Pedro J. Sánchez Gómez

We argue for an account of chemical reactivities as chancy propensities, in accordance with the ‘complex nexus of chance’ defended by one of us in the past (Suárez, 2017, 2020). Reactivities are typically quantified as proportions, and an expression such as “A + B → C” does not entail that under the right conditions some amounts of A and B react to give the amount of C that theoretically would correspond to the stoichiometry of the reaction. Instead, what is produced is a fraction α < 1 of this theoretical amount, and the corresponding percentage is usually known as the yield, which expresses the relative preponderance of its reaction. This is then routinely tested in a laboratory against the observed actual yields for the different reactions. Thus, on our account, reactivities ambiguously refer to three quantities at once. They first refer to the underlying propensities effectively acting in the reaction mechanisms, and which in ‘chemical chemistry’ (Schummer, 1998) are commonly represented by means of Lewis structures. Besides, reactivities represent the probabilities that these propensities give rise to, for any amount of the reactants to combine as prescribed. This last notion is hence best understood as a single case chance and corresponds to a theoretical stoichiometric yield. Finally, reactivities represent the actual yields observed in experimental runs, which account for and provide the requisite evidence for / against both the mechanisms and single case chances ascribed.

Aim: The present work proposes the study of the neuromotor activity of the masseter-jaw-tongue articulation during diadochokinetic exercising to establish functional statistical relationships between surface Electromyography, 3D Accelerometry, and acoustic features extracted from the speech signal, with the aim of characterizing Hypokinetic Dysarthria. A database of multi-trait signals of recordings from an age-matched control and PD participants are used in the experimental study. Hypothesis: The main assumption is that information between sEMG and 3D acceleration, and acoustic features may be quantified using linear regression methods. Methods: Recordings from a cohort of eight age-matched control participants and eight PD participants were collected during the utterance of a diadochokinetic exercise. The dynamic and acoustic absolute kinematic velocities produced during the exercises were estimated by acoustic filter inversion and numerical integration and differentiation of the speech signal. The amplitude distributions of the absolute kinematic and acoustic velocities are estimated to allow comparisons in terms of Mutual Information. Results: The regression results show the relationships between sEMG and dynamic and acoustic estimates. The projection methodology may help in understanding the basic neuromotor muscle activity regarding neurodegenerative speech in remote monitoring neuromotor and neurocognitive diseases using speech as the vehicular tool, and in the study of other speech-related disorders. The study also showed strong and significant cross-correlations between articulation kinematics, both for the control and the PD cohorts. The absolute kinematic variables presents an observable difference for the PD participants compared to the control group. Conclusion: Kinematic distributions derived from acoustic analysis may be useful biomarkers toward characterizing HD in neuromotor disorders providing new insights into PD.

In this article, I study, from the point of view of the analytic philosophy of mind, the compatibility of students’ ideas studies with radical constructivism. I demonstrate that RC is based on a psychology of narrow mental states; that is, the idea that the mental content of an individual can be fully characterised without any reference external to her or him. I show that this fact imposes some severe restrictions to SIS to be incorporated into RC. In particular, I argue that only qualitative studies can comply with the requirement of narrowness. Nevertheless, I propose that quantitative works can be employed as sources of types in order to study token actual students. I use this type-token dichotomy to put forward an outline of a theory of the relation between school contents and mental contents. In this view, token mental contents regarding a given topic can be defined, and probed, only by resorting to typical school contents.

We argue for an account of chemical reactivities as chancy propensities, in accordance with the ‘complex nexus of chance’ defended by one of us in the past. Reactivities are typically quantified as proportions, and an expression such as “A + B → C” does not entail that under the right conditions some given amounts of A and B react to give the mass of C that theoretically corresponds to the stoichiometry of the reaction. Instead, what is produced is a fraction α < 1 of this theoretical amount, and the corresponding percentage is usually known as the yield, which expresses the relative preponderance of its reaction. This is then routinely tested in a laboratory against the observed actual yields for the different reactions. Thus, on our account, reactivities ambiguously refer to three quantities at once. They first refer to the underlying propensities effectively acting in the reaction mechanisms, which in ‘chemical chemistry’ (Schummer in Hyle 4:129–162, 1998) are commonly represented by means of Lewis structures. Besides, reactivities represent the probabilities that these propensities give rise to, for any amount of the reactants to combine as prescribed. This last notion is hence best understood as a single case chance and corresponds to a theoretical stoichiometric yield. Finally, reactivities represent the actual yields observed in experimental runs, which account for and provide the requisite evidence for/against both the mechanisms and single case chances ascribed.

I put forward an inferentialist account of Lewis structures (LSs). In this view, the role of LSs is not to realistically depict molecules, but instead to allow surrogate reasoning and inference in chemistry. I also show that the usage of LSs is a central part of a person’s identity as a chemist, as it is defined within educational identity theory. Taking these conclusions together, I argue that the inferentialist approach to LSs and chemistry identity theory can be studied in parallel, as two complementary sides of the same research programme.