Regular Tree Research Articles

Recovering of Olive Groves Infected by Xylella fastidiosa subsp. pauca in Apulia (Italy) Through a Sustainable Management Strategy

Abstract Xylella fastidiosa subsp. pauca , listed as a quarantine bacterium in the European Union, has spread in Salento (Apulia, Southern Italy) landscape causing severe damage to the olive cultivation. X. fastidiosa is the causal agent of the “olive quick decline syndrome” (OQDS). Through a series of multidisciplinary studies, it has been possible to assess and set up an effective management strategy for maintaining the traditional olive germplasm of Salento. For this aim, a systemic biocomplex containing zinc (4%), copper (2%) and citric acid is sprayed to the tree canopy, once per month, from spring to early autumn. The strategy also includes sustainable vector control through agronomical techniques as well as the regular tree pruning and soil fertilization. Quantitative real-time polymerase chain reaction (PCR) assessments showed a significant reduction of X. fastidiosa subsp. pauca concentration in the xylem tissue of the leaves upon the treatments, thus allowing the olive trees to normally yield. Both 1 H-NMR metabolomic and mass-spectrometry lipidomic analyses of leaf extracts revealed the occurrence of biomarkers linked to the disease or tree restoration. After the spray treatment, a rapid re-programming in the metabolic tree activity has been observed. Multi-scale satellite imagery monitoring confirmed the robustness of the strategy for several years in both experimental and productive olive groves. Currently, the strategy is applied in many olive groves of Salento. Some aggressive fungal species belonging to the Neofusicoccum genus have been found to be associated with olive trees that show symptoms very similar to OQDS and that are also co-infected by X. fastidiosa subsp . pauca . Information © The Author 2024

Automating Unrealizability Logic: Hoare-Style Proof Synthesis for Infinite Sets of Programs

Automated verification of all members of a (potentially infinite) set of programs has the potential to be useful in program synthesis, as well as in verification of dynamically loaded code, concurrent code, and language properties. Existing techniques for verification of sets of programs are limited in scope and unable to create or use interpretable or reusable information about sets of programs. The consequence is that one cannot learn anything from one verification problem that can be used in another. Unrealizability logic (UL), proposed by Kim et al. as the first Hoare-style proof system to prove properties over sets of programs (defined by a regular tree grammar), presents a theoretical framework that can express and use reusable insight. In particular, UL features nonterminal summaries ---inductive facts that characterize recursive nonterminals (analogous to procedure summaries in Hoare logic). In this work, we design the first UL proof synthesis algorithm, implemented as Wuldo. Specifically, we decouple the problem of deciding how to apply UL rules from the problem of synthesizing/checking nonterminal summaries by computing proof structure in a fully syntax-directed fashion. We show that Wuldo, when provided nonterminal summaries, can express and prove verification problems beyond the reach of existing tools, including establishing how infinitely many programs behave on infinitely many inputs. In some cases, Wuldo can even synthesize the necessary nonterminal summaries. Moreover, Wuldo can reuse previously proven nonterminal summaries across verification queries, making verification 1.96 times as fast as when summaries are instead proven from scratch.

Performance Study of Collection Tree Protocol in Mobile Wireless Sensor Network

The Mobile Wireless Sensor Networks (MWSN) are defined as the successor of Wireless Sensor Networks (WSN); geographically distributed autonomous mobile sensors for physical and environmental conditions monitoring. Mobile sensor networks are more flexible than static sensor networks as they can cope with rapid topology changes. Sensor networks are deployed by having their sensors collect information reliably and then relay the sensor readings to a central base station using wireless multi-hop transmission. Multi-hop routes within a rapid-changed topology requires a routing protocol that can adapt to network changes with an efficient communication mechanism among the nodes; to comply with the energy-constraint nature of the wireless sensor networks. Through significant simulation on this study using the AVRora simulator, the Collection Tree Protocol’s (CTP) capacity to respond to MWSN’s changing network topology was assessed by analysing the performance indicators; specifically, the average of packet loss and energy use of mobile nodes with different circumstances considering varied quantities of mobile nodes in the simulation region, with different velocities and network density. In several circumstances, the implementation of CTP in MWSN indicates a rise in energy usage because of broken linkages along with regular tree regeneration brought on by node mobility.

Rational weighted tree languages with storage

We define the class of rational weighted tree languages with storage over complete, not necessarily commutative, semirings and we repeat its characterization by weighted regular tree grammars with storage. Moreover, we show an alternative proof of the fact that the class of rational weighted tree languages with storage is closed under the rational operations, i.e., top-concatenation, scalar multiplication, sum, tree concatenation, and Kleene-star, where the latter two closure results require that the storage has a reset instruction.

H2|2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {H}^{2|2}$$\\end{document}-model and Vertex-Reinforced Jump Process on Regular Trees: Infinite-Order Transition and an Intermediate Phase

We explore the supercritical phase of the vertex-reinforced jump process (VRJP) and the H2|2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {H}^{2|2}$$\\end{document}-model on rooted regular trees. The VRJP is a random walk, which is more likely to jump to vertices on which it has previously spent a lot of time. The H2|2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {H}^{2|2}$$\\end{document}-model is a supersymmetric lattice spin model, originally introduced as a toy model for the Anderson transition. On infinite rooted regular trees, the VRJP undergoes a recurrence/transience transition controlled by an inverse temperature parameter β>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta > 0$$\\end{document}. Approaching the critical point from the transient regime, β↘βc\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta \\searrow \\beta _{\ extrm{c}}$$\\end{document}, we show that the expected total time spent at the starting vertex diverges as ∼exp(c/β-βc)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim \\exp (c/\\sqrt{\\beta - \\beta _{\ extrm{c}}})$$\\end{document}. Moreover, on large finite trees we show that the VRJP exhibits an additional intermediate regime for parameter values βc<β<βcerg\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta _{\ extrm{c}}< \\beta < \\beta _{\ extrm{c}}^{\ extrm{erg}}$$\\end{document}. In this regime, despite being transient in infinite volume, the VRJP on finite trees spends an unusually long time at the starting vertex with high probability. We provide analogous results for correlation functions of the H2|2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {H}^{2|2}$$\\end{document}-model. Our proofs rely on the application of branching random walk methods to a horospherical marginal of the H2|2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {H}^{2|2}$$\\end{document}-model.

Universal inequalities for Dirichlet eigenvalues on discrete groups

We prove universal inequalities for Laplacian eigenvalues with Dirichlet boundary condition on subsets of certain discrete groups. The study of universal inequalities on Riemannian manifolds was initiated by Weyl, Pólya, Yau, and others. Here we focus on a version by Cheng and Yang. Specifically, we prove Yang-type universal inequalities for Cayley graphs of finitely generated amenable groups, as well as for the d -regular tree (simple random walk on the free group).

Dirac walks on regular trees

The study of matter fields on an ensemble of random geometries is a difficult problem still in need of new methods and ideas. We will follow a point of view inspired by probability theory techniques that relies on an expansion of the two point function as a sum over random walks. An analogous expansion for Fermions on non-Euclidean geometries is still lacking. Casiday et al (2022 Linear Multilinear Algebr. 72 325–65) proposed a classical ‘Dirac walk’ diffusing on vertices and edges of an oriented graph with a square root of the graph Laplacian. In contrast to the simple random walk, each step of the walk is given a sign depending on the orientation of the edge it goes through. In a toy model, we propose here to study the Green functions, spectrum and the spectral dimension of such ‘Dirac walks’ on the Bethe lattice, a d-regular tree. The recursive structure of the graph makes the problem exactly solvable. Notably, we find that the spectrum develops a gap and that the spectral dimension of the Dirac walk matches that of the simple random walk ( ds=1 for d = 2 and ds=3 for d⩾3 ).

Parsing Unranked Tree Languages, Folded Once

A regular unranked tree folding consists of a regular unranked tree language and a folding operation that merges (i.e., folds) selected nodes of a tree to form a graph; the combination is a formal device for representing graph languages. If, in the process of folding, the order among edges is discarded so that the result is an unordered graph, then two applications of a fold operation are enough to make the associated parsing problem NP-complete. However, if the order is kept, then the problem is solvable in non-uniform polynomial time. In this paper, we address the remaining case, where only one fold operation is applied, but the order among the edges is discarded. We show that, under these conditions, the problem is solvable in non-uniform polynomial time.

Checking equivalence of corecursive streams: An inductive procedure

In recent work, non-periodic streams have been defined corecursively, by representing them with finitary equational systems built on top of various operators, besides the standard constructor. When only the stream constructor is allowed in equations, only periodic streams can be represented, and the structures of periodic streams and infinite regular trees are isomorphic. Therefore, one can use the theory of regular trees to get a sound and complete procedure to decide whether two equational systems are equivalent, that is, define the same streams. However, such an isomorphism no longer exists if one allows other operators in equations; in particular, there exist systems of equations which have the same unique solution as streams, but not as regular trees. Hence, equality of regular trees becomes stronger then equality of streams, with a negative impact on termination of functions whose definition is based on the equivalence of the representation of streams as finitary equational systems. To overcome this problem, we provide a weaker definition of equivalence, and prove its soundness and relative completeness. This definition is coinductive, hence non-algorithmic. However, we show that it can be turned into an equivalent inductive procedure.

Continuous-Time Quantum Walk in Glued Trees: Localized State-Mediated Almost Perfect Quantum-State Transfer.

In this work, the dynamics of a quantum walker on glued trees is revisited to understand the influence of the architecture of the graph on the efficiency of the transfer between the two roots. Instead of considering regular binary trees, we focus our attention on leafier structures where each parent node could give rise to a larger number of children. Through extensive numerical simulations, we uncover a significant dependence of the transfer on the underlying graph architecture, particularly influenced by the branching rate (M) relative to the root degree (N). Our study reveals that the behavior of the walker is isomorphic to that of a particle moving on a finite-size chain. This chain exhibits defects that originate in the specific nature of both the roots and the leaves. Therefore, the energy spectrum of the chain showcases rich features, which lead to diverse regimes for the quantum-state transfer. Notably, the formation of quasi-degenerate localized states due to significant disparities between M and N triggers a localization process on the roots. Through analytical development, we demonstrate that these states play a crucial role in facilitating almost perfect quantum beats between the roots, thereby enhancing the transfer efficiency. Our findings offer valuable insights into the mechanisms governing quantum-state transfer on trees, with potential applications for the transfer of quantum information.

Sum-connectivity Spectra of Level-wise Regular Trees

Sum-connectivity Spectra of Level-wise Regular Trees

Management of the olive decline disease complex caused by Xylella fastidiosa subsp. pauca and Neofusicoccum spp. in Apulia, Italy

Xylella fastidiosa subsp. pauca (Xfp) is associated with olive quick decline syndrome (OQDS), a severe disease affecting the olive groves of Salento (Apulia, Italy). Through a series of interdisciplinary studies, an effective management strategy aimed at maintaining the traditional olive germplasm has been developed and evaluated. Specifically, a systemic biocomplex formulation containing zinc (4%), copper (2%) and citric acid, is sprayed on the tree canopy once per month from spring to early autumn. The strategy also includes sustainable vector control through agronomical techniques as well as regular tree pruning and soil fertilization. Quantitative real-time PCR assessments performed in a mid- and long-term studies showed a significant reduction in the Xfp concentration in the leaf xylem tissue upon treatment, improving olive tree yield. Both 1H-NMR metabolomic and mass spectrometric lipidomic analyses of leaf extracts revealed the occurrence of biomarkers linked to disease or tree restoration. The effects of mannitol and oleuropein derivatives, 13-oxylipins/DOX-oxylipins and 9-oxylipins appear to be related to the attenuation of disease symptoms. Both techniques indicate rapid reprogramming of metabolic tree activity upon spray treatment to regain tree health. Multiscale satellite imagery monitoring through high-resolution Sentinel-2, very high-resolution Pleiades and vegetation indices confirmed the robustness of the strategy over several years in both experimental and productive olive groves. Currently, this strategy is applied in many infected olive groves in Salento. Notably, some aggressive fungal species belonging to the Neofusicoccum genus have been recently found to be associated with olive trees that show symptoms similar to those induced by Xfp. Coinfections between this bacterium and fungi have also been frequently observed, suggesting the need for a more in-depth assessment of the epidemiology and management of OQDS.

A universal canopy gap fraction model for forests with various tree distributions based on Nilson's models considering directional overlaps among crowns

An accurate estimation of forest canopy gap fraction (GF) is a prerequisite for remote sensing retrievals of several associated canopy parameters e.g. leaf area index, fAPAR (fraction of photosynthetically active radiation absorbed by the canopy), clumping index, etc. A universal canopy GF model for forests is required for various tree distribution patterns on flat and slopping terrains, yet existing models so far do not possess all these abilities simultaneously. For example, the Neyman type-A model, the Poisson model, and the hypergeometric model are suitable only to forests with clumped, random, and regular tree distributions, respectively. In this regard, the suite of Nilson's canopy GF models developed for forests with various tree distributions have the potential to become universal models. For this purpose, this study attempts to overcome the following limitations of these models to make them be true universally applicable: (1) canopy GF calculated by the Nilson's models is mostly accurate for various tree distributions at nadir; whereas at it is either underestimated for clumped tree distributions or overestimated for regular tree distributions at off-nadir; and (2) Nilson's models were developed for flat terrains and untested for sloping terrains. Herein, two Nilson's models are modified by expanding the calculation of overlaps among crowns (OAC) at nadir to the whole hemispherical space. The results show that all canopy GF simulations in the new models (New91 and New99) show higher consistency with ray-tracing results than those in original Nilson's models in all directions, highlighting the need to consider directional OAC. The modified models (especially for New99) are validated in two RAMI forest stands and a Saihanba forest stand: the relative error in canopy GF between the modified models and a ray-tracing model is less than 10 % in all forest stands. The modified models (especially New99) are suitable for various tree distributions on flat and slopping terrains and therefore increased the universality of the original Nilson's models suitable for a wide-range of remote sensing applications. New99 can be deemed as a universal canopy GF model for forests with various tree distributions.

Tree carbon stock analysis in education forest KHDTK Wanadipa UNDIP, Semarang

Global warming occurs due to increased gases from human activity. Efforts that can be made to minimize global warming are through the forestry sector. Trees play an ecological role, namely as carbon sinks and biomass storage throughout the plant body. The purpose of this study was to analyze the estimated value of carbon stocks in tree biomass in the Special Purposes Forest Area (SPFA) Wanadipa UNDIP Semarang Regency. The sampling method used for measuring tree biomass is the non-destructive method. The non-destructive method is a method that is carried out without destroying or taking all parts of the plant. Data analysis used was the calculation of tree biomass and carbon stocks, and statistical tests of the effect of tree diameter and tree height on carbon stocks in tree biomass. The research station that has the highest carbon stock value is the conservation block of 213,621.25 kg/ha or 213.62 tons/ha. The species that have the highest carbon stock value are Tectona grandis (Jati) and Swietenia mahagoni (Mahoni) in the research block. The amount of carbon that is increasing in the atmosphere at this time must be balanced with the amount of absorption, one of which is by conserving forests, namely through regular tree planting and paying attention to their regeneration, so that trees in carrying out their ecological role can be maintained.

Transportation Distance between Probability Measures on the Infinite Regular Tree

Transportation Distance between Probability Measures on the Infinite Regular Tree

A limit law for the most favorite point of simplerandom walk on a regular tree

A limit law for the most favorite point of simplerandom walk on a regular tree

Climate Change Impact Vulnerability Assessment: The Case of Coastal Communities in Central Zambales, Philippines

The Philippines is one of the countries most affected by climate change. As an archipelago country, coastal areas are at high risk of sea level rise due to climate change. This study investigated the vulnerability of coastal areas to sea level rise in selected municipalities in Zambales province, Philippines. The results showed that the coastal barangay of Iba City has a “moderate” to “high” level of vulnerability, while Botolan City has a “high” to “very high” level of vulnerability. Limited areas of nature reserves, such as mangrove, seagrass, and coral reef ecosystems, are one of the key factors contributing to high vulnerability. Concerted efforts of the local government units and the residents play a vital role to mitigate impacts of climate change including regular mangrove tree planting, coastal clean-up drive, and strict implementation of environmental policies. While there are many tools used in vulnerability assessment, a simpler yet reliable is recommended as an appropriate for barangay levels. With the identified vulnerability of the communities in sea level rise, possible mitigation measures to cope with the fast-changing climate could now be established.&#x0D;

Bahaya Hewan Liar (Wild Life Hazard) Terhadap Pelayanan Lalu Lintas Penerbangan di Bandar Udara Internasional Hang Nadim Batam

This research was conducted at Hang Nadim International Airport, Batam, to investigate the handling of wildlife hazards that impact flight operations and safety. The research methodology used was qualitative descriptive. Data collection techniques included documentation study and direct field observations from December 2020 to March 2021. The research findings indicated that the presence of wildlife activities at Hang Nadim International Airport can compromise the safety objectives of Air Traffic Service (ATS). Instances of aircraft experiencing delays during takeoff and landing were identified, along with frequent discoveries of bird carcasses on the runway that could become Foreign Object Debris (FOD), thereby affecting the smooth flow of air traffic. Special attention is required to manage wildlife hazards in order to enhance flight operations and safety at Hang Nadim International Airport. Additionally, effective coordination and structured management systems are needed, including the establishment of a dedicated unit for wildlife prevention, the procurement of bird repellent devices for prevention purposes, surveillance and control of bird disturbances in the vicinity of the airport, regular tree felling and land clearance around the airport to prevent wildlife nesting and foraging, and infrastructure improvements to eliminate potential entry points for wildlife into the manouvering and movement areas.

Systems involving mean value formulas on trees

Abstract In this paper, we study the Dirichlet problem for systems of mean value equations on a regular tree. We deal both with the directed case (the equations verified by the components of the system at a node in the tree only involve values of the unknowns at the successors of the node in the tree) and the undirected case (now the equations also involve the predecessor in the tree). We find necessary and sufficient conditions on the coefficients in order to have existence and uniqueness of solutions for continuous boundary data. In a particular case, we also include an interpretation of such solutions as a limit of value functions of suitable two-players zero-sum games.

Interdisciplinary Perspectives on Green Infrastructure: A Systematic Exploration of Definitions and Their Origins

Green Infrastructure (GI) is rooted in ecology and cuts across multiple disciplines, including landscape architecture, environmental sciences, planning, policy, and engineering. Likewise, the definition of this concept also cuts across disciplines, which creates ambiguity around what GI is and what makes up GI in practice—for example, mistaking bioswales for regular tree planters or green space within communities in which they are installed. We undertook a systematic literature review of 38 peer-reviewed articles for this study using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) method to identify and synthesize the different disciplinary definitions of GI in the literature. This study also presents the types of GI systems mentioned in the peer-reviewed articles while identifying other benefits apart from the primary benefit of GI installation, which is stormwater management. The analysis revealed three clusters of GI definitions: (I) Interconnected natural areas and other open spaces, (II) Strategically planned natural and semi-natural areas, and (III) Decentralized systems and techniques. However, we got rid of the third cluster during the analysis because GI is known to be a decentralized system, and the definition region could not be tracked. These clusters represent a spectrum, one of which employs the structure of natural systems already in place to support human goals (bio-inclusivity). The other includes living systems as components within engineered solutions to achieve objectives (bio-integration). This review points to the need for an encompassing definition that cuts across disciplines with a consensus on the adoption and concise categorization of GI types and the multiple benefits they provide to humans and ecosystems. A consensus definition helps clear misconceptions and improve the understanding of GI, potentially improving receptivity towards these solutions within communities from a community member perspective.