248 research outputs found

    The Philosopher"s Garden: Scepticism within (and from without) Wittgenstein

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    I am sitting with a philosopher in the garden; he says again and again "I know that that"s a tree�, pointing to a tree that is near us. Someone else arrives and hears this, and I tell him: "This fellow isn"t insane. We are only doing philosophy.� On Certainty § 467 If philosophy is disease, the sceptic must surely have a terminal case. There seems to be no relief for one so ill. However, in On Certainty Wittgenstein offers us a new way to examine the problem, a new treatment, as it were. As Wittgenstein"s methodology is so uniquely multi-faceted, so too is his attack on the sceptic, and as it has been said before, Wittgenstein has a marvelous capacity, not for solving problems, but dissolving them. We should not therefore be surprised that the die-hard sceptic remains unconvinced by Wittgenstein"s attack; it is not the sort of maneuver the sceptic is used to. Indeed, at times it does not seem like an attack at all. The sceptic must beware however; behind Wittgenstein"s oblique style there lies an assault of such subtlety and caliber that only a master of could deliver it. But really, for all his mastery, for all his philosophical poignancy, how effective is Wittgenstein"s criticism? It is certainly of a very different order than those we have seen in the past, but can Wittgenstein ultimately avoid the charge of "question begging� that have plagued so many before him? The question is somewhat complicated in the case of Wittgenstein, not only by his philosophical position, but also by his methodology

    Using philosophy to improve the coherence and interoperability of applications ontologies: A field report on the collaboration of IFOMIS and L&C

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    The collaboration of Language and Computing nv (L&C) and the Institute for Formal Ontology and Medical Information Science (IFOMIS) is guided by the hypothesis that quality constraints on ontologies for software ap-plication purposes closely parallel the constraints salient to the design of sound philosophical theories. The extent of this parallel has been poorly appreciated in the informatics community, and it turns out that importing the benefits of phi-losophical insight and methodology into application domains yields a variety of improvements. L&C’s LinKBase® is one of the world’s largest medical domain ontologies. Its current primary use pertains to natural language processing ap-plications, but it also supports intelligent navigation through a range of struc-tured medical and bioinformatics information resources, such as SNOMED-CT, Swiss-Prot, and the Gene Ontology (GO). In this report we discuss how and why philosophical methods improve both the internal coherence of LinKBase®, and its capacity to serve as a translation hub, improving the interoperability of the ontologies through which it navigates

    New Insights into Carboniferous Cyclothems. The Fourth Biennial Field Conference of the American Association of Petroleum Geologists (AAPG) Midcontinent Section Fourth Biennial Field Conference Abstracts and Guidebook

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    The term “cyclothem” was coined by Wanless & Weller (1932) to describe repetitive stratigraphic successions of Carboniferous age in Illinois. Nonetheless, comparable rhythmicity had been identified in Carboniferous rocks both in the central and eastern USA, and in Europe during the preceding century. Cyclothems were found to comprise repetitive vertical successions of sandstones, heterolithic (thinly interbedded) sandstones and mudrocks, mudrocks, limestones, and coals, in many cases with pedogenic overprinting of these lithologies. As usage of the term “cyclothem” increased, so did the diversity of successions to which the term was applied, to the point where many geologists advocated abandonment of the expression. An example of this misuse was the modified term “continental cyclothem”, used to describe alternations of coarse- and fine-grained alluvial and other strata. Using the term “cyclothem” to describe essentially non-cyclic, binary arrays of lithologies is here considered a retrograde step, as it introduces confusion as to what a cyclothem is and represents geologically. The original definition of “cyclothem” as an alternation of marine and nonmarine lithologies, however, is a robust and useful concept, and by this definition cyclothems are largely confined to Carboniferous and Permian systems in the paleotropics of North America and Europe. Their stratigraphic range broadly coincides with the timing of the late Paleozoic Ice Age, and many researchers have postulated that they are a record of eustatically-controlled rises and falls in sea-level associated with waxing and waning of Gondwanan ice centers. We propose a restricted definition of “cyclothems” that is limited to successions that were deposited (1) on low-gradient pericontinental shelves in paleotropical regions, (2) as far-field products of Gondwanan glacial growth and decay at various timescales, and (3) under conditions of low sediment supply in most cases (Fig. 1). As such, they are important archives of late Paleozoic paleoenvironmental change, and the concept can be used in a number of ways. For example, the onset of a cyclothemic motif in stratigraphic successions of late Visean age across Euramerica has been used to infer the onset of the main phase of glaciation in Gondwana. Cyclothems are also important as hosts for economic mineral resources, including oil and gas, coal, lime, water, and base and precious metals. This symposium introduces Field Conference participants to the nature and variety of cyclothems, and their geology. Papers concern aspects of cyclothems in numerous states of the USA from Illinois in the east to Utah in the west, and from Montana in the north to Texas in the south. Papers describe the stratigraphy, sedimentology, and resource geology of Carboniferous cyclothemic successions, including numerous petroleum-prospective regions and plays. The Field Excursion will allow participants to view well-exposed examples of classical Midcontinent cyclothems in SE Nebraska (the Virgilian--or uppermost Pennsylvanian--Indian Cave Sandstone). The Core Workshop will feature examples of cyclothemic Carboniferous successions from Illinois, Iowa, Nebraska, Kansas, and Montana, some of which are in active petroleum-producing areas

    Integration of Tobacco Treatment Services into Cancer Care at Stanford.

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    As part of a National Cancer Institute Moonshot P30 Supplement, the Stanford Cancer Center piloted and integrated tobacco treatment into cancer care. This quality improvement (QI) project reports on the process from initial pilot to adoption within 14 clinics. The Head and Neck Oncology Clinic was engaged first in January 2019 as a pilot site given staff receptivity, elevated smoking prevalence, and a high tobacco screening rate (95%) yet low levels of tobacco cessation treatment referrals (<10%) and patient engagement (<1% of smokers treated). To improve referrals and engagement, system changes included an automated "opt-out" referral process and provision of tobacco cessation treatment as a covered benefit with flexible delivery options that included phone and telemedicine. Screening rates increased to 99%, referrals to 100%, 74% of patients were reached by counselors, and 33% of those reached engaged in treatment. Patient-reported abstinence from all tobacco products at 6-month follow-up is 20%. In July 2019, two additional oncology clinics were added. In December 2019, less than one year from initiating the QI pilot, with demonstrated feasibility, acceptability, and efficacy, the tobacco treatment services were integrated into 14 clinics at Stanford Cancer Center

    TuRMoiL of Survival: A Unified Survival Criterion for Cloud-Wind Interactions

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    Cloud-wind interactions play an important role in long-lived multiphase flows in many astrophysical contexts. When this interaction is primarily mediated by hydrodynamics and radiative cooling, the survival of clouds can be phrased in terms of the comparison between a timescale that dictates the evolution of the cloud-wind interaction, (the dynamical time-scale τdyn\tau_{\rm dyn}) and the relevant cooling timescale τcool\tau_{\rm cool}. Previously proposed survival criteria, which can disagree by large factors about the size of the smallest surviving clouds, differ in both their choice of τcool\tau_{\rm cool} and (to a lesser extent) τdyn\tau_{\rm dyn}. Here we present a new criterion which agrees with a previously proposed empirical formulae but is based on simple physical principles. The key insight is that clouds can grow if they are able to mix and cool gas from the hot wind faster than it advects by the cloud. Whereas prior criteria associate τdyn\tau_{\rm dyn} with the cloud crushing timescale, our new criterion links it to the characteristic cloud-crossing timescale of a hot-phase fluid element, making it more physically consistent with shear-layer studies. We develop this insight into a predictive expression and validate it with hydrodynamic ENZO-E simulations of ∼104 K{\sim}10^4\, {\rm K}, pressure-confined clouds in hot supersonic winds, exploring, in particular, high wind/cloud density contrasts, where disagreements are most pronounced. Finally, we illustrate how discrepancies among previous criteria primarily emerged due to different choices of simulation conditions and cooling properties, and discuss how they can be reconciled.Comment: 6.5 pages, 4 figures, submitted to ApJ

    Scenario-Led Habitat Modelling of Land Use Change Impacts on Key Species

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    Accurate predictions of the impacts of future land use change on species of conservation concern can help to inform policy-makers and improve conservation measures. If predictions are spatially explicit, predicted consequences of likely land use changes could be accessible to land managers at a scale relevant to their working landscape. We introduce a method, based on open source software, which integrates habitat suitability modelling with scenario-building, and illustrate its use by investigating the effects of alternative land use change scenarios on landscape suitability for black grouse Tetrao tetrix. Expert opinion was used to construct five near-future (twenty years) scenarios for the 800 km2 study site in upland Scotland. For each scenario, the cover of different land use types was altered by 5–30% from 20 random starting locations and changes in habitat suitability assessed by projecting a MaxEnt suitability model onto each simulated landscape. A scenario converting grazed land to moorland and open forestry was the most beneficial for black grouse, and ‘increased grazing’ (the opposite conversion) the most detrimental. Positioning of new landscape blocks was shown to be important in some situations. Increasing the area of open-canopy forestry caused a proportional decrease in suitability, but suitability gains for the ‘reduced grazing’ scenario were nonlinear. ‘Scenario-led’ landscape simulation models can be applied in assessments of the impacts of land use change both on individual species and also on diversity and community measures, or ecosystem services. A next step would be to include landscape configuration more explicitly in the simulation models, both to make them more realistic, and to examine the effects of habitat placement more thoroughly. In this example, the recommended policy would be incentives on grazing reduction to benefit black grouse.This study was part of a PhD studentship funded through the World Pheasant Association (from the Henry Angest Foundation, Howman Charitable Foundation, Mactaggart Third Charitable Trust, PF Charitable Trust and AF Wallace Charity Trust) and the Dalton Research Institute

    Characterization of potential superspreader farms for bovine tuberculosis:A review

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    Background: Variation in host attributes that influence their contact rates and infectiousness can lead some individuals to make disproportionate contributions to the spread of infections. Understanding the roles of such ‘superspreaders’ can be crucial in deciding where to direct disease surveillance and controls to greatest effect. In the epidemiology of bovine tuberculosis (bTB) in Great Britain, it has been suggested that a minority of cattle farms or herds might make disproportionate contributions to the spread of Mycobacterium bovis, and hence might be considered ‘superspreader farms’.Objectives and Methods: We review the literature to identify the characteristics of farms that have the potential to contribute to exceptional values in the three main components of the farm reproductive number - Rf: contact rate, infectiousness and duration of infectiousness, and therefore might characterize potential superspreader farms for bovine tuberculosis in Great Britain.Results: Farms exhibit marked heterogeneity in contact rates arising from between-farm trading of cattle. A minority of farms act as trading hubs that greatly augment connections within cattle trading networks. Herd infectiousness might be increased by high within-herd transmission or the presence of supershedding individuals, or infectiousness might be prolonged due to undetected infections or by repeated local transmission, via wildlife or fomites.Conclusions: Targeting control methods on putative superspreader farms might yield disproportionate benefits in controlling endemic bovine tuberculosis in Great Britain. However, real-time identification of any such farms, and integration of controls with industry practices, present analytical, operational and policy challenges.<br/

    RAFT Aqueous Dispersion Polymerization of N -(2-(Methacryloyloxy)ethyl)pyrrolidone: A Convenient Low Viscosity Route to High Molecular Weight Water-Soluble Copolymers

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    RAFT solution polymerization of N-(2-(methacryoyloxy)ethyl)pyrrolidone (NMEP) in ethanol at 70 °C was conducted to produce a series of PNMEP homopolymers with mean degrees of polymerization (DP) varying from 31 to 467. Turbidimetry was used to assess their inverse temperature solubility behavior in dilute aqueous solution, with an LCST of approximately 55 °C being observed in the high molecular weight limit. Then a poly(glycerol monomethacylate) (PGMA) macro-CTA with a mean DP of 63 was chain-extended with NMEP using a RAFT aqueous dispersion polymerization formulation at 70 °C. The target PNMEP DP was systematically varied from 100 up to 6000 to generate a series of PGMA63–PNMEPx diblock copolymers. High conversions (≥92%) could be achieved when targeting up to x = 5000. GPC analysis confirmed high blocking efficiencies and a linear evolution in Mn with increasing PNMEP DP. A gradual increase in Mw/Mn was also observed when targeting higher DPs. However, this problem could be minimized (Mw/Mn < 1.50) by utilizing a higher purity grade of NMEP (98% vs 96%). This suggests that the broader molecular weight distributions observed at higher DPs are simply the result of a dimethacrylate impurity causing light branching, rather than an intrinsic side reaction such as chain transfer to polymer. Kinetic studies confirmed that the RAFT aqueous dispersion polymerization of NMEP was approximately four times faster than the RAFT solution polymerization of NMEP in ethanol when targeting the same DP in each case. This is perhaps surprising because both 1H NMR and SAXS studies indicate that the core-forming PNMEP chains remain relatively solvated at 70 °C in the latter formulation. Moreover, dissolution of the initial PGMA63–PNMEPx particles occurs on cooling from 70 to 20 °C as the PNMEP block passes through its LCST. Hence this RAFT aqueous dispersion polymerization formulation offers an efficient route to a high molecular weight water-soluble polymer in a rather convenient low-viscosity form. Finally, the relatively expensive PGMA macro-CTA was replaced with a poly(methacrylic acid) (PMAA) macro-CTA. High conversions were also achieved for PMAA85–PNMEPx diblock copolymers prepared via RAFT aqueous dispersion polymerization for x ≤ 4000. Again, better control was achieved when using the 98% purity NMEP monomer in such syntheses
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