BackgroundKinarm Standard Tests is a suite of upper limb tasks to assess sensory, motor, and cognitive functions, which produces granular performance data that reflect spatial and temporal aspects of behavior. We have previously used principal component analysis to reduce the dimensionality of multivariate data using the Kinarm End-Point Lab. Here, we performed PCA using data from the Kinarm Exoskeleton Lab, and determined agreement of PCA results across EP and EXO platforms in healthy participants. We additionally examined whether further dimensionality reduction (...) was possible by using PCA across behavioral tasks.MethodsHealthy participants were assessed using the Kinarm EXO and EP. Four behavioral tasks were performed that quantified arm sensory and motor function, including position sense [Arm Position Matching ] and three motor tasks [Visually Guided Reaching, Object Hit, and Object Hit and Avoid ]. The number of components to include per task was determined from scree plots and parallel analysis, and rotation type was decided on a per-task basis. To assess agreement, we compared principal components across platforms using distance correlation. We additionally considered inter-task interactions in EXO data by performing PCA across all six behavioral assessments.ResultsBy applying PCA on a per task basis to data collected using the EXO, the number of behavioral parameters were substantially reduced by 58–75% while accounting for 76–87% of the variance. These results compared well to the EP analysis, and we found good-to-excellent agreement values between PCs from the EXO and those from the EP. Finally, we were able to reduce the dimensionality of the EXO data across tasks down to 16 components out of a total of 76 behavioral parameters, which represents a reduction of 79% while accounting for 73% of the total variance.ConclusionPCA of Kinarm robotic assessment appears to capture similar relationships between kinematic features in healthy individuals and is agnostic to the robotic platform used for collection. Further work is needed to investigate the use of PCA-based data reduction for the characterization of neurological deficits in clinical populations. (shrink)

This article proposes a geostatistical solution for area-to-point spatial prediction (downscaling) taking into account boundary effects. Such effects are often poorly considered in downscaling, even though they often have significant impact on the results. The geostatistical approach proposed in this article considers two types of boundary conditions (BC), that is, a Dirichlet-type condition and a Neumann-type condition, while satisfying several critical issues in downscaling: the coherence of predictions, the explicit consideration of support differences, and the assessment of uncertainty regarding the (...) point predictions. An updating algorithm is used to reduce the computational cost of area-to-point prediction under a given BC. In a case study, area-to-point prediction under a Dirichlet-type BC and a Neumann-type BC is illustrated using simulated data, and the resulting predictions and error variances are compared with those obtained without considering such conditions. (shrink)

People have always been xenophobic, but an explicit philosophical and scientific view of human racial difference only began to emerge during the modern period. Why and how did this happen? Surveying a range of philosophical and natural-scientific texts, dating from the Spanish Renaissance to the German Enlightenment, Nature, Human Nature, and Human Difference charts the evolution of the modern concept of race and shows that natural philosophy, particularly efforts to taxonomize and to order nature, played a crucial role. Smith demonstrates (...) how the denial of moral equality between Europeans and non-Europeans resulted from converging philosophical and scientific developments, including a declining belief in human nature's universality and the rise of biological classification. The racial typing of human beings grew from the need to understand humanity within an all-encompassing system of nature, alongside plants, minerals, primates, and other animals. While racial difference as seen through science did not arise in order to justify the enslavement of people, it became a rationalization and buttress for the practices of trans-Atlantic slavery. From the work of François Bernier to G. W. Leibniz, Immanuel Kant, and others, Smith delves into philosophy's part in the legacy and damages of modern racism. With a broad narrative stretching over two centuries, Nature, Human Nature, and Human Difference takes a critical historical look at how the racial categories that we divide ourselves into came into being. (shrink)

In Hermathena, vol. xiv., pp. 338–359, Professor Charles Exon attempts to prove that the nom. and dat.-abl. pi. of deus were disyllabic in Plautus. The argument upon which he lays most stress is briefly this: Plautus uses iambic words shortened by the law of breves breviantes in the thesis of iambic and trochaic verse about twice as often as he does in the arsis, whereas the long monosyllable cor occurs in dialogue with equal frequency in both parts of the foot. (...) In this respect the nom. pl. of deus agrees with the shortened iambi, and should therefore, he thinks, be considered one of them. (shrink)