Lexical Flexibility, Natural Language, and Ontology

The Realist that investigates questions of ontology by appeal to the quantificational structure of language assumes that the semantics for the privileged language of ontology is externalist. I argue that such a language cannot be (some variant of) a natural language, as some Realists propose. The flexibility exhibited by natural language expressions noted by Chomsky and others cannot obviously be characterized by the rigid models available to the externalist. If natural languages are hostile to externalist treatments, then the meanings of natural language expressions serve as poor guides for ontological investigation, insofar as their meanings will fail to determine the referents of their constituents. This undermines the Realist’s use of natural languages to settle disputes in metaphysics

Reactive oxygen species regulate caspase-11 expression and activation of the non-canonical NLRP3 inflammasome during enteric pathogen infection

Enteropathogenic and enterohemorrhagic bacterial infections in humans are a severe cause of morbidity and mortality. Although NOD-like receptors (NLRs) NOD2 and NLRP3 have important roles in the generation of protective immune responses to enteric pathogens, whether there is crosstalk among NLRs to regulate immune signaling is not known. Here, we show that mice and macrophages deficient in NOD2, or the downstream adaptor RIP2, have enhanced NLRP3-and caspases-11-dependent non-canonical inflammasome activation in a mouse model of enteropathogenic Citrobacter rodentium infection. Mechanistically, NOD2 and RIP2 regulate reactive oxygen species (ROS) production. Increased ROS in Rip2-deficient macrophages subsequently enhances c-Jun N-terminal kinase (JNK) signaling resulting in increased caspase-11 expression and activation, and more non-canonical NLRP3-dependant inflammasome activation. Intriguingly, this leads to protection of the colon epithelium for up to 10 days in Rip2-deficient mice infected with C. rodentium. Our findings designate NOD2 and RIP2 as key regulators of cellular ROS homeostasis and demonstrate for the first time that ROS regulates caspase-11 expression and non-canonical NLRP3 inflammasome activation through the JNK pathway

Locating the source of projectile fluid droplets

The ill-posed projectile problem of finding the source height from spattered droplets of viscous fluid is a longstanding obstacle to accident reconstruction and crime scene analysis. It is widely known how to infer the impact angle of droplets on a surface from the elongation of their impact profiles. However, the lack of velocity information makes finding the height of the origin from the impact position and angle of individual drops not possible. From aggregate statistics of the spatter and basic equations of projectile motion, we introduce a reciprocal correlation plot that is effective when the polar launch angle is concentrated in a narrow range. The vertical coordinate depends on the orientation of the spattered surface, and equals the tangent of the impact angle for a level surface. When the horizontal plot coordinate is twice the reciprocal of the impact distance, we can infer the source height as the slope of the data points in the reciprocal correlation plot. If the distribution of launch angles is not narrow, failure of the method is evident in the lack of linear correlation. We perform a number of experimental trials, as well as numerical calculations and show that the height estimate is insensitive to aerodynamic drag. Besides its possible relevance for crime investigation, reciprocal-plot analysis of spatter may find application to volcanism and other topics and is most immediately applicable for undergraduate science and engineering students in the context of crime-scene analysis.Comment: To appear in the American Journal of Physics (ms 23338). Improved readability and organization in this versio

Internalist Deflationism: On the Limits of Ontological Investigation

Since Frege(1879), the history of semantics identifies the meanings of natural language expressions with the mind external things they denote, be they pedestrian objects (e.g., cows and chairs), less pedestrian objects (e.g. mereological sums), or abstracta (e.g., sets of possible worlds). For the Quinean Realist, a language with such a semantics is fruitful for ontological investigation, insofar as analyzing the denotational meanings of (the constituents of) sentences in that language reveals which objects populate the (external) worldly domain. However, consigning meaning over to truth in this manner comes at a cost. The externalist thesis is only had by sacrificing the explanatory adequacy of our theory of meaning. Three arguments suggest this: first, facts about the rapid human acquisition of natural language suggests that languages are internal to the human mind, as an innate module in cognitive architecture; second, naturalist commitments suggest that there is no sui generis, mind-independent kind `word' to stand in the word-to-world relations posited by the externalist; third, natural languages exhibit lexical flexibility, as manifest in the distribution of natural language speaker judgments, and this property cannot be easily explained by an externalist semantics. The Realist might respond to these arguments by appealing to the languages utilized to express our best scientific theories, using those invented languages as ontological guides. Since these scientific languages are constructed with the expressed purpose of perspicuously describing reality, the Realist could contend that expressions in those languages have an externalist semantics. I argue, using examples from evolutionary biology, that scientific languages exhibit lexical flexibility as well, casting doubt on the claim that these languages have meanings that admit to externalist treatment. The Realist then should reject the metaphysical methodology which assumes the externalist thesis that the meaning of a linguistic expression determines its truth-conditions

Talking about Causing Events

Questions about the nature of the relationship between language and extralinguistic cognition are old, but only recently has a new view emerged that allows for the systematic investigation of claims about linguistic structure, based on how it is understood or utilized outside of the language system. Our paper represents a case study for this interaction in the domain of event semantics. We adopt a transparency thesis about the relationship between linguistic structure and extralinguistic cognition, investigating whether different lexico-syntactic structures can differentially recruit the visual causal percept. A prominent analysis of causative verbs like move suggests reference to two distinct events and a causal relationship between them, whereas non-causative verbs like push do not so refer. In our study, we present English speakers with simple scenes that either do or do not support the perception of a causal link, and manipulate (between subjects) a one-sentence instruction for the evaluation of the scene. Preliminary results suggest that competent speakers of English are more likely to judge causative constructions than non-causative constructions as true of a scene where causal features are present in the scene. Implications for a new approach to the investigation of linguistic meanings and future directions are discussed

Hydrodynamic independence and passive control application of twist and flapwise deformations of tidal turbine blades

The load-induced deformations experienced by axial-flow rotor blades can result in significant hydrodynamic impacts on rotor operation. These changes in hydrodynamics are dominated by the flapwise and twist deformation components, affecting blade loading and performance. This work uses blade-resolved computational fluid dynamics simulations to explore the hydrodynamic interactions of coupled flapwise and twist deformations, and their potential for use in passive control strategies. The rotor blades were simulated under parametrically prescribed flapwise-only, twist-only and coupled flapwise–twist deformations. The results show that the hydrodynamic effects are adequately described by blade-element theory for twist deformations regardless of the presence of flapwise deformations, whereas flapwise deformations induce changes in the local lift and drag coefficients that are independent of twist. For moderate blade deflections, the hydrodynamic changes generated by the two deformation components can be approximated to be independent from each other. The observed hydrodynamic independence between the two deformation components is used to explore passive deformation strategies for a tidal rotor. By extrapolating an existing dataset containing CFD simulations of twist-only and flapwise-only deformation cases at different tip-speed ratios, control paths are designed within a tip-speed ratio, flapwise and twist deformation parameter space. These control paths demonstrate passive control strategies as a potential alternative to active pitch control on tidal turbines, showing similar performance and maximum loading, compared with an active pitch strategy, over a full tidal cycle. In particular, it is shown that flapwise deformations have an important role in power capping above rated flow speed

An Exploratory Analysis of Employment-Related Experiences of Educators with Learning Disabilities

The purpose of this study was to explore the general professional experiences of educators with learning disabilities, the unique skills and challenges among this group attributable to their experience as persons with learning disabilities, and their experience of schools as an employment context

Athlete Perceptions of Flavored, Menthol-enhanced Energy Gels Ingested Prior to Running in the Heat

Thermal perception during exercise is known to influence endurance performance and the onset of fatigue. L-menthol, an organic compound derived from peppermint, evokes a cooling sensation through its action on TRPM8 channels which also respond to cold stimuli. Recent work identified that the internal application of menthol-enhanced fluids can be ergogenic during exercise in the heat. Hence, the addition of menthol to energy gels may be practical and beneficial for athletes. PURPOSE: To determine athlete acceptability and preferences for flavored energy gels with different menthol concentrations. METHODS: With a randomized, crossover, and double-blind placebo-controlled design, 27 endurance athletes (34.8±6.7 y, BMI: 21.7±1.6 kg·m-2, 9 female) ingested an energy gel with a menthol additive at relative concentrations: low (0.1%), medium-low (0.3%), medium-high (0.5%), high (0.7%), or a non-menthol, flavor-matched placebo (CON), on separate days before outdoor running sessions. Athletes rated the gels for cooling sensation, irritation (tingling/burning), flavor, and overall experience on 100-point sensory and hedonic labeled magnitude scales. The duration of any cooling sensation was also reported. Repeated measures ANOVAs with a Bonferroni adjustment for pairwise comparisons were used to determine differences. RESULTS: All menthol gels successfully delivered a greater cooling sensation compared to CON (7.4±8.1 AU) with a significantly greater response for 0.7% (59.9±20.5 AU) and 0.5% (57.7±21.8 AU), compared to all others, which were both rated “moderate-strong” for intensity. Irritation intensity was higher for all menthol gels compared to CON (3.4±7.2 AU), and for 0.7% compared to 0.1% (31.1±31.0 vs 16.3±21.0 AU, p=0.041), with none reported higher than a “mild-moderate” intensity. The menthol gels delivered a significantly longer cooling duration (range: 12.3-19.6 min) compared to CON (2.2±4.8 min) with no significant difference between menthol gels. Ratings of overall experience and flavor were not different between gels (p\u3e.05). CONCLUSION: A flavored energy gel with the addition of menthol at 0.1-0.7% provides a cooling sensation for athletes when ingested before exercise. The 0.5% concentration is recommended to maximize the cooling sensation of the gel whilst minimizing irritation