimental results are in good agreement with selfconsistent bandstructure calculations. These calculation shows that in the sample with the highest electron density also the conduction band at the L point is populated.Comment: 11 pages text (ps), 9 figures (ps), submitted to Semicon. Science Tech

КОМПЬЮТЕРНОЙ ТОМОГРАФИИ В МЕДИЦИНСКИХ ОРГАНИЗАЦИЯХ САНКТ-ПЕТЕРБУРГА И ЛЕНИНГРАДСКОЙ ОБЛАСТИ

Were carried out the selective investigation of the adult patients exposure levels during radiological diagnostic  procedures  with  the  use  of  17  CT  scanners  in  15  medical  organizations  of  Saint-Petersburg  and Leningrad region in 2009–2012. We collected the data on technical parameters of the X-ray computed tomography examinations affecting the level of patient exposure. The effective doses were calculated for scanning of different areas of the patient's body (skull, thorax, abdomen and pelvis). Their mean values were in the range from 0,2 mSv to 31 mSv per examination. The highest doses were observed during the investigation of the abdomen and pelvis. Preliminary values of diagnostic reference levels are proposed for medical organizations of Saint-Petersburg andLeningrad region on the basis of investigation results. These values are defined as the 75% quantile in the distribution  of  dose  length  product  values.  Diagnostic  reference  levels  values  obtained  in  the  investigation  are comparable with the corresponding values currently accepted in the foreign medical practice.В г. Санкт-Петербурге и Ленинградской области в 2009–2012 гг. проведено выборочное региональное исследование уровней облучения взрослых пациентов при проведении рентгенологических диагностических процедур на 17 компьютерных томографах в 15 медицинских организациях. Собраны сведения о технических параметрах проведения рентгеновских компьютерно-томографических исследований, влияющих на уровень облучения пациента. Рассчитаны эффективные дозы при сканировании различных областей тела пациента (череп, грудная клетка, брюшная полость и таз). Их  значения  оказались  в  диапазоне  от  0,2  мЗв  до  31  мЗв  за  исследование.  Наибольшие  дозы  наблюдались при исследованиях брюшной полости и таза. Наименьшие дозы были при рентгеновских компьютерно-томографических исследованиях черепа. По результатам обследования предложены предварительные  значения  референтных  диагностических  уровней  для  медицинских  организаций г. Санкт-Петербурга и Ленинградской области. Эти значения определили как 75% квантиль распределения значений произведения дозы на длину сканирования. Значения референтных диагностических уровней, полученные в данной работе, оказались соизмеримыми в сравнении с соответствующими значениями, принятыми в настоящее время в зарубежной медицинской практике

Large-scale Samples Irradiation Facility at the IBR-2 Reactor in Dubna

The irradiation facility at the beam line no.3 of the IBR-2 reactor of the Frank Laboratory for Neutron Physics is described. The facility is aimed at irradiation studies of various objects with area up to 800 cm$^2$ both at cryogenic and ambient temperatures. The energy spectra of neutrons are reconstructed by the method of threshold detector activation. The neutron fluence and $\gamma$ dose rates are measured by means of alanine and thermoluminescent dosimeters. The boron carbide and lead filters or $(n/\gamma)$ converter provide beams of different ratio of doses induced by neutrons and photons. For the lead filter, the flux of fast neutrons with energy more than 0.1 MeV is $1.4 \cdot 10^{10}$ \fln and the neutron dose is about 96\% of the total radiation dose. For the $(n/\gamma)$ converter, the $\gamma$ dose rate is $\sim$500 Gy h$^{-1}$ which is about 85\% of the total dose. The radiation hardness tests of GaAs electronics and materials for the ATLAS detector to be put into operation at the Large Hadron Collider (LHC) have been performed successfully at this facility

Дополнения и изменения в оценке эффективных доз внешнего облучения пациентов при медицинских исследованиях

The current study was aimed at the justification and proposal of the supplements and corrections that are planned for the implementation in the updated version of the Methodical guidelines “Control of the effective doses of the patients from the X-ray examinations” (MU 2.6.1.2944-11). This study included estimation and/ or update of the values of the conversion coefficients from measurable dose characteristics (entrance-surface dose, dose-area product) to the effective dose for various X-ray examinations. Estimation of the updated conversion coefficients was based both on the home analytical and experimental studies based on the modern protocols of the X-ray examinations, and the results of the published data. Updated values of the conversion coefficients were presented for: fluoroscopic examinations of the gastro-intestinal tract with barium media for adult and pediatric patients; interventional examinations of the adult patients; computed tomography examinations for adult and pediatric patients; dental intraoral examinations. For the first time, the methods of the estimation of the effective dose and corresponding conversion coefficients were presented for: computed tomography of the extremities, whole body, scan of several anatomic regions; angiographic examinations of the heart vessels of the pediatric patients of different age categories; slot-scanning X-ray examinations; bone densitometry.В данной работе обоснованы и представлены изменения и дополнения, планируемые к введению в новую редакцию Методических указаний «Контроль эффективных доз облучения пациентов при проведении медицинских рентгенологических исследований» (МУ 2.6.1.2944-11). Приведены как измененные в связи с появившимися новыми данными расчетов и экспериментов значения коэффициентов перехода от измеряемых на практике дозиметрических характеристик (входная доза, произведение дозы на площадь) к эффективной дозе, так и новые значения коэффициентов перехода для ряда медицинских исследований пациентов. Определение новых значений коэффициентов перехода было основано как на собственных расчетных и экспериментальных исследованиях, согласно протоколам проведения процедур, так и на опубликованных литературных данных. Были изменены значения коэффициентов перехода от измеряемых на практике значений к эффективной дозе для следующих видов медицинских исследований: рентгеноскопических исследований желудочно-кишечного тракта с контрастом для взрослых и детей; интервенционных исследований взрослых пациентов; компьютерно-томографических исследований для взрослых и детей; дентальных внутриротовых исследований. Впервые обсуждаются и приводятся значения коэффициентов перехода для следующих видов медицинских исследований: компьютерно-томографического сканирования всего тела, конечностей и других зон, включающих несколько анатомических областей; ангиографических исследований сосудов сердца у детей различного возраста; рентгенографических исследований с помощью сканирующего щелевого пучка излучения; костной денситометрии

Treatment optimization of patients with epithelial coccygeal passage complicated by an abscess

Background: Despite the wide variety of epithelial coccygeal passage treatment methods, the choice of the type of surgery is still an issue to be discussed. It is due to the heterogeneity of the clinical material, the variety of pathological processes and development of the pathology. In spite of the absence of serious complications in most cases, it causes a significant deterioration of life quality and reduction of work capacity in patients of the most active age group.Objective: Improvement of the treatment results of patients with epithelial coccygeal passage complicated by an abscess by means of vacuum therapy of a sutured postoperative wound (Russian Patent 2764499 date 07.04.2021).Material and methods: The study included 59 patients: 19 people in the main group, who underwent surgical treatment of the epithelial coccygeal passage complicated by an abscess, using vacuum therapy according to the proposed method. A retrospective analysis of the medical histories of patients who underwent surgical treatment of the epithelial coccygeal passage complicated by an abscess has been carried out by means of the traditional method of wound closure with drainage. These patients were included in the control group of 40 people.Results: In the control group purulent-inflammatory complications were recorded in 4 (10%) patients. Out of 19 people of the main group operated on according to the method proposed by us, purulent-septic complications were not recorded in any of the patients. Wound bandaging has been performed 71 times in 19 patients of the main group, and 454 times in 40 patients of the control group. For 19 patients of the main group the duration of the antibiotic therapy lasted 96 days, for 40 patients of the control group - 306 days. The average number of bed-days for patients of the control group was 10.63, in the main group - 7.56.Conclusion: The use of the proposed method of surgical treatment of epithelial coccygeal passage complicated by an abscess, by means of vacuum therapy at all stages of treatment, made it possible to improve treatment results in patients of the main group

Diversity of hard-bottom fauna relative to environmental gradients in Kongsfjorden, Svalbard

A baseline study of hard-bottom zoobenthos in relation to environmental gradients in Kongsfjorden, a glacial fjord in Svalbard, is presented, based on collections from 1996 to 1998. The total species richness in 62 samples from 0 to 30 m depth along five transects was 403 species. Because 32 taxa could not be identified to species level and because 11 species are probably new to science, the total number of identified species was 360. Of these, 47 species are new for Svalbard waters. Bryozoa was the most diverse group. Biogeographic composition revealed features of both Arctic and sub-Arctic properties of the fauna. Species richness, frequency of species occurrence, mean abundance and biomass generally decreased towards the tidal glaciers in inner Kongsfjorden. Among eight environmental factors, depth was most important for explaining variance in the composition of the zoobenthos. The diversity was consistently low at shallow depths, whereas the non-linear patterns of species composition of deeper samples indicated a transitional zone between surface and deeper water masses at 15–20 m depth. Groups of “colonial” and “non-colonial” species differed in diversity, biogeographic composition and distribution by location and depth as well as in relation to other environmental factors. “Non-colonial” species made a greater contribution than “colonial” species to total species richness, total occurrence and biomass in samples, and were more influenced by the depth gradient. Biogeographic composition was sensitive to variation of zoobenthic characteristics over the studied depth range. A list of recorded species and a description of sampling sites are presented