Trunk Height Research Articles

Differentiated In-Row Soil Management in a High-Density Olive Orchard: Effects on Weed Control, Tree Growth and Yield, and Economic and Environmental Sustainability

Two different in-row soil management techniques were compared in the Olive Orchard Innovation Long-term experiment of the Council for Agricultural Research and Economics, Research Centre for Olive, Fruit, and Citrus Crops in Rome, Italy. Rows were managed with an in-row rotary tiller and with synthetic mulching using permeable polypropylene placed after cultivar Maurino olive trees planting. The effects of the two treatments were assessed through weed soil coverage and the growth of the olive trees. Results showed better agronomic performance associated with synthetic mulching. The weed control effect along the row of a young high-density olive orchard was higher with the synthetic mulching compared to hoeing. The effect of the synthetic mulching seemed to disappear when removed from the ground (spring 2023) since no significant differences were found for tree size and yield in the two tested in-row soil management systems at the end of 2023. Finally, the growth of the young olive trees (Trunk Cross Sectional Area, Height, and Canopy expansion) measured across the three years, was higher for the synthetic mulched row than the hoed one. The use of synthetic mulching along the row positively forced the vegetative growth of the young olive trees and anticipated the onset of fruit production compared to periodical hoeing: a significantly higher fruit production was registered three years after planting. Root diameter was higher under synthetic mulching one year after planting, and no differences were observed in the following sampling dates showing similar fluctuations linked to the seasonal growth pattern. The life cycle assessment and costing highlighted that the application of mulching had a higher eco- and economic-efficiency than the periodical in-row soil hoeing.

Physical Fitness and Exercise Performance of Transgender Women.

In spite of the evolving participation of transgender adults in exercise and sports, research investigating the physical fitness of transgender women remains scarce in the scientific literature. In this cross-sectional study, a variety of reference-standard measures of physical fitness of transgender women who had undergone gender-affirming orchiectomy (30 ± 4 years; n = 15) and who had not (27 ± 4 years: n = 15) were compared with reference males (28 ± 5 years; n = 15) and reference females (29 ± 5 years; n = 15) who were matched for age and estimated physical activity level. Transgender women had been undergoing feminizing gender-affirming therapy for 8-10 years. Height and lean mass of arms, legs, and trunk (measured via DXA) of transgender women were greater than those of reference females but lower than those of reference males (all p < 0.05). No significant differences were in isokinetic muscular torque found between reference females and transgender women. Both absolute and relative measures of maximal oxygen consumption were greater in reference males than in reference females and transgender women (all p < 0.05) with no significant difference between the latter two groups. Reference males had greater peak Wingate anaerobic power (expressed in both absolute and relative to body weight), countermovement jump, and squat jump than reference females and transgender women (all p < 0.05). There were no significant differences in anaerobic power between reference females and transgender women. The results on the field tests, including agility T-test and sprint running acceleration, were consistent with the anaerobic power tests. There were no statistical differences in any of the physical fitness measures between transgender women with and without orchiectomy. Transgender women demonstrated similar levels of reference-standard measures of physical fitness to females that were significantly lower than males.

Impact of Wood Structure Variability on the Surface Roughness of Chestnut Wood

Wood constitutes a unique and valuable material that has been used from ancient times until nowadays in a wide variety of applications, in which the surface quality of wood often constitutes a critical factor. In this study, the influence of different wood areas and therefore, of different anatomical characteristic areas of chestnut wood (Castanea sativa Mill.) on the surface quality, was thoroughly studied, in terms of surface roughness. Five different chestnut tree trunks were harvested, from which five different disks were obtained corresponding to five different trunk heights. Surface roughness was measured on these disks on the transverse, radial, and tangential planes, on the areas of sapwood and heartwood, measuring the roughness in each point both vertically and in parallel to the wood grain. The results revealed that the examined roughness indexes (Ra, Rz, Rq) follow a parallel path to one another. In the case of all surfaces (transverse, radial, tangential) of the disks examined, when the measurement was implemented perpendicularly to the wood grain, a significantly higher roughness was recorded, compared to the wood grain measurements being implemented in parallel with the wood grain. Significant differences between heartwood and sapwood roughness were not demonstrated, although sapwood often appeared to exhibit a higher surface roughness than heartwood sites. Among the roughness values of the three different surfaces, the highest roughness in the vertical-to-wood-grain measurements was recorded by tangential surfaces, with slightly lower values on the transverse surfaces and the lowest roughness on radial surfaces. Meanwhile, for the measurements in parallel with the wood grain, the transverse surfaces presented significantly higher roughness values compared to the tangential and radial surfaces. Significant roughness differences were not detected among the surfaces at different trunk heights. Although, significant differences in roughness were recorded among different trees, it was observed that all the studied trees align with the identified and described within-tree trends.

Growth and population structure of Lodoicea maldivica in natural stands in Seychelles.

We monitored leaf production in seedlings, trunkless juvenile, immature, and mature male and female plants of the dioecious palm, Lodoicea maldivica, and studied how internode length changed with trunk height. The fieldwork was conducted in closed forest on Praslin Island and degraded forest on Curieuse Island. Data on numbers of leaves produced and rates of leaf production were used to estimate plant age. On Praslin, the interval between successive leaves increased from 0.47/0.52 years in male/female plants to 4.2 years in seedlings, and on Curieuse from 0.41/0.49 to 2.3 years. Estimated leaf lifespan was 6.4-6.8 years in mature palms and much longer in seedlings and juveniles. On Praslin, internode length increased from the base of the trunk to a mean of 14 cm at leaf 21, before declining to 2.75 cm above leaf 100. Mean internode length of the smaller palms on Curieuse was 1.9 cm and varied little with height. Plants at the same development stage varied widely in age. On Praslin, median time to maturity was 77 (range: 32-209) and on Curieuse 83 (31-191) years. The tallest palms on Praslin (28.4 m trunk height) and Curieuse (8 m) were estimated at 442 and 232 years old, respectively. The ageing method was used to interpret height data of different populations. All showed a marked decline in regeneration in the 19th or early 20th centuries, probably caused by fires. We conclude that slow growth makes this species very vulnerable to disturbance, especially from fire.

Frequency and management of rod fractures following minimally invasive bipolar fusionless surgery in neuromuscular scoliosis patients

IntroductionNeuromuscular scoliosis (NMS) is associated with an abnormal muscle tone. Traditional conservative treatments, with the historical practice of early posterior fusion, have proven ineffective. Recently, growth-sparing techniques have gained traction owing to their ability to maximize trunk height. However, these techniques have a substantial risk of complications, particularly rod breakage, with reported incidence rates ranging from 15 % to 42 %. The objective of this study was to conduct a descriptive analysis of NMS patients who experienced rod breakage following the minimally invasive fusionless surgery (MIFS) technique. MethodsThis was a single-center, retrospective study that included all NMS patients who underwent surgery between January 2015 and January 2021 and subsequently presented with rod breakage after MIFS. The MIFS technique is based on proximal fixation with double hook claws made of pedicular and -sus laminar hooks and pelvic fixation with iliosacral screws. ResultsThe mean follow-up was 5.2 ± 2.2 years. The mean dominant etiology of NMS was cerebral palsy (67 %). Of the 217 patients who underwent surgery, 15 (6.9 %) developed rod breakage. Rod breakage occurred 2.7 ± 1.3 years after the initial surgery. Four cases of rod fracture recurrence were reported in ambulatory patients with dystonia or hyperactivity. ConclusionCompared with other fusionless techniques, the minimally invasive bipolar technique appears promising for patients with NMS, with a lower rate of rod breakage. We recommend the use of a four-rod construct for ambulatory patients or for those with dystonia or hyperactivity.

Climate stabilizing value of oak shelterbelts in Zhytomyr Polissia

Woody forest plantations, including shelterbelts, are one of the stabilizers of the optimal ecological state of the environment in agricultural landscapes. Shelterbelts are able to sequester carbon from the atmosphere in their phytomass and generate oxygen for a long time. These processes contribute to the partial but permanent prevention of global climate change. According to the calculations, we determined the volume of tree trunks in the protective strips, the cross-sectional area of the trunk, and the phytomass of wood, bark, and crown in a completely dry state. Based on the research data, correlations were created between the main taxonomic indicators and phytomass fractions, which showed a close relationship between phytomass fractions and the height and diameter of tree trunks. In the course of the research, a regression equation was built between tree phytomass and biometric indicators such as trunk height and diameter. The amount of carbon sequestered by the oak shelterbelts was determined by determining the proportion of carbon in the phytomass in absolutely dry residue. The main soil and climatic indicators were established, which in most temporary test plots were characterized by pH=7.0 (neutral), the level of atmospheric air temperature under the forest protection strips was 2°C lower than in agroecosystems (field), and the soil temperature was 8°C lower than in the studied agroecosystems. Soil moisture was identical. According to the statistical analysis, the sample was homogeneous in terms of height, diameter, and age of the plantation. The obtained results allow for further analysis and construction of regression equations between tree phytomass and biometric parameters — height, diameter. It has been determined that an increase in tree diameter by 1.94% and height by 1.0% has a direct impact on the growth of phytomass of common oak wood. It has been established that the total phytomass of oak in linear plantations is 157.7 kg for a middle-aged tree and 275.9 kg for a mature tree. According to the established value of the conversion coefficient of the carbon-absorbing capacity of field protection strips of oak plantations, CO2 emissions into the atmosphere in the Zhytomyr Polissia zone are annually reduced by 5%. The obtained equation of the conversion coefficient, with a sufficiently high determination index, makes it possible to use the obtained dependence in further calculations.

Dynamic Analysis of Street Trees in Vehicle-mounted LiDAR Point Clouds

Street trees, as key elements of urban road scenes, play a significant role in the overall ecological environment and aesthetics of city roads through their dynamic growth and changes. With the continuous development of urban roads, the growth conditions of street trees are also constantly changing. Therefore, studying how to infer the dynamic changes of roads through the variations in street trees is a highly valuable technical issue. This paper delves into several critical parameters of street trees, including diameter at breast height (DBH), tree height, trunk height, crown volume, and crown spread. By updating these parameters, determining transplantation and replanting decisions, and analyzing growth states, we comprehensively analyze the dynamic changes of street trees. To achieve this goal, we integrated multiple parameters into the analysis process of street trees and established a comprehensive analysis system centered on the DBH parameter. Combining this with data visualization technology, we provide an intuitive dynamic analysis method. Experimental results indicate that, compared to single-parameter analysis methods, the multi-parameter comprehensive analysis method demonstrates higher accuracy and stronger persuasive power in the study of dynamic changes in street trees, thereby validating the superiority and practicality of the proposed research algorithm. This research can provide more scientific and reliable references for urban road planning and management.

Weak geostrophic wind driven ventilation in street canyons with trees and green walls: Cooperating or opposing dispersions of airborne pollutants?

Urban high-rise buildings and dense street canyons significantly disrupt synchronised wind flows, potentially exacerbating urban heat island effect. Fortunately, urban heat island effect can be mitigated by the green infrastructure in cities, particularly through the presence of roadside trees and green walls. However, the combined mechanisms of tree resistance, shading effects, and cooling effect, along with sensible thermal buoyancy flows within canyon ventilation and pollution dispersion, remain undisclosed. This study employs refined computational fluid dynamics numerical simulations to analyse airflow and pollutant dispersion within urban street canyons. Air exchange rate and pollutant retention time are employed to evaluate ventilation and pollutant dispersion, respectively, inside the street canyons.In scenarios with leeward green wall layout, higher tree canopy spread and trunk height lead to a shift in high pollutant concentrations from the region near the windward side to that near the leeward side of the typical canyon (H/W = 1). Conversely, in deep canyons (H/W = 5), most pollutants are retained near the bottom leeward side. Moreover, differences in pollutant dispersion between typical and deep canyons increase with with rising tree canopy spread. Additionally, higher tree canopy spread and trunk height values result in longer pollutant retention time, which are unfavourable for pollutant removal, and particularly limiting pollutant dispersion as street canyon depth increases. Similarly, increasing tree canopy spread reduces the difference in air exchange rate between windward and leeward green wall layout patterns. Regarding Richardson number variations —indicating thermal buoyancy effects—lower Richardson number values lead to reduced differences in pollutant retention time between typical and deep canyons. Furthermore, ventilation performance of the windward green pattern surpasses that of the leeward pattern. This research provides valuable insights for implementing green infrastructure to locally mitigate urban air pollution.

Urban cemeteries: The forgotten but powerful cooling islands

Urban parks play a key role in UHI mitigation. However, the role of other prominent types of urban green infrastructure has not been comprehensively studied. Thus, the main objective of this study was to evaluate the role of cemeteries and allotments as cooling islands compared to the well-studied park areas. We assessed the LST of cemeteries, allotments and parks based on Landsat 8 TM images across the five largest German cities during summertime. Random forest regressions explain the LST spatial variability of the different urban green spaces (UGS) with spectral indices (NDVI, NDMI, NDBaI) as well as with tree characteristics (tree type, tree age, trunk circumferences, trunk height or canopy density). As a result, allotments were identified as the hottest UGS with the city means varying between 23.1 and 26.9 °C, since they contain a relatively high proportion of sealed surfaces. The LST spatial variability of allotment gardens was best explained by the NDVI indicating that fields with a higher percentage of flowering shrubs and trees reveal lower LST values than those covered by annual crops. Interestingly, cemeteries were characterized as the coolest UGS, with city means between 20.4 and 24.7 °C. Despite their high proportion of sealed surfaces, they are dominated by old trees resulting in intensive transpiration processes. Parks show heterogeneous LST patterns which could not be systematically explained by spectral indices due to the variability of park functionality and shape. Compared to parks, the tree-covered areas of cemeteries have a higher cooling potential since cemeteries as cultural heritage sites are well-protected allowing old tree growth with intensive transpiration. These findings underline the relevance of cemeteries as cooling islands and deepen the understanding of the role of tree characteristics in the cooling process.

Radiological and Pulmonary Results of Surgical Treatment of Severe Idiopathic Scoliosis Using Preoperative Halo Gravity Traction Compared with Less Invasive Temporary Internal Distraction in Staged Surgery in Adolescents.

Background: Severe and rigid scoliosis represents a type of spinal deformity characterized by a Cobb angle exceeding 90° and a flexibility of less than 30%. Halo spinal traction remains the established standard for managing severe scoliosis, although alternative approaches such as temporary internal distraction rods and staged surgical correction exist. The primary objective of this investigation was to compare two cohorts of patients treated using these distinct methods to ascertain any divergences in terms of surgical and radiological outcomes, pulmonary function (PF), and quality of life (QoL). Methods: This study encompassed a total of 62 pediatric patients meeting the specified criteria, which included severe idiopathic scoliosis (major Cobb curve >90) and flexibility <30%. Group 1 (G1) underwent surgical intervention involving preoperative Halo gravity traction (HGT) succeeded by posterior spinal fusion (PSF). On the other hand, Group 2 (G2) underwent a two-stage procedure starting with a less invasive temporary internal distraction technique (LITID) prior to PSF. The radiological outcomes, PF, and QoL were documented and assessed over a monitoring period ranging from 2 to 5 years. Results: The average preoperative major curves (MCs) measured 124° and 122° in G1 and G2, respectively (p < 0.426). Initial flexibility, as observed in preoperative bending films, ranged from 18% in G1 to 21% in G2 (p < 0.001). Following the ultimate surgical intervention, the MCs were corrected to 45° and 37.4° in G1 and G2, respectively (p < 0.001). The percentage correction of the MCs was higher in G2 (63% vs. 70% in G1 and G2, respectively), with significant between-group disparities (p < 0.001). The mean preoperative thoracic kyphoses (TKs) were 96.5° in G1 and 92° in G2 (p = 0.782), which were rectified to 45.8° in G1 and 36.2° in G2 (p < 0.001), equating to correction rates of 55% and 60% in the respective groups. Initially, G2 exhibited lower values for the percentage of predicted lung volume (FVC) and predicted FEV1 compared with G1 (49% and 58% vs. 54.5% and 60.8%; N.S.). Nonetheless, both groups demonstrated enhancements in their FVC and FEV1 values over the follow-up period. Conclusions: The surgical management of severe and untreated spinal curvatures in the pediatric and adolescent population can be considered safe, with a tolerable incidence of minor complications. LITID emerges as a method offering improved QoL and pulmonary function, achieving notably substantial average corrections in deformity by 70% in the coronal plane and 60% in the sagittal plane, alongside a mean increase in trunk height of 10.8 cm. Furthermore, a typical reduction of 76% in rib humps and enhancements in respiratory function, as indicated by improvements in 1 s predicted forced expiratory volume (by 25-56%) and forced vital capacity (by 35-65%), were achieved, leading to a clinically and statistically significant enhancement in QoL when evaluated using SRS-22r, without resorting to more radical, high-risk procedures.

Tree form characteristics as criteria for tree species selection to improve pedestrian thermal comfort in street canyons: Case study of a humid subtropical city

The combined effect of tree characteristics on heat stress in different street canyons has been widely reported. However, there remains a lack of effective methods for improving pedestrian thermal comfort through the use of integrated knowledge of tree characteristics. Here, a tree species selection approach was developed for assessing the dynamic effects of tree forms and canyon geometries on pedestrian thermal comfort to address the issue of the right tree in the right street canyon. The leaf area density (LAD), crown diameter (CD), tree height (HT), and trunk height (TH) were used as criteria for determining tree species characteristics, and the weighted outdoor thermal comfort autonomy (OTCAw) was adopted as a quantitative index of thermal comfort variation over time. In a case study of Wuhan, China, we evaluated the thermal comfort enhancement potential of 45 tree forms in street canyons with varying aspect ratios and orientations from 7:00 to 21:00 by using a validated ENVI-met model. Accordingly, tree pruning strategies and 19 optimal tree forms were proposed for corresponding street canyons. Our study provides insight into the optimal street tree species for minimizing heat exposure of pedestrians under various urban canyon configurations.

Chemical Cues Released by Predators’ Consumption of Heterospecific Prey Alter the Embryogenesis of Zebrafish

Environmentally cued hatching is prevalent, diverse, and crucial to many animals’ survival. Fish embryos use a variety of chemical cues to initiate hatching to avoid potential predators, yet the function of chemical cues released from the predatory consumption of heterospecific prey is largely unknown. Zebra cichlids (Metriaclima estherae) are ferocious predators that can feed on medaka (Oryzias latipes), though it is impossible for this to occur in their natural habitat. Zebrafish (Danio rerio) embryos have been employed as experimental subjects due to their sensitivity to a variety of chemical signals. In this study, zebrafish embryos were subjected to three types of chemical signals: predator cues (PCs, released from cichlids), heterospecific cues (HCs, released from medaka), and heterospecific dietary cues (HDCs, released from cichlids that have ingested medaka). As a result, the hatching times of zebrafish embryos were accelerated by 6.8% and 12.6% by PCs and HDCs, respectively. PCs and HDCs cause significantly reduced morphology in zebrafish embryos, including regarding total length, eye length, dorsal fin length, trunk height, caudal fin height, and body cavity, and increase yolk sac height. The PCs and HDCs diminished the larvae’s motion at 120 and 144 h post fertilization (hpf), which could be attributed to non-developmental embryogenesis. Overall, the impacts of HDCs on embryonic hatching, developmental morphology, and locomotor were more pronounced in comparison with PCs. Our findings demonstrate that predators’ dietary cues, even those released after predation on heterospecific prey, can modify embryogenesis, highlighting the critical functions of chemical signals in predation risk assessment using embryos.

Computer Assisted Bone Age Estimation Using Dimensions of Metacarpal Bones and Metacarpophalangeal Joints Based on Neural Network.

Bone age is a more accurate assessment for biologic development than chronological age. The most common method for bone age estimation is using Pyle and Greulich Atlas. Today, computer-based techniques are becoming more favorable among investigators. However, the morphological features in Greulich and Pyle method are difficult to be converted into quantitative measures. During recent years, metacarpal bones and metacarpophalangeal joints dimensions were shown to be highly correlated with skeletal age. In this study, we have evaluated the accuracy and reliability of a trained neural network for bone age estimation with quantitative and recently introduced related data, including chronological age, height, trunk height, weight, metacarpal bones, and metacarpophalangeal joints dimensions. In this cross sectional retrospective study, aneural network, using MATLAB, was utilized to determine bone age by employing quantitative features for 304 subjects. To evaluate the accuracy of age estimation software, paired t-test, and inter-class correlation was used. The difference between the mean bone ages determined by the radiologists and the mean bone ages assessed by the age estimation software was not significant (p Value= 0.119 in male subjects and p= 0.922 in female subjects). The results from the software and radiologists showed a strong correlation -ICC=0.990 in male subjects and ICC=0.986 in female subjects (p< 0.001). The results have shown an acceptable accuracy in bone age estimation with training neural network and using dimensions of bones and joints.

The relationship between body height and plantar pressure distribution in adult handball players: A cross-sectional study

Background/purpose The relationship between a handball player's upper body posture, body weight distribution in relation to body height is poorly understood. So, this study explored the relationship between body height and sagittal spinal curvatures and plantar pressure distribution in handball players. Method According to handball player's body height, 63 male handball players were divided into two groups; group A (age, 23.54 ± 1.32 years) consisted of 30 handball players with body height above average, and group B (age, 23.40 ± 1.73 years) consisted of 33 handball players with body height below average. The thoracic and lumbar curvatures and trunk height were measured with the Formetric III 4D spine, and the DIERS Pedoscan device was used to assess the plantar pressure distribution for both groups. Results The thoracic kyphosis of group A was significantly higher than that of group B ( p = 0.001), without a significant difference in lumbar lordosis ( p = 0.086). Group A showed a significant increase in the forefeet pressure and a significant decrease in the rearfeet pressure compared to group B ( p = 0.001). There was a high positive correlation between the body height and trunk length, and body height and kyphosis angle ( r = 0.932, r = 0.665, respectively). There was a high positive correlation between the body height and forefoot plantar pressure ( r = 0.665, p &lt; 0.01). Conclusion The taller handball players have an increased thoracic kyphosis angle and forefeet pressure compared to shorter handball players.

Comparison of Various Tree Features for Blocking Solar Radiation in the Arid Urban Environment

In the arid urban environment, pedestrians are often exposed to high amounts of solar radiation during summer, which can limit their activities. Shades are essential for reducing the harmful effects of solar radiation, particularly ultraviolet (UV) rays, which can be dangerous to human health. This study thoroughly evaluated the effect of various tree features for their efficacy in blocking solar radiation, especially photosynthetically active radiation (PAR) and ultraviolet A (UVA). Tree height, trunk height, canopy height and diameter, leaf area index (LAI), leaf size and type, planting techniques (individual and cluster), and agriculture services for eight common tree species used in the Landscape at King Abdulaziz University campus in Jeddah, KSA, were examined. Measurements were taken at noon when the solar zenith angle was perpendicular. The study found that the ability to block PAR and UVA varies based on several factors analyzed. Canopy height and diameter increased a tree's capability to block radiation, with pyramid-shaped trees and simple leaves being the most effective. Higher LAI, cluster planting, and removal of lower branches also increased a tree's radiation-blocking power. In conclusion, shade trees mitigate PAR and UVA and provide pedestrians with more opportunities to enjoy open landscapes in arid regions. KEYWORDS landscape planting, leave index, solar effect, trees benefits, ultraviolet radiation, arid environments

Basculing in elite show jumping horses: a motion analysis study of trunk and neck movement

Abstract The movement of the trunk and neck plays a crucial role in training and assessing the technical performance in show jumping horses. The term ‘bascule’ describes a rounded and harmonious jumping movement characterised by an arched or bulged back and a lower, stretched neck position. However, there is a lack of consensus in the literature regarding the specific kinematic features that define basculing. The question remains whether the impression of a rounded back is the result of spine flexion into an upward curved position or a combination of thorax elongation and a downward movement of the neck. Additionally, the timing of these movement components remains unclear. To address these questions, we conducted kinematic analyses on six ridden show jumpers with varying levels of competition experience. Using a simplified kinematic model, we analysed the trajectories of the trunk length, trunk height, neck length, and trunk-neck angle throughout different phases of a jump over a single 130 cm vertical fence during a training session. Furthermore, we explored potential differences in basculing execution based on the horses’ competition levels. Our findings indicate that the horses’ body posture while jumping over the fence does not exhibit true flexion of the thoracolumbar spine, resulting in an upward arched shape of the spine. Instead, during the take-off phase, the trunk shows elongation, suggesting a reduced curvature of the spine in this region, accompanied by a downward movement of the neck. However, we consistently observed a shortening of the neck segment, indicating flexion of the cervical spine. Correlation analyses suggest that these changes are associated with the horses’ level of competition, with more pronounced basculing observed in horses with higher competition levels.

Cambial Age Influences PCD Gene Expression during Xylem Development and Heartwood Formation

Heartwood formation is an important ontogenetic stage in Scots pine (Pinus sylvestris L.). The amount of heartwood determines the proportion of functionally active sapwood in the total trunk biomass as well as the quality of wood. The key criterion for heartwood formation is the death of xylem ray parenchyma cells. Previously, models that described the patterns of heartwood formation, depending on the cambial age, were derived from Scots pine trees of different ages. The cambial age is the number of annual xylem layers at the core sampling site at a certain trunk height. We studied the features of the occurrence of programmed cell death (PCD) processes during the xylem differentiation and heartwood formation of 80-year-old Scots pine trees, depending on the cambial age, under the lingonberry pine forest conditions in the transition area of the northern taiga subzone and tundra. We have shown that the distance from the cambial zone to the heartwood boundary does not change significantly with stem height. As the cambial age increases, the lifespan of the formed xylem ray parenchyma cells increases and the activity of PCD genes decreases during the formation of both (1) xylem (in the outer layers of sapwood) and (2) heartwood (in the inner layers of sapwood and transition zone). We hypothesized that the decisive factor in the PCD initiation during heartwood formation is the distance of the xylem ray parenchyma cells from the cambial zone. The younger cambium forms wider annual increments, and therefore the xylem ray parenchyma cells in these parts of the trunk reach the distance from the cambial zone earlier, which is necessary for PCD initiation.

Identification of key somatic features that are common and the ones that differ between swim strokes through allometric modeling.

The aim of this study was to explore which key somatic features are common to four swim strokes and medley, and specifically to identify which characteristics benefit only specific strokes. The sample was composed of 130 swimmers (95 males aged 19.5 ± 2.9 years and 35 females aged 18.4 ± 2.8 years). A set of anthropometric variables was used to predict swimming speed in the four swimming strokes and medley. A multiplicative model with allometric body size components was used to identify the demographic and anthropometric predictors of swimming speed. Trunk height and waist circumference were the only variables significantly different among swimming strokes (p < 0.05). Associations between swimming speed and arm length were similar in breaststroke and medley, and in freestyle, backstroke and butterfly (R2 = 60.9%). The model retained as swimming speed predictors the age2, upper body circumference, hand breadth, waist circumference, and subscapular skinfold thickness (these last two had negative associations). All these predictors were common to all four swim strokes and medley. Arm length was also retained as a significant predictor, but this one varied significantly between the four different swim strokes and medley. These findings highlight the importance of having a "V-shape" trunk, longer upper limbs, and large hands as predictors of swimming performance.

Improvement of agrotechnical conditions of growing paulownia in the Forest Steppe of Ukraine

Purpose. The purpose of the study was to improve the agrotechnical conditions for growing paulownia and its artificially bred variety Clone in vitro 112 in the Forest Steppe zone of Ukraine.&#x0D; Methods. Field, laboratory, visual, measuring and weighing, mathematical and statistical.&#x0D; Results. The article presents the results of research on the improvement of agrotechnical growing conditions and establishment of indicators of growth and development of paulownia plants in the Central Forest Steppe of Ukraine. The methods of planting, the optimal width between the rows, and the options for caring for the plantation of plants have been substantiated. It was established that in the first year of vegetation, the root system of paulownia plants is intensively formed. In order to obtain high-quality wood, after the first year of vegetation, it is necessary to make a technical cut at a height of 2–3 cm from the surface of the ground and remove young newly formed shoots (tillers). The highest trunk height of Clone in vitro 112 was formed in the first and second year of vegetation and reached 5–6 m. The optimal planting density is 625 plants per hectare. Conclusions. It was established that paulownia seedlings in vitro should undergo adaptation to the temperature conditions of the growing area for two to three weeks before planting in open ground.

Tree Storey Structure and Condition Dynamics in Middle-Taiga Native Spruce Forests of the Northern Ural Foothills

The paper focuses on the dynamic processes occurring in indigenous spruce phytocenoses developing on the territory of one of the large reserves of spontaneous dark coniferous taiga in the European North – the Pechoro-Ilychsky Reserve. The aim of the study was to assess the size structure dynamics of the forest stands and the undergrowth, as well as changes in their vital status in naturally developing spruce stands of the green moss and long-stem moss groups of forest types in the foothills of the Northern Urals (the basin of the upper reaches of the Pechora River). The spruce stands, mixed in composition and complex in structure, form a cyclic uneven-aged type of structure. For the middle taiga indigenous spruce forests, based on the assessment of inequality in the woody plants’ sizes distribution, the results of the long-term structure monitoring of the forest stands and the undergrowth on four permanent sample plots were analysed. In forest stands of different types, a similar dynamics of tree differentiation by trunk volume and undergrowth by trunk height was observed. There is a significant accumulation of small woody plants individuals, with a smooth, evenly fading distribution of their numbers in the direction of size increase. Under the canopy of forest stands there is a continuous regrowth process. According to the data of stationary observations of the vitality and damage degree of trees and undergrowth of spruce forests, based on a visual assessment of a woody plant state according to the characteristics of the crown, a slightly weakened condition of both the upper tree layers of the phytocenosis and the lower – undergrowth was revealed. Spruce stands are at the stage of initial weakening or are already weakened, the undergrowth is predominantly healthy.