Rayleigh processes, real trees, and root growth with re-grafting

The real trees form a class of metric spaces that extends the class of trees with edge lengths by allowing behavior such as infinite total edge length and vertices with infinite branching degree. Aldous's Brownian continuum random tree, the random tree-like object naturally associated with a standard Brownian excursion, may be thought of as a random compact real tree. The continuum random tree is a scaling limit as N tends to infinity of both a critical Galton-Watson tree conditioned to have total population size N as well as a uniform random rooted combinatorial tree with N vertices. The Aldous--Broder algorithm is a Markov chain on the space of rooted combinatorial trees with N vertices that has the uniform tree as its stationary distribution. We construct and study a Markov process on the space of all rooted compact real trees that has the continuum random tree as its stationary distribution and arises as the scaling limit as N tends to infinity of the Aldous--Broder chain. A key technical ingredient in this work is the use of a pointed Gromov--Hausdorff distance to metrize the space of rooted compact real trees.Comment: 48 Pages. Minor revision of version of Feb 2004. To appear in Probability Theory and Related Field

The spans in Brownian motion

For $d \in \{1,2,3\}$, let $(B^d_t;~ t \geq 0)$ be a $d$-dimensional standard Brownian motion. We study the $d$-Brownian span set Span(d):=\{t-s;~ B^d_s=B^d_t~\mbox{for some}~0 \leq s \leq t\}. We prove that almost surely the random set $Span(d)$ is $\sigma$-compact and dense in $\mathbb{R}_{+}$. In addition, we show that $Span(1)=\mathbb{R}_{+}$ almost surely; the Lebesgue measure of $Span(2)$ is $0$ almost surely and its Hausdorff dimension is $1$ almost surely; and the Hausdorff dimension of $Span(3)$ is $\frac{1}{2}$ almost surely. We also list a number of conjectures and open problems.Comment: 33 pages, 4 figures. This paper is published by http://projecteuclid.org/euclid.aihp/150062403

INTERPAKS-An Attempt to Aid Agricultural Communications Around the World

Like many programs, the International Program for Agricultural Knowledge Systems (INTERPAKS) germinated in the high-acid soil of need and frustration

From flood science to flood policy: The Foresight Future Flooding Project, seven years on.

Purpose: The Foresight Future Flooding (FFF) project researched flood risk in the UK to the year 2100 for central government, using scenarios and a national risk assessment model backed by qualitative analysis from panels of some 45 senior scientists. The purpose of this paper is to assess the impact of the project, both nationally and internationally. Design/methodology/approach: This paper assesses the impact of the FFF project, both nationally and internationally, using web searches, document analysis, and a questionnaire survey of key actors in the flood risk management policy field. Findings: It was found that the penetration of the project into professionals' consciousness was high in relation to other comparable projects and publications, and its impact on policy - both immediately and continuing - was profound. The FFF initiative did not create policy change, however, but facilitated its legitimation, adding impetus to what was already there, as one element of a part-catalytic and part-incremental process of policy evolution. Research limitations/implications: Special circumstances, internal and external to the project, mean that this cannot be a simple model for matching research to policymakers' needs in the future. Practical implications: Important lessons may be learnt from this project about both the methods of forward-looking foresight-type research, and the way that its results are disseminated to its target audiences. Originality/value: This is an innovative attempt to assess the impact of a new type of foresight project. © Emerald Group Publishing Limited

Tackling Structure and Format -- The \u27Great Unknown\u27 in Professional Blogging

This article addresses a gap in guidelines for those who blog professionally. It does so in a way that uniquely serves extension and research communicators. Many types of blogs have been used and described. Plenty of generic advice is available about writing blogs. However, little of it involves how to organize them. In this analysis, for example, advice about structure and format of blogs made up less than 3 percent of the 315 tips identified. A review of journalism literature identif ied some of the practices used in structuring news and information for media. The review also identified formats for organizing several other cousins of blogs. This article introduces a unique hybrid format for blogs, based on experiences of one of the authors. It involves a seven-step process that incorporates elements of objective reporting (explaining) with those of subjective expression (stimulating and advocating)

Decision Data Services: A New Resource For Communications Planning

While communicators benefit from communication research to guide their planning, external and internal constraints often prevent them from carrying out the research

Fitting Farm Safety into Risk Communications Teaching, Research and Practice

New safety challenges are emerging as agriculture evolves within the complexity of serving a growing world population. The nation’s most hazardous industry is struggling to provide safe working environments in the face of demographic changes in the agricultural work force, new technologies, new kinds of enterprises, pushback against regulation, and other forces. Such changes introduce new forms of occupational risk and create greater need for appropriate safety communications. This study examined potentials for improving engagement of the agricultural media, which serve as primary information channels for farmers. Those who teach agricultural communications are key gatekeepers in preparing skilled professional agricultural journalists and other agricultural communicators. Therefore, the study focused on potentials for strengthening skills in farm safety communications through teaching programs in agricultural journalism and communications. The second and related purpose involved advancing understanding of conceptual linkages between farm safety communications and risk communications, using a safety-oriented framework of risk communications. A mixed methods research design involved quantitative and qualitative approaches using an online survey among faculty representatives in 23 agricultural communications programs at universities throughout the nation. Responses identified encouraging potentials and useful direction for integrating farm safety into agricultural communications courses. Findings also shed helpful light on conceptual linkages between risk communications and a seemingly “lost cousin” — farm safety communications. They pointed to new potentials for agricultural communications teaching and scholarship in strengthening connections between theory and practice in risk communications (including farm safety communications) related to agriculture

The Spirit Lives On: Communication Seminars as a Surprisingly Hardy, Valuable, and Promising Heritage of NPAC

After many decades, dwindling numbers of communicators, extension personnel, and development professionals recall the National Project in Agricultural Communications (NPAC) of the 1950s and early 1960s. But around the world many professionals, scholars, and organizations can recognize the spirit and legacy of NPAC, which has had substantial impact well beyond its original national mission. NPAC became the springboard for a long-running series of communication seminars that built the capacity of foreign students, studying in the United States, to return home better able to communicate as change agents in fostering development. Seminars of NPAC also point to key ingredients for addressing urgent issues facing our nation and world today. This study addresses the origins, features, transitions, durability, and impacts of those communication seminars across nearly 60 years. The authors used historical analysis to reveal a surprising trail of service that leads to the present day and beyond. It provides new insights about how the NPAC communication training program has exerted more than 15 kinds of impact on agricultural development, on organizations at all levels throughout the world - and on individuals touched by it. The analysis highlights insightful, unpublished backstories about the communication training heritage of NPAC. It also identifies key elements of effective communication training programs and identifies opportunities for further research and practice. It could help readers identify professional development innovations the Journal of Applied Communications will advance and report during its second century

Marine Archaeological Survey at the Texas Park and Wildlife Department’s North Todd, Resignation, and South Dollar Reef Sites, Galveston Bay, Chambers and Galveston Counties, Texas

Under contract to the Texas Parks and Wildlife Department, Gray & Pape, Inc., of Houston, Texas, conducted a Phase I marine archaeological survey for the Texas Parks and Wildlife Department’s North Todd, Resignation, and South Dollar proposed artificial reef sites in Chambers and Galveston Counties, Texas. The archaeological survey was sponsored by the Texas Parks and Wildlife Department. The Areas of Potential Effect for the proposed reef sites cover an approximate total of 84.4 hectares (209 acres) over three separate project areas. All three areas are on National Oceanic and Atmospheric Administration nautical chart #11327, Upper Galveston Bay – Houston Ship Channel – Dollar Point to Atkinson. The submerged land for the project areas are in State Tract numbers which administered by the Texas General Land Office; therefore, work was completed under Texas Antiquities Permit Number 9514. The United States Army Corps of Engineers, Galveston District has been identified as the lead federal agency, and the conduct of the project meets the requirements contained in Section 106 of the National Historic Preservation Act of 1966, as amended, the regulations of the Advisory Council of Historic Preservation (30 CFR Part 800), the National Environmental Policy Act of 1969, as amended. All marine fieldwork and reporting activities were completed with reference to state law (Antiquities Code of Texas [Title 9, Chapter 191 of the Texas Natural Resources Code] and Texas State rules found in the Texas Administrative Code [Title 13, part 2, Chapters 26 and 28]) for cultural resources investigations. All project records are curated with the Texas Park and Wildlife Department in Austin, Texas. The Texas Parks and Wildlife Department requested this archaeological survey over the proposed areas in support of planned oyster reef habitat restoration and enhancement projects. All restoration work will be done under a Nationwide 27 permit to be issued by the United States Army Corps of Engineers. Proposed restoration activities include multiple phases of cultch placement; Texas Parks and Wildlife Department designed the project areas to include more acreage than planned for the first phase of restoration, and all three areas include an additional 60-meter (197-foot) buffer around the proposed Areas of Potential Effect. The Phase I underwater archaeological investigation assessed the number, locations, cultural affiliations, components, spatial distribution, data potential, and other salient characteristics of potential submerged cultural resources within the proposed reefing project areas. The marine field investigations of the North Todd, Resignation, and South Dollar Artificial Reef Project survey areas consisted of a bathymetric, magnetometer, and side-scan sonar survey of a combined 84.4 hectares (209 acres) covering the three Areas of Potential Effect in safely navigable waters on July 28, 2020. The comprehensive analysis of the magnetometer data resulted in the identification of one magnetic anomaly (NT-040) that is interpreted as a potential cultural resource (i.e. historic shipwrecks). The remaining magnetic anomalies are interpreted as modern debris associated with recreational and commercial fishing activities, miscellaneous debris from previous tropical storms, existing pipelines, and infrastructure installation and/or maintenance, and as such do not represent significant cultural resources. Side-scan sonar imagery identified a total of three sonar targets, none of which were interpreted as potentially significant cultural material. The recommended management action for the North Todd, Resignation, and South Dollar Areas of Potential Effect is avoidance of bottom disturbance activities within the 50-meter (164-foot) avoidance area, as mandated by Texas Administrative Code, Title 13, Part 2, Chapter 26, for magnetic anomaly NT-040. If avoidance is not possible, then Gray & Pape, Inc. recommends archaeological diver-ground truthing to identify and evaluate the potential for National Register of Historic Places significance of each anomaly