Additive model of Larix sp. forest stand biomass sensitive to temperature and precipitation variables in Eurasia

The first attempt of modeling changes in additive component composition of biomass of Larix sp. communities on the Trans-Eurasian hydrothermal gradients based on regional peculiarities of age and morphology of the forests is attempted. The increase of all biomass components of the tree layer with increasing temperature at the constant precipitation and its decrease with increasing precipitation at the constant temperature is established. The positive relationship of the understory biomass with the temperature in the areas of insufficient moisture as the transition to moisture-rich areas is replaced by the opposite one. The development of such models for basic forest-forming species in Eurasia will give possibility to predict any changes in the biological productivity of forest cover of Eurasia in relation to climate change. © 2019 IOP Publishing Ltd. All rights reserved

Aboveground biomass of mongolian larch (Larix sibiricledeb.) forests in the eurasian region

We used our database of tree biomass with a number of 433 sample trees of Larix from different ecoregions of Eurasia, involving 61 trees from Mongolia for developing an additive model of biomass tree components. Our approach solved the combined problem of additivity and regionality of the model. Our additive model of tree aboveground biomass was harmonized in two ways: first, it eliminated the internal contradictions of the component and of the total biomass equations, secondly, it took into account regional (and correspondingly species-specific) differences of trees in its component structure. A significant excess of larch biomass in the forest-tundra is found that may be explained by permafrost conditions, by tree growth in low-yielding stands with a high basic density of stem wood and relatively high developed tree crown in open stands. The aboveground biomass of larch trees in Mongolia does not stand out against the background of the most ecoregions of Eurasia. Based on our results, we conclude that the growing conditions of larch in Mongolia are not as tough as it was suggested earlier by other scientists. Biomass relations between regions may be explained by unknown and unaccounted factors and errors of measurements in all their phases (assessment of age, diameter, height of a tree, the selection of supposedly representative samples of component biomass, their drying, weighing, etc.). The question what explains the regional differences in the structure of biomass of trees with the same linear dimensions of their stems, remains open. Undoubtedly, the differences in tree age here play an important role. Also, important factor is the variation in the morphological structure of stands, which, in turn, is determined by both climatic and edaphic factors. The obtained models allow the determination of larch forest biomass in different ecoregions of Eurasia with the help of height and diameter data. © 2019, Lomonosov Moscow State University. All rights reserved

Fir (Abies spp.) stand biomass additive model for Eurasia sensitive to winter temperature and annual precipitation

Climate change, especially modified courses of temperature and precipitation, has a significant impact on forest functioning and productivity. Moreover, some alterations in tree biomass allocation (e.g. root to shoot ratio, foliage to wood parts) might be expected in these changing ecological conditions. Therefore, we attempted to model fir stand biomass (t ha(-1)) along the trans-Eurasian hydrothermal gradients using the data from 272 forest stands. The model outputs suggested that all biomass components, except for the crown mass, change in a common pattern, but in different ratios. Specifically, in the range of mean January temperature and precipitation of -30 degrees C to +10 degrees C and 300 to 900 mm, fir stand biomass increases with both increasing temperature and precipitation. Under an assumed increase of January temperature by 1 degrees C, biomass of roots and of all components of the aboveground biomass of fir stands increased (under the assumption that the precipitation level did not change). Similarly, an assumed increase in precipitation by 100 mm resulted in the increased biomass of roots and of all aboveground components. We conclude that fir seems to be a perspective taxon from the point of its productive properties in the ongoing process of climate change.This paper was prepared within the programs of the current scientific research of the Ural Forest Engineering University and Botanical Garden of the Ural Branch of Russian Academy of Sciences. This work was supported by grant "EVA4.0", No. CZ.02.1.01/0.0/0.0/16_019/0000803 financed by OP RDE, by the Slovak Research and Development Agency under contracts No. APVV-15-0265, APVV-16-0325, APVV-18-0086 and the Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic under contracts No. VEGA 1/0367/16

Using biodegradable screws in treatment of hallux valgus

The aim of the research was to assess using biodegradable screws in treatment of hallux valgus. We managed 40 female patients (average age 50 ± 2.51) with hallux valgus who where admitted to the orthopedic unit of Irkutsk Scientific Center of Surgery and Traumatology for operative treatment. All patients had X-ray, MRI and intraoperational examination of affected foot before the surgery and in postoperative period. All patients were operated using own surgical technique. Patients were divided into two groups: group 1 (22 patients) - osteosynthesis using biodegradable (PLGA) screws; group 2 (18 patients) - osteosynthesis using metal cannulated screws. In group 1 postoperative values of M1P1 angle were within normal range (9.67 ± 0.78°). According to MRI, proximal articular set angle (PASA) was corrected from 21.5 ± 0.35 to 4.17 ± 0.09°. 6 patients of the group 1 were complaining of pain and discomfort in the area of screw-head contacting soft tissues. The result of operative treatment in the group 2 resulted in the correction of M1P1 angle from 34 ± 1.63 to 7.67 ± 0.75°. After the surgery intraoperative PASA was back to the normal range (4.33 ± 0.34°). The comparison of the results of treatment of patients of groups 1 and 2 didn't reveal any statistically significant differences in the values of М1Р1, М1М2, М1М5 angles and PASA. The advantage of using biodegradable screws, compared to the metal ones, in the treatment of hallux valgus is the possibility of postoperative MRI of the foot with calculation of PASA to evaluate treatment results. The disadvantage of using biodegradable screws is engineering deficiency preventing screw-head from dipping into bone tissue and causing soft tissue traumatizing. Biodegradable and metal screws allow to obtain similar results of hallux valgus treatment

PROBLEMS OF DIAGNOSIS AND SURGICAL TREATMENT OF HALLUX VALGUS (LITERATURE REVIEW)

Treatment of valgus deformity of the first toe is today one of the intensively developing areas of modern orthopedics. The complexity of treatment of this pathology is predetermined, first of all, by its multicomponent nature. Forefoot deformities are often the main cause of a decreased quality of life, which makes the patient irritable, inactive, and also makes it impossible to use standard footwear, and sometimes even orthopedic one. The purpose of our study was the analysis of scientific literature devoted to the problems of diagnosis and surgical treatment of valgus deviation of the 1st toe (hallux valgus). The materials of the study were domestic and foreign articles, reviews and monographs on the surgical treatment of hallux valgus, with mandatory analysis of long-term treatment outcomes. The history of the development of treatment of this pathology is presented with the analysis of surgical treatment methods aimed at different links of pathogenesis, as well as complications arising from the use of different techniques. The article presents modern trends in development and ways to improve the methods of surgical treatment of valgus deviation of the first toe. The analysis of the literature data showed significant success in the surgical treatment of valgus deviation of the first toe. However the current percentage of relapses may be due to the lack of an accurate method for determining proximal articular set angle (PASA) in the preoperative period, as well as the lack of the hallux valgus treatment able to eliminate valgus deviation of the first toe and avoid recurrence of the disease due to a more accurate correction of PASA

Surgical Treatment of Severe Deformities of the Toes in Rheumatoid Arthritis

The article presents the case of successful surgical treatment of a female patient with severe deformities of the toes arising from rheumatoid arthritis. After clinical and radiological examination the patient was diagnosed with a hallux valgus deviation of the first toe, with 64 degrees of valgus deviation angle, and a valgus-hammered deformity of the II, III, IV toes with a dislocation of the III and IV toes. There was a violation of the stato-dynamic function of the foot, severe pain. Two techniques of joint-preserving surgical treatment were selected. Correction of deformation of the first toe was carried out according to the author's technology, to correct the deformation of other toes, the Helal technique was used in the author's modification. The result of the treatment was the achievement of correction of the deformation of the first toe and the elimination of the deformation of the second, third, and fourth toes. The patient is satisfied with the outcome, the appearance of the left foot, its function, the ability to walk without pain and wear ordinary shoes.This clinical case of surgical treatment of severe deformities of the toes with rheumatoid arthritis shows the possibility and importance of joint-saving operations to obtain a good cosmetic and functional result. Performing osteotomy of the metatarsal bones in the proposed modifications allows to correct the hallux valgus deviation of the first toe and deformation of the other toes. As a result of using these technologies, it is possible to maintain metatarsophalangeal joints, eliminate dislocations and subluxations, restore joint function, form an arch of the transverse arch of the foot, relieve pain, thereby improving the anatomical and functional state of the entire foot

Hip replacement at posttraumatic defects of coxal cavity

From 2009 to 2014 total hip replacement on the account of posttraumatic coxarthrosis of the of the 3rd degree in combination with coxal cavity defect, dislocation or incomplete dislocation of femoral head was conducted in our clinic in 12 patients (10 (83,3 %) men and 2 (16,7 %) women) of 23-51 years (42 on the average). It took from 3 weeks to 8 years (26 months on the average) from the moment of trauma till the operation. We used the method of the replacement of defect of posterosuperior edge of coxal cavity of femoral head. We used acetabular components of cementless fixation in 3 (25 %) cases and mounted a cup of cement-retained fixation in 9 (75 %) cases. The operation lasted from 45 to 225 minutes (90 minutes on the average). Blood loss was from 500 to 2100 ml(1100 ml on the average). 3 (25 %) patients had complications in postoperative period. 2 (16,7 %) patients in consequence of noncompliance of orthopedic regimen had dislocation of prosthesis head on the 8th and 14th day after the operation. 1 (8,3 %) patient had soft tissues infection in the zone of operative intervention in postoperative period. Terms of observation of alteration of massive autografts and functional results of hip replacement were from 1 to 5 years. 11 (91,7 %) patients didn't have any signs of acetabular component instability and osteolysis in the zone of contact between bone cavity and cup. No patient had signs of instability of stem of joint. Harris score increased from 34,1 ± 7,2 to 78 ± 8,4 points

Система лазерного мониторинга загрязнений водной среды с применением относительного описания формы сигналов

As a rule, the wastewater treatment system is not designed to filter substances formed, as a result of beyond design basis accident. The nature of the beyond design basis accident is associated with the shortterm appearance of a clot of these substances in wastewater, determined by the volume of the substance storage tank. Therefore, a rational approach is to divert this portion of the formed substances into a separate branch of the sewage system or sedimentation tanks. The aim of the work is to implement this approach by creating a laser monitoring system for water pollution. The article proposes a system for automatic detection of a clot of emergency discharge of pollutants into the wastewater of an industrial enterprise. The structural diagram of the system and the purpose of its main elements are given. The system should provide clot detection in real time. To ensure this function, a preliminary study is made of the spectral characteristics of all substances that may appear in wastewater in the event of an emergency. Based on these data, the wavelengths of laser radiation in the system are selected. The obtained measurement data from several probes are presented in the form of a lattice function, which is translated into a relative description representing the order relationship matrix on the set of lattice function components. The relative description is invariant to linear changes in the lattice function. The decision to detect any substance from emergency discharges is made based on a comparison of the relative description of the measurements with the standards prepared at the stage of system setup. The article provides an example of the formation of standards for emergency clots from glycerin and allyl alcohol. The graphs of the lattice functions obtained from the IR spectra of emergency discharges of these substances are given; algorithms for constructing a lattice function and comparison of lattice functions. Thus, using the developed mathematical description of the shape of digital signals based on the relative description, the signal of the monitoring curve can be described in the form of a curve of the optical density change of an aqueous medium

Carbon deposition by Russian forests on the example of taiga and forest-steppe zones

Due to the global warming of the climate, the assessment of the carbon cycle in forest ecosystems has become particularly important. One method for determining deposited carbon is based on the use of biomass expansion factors (BEF) and State Forest Inventory (SFI) data. By combining BEF models with SFI data in two ecoregions of Russia - taiga and forest-steppe - it was found that over a 20-25-year period, accumulating the carbon deposition in the taiga zone is significantly less (5%) compared to the forest-steppe zone (39%). Comparable results were obtained by the same method in different ecoregions of the planet (from 8% in 5 years in China to 68% in 50 years in Japan). A comparison of the results obtained by the proposed method and the IIASA method showed a minimal discrepancy (3 %), which gives reason to consider the above estimates of carbon deposition close to reality. However, uncertainties remain related to the quality of the SFI data and the carbon deposition in the soil. © 2021 Nicolaus Copernicus University. All rights reserved

New method of surgical correction of lesser toes deformity

Background. Patients’ dissatisfaction with the results of surgical correction of lesser toes deformities, the shortcomings of methods aimed at eliminating the lateral deviation of the toe in the metatarsophalangeal joint necessitated the development of a new surgical method.The aim. To evaluate short-term results of the new surgical method for the treatment of patients with lesser toes deformity, accompanied with deviation of the toe.Materials and methods. A method of surgical treatment of deviated deformity of the small toes is proposed. The method includes precise marking of the metatarsal osteotomy line according to the previously calculated parameters of optimal shortening and displacement of the metatarsal bone, performing oblique diaphyseal osteotomy of the metatarsal bone, displacing its distal part along the osteotomy plane. According to the proposed method, nine patients were operated on who had a syndrome of nonrigid hammer-like deformity of the second toe with lateral deviation of the toe in the metatarsophalangeal joint. In all patients, the deformity of the second toe was associated with hallux valgus.Results. As a result of the application of the proposed method, it was possible to achieve deformity correction, eliminate the lateral deviation of the second toe in the metatarsophalangeal joint, restore congruence in the joint, achieve consolidation of bone fragments without loss of correction, and improve the appearance and function of the foot. Three months after the operation, a statistically significant improvement was determined, according to the AOFAS LMIS scale, having reached 94.5 ± 4.64 points, which made it possible to speak about the achievement of a good functional result of treatment. Patients noted the opportunity to wear standard footwear, to carry out their labor activity, to engage in physical culture, were satisfied with the result.Conclusion. The use of the proposed new surgical method for deflected deformity of the lesser toes makes it possible to correct the deformity, eliminate lateral deviation of the toe, relieve pain syndrome, achieve a good cosmetic and functional result, restoring the patients’ ability to wear standard shoes