On the microstructures of equilibrated and quenched spinel-containing nickel titanates

Electron microscopy has been used to study the microstructures of equilibrated and quenched NiO-TiO₂ mixtures containing 5, 10, 15, 20 and 25wt% TiO₂. All the specimens contained rocksalt- and spinel-structured phases on a nanometre scale. The microstructure suggests that a nonstoichiometric spinel decomposed during quenching. The 25wt% TiO₂ specimen exhibited a lamellar microstructure composed of NiTiO₃ and spinelNiO. These phases had the usual orientation relationships, i.e., (111)_cubic||(0001)_hex and (110)_cubic|| (1100>_hex. Faceted NiO solid-solution regions with coherent cube-on-cube interfaces with the spinel were found in the four specimens of lower TiO₂ contents. When large (15 and 20wt% TiO₂), these regions were faceted cuboidal particles. With lower TiO₂ contents, these regions were no longer equiaxed and could be interconnected. The specimens were chemically homogeneous on a length scale of about 1mum. Morphological evidence is presented to explain which part of the microstructure most probably already existed in this form during equilibration. In particular, the large-scale NiTiO₃ and the spinel lamella in the 25wt% TiO₂ material form during long-term equilibration.     

Factors Associated with Non-Reimbursable Activity on an Inpatient Pediatric Consultation–Liaison Service

The aim of this study was to identify factors contributing to clinician time spent in non-reimbursable activity on an inpatient pediatric consultation–liaison (C–L) service. A retrospective study was conducted using inpatient C–L service data on 1,246 consecutive referrals. For this patient population, the strongest predictor of level of non-reimbursable clinical activity was illness chronicity and the number of contacts with C–L service clinicians during their hospital stay. Patients with acute life-threatening illnesses required the highest mean amount of non-reimbursable service activity. On average, 28 % of total clinician time in completing a hospital consultation was spent in non-reimbursable activity. Effective C–L services require a proportion of time spent in non-reimbursable clinical activity, such as liaison and coordinating care with other providers. Identifying referral and systemic factors contributing to non-reimbursable activity can provide insight into budgeting/negotiating for institutional support for essential clinical and non-clinical functions in providing competent quality patient care.     

Speech and Language Disorders in Kenyan Children: Adapting Tools for Regions with Few Assessment Resources

This study sought to adapt a battery of Western speech and language assessment tools to a rural Kenyan setting. The tool was developed for children whose first language was KiGiryama, a Bantu language. A total of 539 Kenyan children (males=271, females=268, ethnicity=100% Kigiryama) were recruited. Data were initially collected from 52 children (pilot assessments), and then from a larger group of 487 children (152 cerebral malaria, 156 severe malaria and seizures, 179 unexposed). The language assessments were based upon the Content, Form and Use (C/F/U) model. The assessment was based upon the adapted versions of the Peabody Picture Vocabulary Test, Test for the Reception of Grammar, Renfrew Action Picture Test, Pragmatics Profile of Everyday Communication Skills in Children, Test of Word Finding and language specific tests of lexical semantics, higher level language. Preliminary measures of construct validity suggested that the theoretical assumptions behind the construction of the assessments were appropriate and re-test and inter-rater reliability scores were acceptable. These findings illustrate the potential to adapt Western speech and language assessments in other languages and settings, particularly those in which there is a paucity of standardised tools.     

Exploring the fruitfulness of diagrams in mathematics

Synthese - The paper asks whether diagrams in mathematics are particularly fruitful compared to other types of representations. In order to respond to this question a number of examples of...     

An Ecological Risk Model for Early Childhood Anxiety: The Importance of Early Child Symptoms and Temperament

Childhood anxiety is impairing and associated with later emotional disorders. Studying risk factors for child anxiety may allow earlier identification of at-risk children for prevention efforts. This study applied an ecological risk model to address how early childhood anxiety symptoms, child temperament, maternal anxiety and depression symptoms, violence exposure, and sociodemographic risk factors predict school-aged anxiety symptoms. This longitudinal, prospective study was conducted in a representative birth cohort (n = 1109). Structural equation modeling was used to examine hypothesized associations between risk factors measured in toddlerhood/preschool (age = 3.0 years) and anxiety symptoms measured in kindergarten (age = 6.0 years) and second grade (age = 8.0 years). Early child risk factors (anxiety symptoms and temperament) emerged as the most robust predictor for both parent-and child-reported anxiety outcomes and mediated the effects of maternal and family risk factors. Implications for early intervention and prevention studies are discussed.