Stem Inclination Research Articles

Determination of lignin composition in compression wood-like reaction wood of angiosperm Gardenia jasminoides by pyrolysis–gas chromatography–mass spectrometry

Abstract Using pyrolysis–gas chromatography–mass spectrometry, the lignin composition was analysed in normal and reaction wood samples grown at three stem inclination angles in Gardenia jasminoides, which forms compression wood-like reaction wood. Lignin content among the samples was not significantly different. However, the reaction wood samples with larger stem inclination angles showed a lower syringyl/guaiacyl ratio. In conclusion, the degree of inclination affected the lignin composition in G. jasminoides reaction wood, and qualitative changes in lignin might be necessary to mechanically support the stems in this species.

Experimental Test of Non-Destructive Methods to Assess the Anchorage of Trees

More than 280 trees were uprooted in winching tests monitored by high resolution inclinometers at the base of the trees and a forcemeter mounted in the winching line. The dataset comprises trees growing on different urban and forest sites in Europe and North America and mainly consists of fifteen widespread tree species. For the first time, a large number of trees were measured non-destructively prior to uprooting failure, as commonly practiced by consulting arborists in static load tests. With these tests, the bending moment required to cause 0.25° root plate inclination (rotational stiffness) was determined and used to predict the strength of the root system from equations described in two evaluation methods currently used in arboriculture. The predictions were tested against the measured anchorage strength, i.e., the maximum bending moment that was required to uproot the trees. Both methods delivered good estimates, which indicates that rotational stiffness at 0.25° inclination of the stem base is a suitable proxy for anchorage strength. Both equations can be considered valid for assessing the likelihood of uprooting failure, as they systematically underestimate and rarely overestimate the actual resistance to failure of a tree’s root system. As a trend, the differences between predicted and measured anchorage strength were larger for small trees, for which the resistance of the root system was overcome at larger inclination angles. While the quality of the predictions differed for species, it did not differ between sites. The angles of stem inclination at which the anchorage strength was overcome for all trees in our dataset support models for the mechanics involved in uprooting failure that previously have been described only for conifers with a shallow root system.

Stem size prediction in shoulder arthroplasty with preoperative 3D planning.

Three-dimensional surgical planning software provides virtual reconstructions of the shoulder with automated joint indices for a preoperative case assessment. The aim of this single center study was to evaluate the concordance between the preoperatively selected humeral components and the final implants used in shoulder arthroplasty. 129 cases who had undergone anatomic (n = 16) or reverse shoulder arthroplasty (n = 117) using the same type of uncemented short stem implant and were included for review in this study. The type of arthroplasty, stem size, stem inclination, tray-offset and liner-thickness were noted preoperatively and compared to the final implant specifications used in surgery. The type of arthroplasty matched the surgical plan in 99.2% of cases, as one case was converted from RSA to TSA. The concordance of planned to implanted stem size was 44.2% and the planned size was in range of one adjacent size in 87.6% of cases. Stem inclination in TSA matched the surgical plan in 50% of cases. Tray offset in RSA was predicted correctly in 65% and liner-thickness matched the surgical plan in 98.3% of cases. Despite a low degree of concordance of planned to implanted stem sizes of 44.2%, the choice of stem size was found to be in range of one adjacent size in 87.6% of cases. Further investigations of other contributing factors are necessary to increase the accuracy of the preoperative selection of humeral implants. level IV, retrospective case study.

Siberian stone pine, Siberian dwarf pine, their hybrids, and backcrosses: comparative analysis of crone formation in the first 10 years of life

For the first time, a comparative analysis of crown morphogenesis in Siberian stone pine (Pinus sibirica), Siberian dwarf pine (P. pumila), their hybrids and backcrosses was carried out using the example of 10-year-old seed offspring from the Northern Baikal natural population. The goal is to “decompose” the life form phenomenon into elementary traits, to trace their formation at the beginning of ontogenesis on two contrasting examples (an upright tree vs. prostrate tree) and inheritance after interspecific hybridization. The parent species differed fundamentally in (1) stem inclination and (2) apical dominance at two levels (1-year-old shoots and perennial branches). The phototropic slope of the Siberian dwarf pine stem “triggered” the mechanism of prostrate tree formation. Apical dominance in the system of perennial branches was the main factor in the crown formation. It, in turn, consisted of two key characteristics: strength and selectivity. In Siberian stone pine, apical dominance was strong and nonselective. In Siberian dwarf pine, apical dominance was weak and selective: some of the largest branches did not obey him. All key traits were inherited by hybrids and backcrosses strictly intermediate in accordance with the proportion of species in the offspring genome.

Effect of reverse total shoulder arthroplasty humeral inclination on glenohumeral range of motion, deltoid force, and glenoid strain: a biomechanical study

BackgroundReverse total shoulder arthroplasty (RSA) primarily varies between 2 implant design options: a 135 humeral stem inclination that closely resembles anatomic orientation, versus the Grammont-style 155 humeral stem inclination that further medializes and distalizes the center of rotation (COR). The purpose of this study was to compare deltoid force, glenoid strain, and simulated glenohumeral range of motion (ROM) between RSA 135 and RSA 155 designs, with a series of standardized permutations of glenosphere offset and rotator cuff pathology. MethodsTwelve fresh-frozen cadaveric shoulder specimens were studied using a shoulder simulator. Native shoulder motion profiles for reproducible abduction range of motion were established using a customized testing device. Optical 3-dimensional tracking and pressure sensors were used to accurately record glenohumeral range of motion (ROM), deltoid force, and glenoid strain for RSA 135 and RSA 155 designs. For each cohort, all combinations of glenosphere offsets and rotator cuff tendon involvement were evaluated. ResultsThere was no significant difference in the overall abduction ROM between the 155 and the 135 humeral stem implants (P = .75). Resting abduction angle and maximum abduction angle were significantly greater with a 155 + STD (standard offset) construct than with a 135 + STD construct (P < .001 and P = .01, respectively). Both stem inclinations decreased combined deltoid force requirements as compared the native shoulder with a massive cuff tear. Effective glenoid strain did not vary significantly between 135 + STD and 155 + STD constructs (P = .66). ConclusionOverall, range of motion between the 135 and the 155 humeral stem inclinations was not significantly different. The cumulative deltoid force was lower in RSA shoulders when compared to native shoulders with massive rotator cuff tears, highlighting the utility of both implant designs. The Grammont-style 155 stem coupled with a 2.5 mm inferior offset glenosphere required less deltoid force to reach maximum abduction than did the more anatomic, lateralized 135 stem coupled with a 4 mm lateral offset glenosphere. Level of EvidenceBasic Science, Biomechanics Controlled Laboratory Study

Stand Stability of Pure and Mixed-Eucalyptus Forests of Different Tree Species in a Typhoon-Prone Area

Background and Objectives: The stable stand structure of mixed plantations is the basis of giving full play to forest ecological function and benefit. However, the monocultural Eucalyptus plantations with large-scale and successive planting that caused ecological problems such as reduced species diversity and loss of soil nutrients have presented to be unstable and vulnerable, especially in typhoon-prone areas. The objective of this study was to evaluate the nonspatial structure difference and the stand stability of pure and mixed-Eucalyptus forests, to find out the best mixed pattern of Eucalyptus forests with the most stability in typhoon-prone areas. Materials and Methods: In this study, we randomly investigated eight plots of 30 m × 30 m in pure and mixed-Eucalyptus (Eucalyptus urophylla S. T. Blake × E. grandis W. Hill) plantations of different tree species (Neolamarckia cadamba (Roxb.) Bosser, Acacia mangium Willd., and Pinus elliottii var. Elliottii Engelm. × P. caribaea Morelet) on growth status, characterized and compared the distribution of nonspatial structure of the monoculture and mixtures, and evaluated the stand quality and stability from eight indexes of the nonspatial structure, including preservation rate, stand density, height, diameter, stem form, degree of stem inclination, tree-species composition, and age structure. Results: Eucalyptus surviving in the mixed plantation of Eucalyptus and A. mangium (EA) and in the mixed plantation of Eucalyptus and P. elliottii × P. caribaea (EP) were 5.0% and 7.6% greater than those in pure Eucalyptus plantation (EE), respectively, while only the stand preservation rate of EA was greater (+2.9%) than that of the pure Eucalyptus plantation. The proportions of all mixtures in the height class greater than 7 m were fewer than that of EE. The proportions of EA and mixed plantation of Eucalyptus and N. cadamba (EN) in the diameter class greater than 7 m were 10.6% and 7.8%, respectively, more than that of EE. EN had the highest ratio of branching visibly (41.0%), EA had the highest ratio of inclined stems (8.1%), and EP had the most straight and complete stem form (68.7%). The stand stability of the mixed plantation of Eucalyptus and A. mangium presented to be optimal, as its subordinate function value (0.76) and state value (ω = 0.61) of real stand were the largest. Conclusions: A. mangium is a superior tree species to mix with Eucalyptus for a more stable stand structure in the early growth stage to approach an evident and immense stability and resistance, which is of great significance for the forest restoration of Eucalyptus in response to extreme climate and forest management.

ALS as Tool to Study Preferred Stem Inclination Directions

Although gravitropism forces trees to grow vertically, stems have shown to prefer specific orientations. Apart from wind deforming the tree shape, lateral light can result in prevailing inclination directions. In recent years a species dependent interaction between gravitropism and phototropism, resulting in trunks leaning down-slope, has been confirmed, but a terrestrial investigation of such factors is limited to small scale surveys. ALS offers the opportunity to investigate trees remotely. This study shall clarify whether ALS detected tree trunks can be used to identify prevailing trunk inclinations. In particular, the effect of topography, wind, soil properties and scan direction are investigated empirically using linear regression models. 299.000 significantly inclined stems were investigated. Species-specific prevailing trunk orientations could be observed. About 58% of the inclination and 19% of the orientation could be explained by the linear models, while the tree species, tree height, aspect and slope could be identified as significant factors. The models indicate that deciduous trees tend to lean down-slope, while conifers tend to lean leeward. This study has shown that ALS is suitable to investigate the trunk orientation on larger scales. It provides empirical evidence for the effect of phototropism and wind on the trunk orientation.

Genetic variation among and within Quercus suber L. populations in survival, growth, vigor and plant architecture traits

Cork oak is an important forest tree species in the Western Mediterranean region due to the high economic value of its renewable cork and its ecological and social services. However, studies regarding the genetic variation within cork oak populations are scarce, and this gap of knowledge is contributing to the delay of the set-up of a breeding and conservation strategy for the species. In this study, the genetic variation in fitness (survival, height, and stem diameter) and plant architecture traits (apical dominance, stem straightness, stem inclination degree, branchiness), and tree vigor was evaluated among and within cork oak populations in two progeny field trials established in Portugal. Measurements were carried out in each trial in two different periods: ages 9 and 14 years at Monte da Fava trial and 8 and 14 years at Herdade da Caniceira trial. A significant genetic variation among and within cork oak populations was detected for survival, growth, and form traits (stem straightness and inclination). Growth traits presented high values of heritability estimates at the family mean level (≥0.75), and genetic gains were obtained when families with superior growth were selected. Additionally, results highlighted that early selection of families with superior performance could be performed, and it is possible to achieve improvement in both growth and form traits simultaneously, with implications on the profitability and sustainability of cork oak stands.

Accurate derivation of stem curve and volume using backpack mobile laser scanning

Forest inventories rely on field plots, the measurement of which is costly and time consuming by manual means. Thus, there is a need to automate plot-level field data collection. Mobile laser scanning has yet to be demonstrated for deriving stem curve and volume from standing trees with sufficient accuracy for supporting forest inventory needs. We tested a new approach based on pulse-based backpack mobile laser scanner (Riegl VUX-1HA) combined with in-house developed SLAM (Simultaneous Localization and Mapping), and a novel post-processing algorithm chain that allows one to extract stem curves from scan-line arcs corresponding to individual standing trees. The post-processing step included, among others, an algorithm for scan-line arc extraction, a stem inclination angle correction and an arc matching algorithm correcting for the drifts that are still present in the stem points after applying the SLAM algorithm. By using the stem curves defined by the detected arcs and tree heights provided by the pulse-based scanner, stem volume estimates for standing trees in easy (n = 40) and medium (n = 37) difficult boreal forest were calculated. In the easy and medium plots, 100% of pine and birch stems were correctly detected. The total RMSE of the extracted stem curves was 1.2 cm (5.1%) and 1.7 cm (6.7%) for the easy and medium plots, respectively. The RMSE were 1.8 m (8.7%) and 1.1 m (4.9%) for the estimated tree heights, and 9.7% and 10.9% for the stem volumes for the easy and medium plots, correspondingly. Thus, our processing chain provided stem volume estimates with a better accuracy than previous methods based on mobile laser scanning data. Importantly, the accuracy of stem volume estimation was comparable to that provided by terrestrial laser scanning approaches in similar forest conditions. To further demonstrate the performance of the proposed method, we compared our results against stem volumes calculated using the standard Finnish allometric volume model, and found that our method provided more accurate volume estimates for the two test sites. The findings are important steps towards future individual-tree-based airborne laser scanning inventories which currently lack cost-efficient and accurate field reference data collection techniques. The tree geometry defined by the stem curve is also an important input parameter for deriving quality-related information from trees. Forest management decision making will benefit from improvements to the efficiency and quality of individual tree reference information.

Differences between the responses of European larch (Larix decidua Mill.) and Norway spruce (Picea abies (L.) Karst) to landslide activity based on dendrogeomorphic and dendrometric data

Investigations of mass movement hazards need to be supported by accurate data regarding past frequencies of landslide reactivations. Dating landslide events using tree rings is a reliable approach for vegetated slopes in temperate climates. Despite the enhanced use of dendrogeomorphic research during recent decades, little is known about the specific responses of Larix spp. to landslide movements. We investigated the active section (~0.6 ha) of a complex landslide in the Vsetínské vrchy Mts. (Outer Western Carpathians) that is overgrown by a forest stand composed of European larch (Larix decidua Mill.) and Norway spruce (Picea abies (L.) Karst.). Using the dendrometric and dendrogeomorphic data identified from 74 trees (33 L. decidua and 41 P. abies), including the number and types of growth disturbances (GDs) and compiled event chronologies, we compared the responses of both tree species to the same landslide reactivations.We observed the same mean tree stem inclination for both tree species, whereas the inclination azimuths differed. L. decidua generally showed a higher number of stem bends compared to P. abies. Similar proportions of subjectively identified GDs (compression wood, CW, and abrupt growth suppression, GS) and mathematically identified GDs (tree-ring eccentricities) were observed in both tree species. However, the total number of GD.tree−1 was slightly higher in L. decidua (4.1) than in P. abies (3.2). A higher abundance of GS was identified in L. decidua at the expense of CW compared to P. abies. The event chronology based on the mathematical approach revealed slightly more landslide signals than for the subjective approach, mainly in L. decidua. However, the largest known landslide reactivation (in 1997) was recorded in all cases in both tree species. Based on the CW analysis, it was shown that larger stem inclinations are associated with longer persistence of CW in P. abies (rather than L. decidua), resulting in the possible masking of younger landslide events. By contrast, P. abies compensates for that limitation by having a generally shorter mean duration of CW than L. decidua. Overall, it seems that the complexity of landslide movements and root system architecture influenced the number and character of GDs in both tree species. In addition, we did not find any relationships between the measured dendrometric parameters and number of GDs to better assess the most suitable trees for dendrogeomorphic dating prior to sampling. Therefore, we recommend sampling both tree species when they overgrow the same landslide body so that the final event chronology will be more robust and possible limitations of one tree species can be eliminated by the benefits of the second.

Tree-ring eccentricity in the dendrogeomorphic analysis of landslides – A comparative study

The chronological aspects of landslide research are of great interest regarding the hazard assessment of landslide triggers. Dendrogeomorphic methods provide a good ratio of chronology length and dating resolution. An alternative to the standard dendrogeomorphic approaches used in landslide research (based on reaction wood analysis – a reaction to stem inclination) is the analysis of tree-ring eccentricity. This study tests three frequently used dendrogeomorphic approaches based on tree-ring eccentricity and verifies the results by comparing them with the results obtained by the standard dendrogeomorphic expert approach. In total, 125 individual Fagus sylvatica L. trees growing on the block-type landslide of Lipová stráň in the foothills of the Orlické hory Mts. (central Europe) were sampled and used for the analysis. The first tested approach identifies landslide signals based on the analysis of mean eccentricity values from two moving windows. The second tested approach determines landslide signals from a series of eccentricity values based on the use of an eccentricity threshold from reference trees. The last tested approach organizes the eccentricity values into categories and identifies landslide signals based on the defined temporal patterns of the individual categories. The limitations of each approach are revealed, and recommendations for increasing the robustness of each approach are presented. Moreover, the sensitivity of F. sylvatica trees to landslide signals was tested using each approach. The obtained results suggest the need for a specific sampling design (regarding tree age) for each tree-ring eccentricity-based approach.

Structural response of black locust (Robinia pseudoacacia L.) and small-leaved lime (Tilia cordata Mill.) to varying urban environments analyzed by terrestrial laser scanning: Implications for ecological functions and services

Quantitative measurements of structure and morphology of urban trees are hardly exhausted so far, especially in regard to variations caused by altering urban environments. However, structure and functions of trees are heavily interwoven. In fact, knowledge about structural attributes is essential for a better understanding of urban ecosystem functions and services. In order to scrutinize spatially explicit and detailed structural attributes under varying urban environments, we acquired terrestrial laser scans and applied the according methodological approaches to the common urban tree species black locust (Robinia pseudoacacia L.) and small-leaved lime (Tilia cordata Mill.). We analyzed 52 small-leaved limes and 41 black locust trees within the city of Munich (Germany). Species as well as growing location had a significant effect on the height-diameter relation. We also found greater crown volumes for small-leaved lime. Black locust however, displayed more crown projection area and likely more shade efficient crown shapes at similar volumes. Stem inclination of black locust was found to be higher in parks than in street canyons with town squares lying in between. Furthermore, black locust displayed strong crown asymmetry in park areas, likely caused by competition with neighbors. The angles of main branches did not differ significantly between both species nor between the growing location. Branch angles, branch bending, the length of the branches as well as species and growing location had a significant effect on vertical crown center position, i.e. general crown shape. Surface complexity of lime is lower than of black locust, with its lowest manifestation in parks. Fractal-like crown surface structures, increasing surface roughness and complexity, were found to be more pronounced for black locust than for small-leaved lime. Thereby, black locust featured the highest crown surface complexity in parks, the lowest in street canyons. The results suggest that studies on spatially explicit tree structures may contribute to more target oriented tree plantings and thus, more effective exploitation of ecosystem services and benefits.

PROPOSAL FOR A SYSTEM OF TREES FALL POTENTIAL RISK ASSESSMENT IN URBAN PARKS1

ABSTRACT This study aimed to create a system to assess the potential tree fall risk (SARPQA) and to assess all the trees in the Museum Paraense Emílio Goeldi Zoo (PZB/MPEG) and in the Rodrigues Alves Park/Botanical Garden of Amazônia (BRA/JBA). We analyzed aspects, such as diameter at breast height (DBH), tree total heigh, surface biomass, apparent phytosanitary, stem inclination, canopy balance and presence of lianas. We assessed 1074 trees (DBH e” 20 cm) distributed in 229 species and 40 families. The average stem height, the total height and diameter at breast height were 10.9 m, 18.7 m and 41.9 cm respectively. The SARPQA showed that 23 trees had very high risk of fall, 142 had high risk, 750 individuals had medium and low risk and 159 had very low risk. Both parks have hundreds of large trees, which associated with the amount of people using these spaces, can increase the risk of accidents by tree fall. Trees with high risk of fall need immediate attention because they present risks to human life and/or property. The system proposed in this study proved to be practical and can be an effective tool for decision makers in the management of urban parks.

Phloem fibres as motors of gravitropic behaviour of flax plants: level of transcriptome.

Restoration of stem vertical position after plant inclination is a widely spread version of plant orientation in accordance with gravity vector direction. Gravitropic behaviour of flax plants involves the formation of curvature in stem region that has ceased elongation long in advance of stem inclination. The important participants of such behaviour are phloem fibres with constitutively formed tertiary cell wall (G-layer). We performed the large-scale transcriptome profiling of phloem fibres isolated from pulling and opposite sides of gravitropic curvature and compared with control plant fibres. Significant changes in transcript abundance take place for genes encoding proteins of several ion channels, transcription factors and other regulating elements. The largest number of upregulated genes belonged to the cell wall category; many of those were specifically upregulated in fibres of pulling stem side. The obtained data permit to suggest the mechanism of fibre participation in gravitropic reaction that involves the increase of turgor pressure and the rearrangements of cell wall structure in order to improve contractile properties, and to identify the regulatory elements that operate specifically in the fibres of the pulling stem side making gelatinous phloem fibres an important element of gravitropic response in herbaceous plants.

Tree Stem Shapes Derived from TLS Data as an Indicator for Shallow Landslides

Landslides or other forms of mass movement influence slope stability, and are known to have significant effects on vegetation patterns. Observation of such surface patterns may result in valuable information for understanding the kinematics of the landslide. In forested regions, tree growth anomaly is often served as an indicator of shallow landslide activity. Terrestrial laser scanning (TLS) is able to acquire accurate and dense 3D point cloud which provides the potential of reconstructing forest structure. In this study, we obtained high density TLS data in the northern Walgau in the federal state of Vorarlberg in Austria, where translational mass movement phenomenon exists in a forested region. A novel algorithm was developed to fast and robustly characterize single tree parameters (e.g. diameter at breast height (DBH), inclination angle of the stem and stem volume). Consequently, these tree parameters were successfully determined at single tree level. Field measurements were conducted in order to validate the results from the modelling algorithm. The root mean square error of DBH is 1.6cm (4.9%). The average stem inclination angle is 8.2°. The results of this study revealed that characterization of trees (i.e. inclination of the stems) can be used to indicate shallow landslide activities in forested regions. The quantification of tree parameters could also contribute to a better understanding of the interaction between landslides and trees.

Can tree tilting indicate mechanisms of slope movement?

Slope movements are a common natural hazard. That is why considerable funds are spent annually to limit their effects or to research their prevention. This study evaluates dendrometric approaches as a fast and low-cost alternative to classical methods of slope movement mechanism analysis. A total of 1688 trees growing on the Mazák landslide in the Moravskoslezské Beskydy Mts. and 100 reference trees growing out of the landslide area were analysed. The Mazák landslide is approximately 400m in length and presents varied morphological features (scarps, rotated blocks, scree slopes, shallow landslide areas, etc.). The slope and direction of stem inclination was recorded for each tree. The results were categorized into four distinct landforms (scarp with outcrops of bedrock, scree slope, front of partial landslide block, plateau of partial landslide block) and were then compared with parameters for the reference trees.The general model of tree tilting for the landslide area was verified and partially confirmed. Trees growing on the plateau of rotated blocks are predominantly oriented upslope; trees growing on scree slopes of shallow movement and creep are predominantly oriented downslope. Trees growing on rocky scars do not differ significantly from the reference trees. Trees growing from fronts of rotated blocks are oriented both upslope and downslope. From these results, several recommendations regarding dendrometric evidence of slope movement mechanisms are presented: (i) all trees growing on the landslide are to be analysed; (ii) old trees maintain stem tilt intensities and directions for long periods, but young trees are more sensitive to ground movements; (iii) tree root depth influences root sensitivity to movements of various depths; (iv) the general shape of a stem can denote specific mechanisms of slope movement and (v) comparisons with reference trees should always be conducted to exclude potential non-geomorphic effects on tree stem tilt.

Impact of stand density on tree morphology and growth stresses in young beech (Fagus sylvatica L.) stands

According to biomechanical processes, tree morphology (trunk inclination, height-to-diameter ratio and crown area) explains statistically silvicultural effects on growth stress variation. Growth stresses constitute the main mechanism allowing the tree to control its posture against its mechanical environment, but are also among the most important factors contributing to the depreciation of timber value. This study aimed at assessing the link between stand planting density and growth stress level in European beech (Fagus sylvatica) stands. Beech seedlings were planted in four plots corresponding to four planting densities: 2,500, 5,000, 10,000 and 40,000 stems/ha. They were left to grow for 26 years without any intervention, resulting in trees with highly different morphologies but of the same age and provenance. After 26 years of growth, both the tree morphology and growth stress indicators were measured on the standing trees in each plot and an attempt was made to establish a link between them. Our results showed that initial stand density influences growth stresses of the first order as a result of its impact on tree morphology. The best predictors of high growth stresses were high trunk inclination, high height-to-diameter ratio (slenderness factor) and low crown area. According to mechanosensing theories, these morphological criteria emphasised that growth stresses are due to a global mechanical stimulation rather than to local stem inclination alone. Research now has to be undertaken on new methods that combine the integrative assessment of tree morphology as well as its monitoring over time.

ANATOMY AND CHEMICAL COMPOSITION OF LIRIODENDRON TULIPIFERA STEMS INCLINED AT DIFFERENT ANGLES

The anatomical and chemical characteristics of reaction wood (RW) were investigated in Liriodendron tulipifera Linn. Stems of seedlings were artificially inclined at angles of 30 (RW-30), 50 (RW-50) and 70° (RW-70) from the vertical, and compared with normal wood (NW) from a vertical seedling stem. The smallest values for the wood fibre length and vessel number were observed in RW-50. The pit aperture angle was less than 10° in RW-30 and RW-50, in which reduced lignin content was observed in the S2 layer of the wood fibres. An increase in the glucose content and a decrease in the lignin and xylose content was observed in RW-50. The stem inclination angle affected the degree of RW development with regard to anatomical and chemical characteristics: the severest RW was observed in RW-50, followed by RW-30. RW-70 was similar in anatomical and chemical characteristics to NW, apparently because the inclination was too strong to enable recovery of its original position. In this case a vertical sprouting stem was formed to replace the inclined stem.

Comparison between preoperative digital planning and postoperative outcomes in 197 hip endoprosthesis cases using short stem prostheses

BackgroundPreservation of hip geometry is important for treatment success in endoprosthesis implantation. Digital planning can be used to estimate postoperative hip geometry. This study examined whether digital planning accurately predicts surgical outcomes for two femoral neck resecting short stem implants, Mayo® (Zimmer) and Metha® (Aesculap). MethodsPreoperative digital planning of the short stem and acetabular cup was performed for 191 patients (197 endoprostheses) with hip osteoarthritis. Digital planning was done with mediCAD II (Hectec) to evaluate types of prosthesis stems and sizes, leg lengthening and offset, and angle of stem inclination within the femur. The predicted values for these parameters were compared to the postoperative measurements. A double coordinate system was developed to measure pelvic and femoral distances separately. Individual scale factors were applied to minimize measurement bias. FindingsImplantation of the planned short stem prostheses resulted in a mean femoro-acetabular leg lengthening of 4.2mm (SD 5.8mm) and a mean femoro-acetabular offset-reduction of 4.2mm (SD 5.9mm) in comparison with preoperative planning. Implantation of both stems resulted in increased valgization compared to planning (Metha®, mean 5.4° (SD 3.7°); Mayo®, mean −3.2° (SD 3.4°)). InterpretationDifferences between preoperative planning and postoperative outcomes were greater for femoro-acetabular than for cup-related leg length and offset. On average, leg length was longer than predicted and there was loss of femoro-acetabular offset. Compared with the planning, valgization of the implanted stems was frequently observed.

Main complications at treatment of nontraumatic intracerebral hematomas of brain hemispheres

Objective: to identify clinically significant complications. Materials and methods. Surgical treatment using different methods was performed in 116 patients with nontraumatic intracerebral hematomas; conservative treatment was performed in 100 patients. Results. The overall mortality at surgical treatment was 19.8% (at transcortical approach — 29%, trans- and parasilvial — 25%, after stereotactic removal — 7.1%), at conservative treatment — 19%. Causes of death: a) hemorrhage with brain stem inclination (after surgery — 65.2%, conservative treatment — 73.4%); b) thromboembolism (after surgery — 26%, conservative treatment — 15.8%); c) pneumonia (after surgery — 8.7%, conservative treatment — 10.5%); d) re-bleeding in the bed of the removed hematoma — 4.3%. Main clinically significant complications were identified: a) intra- and postoperative (marked brain edema, new bleeding in the cavity of removed hematoma, bacterial meningitis after ventricular drainage), somatic (thromboembolism, thrombophlebitis, pneumonia, septic condition), neurological (pain and spastic syndromes). Conclusions. The most significant cause of death is dislocation and impaction of the brain stem that necessitates further improve of operative techniques, including implementation of fasting-reclinating interventions. The second direction for complications incidence reducing and functional outcome improving is to optimize drug therapy, including widespread use of antioxidants, especially in comatose patients.