Tree Level Research Articles

A Fast Time Synchronization Method for Large Scale LEO Satellite Networks Based on A Bionic Algorithm

A fast time synchronization method for large-scale LEO satellite networks based on a bionic algorithm is proposed. Because the inter-satellite links are continuously established and interrupted due to the relative motion of the satellites, the topology of the LEO satellite networks is time varying. Firstly, according to the ephemeris information in navigation messages, a connection table which records the connections between satellites is generated. Then, based on the connection table, the current satellite network topology is calculated and generated. Furthermore, a bionic algorithm is used to select some satellites as time source nodes and calculate the hierarchy of the clock transmission tree. By taking the minimum level of the time transmission tree as the optimization objective, the time source nodes and the clock stratums of the whole satellite networks are obtained. Finally, the onboard computational center broadcasts the time layer table to all the satellites in the LEO satellite networks and the time synchronization links can be established or recovered fast.

A citizen science method to monitor a polyphagous shot hole borer infestation in Johannesburg's urban forest

Citizen science has become a powerful tool for gathering data, and the validity of these data should be tested. The accuracy of a citizen science database used to monitor the polyphagous shothole borer (PSHB) (Euwallacea fornicatus) (Coleoptera: Curculionidae: Scolytinae) infestation in a suburb of the city of Johannesburg was assessed. Out of 785 trees surveyed by the citizen scientists, 157 trees (20%) were selected as a validation data set to confirm the tree identity, tree health status and level of PSHB infestation. A chi-square (χ2) test was performed to examine whether there was a significant agreement between the citizen scientists’ and researcher’s data used for the classification of the tree infestation, tree health status and PSHB infestation holes. A Cohen’s kappa coefficient was calculated to determine the level of agreement between the two different sources of data, for the infested parts (trunk, main branches, and canopy branches) of the trees surveyed and PSHB infestation signs. The two surveys showed no significance difference for classifying tree health status and PSHB infestation holes. There was a high level of agreement between citizen scientists and the researcher ratings for measures of PSHB infestation (kappa values ranging between 0.71 and 0.89) and the level of agreement was significant. In conclusion, citizen science allowed us to obtain a large quantity of data at a low cost that correlated with the researchers’ validation dataset. Citizen science is a useful method for monitoring PSHB in a diverse urban forest in trees that show obvious signs of infestation.

Cosmological constraints from the EFT power spectrum and tree-level bispectrum of 21 cm intensity maps

We explore the information content of 21 cm intensity maps in redshift space using the 1-loop Effective Field Theory power spectrum model and the bispectrum at tree level. The 21 cm signal contains signatures of dark matter, dark energy and the growth of large-scale structure in the Universe. These signatures are typically analysed via the 2-point correlation function or power spectrum. However, adding the information from the 3-point correlation function or bispectrum will be crucial to exploiting next-generation intensity mapping experiments. The bispectrum could offer a unique opportunity to break key parameter degeneracies that hinder the measurement of cosmological parameters and improve on the precision. We use a Fisher forecast analysis to estimate the constraining power of the HIRAX survey on cosmological parameters, dark energy and modified gravity.

Characteristics of logs with signs of oviposition by the polyphagous xylophage Asian longhorned beetle (Coleoptera: Cerambycidae).

During the eradication program undertaken against Anoplophora glabripennis (Motschulsky) in the Greater Toronto Area, information was collected on the numerous signs of injury found on wounded trees. Herein, we used a portion of this information to assess the characteristics of logs with signs of oviposition (i.e., pits). Specifically, we related the basal diameter, type (log bole vs. log branch), height above ground, and branch hierarchy level of logs with pits to tree size (i.e., height and diameter at breast height) and level of infestation intensity. In general, pits were concentrated on logs from the bole and branches that were 8-14cm in diameter in the lower 8 m of the bole and in the first 2 levels of the branching hierarchy. Oviposition pit location was strongly influenced by tree size-both height and diameter at breast height, with more pits on the lower bole in small trees and then higher on the bole and into the branches as tree size increased. As tree-level infestation intensity increased, pits were found on both larger and smaller diameter portions of the trees, presumably as preferred oviposition sites became saturated. These findings can improve the efficacy of surveillance activities for A. glabripennis.

Phenomenology of isospin-symmetry breaking with vector mesons

We study the effect of isospin-symmetry breaking in the framework of the extended linear σ model in vacuum. In this model, several particles mix with each other at tree level, due to the three nonzero scalar condensates (nonstrange, strange, isospin). We resolve these mixings with the help of various field transformations. We compute all possible meson mixings and decay widths at tree level and perform a χ2 fit to PDG data. A very good fit is found if we exclude the (very small ∼130 keV) ω→ππ decay. We also investigate the violation of Dashen’s theorem. Published by the American Physical Society 2024

One-Loop Double Copy Relation in String Theory

We discuss relations between closed and open string amplitudes at one loop. While at tree level these relations are known as Kawai-Lewellen-Tye (KLT) and/or double copy relations, here we investigate how such relations are manifested at one loop. Although, we find examples of one-loop closed string amplitudes that can strikingly be written as sum over squares of one-loop open string amplitudes, generically the one-loop closed string amplitudes assume a form reminiscent of the one-loop double copy structure of gravitational amplitudes involving a loop momentum. This double copy structure represents the one-loop generalization of the KLT relations. Published by the American Physical Society 2024

Incorporating pruning into the carbon footprint of tree production based on terrestrial laser scanning

Pruning is a major source of carbon emissions from urban trees. The high cost of evaluating pruning quantities by destructive measurements has limited the research on pruning. By combining terrestrial laser scanning and quantitative structure models, pruning quantities can be assessed non-destructively. This study focuses on the impact of pruning during tree production, as it is intense and has been rarely evaluated. Using Sophora japonica from a nursery in Beijing as an example, point cloud data were collected from 181 uneven-aged Sophora japonica for the simulation of pruning at a single tree level. All pruning stages were incorporated into the assessment of the carbon footprint of Sophora japonica production for 15-year-old trees. The results show that previous studies have underestimated the tree carbon footprints of pruning, leading to a severe underestimation of the carbon footprint of tree production. Crown reduction removes the most above-ground woody biomass during tree production, over half, while the decomposition of pruning waste is the most significant source of carbon emissions. The removal ratio from pruning of individual trees is consistent within the same pruning pattern. The tree volume can serve as a good predictor for estimating pruning quantities, but crown diameter sometimes needs to be considered. Implementing pruning interventions, harvesting in advance, and choosing appropriate methods for pruning waste disposal can reduce carbon emissions from pruning.

Study On The Distribution Of Pongamia Pinnata Trees In The Coastal Forest Of Hatusua Village, Kairatu Subdistrict, West Seram Regency

Study on the Distribution of Pongamia Pinnata (Pongamia Pinnata) Wood Species on the Coastal Forest of Hatusua Village, Kairatu Subdistrict, West Seram Regency. The research objective is to determine the morphology and distribution pattern of Pongamia Pinnata wood, using data collection methods such as purposive sampling surveys, a combination of transect and quadrat line methods conducted along the observation paths on the coastal forest. The results of the study show that morphologically, Pongamia Pinnata wood is a tree with woody stems, grayish in color, round in shape with rough and protruding stem surfaces. The height of this tree ranges from 8 to 37.5 meters with a stem diameter reaching 84 cm. The vegetation species diversity for seedling level = H’=2.79, Sapling = 3.46, and tree level H’ =3.17, which is classified as experiencing moderate to high diversity with a clustered distribution pattern

Keragaman Tumbuhan Pakan Burung Cenderawasih di Hutan Kampung Rhepang Muaif Kabupaten Jayapura

The aim of this research is to carry out a vegetation analysis looking at the types of plants at the seedling, sapling, pole and tree level which have the potential to serve as food for birds of paradise. The plotted line method is a measuring tool used to collect vegetation data at the seedling, sapling, pole and tree level. The data obtained is then analyzed to determine Density, Relative Density, Dominance, Relative Dominance, Frequency, Relative Frequency, Importance Value Index and Diversity Index. The research results showed that 5 types of food sources were obtained, namely Palaquium amboinense, Gnetum gnemon, Pometia acuminata and Syzygium sp. The structure and composition of vegetation at the seedling level consists of 21 species with H' (2.74) or medium, the sapling level consists of 34 species with H' (3.16), the pole level 27 species with H' (2.83), tree level 38 species with H' (3.06). Keywords: Bird of Paradise, Food, Muaif Rhepang, Vegetation

The BOSS bispectrum analysis at one loop from the Effective Field Theory of Large-Scale Structure

We analyze the BOSS power spectrum monopole and quadrupole, and the bispectrum monopole and quadrupole data, using the predictions from the Effective Field Theory of Large-Scale Structure (EFTofLSS). Specifically, we use the one loop prediction for the power spectrum and the bispectrum monopole, and the tree level for the bispectrum quadrupole. After validating our pipeline against numerical simulations as well as checking for several internal consistencies, we apply it to the observational data. We find that analyzing the bispectrum monopole to higher wavenumbers thanks to the one-loop prediction, as well as the addition of the tree-level quadrupole, significantly reduces the error bars with respect to our original analysis of the power spectrum at one loop and bispectrum monopole at tree level. After fixing the spectral tilt to Planck preferred value and using a Big Bang Nucleosynthesis prior, we measure σ 8 = 0.794 ± 0.037, h = 0.692 ± 0.011, and Ω m = 0.311 ± 0.010 to about 4.7%, 1.6%, and 3.2%, at 68% CL, respectively.This represents an error bar reduction with respect to the power spectrum-only analysis of about 30%, 18%, and 13% respectively. Remarkably, the results are compatible with the ones obtained with a power-spectrum-only analysis, showing the power of the EFTofLSS in simultaneously predicting several observables. We find no tension with Planck.

Damage to tropical forests caused by cyclones is driven by wind speed but mediated by topographical exposure and tree characteristics.

Each year, an average of 45 tropical cyclones affect coastal areas and potentially impact forests. The proportion of the most intense cyclones has increased over the past four decades and is predicted to continue to do so. Yet, it remains uncertain how topographical exposure and tree characteristics can mediate the damage caused by increasing wind speed. Here, we compiled empirical data on the damage caused by 11 cyclones occurring over the past 40 years, from 74 forest plots representing tropical regions worldwide, encompassing field data for 22,176 trees and 815 species. We reconstructed the wind structure of those tropical cyclones to estimate the maximum sustained wind speed (MSW) and wind direction at the studied plots. Then, we used a causal inference framework combined with Bayesian generalised linear mixed models to understand and quantify the causal effects of MSW, topographical exposure to wind (EXP), tree size (DBH) and species wood density (ρ) on the proportion of damaged trees at the community level, and on the probability of snapping or uprooting at the tree level. The probability of snapping or uprooting at the tree level and, hence, the proportion of damaged trees at the community level, increased with increasing MSW, and with increasing EXP accentuating the damaging effects of cyclones, in particular at higher wind speeds. Higher ρ decreased the probability of snapping and to a lesser extent of uprooting. Larger trees tended to have lower probabilities of snapping but increased probabilities of uprooting. Importantly, the effect of ρ decreasing the probabilities of snapping was more marked for smaller than larger trees and was further accentuated at higher MSW. Our work emphasises how local topography, tree size and species wood density together mediate cyclone damage to tropical forests, facilitating better predictions of the impacts of such disturbances in an increasingly windier world.

Floristic composition of kemenyan toba (Styrax sumatrana) in the community forest Aek Nauli Village, Humbang Hasundutan District, North Sumatra

Kemenyan (Styrax sumatrana) is an local species Tapanuli plant that produces sap with quite high economic value. One of the distribution areas of Styrax sumatrana is Aek Nauli Village, Pullong District, Humbang Hasundutan Regency. Ecologically, research on Styrax sumatrana in Aek Nauli Village has not been carried out much. This study aims to determine the composition of the vegetation and the association of Styrax sumatrana with other plants in the Community Forest of Aek Nauli Village. The method of data collection is done by using the Nested plot method. The results showed that there were 47 types of vegetation included in the seedling, sapling, pole and tree levels. At the Styrax sumatrana seedling level, 29 individu were found, 25 individu at the sapling level, 23 individu at the pole level, and 117 individu at the tree level.

Potential biodiversity of biopesticide plants in the Sopotinjak Sector, Batang Gadis National Park (BGNP), Mandailing Natal, North Sumatera

Indonesia is rich in biodiversity of plant species as a source of medicinal chemicals and biopesticides, most of which have not been identified for their chemical potential. One potential that has not been explored is a source of poisons for the manufacture of biopesticides. This research aims to identify and diversify poisonous plants in the Sopotinjak sector, Batang Gadis National Park (BGNP), Mandailing Natal. The results of the study show that the sopotinjak forest is included in secondary to a primary forest where the H” index (Shannon-Wienner Index) includes height (>3.00) at the level of trees (3.74), poles (3.11), and understoreys (3.41), and moderate (2.00-3.00) at the saplings (2.81) and seedlings (2.23). Vegetation analysis measurements showed that there were 16 species of biopesticide plants where all species had itching, burning, burning, and excessive irritation if exposed to the skin. Based on the level it shows that there are 8 species of tree level, 6 species of saplings and undergrowth, 4 species of poles, and 2 species of seedlings. Based on height it shows that the measurement area is from 1000-1600 masl was not significantly related to the number of individuals found and the species present, found 19-30 species of undergrowth, 9-14 species at seedling level, 16-21 species at sapling level, 10-30 species at pole level, and 32-50 species at tree level.

The effect of local habitat and spatial connectivity on urban seed predation.

During the last centuries, the area covered by urban landscapes is increasing all over the world. Urbanization can change local habitats and decrease connectivity among these habitats, with important consequences for species interactions. While several studies have found a major imprint of urbanization on plant-insect interactions, the effects of urbanization on seed predation remain largely unexplored. We investigated the relative impact of sunlight exposure, leaf litter, and spatial connectivity on predation by moth and weevil larvae on acorns of the pedunculate oak across an urban landscape during 2018 and 2020. We also examined whether infestations by moths and weevils were independent of each other. While seed predation varied strongly among trees, seed predation was not related to differences in sunlight exposure, leaf litter, or spatial connectivity. Seed predation by moths and weevils was negatively correlated at the level of individual acorns in 2018, but positively correlated at the acorn and the tree level in 2020. Our study sets the baseline expectation that urban seed predators are unaffected by differences in sunlight exposure, leaf litter, and spatial connectivity. Overall, our findings suggest that the impact of local and spatial factors on insects within an urban context may depend on the species guild. Understanding the impact of local and spatial factors on biodiversity, food web structure, and ecosystem functioning can provide valuable insights for urban planning and management strategies aimed at promoting urban insect diversity.

Height-diameter models for King Boris fir (Abies borisii regis Mattf.) and Scots pine (Pinus sylvestris L.) in Olympus and Pieria Mountains, Greece

In forest science and practice, the total tree height is one of the basic morphometric attributes at the tree level and it has been closely linked with important stand attributes. In the current research, sixteen nonlinear functions for height prediction were tested in terms of their fitting ability against samples of Abies borisii regis and Pinus sylvestris trees from mountainous forests in central Greece. The fitting procedure was based on generalized nonlinear weighted regression. At the final stage, a five-quantile nonlinear height-diameter model was developed for both species through a quantile regression approach, to estimate the entire conditional distribution of tree height, enabling the evaluation of the diameter impact at various quantiles and providing a comprehensive understanding of the proposed relationship across the distribution. The results clearly showed that employing the diameter as the sole independent variable, the 3-parameter Hossfeld function and the 2-parameter Näslund function managed to explain approximately 84.0% and 81.7% of the total height variance in the case of King Boris fir and Scots pine species, respectively. Furthermore, the models exhibited low levels of error in both cases (2.310m for the fir and 3.004m for the pine), yielding unbiased predictions for both fir (−0.002m) and pine (−0.004m). Notably, all the required assumptions for homogeneity and normality of the associated residuals were achieved through the weighting procedure, while the quantile regression approach provided additional insights into the height-diameter allometry of the specific species. The proposed models can turn into valuable tools for operational forest management planning, particularly for wood production and conservation of mountainous forest ecosystems.

Effect of Spraying with Marvel Nutrient and Antioxidants on the Mineral Content of Apricot leaves Labib Cultivar

This study was carried out in one of the orchards of Kerbala city/Al-Hussainiya district. Where 30 apricot trees of Labib cultivar were selected, each tree was considered as an independent experimental unit with three replications. Foliar fertilizer by Marvel Nutrient solution at a concentration (0,2) ml/L was the first factor and the second factor was antioxidants which represented by ascorbic acid and citric acid at concentrations (500,1000) mg/L. for each tree. In addition, water was sprayed as the control application. The results showed that there was a significant effect for experimental treatments on the content apricot trees leaves of the mineral elements (Nitrogen, phosphorus, potassium, zinc and iron as the nutrient solution F2 and the antioxidant factor A2, S2 were superior. The interactions between factors F2*A2, F2* S2 (nutrient solution and antioxidants) was greater in giving the highest results levels of the content apricot trees leaves of the mineral elements (NPK, Fe and Zn).

A mechanism relating the fermionic mass hierarchy to the flavor mixing

Considering the hierarchical structure of fermionic masses and the fermionic flavor mixing puzzles in the Standard Model, we propose to relate them by the see-saw mechanism, i.e. only the third generation of quarks and charged leptons achieves the masses at the tree level, the first two generations achieve masses through the mixings with the third generation, and the neutrinos achieve tiny Majorana masses by the so-called Type-I see-saw mechanism. This new picture at the fermion sector can explain simultaneously the flavor mixing puzzle and mass hierarchy puzzle in the SM. In addition, a flavor-dependent model (FDM) is proposed to realize the new mechanism, and observing the top quark rare decay processes t→ch, t→uh and the lepton flavor violation processes μ→3e,τ→3e,μ→3μ is effective to test the proposed FDM.

S-matrix positivity without Lorentz invariance: a case study

We investigate the analytic structure of scattering amplitudes in theories in which Lorentz invariance is spontaneously broken. We do so by computing and studying the S-matrix for a simple example: a superfluid described by a complex scalar with quartic interactions. The computation is confined to tree-level, for there are no absolutely stable single-particle states, though the lifetime can be made long by lowering the chemical potential. For the 2 → 2 amplitude in center-of-mass configurations, not only is crossing symmetry violated, there appears a tree level branch cut for unphysical kinematics. Its appearance is a consequence of non-analyticity in the dispersion relation. The branch point defines a new scale in the problem, which scales inversely with the chemical potential. In this example, even derivatives of the forward amplitude are positive while odd derivatives are negative. This pattern can be understood in a general way in the limit of a small chemical potential, or weak Lorentz breaking.

95 GeV Higgs boson in the Georgi-Machacek model

CMS and ATLAS have reported small excesses in the search for low-mass Higgs bosons in the diphoton decay channel at exactly the same mass, 95.4 GeV. These searches rely on improved analysis techniques, enhancing in particular the discrimination against the Z→e+e− background. In models beyond the Standard Model (SM) that extend the Higgs sector with triplets, doubly charged Higgs bosons are predicted which can contribute substantially to the diphoton decay rate of a light Higgs boson. The Georgi-Machacek (GM) Model is of particular interest in this context, since despite containing Higgs triplets it preserves the electroweak ρ-parameter to be 1 at the tree level. We show that within the GM model, a Higgs boson with a mass of ∼95 GeV with a diphoton decay rate as observed by CMS and ATLAS can be well-described. We discuss the diphoton excess in conjunction with an excess in the bb¯ final state observed at LEP and an excess observed by CMS in the ditau final state, which have been found at comparable masses with local significances of about 2σ and 3σ, respectively. The presence of a Higgs boson at about 95 GeV within the GM model would imply good prospects of the searches for additional light Higgs bosons. In particular, the observed excess in the diphoton channel would be expected to be correlated in the GM model with a light doubly charged Higgs boson in the mass range between 100 and 200 GeV, which motivates dedicated searches in upcoming LHC Runs. Published by the American Physical Society 2024

Zonal Chemical Signal Pathways Mediating Floral Induction in Apple.

Phytohormones that trigger or repress flower meristem development in apple buds are thought to be locally emitted from adjacent plant tissues, including leaves and fruitlets. The presence of fruitlets is known to inhibit adjacent buds from forming flowers and thus fruits. The resulting absence of fruitlets the following season restores flower-promoting signalling to the new buds. The cycle can lead to a biennial bearing behaviour of alternating crop loads in a branch or tree. The hormonal stimuli that elicit flowering is typically referred to as the floral induction (FI) phase in bud meristem development. To determine the metabolic pathways activated in FI, young trees of the cultivar 'Ruby Matilda' were subjected to zonal crop load treatments imposed to two leaders of bi-axis trees in the 2020/2021 season. Buds were collected over the expected FI phase, which is within 60 DAFB. Metabolomics profiling was undertaken to determine the differentially expressed pathways and key signalling molecules associated with FI in the leader and at tree level. Pronounced metabolic differences were observed in trees and leaders with high return bloom with significant increases in compounds belonging to the cytokinin, abscisic acid (ABA), phenylpropanoid and flavanol chemical classes. The presence of cytokinins, namely adenosine, inosine and related derivatives, as well as ABA phytohormones, provides further insight into the chemical intervention opportunities for future crop load management strategies via plant growth regulators.