Branching Order Research Articles

Enhancing Surgical Guidance: Deep Learning-Based Liver Vessel Segmentation in Real-Time Ultrasound Video Frames.

In the field of surgical medicine, the planning and execution of liver resection procedures present formidable challenges, primarily attributable to the intricate and highly individualized nature of liver vascular anatomy. In the current surgical milieu, intraoperative ultrasonography (IOUS) has become indispensable; however, traditional 2D ultrasound imaging's interpretability is hindered by noise and speckle artifacts. Accurate identification of critical structures for preservation during hepatectomy requires advanced surgical skills. An AI-based model that can help detect and recognize vessels including the inferior vena cava (IVC); the right (RHV), middle (MHV), and left (LVH) hepatic veins; the portal vein (PV) and its major first and second order branches the left portal vein (LPV), right portal vein (RPV), and right anterior (RAPV) and posterior (RPPV) portal veins, for real-time IOUS navigation can be of immense value in liver surgery. This research aims to advance the capabilities of IOUS-guided interventions by applying an innovative AI-based approach named the "2D-weigthed U-Net model" for the segmentation of multiple blood vessels in real-time IOUS video frames. Our proposed deep learning (DL) model achieved a mean Dice score of 0.92 for IVC, 0.90 for RHV, 0.89 for MHV, 0.86 for LHV, 0.95 for PV, 0.93 for LPV, 0.84 for RPV, 0.85 for RAPV, and 0.96 for RPPV. In the future, this research will be extended for real-time multi-label segmentation of extended vasculature in the liver, followed by the translation of our model into the surgical suite.

Ortaokul Öğrencilerinin Kitap Edinme Eğilimleri

Bu araştırmada kitap okuma alışkanlığının somut göstergelerinden biri olan öğrencilerin kitap edinme eğilimleri incelenmiştir. Kitap edinme eğilimi, kitap okuma alışkanlığına sahip öğrencilerin ilk ve en öncelikli davranışıdır. Araştırmada öğrencilerin kitap edinme eğilimlerini yönlendiren değişkenler belirlenmeye çalışılmıştır. Araştırma kapsamında ders kitabındaki metinler ile araştırmacılar tarafından tasarlanan kitap önerisi, sınav yapılması, yazar söyleşisi, müze gezisi ve disiplinlerarası çalışma gibi değişkenlerin öğrencilerin kitap edinme eğilimleri üzerindeki rolü araştırılmıştır. Araştırma nitel araştırma yönteminin desenlerinden olan durum çalışması deseni kullanılarak hazırlanmıştır. Araştırmanın çalışma grubunu, 2021-2022 eğitim-öğretim yılında İstanbul’daki bir ortaokulun 6. sınıf öğrencileri oluşturmaktadır. Araştırma 29 hafta sürmüştür. Çalışmanın başlangıcında yapılandırılmamış görüşme formu ile öğrencilerin kitap edinmelerindeki etkenler sorgulanmıştır. Araştırmanın 19 haftası I. dönem ders kitabındaki metinlere yöneliktir. Bu metinlere yönelik yarı yapılandırılmış görüşme formu ve bireysel görüşmeler ile öğrencilerin kitap edinme eğilimleri ve ders kitaplarındaki metinler, yazar bilgisi, yazarların farklı kitapları, metinlere yönelik görüşleri alınmıştır. II. dönem ise 10 hafta boyunca beş kitap edinme etkinliği öğrencilere uygulanmış ve öğrencilerin görüşleri yarı yapılandırılmış görüşme formu ve bireysel görüşmeler ile alınmıştır. Yarı yapılandırılmış görüşme formu ile toplanan araştırma verileri içerik analizine tabi tutularak kodlanmış ve ulaşılan bulgular yorumlanmıştır. Alınan görüşlerden her bir etkinliğin güçlü ve zayıf yönleri ile fırsat ve tehditleri ortaya çıkartılarak SWOT analizi yapılmıştır. Araştırma sonucunda ders kitaplarındaki metinlerin öğrencileri kaynak kitaba yönlendirmediği sonucuna ulaşılmıştır. II. dönem yapılan etkinlikler sonucunda öğrencilerin bir kitabı en çok sınav yapılacağı uyarısı ile edindiği, öğrencilerin %88’inin yazar söyleşisi ve disiplinlerarası çalışma etkinlikleri sonrası kitap edindikleri görülmüştür. Öğretmenlere, öğrencilerinin kitap edinme eğilimlerini etkilemek için okullarına yazar davet etmeleri veya farklı branştaki öğretmenler ile iş birliği yaparak aynı kitabı önermeleri önerilmiştir.

Depth-Dependent Contributions of Various Vascular Zones to Cerebral Autoregulation and Functional Hyperemia: An In-Silico Analysis.

Autoregulation and neurogliavascular coupling are key mechanisms that modulate myogenic tone (MT) in vessels to regulate cerebral blood flow (CBF) during resting state and periods of increased neural activity, respectively. To determine relative contributions of distinct vascular zones across different cortical depths in CBF regulation, we developed a simplified yet detailed and computationally efficient model of the mouse cerebrovasculature. The model integrates multiple simplifications and generalizations regarding vascular morphology, the hierarchical organization of mural cells, and potentiation/inhibition of MT in vessels. Our analysis showed that autoregulation is the result of the synergy between these factors, but achieving an optimal balance across all cortical depths and throughout the autoregulation range is a complex task. This complexity explains the non-uniformity observed experimentally in capillary blood flow at different cortical depths. In silico simulations of cerebral autoregulation support the idea that the cerebral vasculature does not maintain a plateau of blood flow throughout the autoregulatory range and consists of both flat and sloped phases. We learned that small-diameter vessels with large contractility, such as penetrating arterioles and precapillary arterioles, have major control over intravascular pressure at the entry points of capillaries and play a significant role in CBF regulation. However, temporal alterations in capillary diameter contribute moderately to cerebral autoregulation and minimally to functional hyperemia. In addition, hemodynamic analysis shows that while hemodynamics within capillaries remain relatively stable across all cortical depths throughout the entire autoregulation range, significant variability in hemodynamics can be observed within the first few branch orders of precapillary arterioles or transitional zone vessels. The computationally efficient cerebrovasculature model, proposed in this study, provides a novel framework for analyzing dynamics of the CBF regulation where hemodynamic and vasodynamic interactions are the foundation on which more sophisticated models can be developed.

STUDY OF THE INFLUENCE OF THE CHEMICAL COMPOSITION OF RAILWAY AXLE STEEL ON THE UNIFORMITY OF THE FINAL MICROSTRUCTURE

The relevance of the work. For modern railway transport, increasing the strength and operational reliability of rolling stock parts, in particular railway axles, is an urgent task. It is known that the inhomogeneity of the distribution of chemical elements in the structure of structural grade carbon steels is formed mainly during their crystallization and may subsequently affect the final structural state and set of properties. Purpose. Study of the influence of the chemical composition of steels for railway axles on the uniformity of the structure. Methodology. Experimental ingots of different chemical compositions with different amounts and ratios of the main chemical elements within the range of OS and EA1N were produced in laboratory conditions. The grain structure was studied on microsections after etching with nital. Chemical inhomogeneity (“traces” of the dendritic structure) − the distribution of chemical elements in the microstructure of cast samples was detected by etching in a hot solution of sodium picrate. Metallographic analysis was performed on a light (optical) microscope “Axiovert 200 M MAT” manufactured by “Carl Zeiss”. The results. The effect of changing the chemical composition of carbon steel, which is intended for the manufacture of railway axles, on the peculiarities of the formation of ferrite-pearlite heterogeneity and grain size is determined. It is shown that in samples of steels corresponding to the EA1N brand with a lower carbon content, the distribution of phases is uneven. The mechanism of formation of such a structure is explained from the point of view of two theories. In samples of steels with an average carbon content, which correspond to steel of the OS grade, the distribution of the pearlite and ferrite phases is more uniform, the relationship between the size and the degree of darkening of the pearlite areas with the order of the former dendritic branches has been established. Based on the results of the quantitative analysis of the final grain structure, it was established that OS steel with an average carbon content at different Mn/Si ratios has a more uniform grain structure. EA1N steel with a lower carbon content has a pronounced grain size, with an increase in the Mn/Si ratio, the largest maximum of the dependence of the distribution shifts to a larger grain size (smaller number). Practical results. Increasing the homogeneity of the final microstructure contributes to increasing the plasticity and viscosity of steel, which directly affects the reliability and durability of railway axles.

L1-Tree: A novel algorithm for constructing 3D tree models and estimating branch architectural traits using terrestrial laser scanning data

Branch architecture provides crucial information for the understanding of plant trait variability and the adaptive strategies employed by trees in response to their environment. High-fidelity terrestrial laser scanning (TLS) data provide an accurate, efficient, and non-destructive means for constructing three-dimensional (3D) tree models and estimating architectural traits. However, the complex canopy structure of trees in natural forests and the presence of occlusion in TLS data pose significant challenges to achieving this goal. In this study, we present a novel algorithm, L1-Tree, for the construction of 3D tree models and the estimation of architectural traits from TLS data. This algorithm is grounded in the L1-Median algorithm and integrates a tree skeleton optimization procedure that considers the structural characteristics of tree branches. By comparing modeling results and manually derived branch traits for 24 trees of 24 species, we found that the L1-Tree algorithm achieved precision, recall, and F-score values of 0.94 for branch identification, coefficient of determination, root-mean-squared error, and normalized root-mean-squared error of 0.998, 0.068 m, and 0.3 % for branch length estimation, and a respective value of 0.958, 0.257 cm and 0.9 % for branch radius estimation. Additionally, the branch identification accuracy and accuracy in branch architectural trait estimation remained satisfactory across branch orders. Compared to established 3D tree model construction algorithms (e.g., TreeQSM), our L1-Tree algorithm demonstrated a superior capability in handling noisy environments and data gaps, making it a robust tool for TLS data-based tree architecture studies. Leaf-wood separation emerged as a crucial step influencing the performance of the L1-Tree algorithm. We observed significant drop in branch identification accuracy when using an automatic leaf-wood separation algorithm as input, highlighting the urgent need to develop effective leaf-wood separation algorithms to generate high-quality wood point clouds for tree architecture studies.

Specific leaf area and its within-individual variation in understory evergreen and deciduous woody species in New Zealand

Specific leaf area (SLA) plays a critical role in carbon assimilation and nutrient cycling. While leaf habit (deciduous vs. evergreen) has often been recognized as a reliable predictor of SLA—with deciduous species typically having higher mean SLA values due to lower concentration of structural components compared to evergreens—high variation in SLA among evergreen species suggests further investigation of variation for species with this leaf habit could improve predictions of SLA effects on community and ecosystem processes. Furthermore, the presence of leaves of different ages in evergreen plants, emerging over multiple years, could amplify the within-individual variation in SLA, which remains underexplored. Here we report variations of SLA measured from c. 2000 leaves collected from 36 individuals across 19 woody species in an understory environment in New Zealand (NZ). We found that while most deciduous species, predominantly non-native, clustered towards higher SLA values, evergreen species presented a wide SLA spectrum. Moreover, we found that while being deciduous, having a smaller leaf size, and younger leaves, collected from lateral branches, correlated with elevated SLA values, the leaf habit did not primarily drive the within-individual SLA variation. Instead, smaller leaf size emerged as a significant predictor of within-individual SLA variation. The branch-order effect on SLA underscores a methodological consideration: accurate estimation of total leaf area in evergreen trees requires representative sampling across all branch orders. Our study also highlights the need for integrating leaf traits such as leaf size and branch order into functional trait analyses. Further research is vital to understand the underlying mechanisms of these trait variations and their impacts on ecosystem functioning.

Branching response to stem density and its impact on yield in hybrid potato grown from true seeds and seedling tubers

ContextHybrid potato crops can be grown from true potato seeds or from seedling tubers. True-seed-grown plants produce lower marketable tuber yield than seedling-tuber-grown plants, because of their low early vigour and distinct growth and development patterns, notably in term of main stem number and stem branching. These differences are pivotal for yield formation but their impacts on crop performance and yield are not well understood. ObjectivesWe quantified the differences between the propagule types (true seeds vs seedling tubers) in their branching responses to stem density and assessed to what extent these differences contribute to differences in crop development and tuber production. MethodsTwo field experiments were conducted in different years, planting transplants from true seeds and pre-sprouted seedling tubers from the same genotype, while controlling their stem density per unit area. Responses in stem branching and biomass partitioning to stem density were quantified on individual main stems, followed by an evaluation of the impact of these responses on crop performance. ResultsOn individual main stems in both propagule types, higher stem density decreased branch development, decreased the number of branches above- and belowground, resulted in shifts in aboveground branch distribution towards lower branching orders, and led to smaller tuber sizes. However, such branching responses were stronger in true-seed-grown plants than in seedling-tuber-grown plants. At crop level, differences between propagule types were significant in canopy duration, number of tubers, tuber size distribution and marketable yield, but there was no stem density effect. ConclusionOur results emphasized the differences between propagule types in branching and its impact on crop development and tuber yield, due to the absence of stem density effects. Propagule type effects could be attributed to intrinsic differences between propagule types in branching control, growth habit and source-sink relations. These effects are relevant for hybrid potato breeding and require further research. Management practices were partly responsible for year-to-year differences in branching and yield formation, which highlights their significance for hybrid potato production.

The genus Cortinarius should not (yet) be split

The genus Cortinarius (Agaricales, Basidiomycota) is one of the most species-rich fungal genera, with thousands of species reported. Cortinarius species are important ectomycorrhizal fungi and form associations with many vascular plants globally. Until recently Cortinarius was the single genus of the family Cortinariaceae, despite several attempts to provide a workable, lower-rank hierarchical structure based on subgenera and sections. The first phylogenomic study for this group elevated the old genus Cortinarius to family level and the family was split into ten genera, of which seven were described as new. Here, by careful re-examination of the recently published phylogenomic dataset, we detected extensive gene-tree/species-tree conflicts using both concatenation and multispecies coalescent approaches. Our analyses demonstrate that the Cortinarius phylogeny remains unresolved and the resulting phylogenomic hypotheses suffer from very short and unsupported branches in the backbone. We can confirm monophyly of only four out of ten suggested new genera, leaving uncertain the relationships between each other and the general branching order. Thorough exploration of the tree space demonstrated that the topology on which Cortinarius revised classification relies on does not represent the best phylogenetic hypothesis and should not be used as constrained topology to include additional species. For this reason, we argue that based on available evidence the genus Cortinarius should not (yet) be split. Moreover, considering that phylogenetic uncertainty translates to taxonomic uncertainty, we advise for careful evaluation of phylogenomic datasets before proposing radical taxonomic and nomenclatural changes.

ЭФФЕКТИВНОСТЬ ИСПОЛЬЗОВАНИЯ НОВЫХ МОРФОБИОТИПОВ ГРЕЧИХИ В СЕЛЕКЦИИ ДЛЯ ЗАСУШЛИВЫХ УСЛОВИЙ СРЕДНЕГО ПОВОЛЖЬЯ

The research was carried out to evaluate the effectiveness of using fasciated buckwheat morphobiotypes in the breeding process when creating varieties for the conditions of the Middle Volga region. The single-factor experiment was laid in 2018-2023 on gray forest soils of the Republic of Tatarstan. The soil of the experimental plot contained 3.2...4.4% humus (according to Tyurin), 110...123 mg/kg of potassium and 145...377 mg/kg of phosphorus (according to Kirsanov), pH - 5.3...6.6. The objects of the study were Batyr variety, which in plant habit corresponds to “Krasnostreletskiy” variety, Yashlek variety and the hybrid population of K-990, with a predominance of forms with fasciations of the stem and generative zone in the population. The inclusion of fasciated genotypes with reduced branching in hybrid populations forms a compact plant habit, compared to the “Krasnostreletskiy” variety, due to a decrease in plant height by 5.6...9.1%, a 1.3...1.6 times reduction in the number of laterals first order branches. At the same time, due to an increase in the number of inflorescences on the main stem by 25...30%, the productivity of the plant increases by 1.2 times. The grain yield of the hybrid population K-990 was the highest in both unfavorable and favorable years (1.68 t/ha and 2.17 t/ha, respectively). As for Batyr variety, it directly depended on the amount of precipitation that fell during the interphase period “the beginning of fruit formation - the beginning of fruit browning” (r = 0.77) and had a strong inverse relationship with the average daily temperature during the period of grain ripening (r = -0.77). The productivity and grain size of Yashlek variety depended on average daily temperatures, while in the hybrid population K-990 there was a direct strong relationship between the yield and the amount of precipitation that fell in the initial growing season (r = 0.93).

Crashworthiness analysis of bio-inspired hierarchical multi-cell circular tubes under axial crushing

Drawing inspiration from nature’s hierarchical organization, we propose a novel bio-inspired hierarchical multi-cellular circular tubes (BHMC) with a fractal structure. Using an experimentally validated LS-DYNA finite element model, we investigated the impact resistance of this structure under axial loading. Numerical analysis was conducted to explore the energy absorption performance of BHMC tubes with varying numbers of branches, fractal orders, and tube masses. The numerical findings indicate that specific energy absorption (SEA) increases with higher numbers of fractal orders. Specifically, the SEA of 2nd order BHMC tubes surpasses that of conventional multicellular circular and single-layer tubes by approximately 35.07% and 17.10%, respectively. Optimal performance is achieved with the proposed structure featuring tree branching (N = 6) and 2nd order fractal characteristics, yielding the highest specific absorption energy across different parameters. These results offer valuable insights for designing multicellular bilayer tubes with superior energy absorption efficiency, providing an effective guideline for structural optimization.

Effect of competition intensity and neighbor identity on architectural traits of Fagus sylvatica

Key messageDifferences in architectural traits of European beech saplings submitted to different levels of competition intensity and neighborhood diversity show a shift toward lateral growth exploration for overtopped trees but less expressed apical control is maintained for beech grown with conifers.Crown plasticity is a fundamental process to optimize the acquisition of light in forests, where it is often the limiting factor for growth. The processes leading to crown dynamics in response to biotic interaction are controlled by the competitive status of a tree, as well as the species diversity of the neighborhood. Yet, the ontogenic diversity of the different branches leading to crown structure makes it difficult to model crown plasticity. In this study, we used single-image photogrammetry and a semi-automatic topology reconstruction software to map the architecture of 3-year-old European beech trees (Fagus sylvatica L.) grown in pure pots or mixed with Douglas fir (Pseudotsuga menziesii (Mirbel) Franco) or Norway spruce (Piceaabies L. H.Karst). Further, we investigated the effect of competition intensity (estimated with height rank) and neighbourhood diversity on architectural traits. To do so, we quantified the mean volume, slenderness, number of branches, branching rate, internode length, and diameter ratio for each stem and branch, up to the order three. Overtopped trees developed fewer branches and biomass but allocated more biomass to branches of a higher order than to the stem. The increase in the ramification of the stem and the diameter ratio of the first-order branches for overtopped trees indicate a shift in the growth strategy and a decrease in apical control. As competition intensity and neighbour identity have opposite effects on stem traits, it seems that the positive effect of plant diversity on growth can be attributed to the intrinsic effects of species identity rather than to competition release.

Genotypic variations appear in fine root morphological traits of Cryptomeria japonica trees grown in a common garden

AbstractFine root morphological traits regulate the belowground resource acquisition strategies of trees. Therefore, investigating genotypic variations isolated from environmental variations within tree species helps in understanding how genotypic backgrounds affect intragenerational tree acclimation to the growing environment. Thus, this study aimed to clarify the effects of genotypic variations on the fine root morphology of three types of Japanese cedar (Cryptomeria japonica), which were derived from different provenances but were grown in a common garden. In the three geographically different provenances of C. japonica stands (Yanase, Yoshino, and Yaku), fine root morphological traits, such as root length and diameter and specific root length (SRL), were measured for each root up to the 4th branching order. Yaku cedar exhibited root traits distinct from the other provenances, such as growing longer and thinner roots in 1st root order to enhance root surface area. In addition, the SRL patterns with root orders and higher root tissue density suggested a resource conservation strategy. Yanase cedar demonstrated a significantly higher root branching ratio and specific root tips than the other provenances, indicating a strategy for investing resources in absorptive roots. Although Yoshino cedar had traits similar to those of Yanase cedar or intermediate between Yanase and Yaku cedars, high aboveground production may be achieved through nutrient acquisition with root exudates instead of absorptive root growth. Genotypic variations appeared in fine root morphological traits of C. japonica trees, even when grown in the same environments, implying distinct resource acquisition strategies characterized by each provenance.

Treegraph: tree architecture from terrestrial laser scanning point clouds

AbstractAccurate quantification of tree architecture is critical to interpreting the growth, health and functioning of trees and forests. Terrestrial laser scanning (TLS) offers millimetre‐level point cloud data, but current approaches to 3D tree reconstruction from TLS point clouds primarily focus on retrieving total volume at tree scale for aboveground biomass (AGB) estimation. Few methods have been designed specifically to provide tree architectural properties, including branch‐level morphology and topology, rather than AGB; derived topological traits have tended to be a compromise, and of secondary importance to volume. We present Treegraph, a new approach explicitly designed to retrieve the architectural traits of trees at multiple scales, from the whole tree scale down to individual branches and internodes, using TLS data with limited assumptions about tree form. It provides morphological traits such as branch length and diameter, alongside topological traits including parent–daughter connections of branches and internodes, furcation (branching) number and branch order. We compare Treegraph‐derived morphological and topological traits with manual measurements of branches from eight destructively harvested trees, yielding RMSE values of 0.60 m (5.96%) for branch length, 2.99 cm (33.45%) for branch diameter, 0.46 (19.38%) for furcation number and 0.08 m (33.16%) for internode length, respectively. In a broader application to 603 trees from tropical, temperate and urban forests, we demonstrate that the derived morphological and topological traits support testing of structure‐related metabolic scaling theories. Testing branches over 10 cm in diameter across 18 657 branching nodes shows that Treegraph‐derived branch‐level scaling exponents deviate from WBE predictions, exhibiting area‐preserving behaviour while displaying asymmetry in length and diameter of daughter branches. Available as open‐source Python software, Treegraph provides fine‐level branching network information, promoting improved insights into tree structure and function. This data‐driven approach reduces the need for empirical heuristic parameters, which has the potential for advancing large‐scale ecological studies on tree architecture.

Towards an objective assessment of tree vitality: a case study based on 3D laser scanning

Key messageAnalyzing fine branch length characteristics in beech trees using single-tree QSMs derived from laser scanning reveals insights into drought-induced changes in vitality, which include branch shedding and reduced shoot growth.Climate change causes increasing temperatures and precipitation anomalies, which result in deteriorations of tree health and declines in ecosystem services of forests. It is therefore crucial to monitor tree vitality to preserve forests and their functions. However, methods describing tree vitality in situ are lacking reproducibility or are too laborious. Thus, we tested a laser-scanning based approach, assuming that an objective measurement of a tree’s outer shape should reveal changes according to tree vitality. QSMs of similarly sized beech trees from stands with varying degrees of drought damage were used. Absolute and relative fine branch lengths, their ratio to lower order branches’ lengths and their progressions over relative height were targeted to identify fine branch dieback and reduced growth. The absolute fine branch length was significantly lower for less vital beech trees, especially within the upper crown, leading to a less top-heavy vertical distribution of fine branches and a reduced fine-to-base order branch length ratio. Hence, height-dependent characteristics of fine branch lengths differed between vitalities. We conclude that using fine branch length characteristics derived from QSMs can be helpful in vitality assessments of beech trees. Still, uncertainties with regard to the plotwise assessment and problems with QSM quality are present.

Patterns and controlling factors of decomposition in distal shoot systems by branch order across 10 temperate tree species

Patterns and controlling factors of decomposition in distal shoot systems by branch order across 10 temperate tree species

Stretched sapwood, ultra-widening permeability, and ditching da Vinci: revising models of plant form and function.

The mechanisms leading to dieback and death of trees under drought remains unclear. For constructing an understanding of these mechanisms, addressing major empirical gaps regarding tree structure-function relations remains essential. We give reasons to think that a central factor shaping plant form and function is selection favoring both constant leaf specific conductance with height growth and isometric (1:1) scaling between leaf area and the volume of metabolically active sink tissues ("sapwood"). Sapwood volume-leaf area isometry implies that per-leaf area sapwood volumes become transversely narrower with height growth; we call this "stretching." Stretching means that selection must favor increases in permeability above and beyond that afforded by tip-to-base conduit widening (ultra-widening permeability), as via fewer and wider vessels or tracheids with larger pits or larger margo openings. Leaf area-metabolically active sink tissue isometry would mean that it is unlikely that larger trees die during drought because of carbon starvation due to greater sink-source relationships as compared to shorter plants. Instead, increase in permeability is most plausibly associated with greater risk of embolism, and this seems a likelier culprit of the preferential vulnerability of larger trees to climate change-induced drought. Other implications of selection favoring constant per-leaf area sapwood construction and maintenance costs are departure from the da Vinci rule expectation of similar sapwood areas across branching orders, and that extensive conduit furcation in the stem seems unlikely. Because all of these considerations impact the likelihood of vulnerability to hydraulic failure versus carbon starvation, both implicated as key suspects in forest mortality, we suggest that these predictions represent essential priorities for empirical testing.

A novel, proof-of-concept radiofrequency renal denervation strategy to improve procedural efficiency: 12-month results from the SPYRAL DYSTAL pilot study

BackgroundCatheter-based renal sympathetic denervation (RDN) reduced blood pressure (BP) in multiple randomized sham-controlled trials of patients with uncontrolled hypertension (HTN). We tested proof-of-concept for a more selective treatment strategy, exclusively targeting these areas to improve the efficiency of the procedure. MethodsThe SPYRAL DYSTAL Pilot study was designed to mirror the SPYRAL HTN-OFF MED Pivotal study, enabling comparison with a propensity score adjusted active-control group. Patients were antihypertensive medication-free for one month before undergoing BP assessment. Those with office BP of 150–180/>90 mmHg and with an ambulatory systolic BP of 140–170 mmHg were selected to undergo open label treatment, delivering energy only to the distal main renal arteries and first order branches. Patients from DYSTAL were compared with patients who underwent maximized RF RDN treatment in the prior randomized OFF MED trial at 3 months. After 3 months, patients resumed antihypertensive medications as indicated. Safety and efficacy outcomes were assessed post hoc through 12 months. ResultsThe SPYRAL DYSTAL Pilot study treated 56 HTN patients. Baseline office systolic BP (OSBP) and 24-h ambulatory systolic BP (ASBP) were similar between DYSTAL and OFF MED patient groups. The number of ablations (32.3 ± 8.0 vs 46.6 ± 15.3, p < 0.001), procedure time (67 ± 21 min vs 99 ± 36 min; p < 0.001), and contrast volume (173 ± 77 cc vs 208 ± 96 cc; p = 0.014) were significantly lower with the simplified treatment strategy. OSBP and ASBP changes compared with baseline were −9.0 and −1.4 mmHg at 3 months, −20.3 and −13.9 mmHg at 6 months, and −20.3 and −16.6 mmHg at 12 months, respectively. During the medication up-titration phase, BP reductions among DYSTAL patients were similar to reductions observed in OFF MED through 12 months, with comparable number of drugs (1.4 and 1.5 medications, respectively (P=NS)). Two adverse events related to guidewire placement were reported. ConclusionIn this pilot study, focusing ablation treatment on the distal main and proximal branch renal arteries was performed, resulting in fewer RF lesions, and reduced contrast volume and procedure time. Whether BP reductions are similar between a selective vs. maximized RDN approach requires further prospective study.

Optimization of RNAi efficiency in PVD neuron of C. elegans.

PVD neuron of C. elegans has become an attractive model for the study of dendrite development and regeneration due to its elaborate and stereotype dendrite morphology. RNA interference (RNAi) by feeding E. coli expressing dsRNA has been the basis of several genome wide screens performed using C. elegans. However, the feeding method often fails when it comes to knocking down genes in nervous system. In order to optimize the RNAi conditions for PVD neuron, we fed the worm strains with E. coli HT115 bacteria expressing dsRNA against mec-3, hpo-30, and tiam-1, whose loss of function are known to show dendrite morphology defects in PVD neuron. We found that RNAi of these genes in the available sensitive backgrounds including the one expresses sid-1 under unc-119 promoter, although resulted in reduction of dendrite branching, the phenotypes were significantly modest compared to the respective loss of function mutants. In order to enhance RNAi in PVD neurons, we generated a strain that expressed sid-1 under the promoter mec-3, which exhibits strong expression in PVD. When Pmec-3::sid-1 is expressed in either nre-1(-)lin-15b(-) or lin-15b(-) backgrounds, the higher order branching phenotype after RNAi of mec-3, hpo-30, and tiam-1 was significantly enhanced as compared to the genetic background alone. Moreover, knockdown of genes playing role in dendrite regeneration in the nre-1(-)lin-15b(-), Pmec-3-sid-1[+] background resulted in significant reduction in dendrite regeneration following laser injury. The extent of dendrite regrowth due to the RNAi of aff-1 or ced-10 in our optimized strain was comparable to that of aff-1 and ced-10 mutants. Essentially, our strain expressing sid-1 in PVD neuron, provides an RNAi optimized platform for high throughput screening of genes involved in PVD development, maintenance and regeneration.

Tibial nerve branching pattern and compatibility of branches for the deep fibular nerve.

In individuals who develop drop foot due to nerve loss, several methods such as foot-leg orthosis, tendon transfer, and nerve grafting are used. Nerve transfer, on the other hand, has been explored in recent years. The purpose of this study was to look at the tibial nerve's branching pattern and the features of its branches in order to determine the suitability of the tibial nerve motor branches, particularly the plantaris muscle motor nerve, for deep fibular nerve transfer. There were 36 fixed cadavers used. Tibial nerve motor branches were observed and measured, as were the lengths, distributions, and thicknesses of the common fibular nerve and its branches at the bifurcation region. The motor branches of the tibial nerve that supply the soleus muscle, lateral head, and medial head of the gastrocnemius were studied, and three distinct forms of distribution were discovered. The motor branch of the gastrocnemius medial head was commonly observed as the first branch to divide, and it appeared as a single root. The nerve of the plantaris muscle was shown to be split from many origins. When the thickness and length of the motor branches measured were compared, the nerve of the soleus muscle was determined to be the most physically suited for neurotization. In today drop foot is very common. Traditional methods of treatment are insufficient. Nerve transfer is viewed as an application that can both improve patient outcomes and hasten the patient's return to society. The nerve of the soleus muscle was shown to be the best candidate for transfer in our investigation.

Responses of Fine Root Morphological and Chemical Traits among Branch Orders to Forest Thinning in Pinus massoniana Plantations

Fine roots play an essential role in biogeochemical cycling in forest ecosystems; however, little is known about the response of fine root morphology and chemistry in different root orders to forest management activities such as forest thinning. We investigated the fine root morphological and chemical traits in different root orders of Pinus massoniana under different thinning intensities, namely no thinning, low-intensity thinning (LIT), middle-intensity thinning (MIT), and high-intensity thinning (HIT) (0%, 25%, 45%, and 65% of individual trees eliminated, respectively). We found that forest thinning increased the root diameter (RD) of absorptive roots and decreased that of transport roots, while the trend for the specific root length (SRL) was the opposite. LIT and MIT could increase specific surface area (SSA), especially the SSA of absorptive roots in the MIT treatment. The root tissue density (RTD) of all root sequences in the LIT treatment decreased but increased in the HIT treatment. For the fine root chemical traits, thinning increased the root carbon concentration (RCC) of absorptive roots. The root nitrogen concentration (RNC) and root phosphorus concentration (RPC) of first- to fourth-order roots increased in the LIT and MIT treatments after thinning. Meanwhile, thinning increased root lignin, cellulose, and non-structural carbohydrate (NSC) concentrations. Soil temperature, nitrate, and microbial biomass carbon were factors affecting variations in fine root morphology and chemistry. Forest thinning was likely to shift the absorptive roots’ foraging strategy into a resource-conserving one. Thinning increased fine root chemical traits in most root orders. These findings contributed to our ability to predict how belowground ecological processes are mediated by fine roots under forest management activities.