Virginia\u27s pelagic recreational fishery: Biological, socioeconomic and fishery components

Catch, effort, fleet size and boat owner expenditure data were collected on Virginia\u27s recreational marlin/tuna fishery for the 1983-1985 seasons. Logbooks, dockside interviews and a telephone survey were evaluated to determine which method was the most efficient and effective for collecting and estimating catch and effort for Virginia\u27s pelagic recreational fishery. In 1984, logbooks were used to collect catch and effort data and fishing effort was estimated using Bochenek\u27s method. Very few fishermen returned their logbooks and as a result this data is probably less reliable than the data collected in other years. Due to the poor return of logbooks, this method should not be used to assess Virginia\u27s marlin/tuna fishery. For the 1985 season, Figley\u27s telephone survey (1984) was compared to the NMFS dockside interview technique for large pelagics. Both the telephone survey using Figley\u27s technique (1984) and dockside interviews using Bochenek\u27s method for calculating effort appear to provide similar estimates of projected total catch. However, the dockside method is very labor intensive, costly and fraught with problems in estimating fishing effort. Therefore, the telephone survey technique using Figley\u27s method for estimating effort appears to be a better method for analyzing this fishery. If telephone interviewing will not work in an area and dockside sampling methods must be relied upon to study the pelagic fishery, Bochenek\u27s method appears to produce a better estimate of fishing effort. Using Figley\u27s (1984) mark-recapture technique, Virginia\u27s pelagic recreational fleet was estimated at 455 and 774 vessels in 1983 and 1985, respectively. Boat owner expenditures for this fleet were estimated at &3,863,045 in 1983, \&4,057,020 in 1984 and &5,538,191 in 1985. Bluefin tuna were caught at SST ranging from 58-83 F but seem to prefer SST of 70 to 75 F. Yellowfin tuna were caught at SST ranging from 68-86 F with the majority landed at SST of 76-80 F. White marlin appear to prefer SST of 74 to 81 F

Undecidability in some field theories

This thesis is a study of undecidability in some field theories. Specifically, we are interested in geometrically oriented problems and have focused our attention in two directions along these lines. The first direction bases on determining the decidability of certain sets of first-order sentences over positive characteristic function fields. We will draw parallel to the problem of algorithmically determining in some cases the existence of points on varieties in positive characteristic function fields; equivalently the existence of certain maps between varieties over other positive characteristic fields. The second direction bases on determining the decidability of first-order consequences of nonempty finite collections of L_r-sentences, true in fields with plenty of geometric structure. This is connected to the former direction by the fact that a decidable field has a recursive axiomatisation – what if we study a (nonempty) finite subset of the axiomatisation? Undecidability results. Motivated by classification-theoretic conjectures, we will examine ‘wilder’ classes of fields in turn and generalise a result of Ziegler to NIP henselian nontrivially valued fields (and beyond). We move to PAC & PRC fields and prove they are finitely undecidable, resolving two open questions of Shlapentokh & Videla, and describe the difficulties that arise in adapting the proof to PpC fields. We pose the question: is every infinite field finitely undecidable

Secondary use of electronic medical records for early identification of raised condition likelihoods in individuals: a machine learning approach

With many symptoms being common to multiple diseases, there is a challenge in producing an initial diagnosis or recommendation for diagnostic tests from a set of symptoms that could have been produced by a number of diseases. Often the initial choice of diagnosis or testing is based on a clinician’s impression of the likelihood of that condition in a general population; however the opportunity may exist for modification of these likelihoods based on individuals’ recorded medical histories. This data-driven approach utilises existing data and is thus cheap and non-invasive. A method is proposed by which an individual’s likelihoods of having specified medical conditions are modified by the similarity of that individual’s medical history to the medical histories of other individuals, comparing the prevalence of conditions in those other individuals’ records who are similar to the individual of interest versus the prevalence of the conditions in those individuals who are dissimilar. In order to maximise the number of records available for analysis, a process was developed for the merging of data from disparate sources that used different clinical coding systems, including extensive development of a technique for semi automatically mapping clinical events coded in ICD9-CM to Clinical Terms Version 3 (CTV3), for which no existing mapping table was found. Semantically similar fields in the source code sets were identified and retained in the combined data set. ‘Codelists’ comprising multiple CTV3 codes for a variety of conditions were built that defined the presence of those conditions within individual records. The hierarchical structure of the CTV3 code table was utilised as a method of identifying codes that differed in structure but had clinically similar or related meaning. The optimum degree of granularity of the coded data to use in identifying similar records was investigated and used in subsequent analysis. Two methods were used for discovering groups of similar and dissimilar individuals: the ‘nearest neighbours’ method and the grouping of records using a clustering process. Altered likelihoods for a range of conditions were investigated and results for the nearest-neighbours approach compared to the clustering approach. Results for adjusted condition likelihoods for 18 conditions are reported, together with a discussion of possible reasons for a change, or otherwise, in the condition likelihood, and a discussion of the clinical significance and potential use of information about such a change. logistic regressions performed on a selection of conditions KNN performed better than logistic regression when judged by F-score (or sensitivity and specificity separately), however situation more nuanced when looking at likelihood ratios: Logistic regression produced higher (better) positive likelihood ratios, but KNN produced lower (better) negative likelihood ratios. Logistic regression produced higher odds ratios

Automated Reasoning

This volume, LNAI 13385, constitutes the refereed proceedings of the 11th International Joint Conference on Automated Reasoning, IJCAR 2022, held in Haifa, Israel, in August 2022. The 32 full research papers and 9 short papers presented together with two invited talks were carefully reviewed and selected from 85 submissions. The papers focus on the following topics: Satisfiability, SMT Solving,Arithmetic; Calculi and Orderings; Knowledge Representation and Jutsification; Choices, Invariance, Substitutions and Formalization; Modal Logics; Proofs System and Proofs Search; Evolution, Termination and Decision Prolems. This is an open access book

The Chilean Communist Party 1922 - 1947.

Founded in 1922 by Socialist who already exerted considerable influence in the Chilean trade union movement, the Chilean Communist Party was a communist party in name only during its early years. It was not until the later 1920s that it began to acquire the organisational forms and practices characteristic of all members of the Third Communist International and not until the early 1930s that it was led by men who gave unquestioning allegiance to Moscow. Reduced to a shadow of its former self by prolonged persecution in the late 1920s and early 1930s, the party's fortunes did not begin to revive until after 1935, when the Third International adopted policies which encouraged it to become a regular participant in Chilean coalition politics. Between 1935 and 1947, the party's fortunes fluctuated somewhat in accordance with changing national and international circumstances but coalition politics enabled it to play important roles in the election of three successive Presidents of the Republic, to extend its appeal to wider sectors of society, to expand its electoral and trade union support and, indirectly, to lay the basis for an increasingly effective and professional party machine. In 1946, the party became the first Latin American Communist Party to hold designated portfolios in cabinet but its experience of high government office was cut short by Cold War pressures - pressures which eventually forced the party into a period of clandestinity which lasted from 1947 until 1958. This, then, is the broad chronological sweep of this study. Within its context, particular attention is paid to the party's relations with the International Communist Movement, to its links with organised labour, to its organisational development, to its electoral support and to its changing relations with other Chilean parties. 0 i

Decidable fragments of first-order logic and of first-order linear arithmetic with uninterpreted predicates

First-order logic is one of the most prominent formalisms in computer science and mathematics. Since there is no algorithm capable of solving its satisfiability problem, first-order logic is said to be undecidable. The classical decision problem is the quest for a delineation between the decidable and the undecidable parts. The results presented in this thesis shed more light on the boundary and open new perspectives on the landscape of known decidable fragments. In the first part we focus on the new concept of separateness of variables and explore its applicability to the classical decision problem and beyond. Two disjoint sets of first-order variables are separated in a given formula if none of its atoms contains variables from both sets. This notion facilitates the definition of decidable extensions of many well-known decidable first-order fragments. We demonstrate this for several prefix fragments, several guarded fragments, the two-variable fragment, and for the fluted fragment. Although the extensions exhibit the same expressive power as the respective originals, certain logical properties can be expressed much more succinctly. In two cases the succinctness gap cannot be bounded using elementary functions. This fact already hints at computationally hard satisfiability problems. Indeed, we derive non-elementary lower bounds for the separated fragment, an extension of the Bernays-Schönfinkel-Ramsey fragment (E*A*-prefix sentences). On the semantic level, separateness of quantified variables may lead to weaker dependences than we encounter in general. We investigate this property in the context of model-checking games. The focus of the second part of the thesis is on linear arithmetic with uninterpreted predicates. Two novel decidable fragments are presented, both based on the Bernays-Schönfinkel-Ramsey fragment. On the negative side, we identify several small fragments of the language for which satisfiability is undecidable.Untersuchungen der Logik erster Stufe blicken auf eine lange Tradition zurück. Es ist allgemein bekannt, dass das zugehörige Erfüllbarkeitsproblem im Allgemeinen nicht algorithmisch gelöst werden kann - man spricht daher von einer unentscheidbaren Logik. Diese Beobachtung wirft ein Schlaglicht auf die prinzipiellen Grenzen der Fähigkeiten von Computern im Allgemeinen aber auch des automatischen Schließens im Besonderen. Das Hilbertsche Entscheidungsproblem wird heute als die Erforschung der Grenze zwischen entscheidbaren und unentscheidbaren Teilen der Logik erster Stufe verstanden, wobei die untersuchten Fragmente der Logik mithilfe klar zu erfassender und berechenbarer syntaktischer Eigenschaften beschrieben werden. Viele Forscher haben bereits zu dieser Untersuchung beigetragen und zahlreiche entscheidbare und unentscheidbare Fragmente entdeckt und erforscht. Die vorliegende Dissertation setzt diese Tradition mit einer Reihe vornehmlich positiver Resultate fort und eröffnet neue Blickwinkel auf eine Reihe von Fragmenten, die im Laufe der letzten einhundert Jahre untersucht wurden. Im ersten Teil der Arbeit steht das syntaktische Konzept der Separiertheit von Variablen im Mittelpunkt, und dessen Anwendbarkeit auf das Entscheidungsproblem und darüber hinaus wird erforscht. Zwei Mengen von Individuenvariablen gelten bezüglich einer gegebenen Formel als separiert, falls in jedem Atom der Formel die Variablen aus höchstens einer der beiden Mengen vorkommen. Mithilfe dieses leicht verständlichen Begriffs lassen sich viele wohlbekannte entscheidbare Fragmente der Logik erster Stufe zu größeren Klassen von Formeln erweitern, die dennoch entscheidbar sind. Dieser Ansatz wird für neun Fragmente im Detail dargelegt, darunter mehrere Präfix-Fragmente, das Zwei-Variablen-Fragment und sogenannte "guarded" und " uted" Fragmente. Dabei stellt sich heraus, dass alle erweiterten Fragmente ebenfalls das monadische Fragment erster Stufe ohne Gleichheit enthalten. Obwohl die erweiterte Syntax in den betrachteten Fällen nicht mit einer erhöhten Ausdrucksstärke einhergeht, können bestimmte Zusammenhänge mithilfe der erweiterten Syntax deutlich kürzer formuliert werden. Zumindest in zwei Fällen ist diese Diskrepanz nicht durch eine elementare Funktion zu beschränken. Dies liefert einen ersten Hinweis darauf, dass die algorithmische Lösung des Erfüllbarkeitsproblems für die erweiterten Fragmente mit sehr hohem Rechenaufwand verbunden ist. Tatsächlich wird eine nicht-elementare untere Schranke für den entsprechenden Zeitbedarf beim sogenannten separierten Fragment, einer Erweiterung des bekannten Bernays-Schönfinkel-Ramsey-Fragments, abgeleitet. Darüber hinaus wird der Ein uss der Separiertheit von Individuenvariablen auf der semantischen Ebene untersucht, wo Abhängigkeiten zwischen quantifizierten Variablen durch deren Separiertheit stark abgeschwächt werden können. Für die genauere formale Betrachtung solcher als schwach bezeichneten Abhängigkeiten wird auf sogenannte Hintikka-Spiele zurückgegriffen. Den Schwerpunkt des zweiten Teils der vorliegenden Arbeit bildet das Entscheidungsproblem für die lineare Arithmetik über den rationalen Zahlen in Verbindung mit uninterpretierten Prädikaten. Es werden zwei bislang unbekannte entscheidbare Fragmente dieser Sprache vorgestellt, die beide auf dem Bernays-Schönfinkel-Ramsey-Fragment aufbauen. Ferner werden neue negative Resultate entwickelt und mehrere unentscheidbare Fragmente vorgestellt, die lediglich einen sehr eingeschränkten Teil der Sprache benötigen