Profiles of Contextual Risk at Birth and Adolescent Substance Use

This study examined whether there are subgroups of families with distinct profiles of prenatal/birth contextual risk, and whether subgroup membership was differentially related to adolescent substance use. Data from the Northern Finland Birth Cohort 1986 were used. A five-class model provided the most meaningful solution. Large Family Size (7.72%) and Low Risk (69.69%) groups had the lowest levels of alcohol, cigarette, and illegal drug use. Similar high levels for each of the three substance-related outcomes were found for Parent Substance Misuse (11.20%), Maternal School Dropout (4.66%), and Socioeconomic Disadvantage (6.72%) groups. Maternal smoking and drinking while pregnant and paternal heavy alcohol use were found to be key prenatal risk factors that tended to cluster together and co-occur with other prenatal risk factors differently for different subgroups of youth.     

Living in Harmony: Nominalism and the Explanationist Argument for Realism

According to the indispensability argument, scientific realists ought to believe in the existence of mathematical entities, due to their indispensable role in theorising. Arguably the crucial sense of indispensability can be understood in terms of the contribution that mathematics sometimes makes to the super‐empirical virtues of a theory. Moreover, the way in which the scientific realist values such virtues, in general, and draws on explanatory virtues, in particular, ought to make the realist ontologically committed to abstracta. This paper shows that this version of the indispensability argument glosses over crucial detail about how the scientific realist attempts to generate justificatory commitment to unobservables. The kind of role that the Platonist attributes to mathematics in scientific reasoning is compatible with nominalism, as far as scientific realist arguments are concerned.     

A microcomputer system for controlling classical conditioning experiments

A microcomputer-based laboratory system for controlling stimulus presentations and data acquisition in classical conditioning experiments is described. The system comprises an Intel 386/486-based microcomputer and a commercially obtained low-cost counter/timer board with input/output lines for stimulus timing and external device control. A simple, yet versatile custom-designed structured programming language is provided for performing an unlimited number of stimulus configurations and their sequences. In electrophysiological studies, the system can be flexibly connected to computer-controlled signal conditioning systems for the amplification and filtering of multiunit and evoked field potential responses and to high-speed data acquisition systems for sampling and analyzing the responses. The costs of reserving an entire microcomputer for experiment control are well compensated for by the simplicity and efficiency of programming and transportability of the control protocols between different setups and laboratories. Furthermore, a data acquisition and analysis system most suitable for the aims of a research project can be selected.