Canonical Regression Analyses Research Articles

An Investigation of Structure, Flexibility, and Function Variables that Discriminate Asymptomatic Foot Types.

It has been suggested that foot type considers not only foot structure (high, normal, low arch), but also function (overpronation, normal, oversupination) and flexibility (reduced, normal, excessive). Therefore, this study used canonical regression analyses to assess which variables of foot structure, function, and flexibility can accurately discriminate between clinical foot type classifications. The feet of 61 asymptomatic, healthy adults (18-77 years) were classified as cavus (N = 24), rectus (N = 54), or planus (N = 44) using standard clinical measures. Custom jigs assessed foot structure and flexibility. Foot function was assessed using an emed-x plantar pressure measuring device. Canonical regression analyses were applied separately to extract essential structure, flexibility, and function variables. A third canonical regression analysis was performed on the extracted variables to identify a combined model. The initial combined model included 30 extracted variables; however 5terminal variables (malleolar valgus index, arch height index while sitting, first metatarsophalangeal joint laxity while standing, pressure-time integral and maximum contact area of medial arch) were able to correctly predict 80.7% of foot types. These remaining variables focused on specific foot characteristics (hindfoot alignment, arch height, midfoot mechanics, Windlass mechanism) that could be essential to discriminating foot type.

Can wood properties be predicted from the morphological traits of a tree? A canonical correlation study of plantation-grown white spruce

There is a growing interest in predicting wood quality from tree morphology traits, which can be measured using remote sensing techniques such as LiDAR, to enhance forest inventory for operational planning. In this study, we investigated the correlation structure between these two categories of traits in white spruce (Picea glauca (Moench) Voss) using canonical and multiple regression analyses with the objective of identifying key morphology variables that are predictive of wood quality. For 495 trees from a 30-year-old plantation, we obtained measurements of tree height and dimensions of the living crown, as well as the number and diameter of live branches at selected whorls. Wood traits were assessed from wood cores with SilviScan technology. Morphological traits explained almost 29% of the overall variation observed in wood traits. However, the magnitude of the correlations and the ability of crown morphological traits to predict wood traits differed widely among the latter. Average ring width and radial cell diameter, both related to increment, were well correlated with tree morphology, whereas traits related to subcellular structure, for instance, microfibril angle, were poorly correlated. These results could guide the choice of wood traits to improve inventory techniques aiming to optimize the forest product value chain.

From Higher-Order to Underlying Constructs: Examining the Relationships Between Affect and Fundamental Fears

Targeting constructs that contribute to positive and negative affect may lead to clinically significant reductions in symptoms of principal and co-occurring psychopathology. Anxiety sensitivity, the fear of negative evaluation, and illness/injury sensitivity have been described as three fundamental fears that underlie anxiety-related disorders. Despite the contemporary relevance of the fundamental fears, positive affect, and negative affect as treatment targets, research into how these constructs relate to each other remains scant. Community participants (n = 287) completed measures of affect and the fundamental fears. Canonical correlations, regression analyses, and moderator analyses revealed strong associations between negative affect and each of anxiety sensitivity, the fear of negative evaluation, and illness/injury sensitivity and a weaker but significant inverse relationship with positive affect. The fundamental fears shared a substantive amount of variance (42 %) with positive and negative affect, and this overlap may warrant attention from researchers and clinicians focusing on specific or transdiagnostic features of anxiety.

Predicting antitrichomonal activity: A computational screening using atom-based bilinear indices and experimental proofs

Existing Trichomonas vaginalis therapies are out of reach for most trichomoniasis people in developing countries and, where available, they are limited by their toxicity (mainly in pregnant women) and their cost. New antitrichomonal agents are needed to combat emerging metronidazole-resistant trichomoniasis and reduce the side effects associated with currently available drugs. Toward this end, atom-based bilinear indices, a new TOMOCOMD-CARDD molecular descriptor, and linear discriminant analysis (LDA) were used to discover novel, potent, and non-toxic lead trichomonacidal chemicals. Two discriminant functions were obtained with the use of non-stochastic and stochastic atom-type bilinear indices for heteroatoms and H-bonding of heteroatoms. These atomic-level molecular descriptors were calculated using a weighting scheme that includes four atomic labels, namely atomic masses, van der Waals volumes, atomic polarizabilities, and atomic electronegativities in Pauling scale. The obtained LDA-based QSAR models, using non-stochastic and stochastic indices, were able to classify correctly 94.51% (90.63%) and 93.41% (93.75%) of the chemicals in training (test) sets, respectively. They showed large Matthews’ correlation coefficients (C); 0.89 (0.79) and 0.87 (0.85), for the training (test) sets, correspondingly. The result of predictions on the 15% full-out cross-validation test also evidenced the robustness and predictive power of the obtained models. In addition, canonical regression analyses corroborated the statistical quality of these models (Rcan of 0.749 and of 0.845, correspondingly); they were also used to compute biological activity canonical scores for each compound. On the other hand, a close inspection of the molecular descriptors included in both equations showed that several of these molecular fingerprints are strongly interrelated with each other. Therefore, these models were orthogonalized using the Randić orthogonalization procedure. These classification functions were then applied to find new lead antitrichomonal agents and six compounds were selected as possible active compounds by computational screening. The designed compounds were synthesized and tested for in vitro activity against T. vaginalis. Out of the six compounds that were designed, and synthesized, three molecules (chemicals VA5-5a, VA5-5c, and VA5-12b) showed high to moderate cytocidal activity at the concentration of 10μg/ml, other two compounds (VA5-8pre and VA5-8) showed high cytocidal and cytostatic activity at the concentration of 100μg/ml and 10μg/ml, correspondingly, and the remaining chemical (compound VA5-5e) was inactive at these assayed concentrations. Nonetheless, these compounds possess structural features not seen in known trichomonacidal compounds and thus can serve as excellent leads for further optimization of antitrichomonal activity. The LDA-based QSAR models presented here can be considered as a computer-assisted system that could potentially significantly reduce the number of synthesized and tested compounds and increase the chance of finding new chemical entities with antitrichomonal activity.

Relationship Between Self Reported Pain and Disability and Physical Measures in Chronic Whiplash Associated Disorder (WAD)

AbstractIntroduction. Restricted range of cervical motion (ROM), decreased pressure pain thresholds (PPTs) and hypersensitive responses to the brachial plexus provocation test (BPPT) are features of chronic whiplash associated disorders (WAD). It is not known if these physical measures are related to self reported pain and disability. The aim of this study was to examine the relationships between ROM, PPT and responses to the BPPT with self reported pain and disability in subjects with chronic WAD.Method. ROM, PPTs and responses to the BPPT were measured in 151 subjects with chronic WAD. Self reported pain and disability was measured using the Northwick Park Neck Pain and Disability Questionnaire (NPQ) and pain description using the McGill Pain Questionnaire (MPQ). Canonical correlations and stepwise regression analyses were performed.Results. There were weak to moderate correlations between NPQ scores and ROM (r = −0.41) and responses to the BPPT (r = 0.36) (p < 0.01). Rotation ROM, pain scores with the ...

Students' Implicit Theories of Ability in Physical Education Classes: The Influence of Motivational Aspects of the Learning Environment

This study examined the influence of the perceived situational climate on students' implicit theories of ability in physical education (PE) classes. The empirical data stem from a questionnaire survey of ninth grade students conducted in the county of Buskerud in Norway. Canonical correlation, multiple regression and one-way MANOVA analyses revealed a consistent pattern of relationships between the motivational climate in PE as perceived by the students and their implicit theories of ability. A learning environment that is perceived to emphasise competition and social comparison and to raise concern about one's ability seems to induce fixed implicit theories of ability. By contrast, a climate in which effort, progress and teacher support of all students is seen as prevailing seems to generate a theory of ability as expandable and learning induced. Results were interpreted as providing evidence for the importance of a mastery-oriented climate in PE in terms of fostering optimism for learning in school physical education.

Plant–animal associations in two species of seagrasses in Western Australia

Relationships between algal epiphytes and epifaunal invertebrates (amphipods, molluscs and polychaetes) occurring within meadows of the seagrasses Posidonia sinuosa and Amphibolis griffithii were compared along the south west coast of Western Australia. Although the seagrasses are very different structurally, many species of algal epiphytes and epifaunal grazers were common to both. However, meadows of Amphibolis supported a greater number of both algal epiphyte and epifaunal species. The long-lived stems of Amphibolis supported a larger biomass of algal epiphytes and grazers than did the leaves of either Posidonia or Amphibolis. The densities and biomass of epifauna were variable but on a comparison adjusted to the biomass of seagrass, both the density and biomass of the taxonomic groups were similar between seagrass species except that the density of grazing gastropods and the biomass of polychaetes were greater in Amphibolis (by 238% and 252%, respectively). Nested analyses of variance (ANOVA) indicated that variations in plant and animal biomass differed at all spatial scales (sites, meadows within sites and replicates) and the pattern was inconsistent amongst biota. However, a significant proportion of the variability occurred between replicate samples. Canonical correlation and multiple regression analyses indicated that associations between algal epiphytes and epifauna were also inconsistent and differed between seagrass species. These patterns highlight the importance of seagrass species and structural complexity in affecting both the epiphytic and grazer community. The importance of spatial scales at which seagrasses and their associated communities are sampled are equally important because of the differing levels of spatial patchiness.