In defense of the possibilism–actualism distinction

In Modal Logic as Metaphysics, Timothy Williamson claims that the possibilism-actualism (P-A) distinction is badly muddled. In its place, he introduces a necessitism-contingentism (N-C) distinction that he claims is free of the confusions that purportedly plague the P-A distinction. In this paper I argue first that the P-A distinction, properly understood, is historically well-grounded and entirely coherent. I then look at the two arguments Williamson levels at the P-A distinction and find them wanting and show, moreover, that, when the N-C distinction is broadened (as per Williamson himself) so as to enable necessitists to fend off contingentist objections, the P-A distinction can be faithfully reconstructed in terms of the N-C distinction. However, Williamson’s critique does point to a genuine shortcoming in the common formulation of the P-A distinction. I propose a new definition of the distinction in terms of essential properties that avoids this shortcoming

Modal Set Theory

This article presents an overview of the basic philosophical motivations for, and some recent work in, modal set theory

IDEF5 Ontology Description Capture Method: Concept Paper

The results of research towards an ontology capture method referred to as IDEF5 are presented. Viewed simply as the study of what exists in a domain, ontology is an activity that can be understood to be at work across the full range of human inquiry prompted by the persistent effort to understand the world in which it has found itself - and which it has helped to shape. In the contest of information management, ontology is the task of extracting the structure of a given engineering, manufacturing, business, or logistical domain and storing it in an usable representational medium. A key to effective integration is a system ontology that can be accessed and modified across domains and which captures common features of the overall system relevant to the goals of the disparate domains. If the focus is on information integration, then the strongest motivation for ontology comes from the need to support data sharing and function interoperability. In the correct architecture, an enterprise ontology base would allow th e construction of an integrated environment in which legacy systems appear to be open architecture integrated resources. If the focus is on system/software development, then support for the rapid acquisition of reliable systems is perhaps the strongest motivation for ontology. Finally, ontological analysis was demonstrated to be an effective first step in the construction of robust knowledge based systems

The Argument from Collections

Very broadly, an argument from collections is an argument that purports to show that our beliefs about sets imply — in some sense — the existence of God. Plantinga (2007) first sketched such an argument in “Two Dozen” and filled it out somewhat in his 2011 monograph Where the Conflict Really Lies: Religion, Science, and Naturalism. In this paper I reconstruct what strikes me as the most plausible version of Plantinga’s argument. While it is a good argument in at least a fairly weak sense, it doesn’t initially appear to have any explanatory advantages over a non-theistic understanding of sets — what I call set theoretic realism. However, I go on to argue that the theist can avoid an important dilemma faced by the realist and, hence, that Plantinga’s argument from collections has explanatory advantages that realism does not have

Theoretical foundations for information representation and constraint specification

Research accomplished at the Knowledge Based Systems Laboratory of the Department of Industrial Engineering at Texas A&M University is described. Outlined here are the theoretical foundations necessary to construct a Neutral Information Representation Scheme (NIRS), which will allow for automated data transfer and translation between model languages, procedural programming languages, database languages, transaction and process languages, and knowledge representation and reasoning control languages for information system specification

Climate change increases net CO2 assimilation in the leaves of strawberry, but not yield

Fruit growth in strawberry is dependent on photosynthesis in the leaves. The main scenarios for climate change include an increase in the concentration of CO2 in the atmosphere and an increase in temperature. This review examined photosynthesis in strawberry. The mean photosynthetic photon flux (PPF) for the saturation of CO2 assimilation was 1,031?±?447?µmol per m2 per s, the median was 1,000?µmol per m2 per s, and the range was from 467 to 2,200?µmol per m2 per s (N?=?59). The mean concentration of CO2 for the saturation of assimilation was 869?±?306 ppm, the median was 900 ppm, and the range was from 410 to 1,750 ppm (N?=?32). The optimum temperature range for CO2 assimilation was 20° to 30°C, with lower photosynthesis at lower or higher temperatures. The optimum temperatures for photosynthesis are higher than those for flowering and fruit growth. The impact of climate change on production varies across growing areas. In warm locations, higher temperatures increase photosynthesis, but not yield. In cool locations, higher temperatures increase plant growth and the length of the production season, but this comes at the expense of flower initiation

Controlling plant and fruit diseases in strawberry fields

Grey mould and stem-end rot affect the strawberry industry in Australia. Losses of 10% of the crop are equivalent to a loss of $46 million across the different growing areas. The effect of different fungicides on the control of grey mould and stem-end rot affecting ‘Festival’ strawberry plants was studied in south-east Queensland over three years. This work followed recent changes to the use pattern for the multi-site fungicides thiram and captan, which can now be used more regularly than previously in Australia. There was a restriction on the use of captan with no more than five sprays allowed in a season. Thiram could be used only up to the first flowering. A program based on captan and thiram along with several single-site fungicides during wet weather controlled grey mould and stem-end rot. These treatments in turn provided high marketable yields. Applications of a plant-defence promoter, plant extracts, organic acids, fatty acids, a salt, four bacteria, and a fungus were not as successful as the standard program, even when the soft fungicides were applied alternately with thiram and captan. The plant-defence promoter acibenzolar-S-methyl, organic acids, B. subtilus (strain QST 713), B. amyloliquefaciens and potassium bicarbonate gave intermediate control. In contrast, B. subtilus (strain MBI 600), Streptomyces lydicus, Trichoderma harzianum, potassium salts of fatty acids, and two plant extracts were ineffective. A strategy based on thiram and captan applied alternately, with the addition of single-site fungicides during wet weather provided the best control of disease, with 3 to 4% losses. Control plots had losses of 25 to 38%. The soft chemicals were less effective than the programs based on captan, thiram and single-site fungicides. The use of the thiram and captan in rotation with other fungicides from different chemical groups in wet weather will reduce the risk of fungicide resistance and extend the useful life of registered products. This strategy has not been available to growers previously

Higher Temperatures Decrease Fruit Size in Strawberry Growing in the Subtropics

Five strawberry (Fragaria × ananassa Duch.) cultivars were grown in Queensland, Australia to determine whether higher temperatures affect production. Transplants were planted on 29 April and data collected on growth, marketable yield, fruit weight and the incidence of small fruit less than 12 g until 28 October. Additional data were collected on fruit soluble solids content (SSC) and titratable acidity (TA) from 16 September to 28 October. Minimum temperatures were 2 °C to 4 °C higher than the long-term averages from 1965 to 1990. Changes in marketable yield followed a dose-logistic pattern (p 0.05). The plants continued to produce a marketable crop towards the end of the season, but the fruit were small and more expensive to harvest. Higher temperatures in the future are likely to affect the economics of strawberry production in subtropical locations

Changes in the Concentration of Leaf Nitrogen over the Season Affect the Diagnosis of Deficiency or Sufficiency in Strawberries in the Subtropics

Optimum leaf nitrogen (N) concentrations have been identified for strawberry (Fragaria ×ananassa Duch.) in temperate and Mediterranean areas, but whether these values are appropriate for the subtropics is unclear. Two experiments were conducted for 2 years to determine if the seasonal changes in the concentration of leaf N affect the diagnosis of deficiency or sufficiency of strawberry plants in Queensland, Australia. In 2014, ‘Festival’, ‘Fortuna’, and ‘Winter Dawn’ were planted in early April and grown with and without N for the entire season. Then, ‘Festival’ was planted the following year in mid- or late April and, again, was grown with and without N. Yield was slightly lower with N in 2014, but higher with it the following year, particularly in the early planting. The concentration of total N in young, fully expanded leaves decreased from 3.0% to 2.0% as leaf, crown, and root dry weight increased, while the concentration of nitrate-N (NO3-N) decreased from 1200–3200 to 50–500 mg/kg. These changes in leaf N were large enough to affect the diagnosis of N deficiency or sufficiency. The concentration of leaf N was less variable than the concentration of leaf NO3-N and, therefore, better for estimating the nutrient status of strawberry plants in the subtropics