Two different methods for kinematic analysis of head movements relating to eye-head coordination in infants

BACKGROUND: Kinematic analysis is a method for quantitative assessment applied in different fields of study. In the field of motor development, this analysis may promote better understanding of the acquisition and development of motor skills. OBJECTIVE: To develop and compare two experimental set-ups for kinematic analysis of head movements relating to eye-head coordination (EHC) in infants. METHODS: Two experimental set-ups (A and B) were tested. They differed from each other regarding the numbers and locations of the cameras, and regarding the volume of the calibration system. RESULTS: The accuracy of the two experimental set-ups was 2.47mm, thus indicating that both can provide realistic reconstructions of the movement. The three cameras used in set-up B made it possible to view the full range of motion with at least one of the cameras. This led to improvement of the qualitative analysis and reduction of the time taken to process quantitative data, which was 33% shorter than seen with set-up A. In addition, set-up B presented a better cost-benefit relationship. CONCLUSIONS: Although both set-ups were adequate for kinematic analysis of head movements relating to EHC in infants, set-up B is more advantageous. The methodology for set-up B can be used in studies investigating head movements in either typical or atypical infants. The results from such studies could be used to complement assessments on at-risk infants and consequently could assist in implementing early interventions.CONTEXTUALIZAÇÃO: A análise cinemática é um método de avaliação quantitativa empregada em diferentes áreas de estudo. Na área do desenvolvimento motor, essa análise pode proporcionar uma melhor compreensão da aquisição e do desenvolvimento das habilidades motoras. OBJETIVOS: Desenvolver e comparar dois arranjos experimentais para análise cinemática dos movimentos de cabeça durante a coordenação viso-cefálica (CVC) em lactentes. MATERIAIS E MÉTODOS: Foram testados dois arranjos experimentais (A e B) que diferiam quanto ao número e posicionamento das câmeras, bem como quanto ao volume do sistema de calibração. RESULTADOS: A acurácia dos dois arranjos experimentais foi de 2,47mm, indicando que ambos podem fornecer uma reconstrução verossímil do movimento. As três câmeras usadas no arranjo B favoreceram a visualização de toda a amplitude do movimento por pelo menos uma das câmeras. Isso levou à melhora da análise qualitativa e à redução do tempo de processamento dos dados quantitativos, reduzindo-o em 33% quando comparado ao arranjo A. Além disso, o arranjo B apresentou melhor relação custo-benefício. CONCLUSÕES: Ambos os arranjos são adequados para a análise cinemática dos movimentos de cabeça durante a CVC de lactentes, entretanto, o arranjo B é mais vantajoso. A metodologia do arranjo B pode ser empregada em estudos que investigam o movimento de cabeça de lactentes, sejam eles típicos ou atípicos. Os resultados de tais estudos poderão ser empregados para complementar a avaliação de lactentes de risco e, conseqüentemente, auxiliar na intervenção precoce destes.42543

Decision Making for Inconsistent Expert Judgments Using Negative Probabilities

In this paper we provide a simple random-variable example of inconsistent information, and analyze it using three different approaches: Bayesian, quantum-like, and negative probabilities. We then show that, at least for this particular example, both the Bayesian and the quantum-like approaches have less normative power than the negative probabilities one.Comment: 14 pages, revised version to appear in the Proceedings of the QI2013 (Quantum Interactions) conferenc

Tissue-specific Butyrophilin-like Molecules are Master Regulators of Intraepithelial γδ T cell Composition

Many epithelial barriers are constitutively populated by large numbers of organ-specific γδ T cells that collectively make up a substantial proportion of the body’s T cells. In mice, these intraepithelial lymphocytes (IEL) display striking site-specific T cell receptor (TCR) Variable (V)γ chain usage, such that Vγ5+, Vγ6+ and Vγ7+ T cells form lifelong associations with the murine epidermis, uterine and the small intestinal epithelium, respectively. The maintenance of IEL composition is critically important to host physiology and its disruption in murine epidermis is associated with dysregulated cutaneous inflammation and heightened susceptibility to carcinogenesis. Furthermore, tumour-associated γδ T cell gene-expression signatures were recently found to be the greatest correlate with overall survival in a genome-wide expression analysis of ~18,000 human tumours. Thus, there is considerable interest in identifying molecules that regulate infiltration, composition and activation of tissue-resident γδ T cells. Skint1 is a Butyrophilin-like (Btnl) gene expressed by thymic medullary epithelium and suprabasal keratinocytes, which shapes DETC composition. However, as neither Skint1 nor DETC are conserved, a general mechanism by which epithelia shape IEL composition remains unelucidated. Here we show that enterocyte Btnl1 expression shapes small intestinal IEL composition by driving extrathymic maturation and expansion of Vγ7+ IEL in trans upon their arrival in the gut. Uninfluenced by microbial or solid food antigens, this mechanism evokes the Major Histocompatibility Complex-driven selection of αβ T cell repertoires. Consistent with this, we show that Btnl1 together with Btnl6 elicits specific TCR-dependent responses of intestinal Vγ7+ cells in vitro. From these data, a generalizable mechanism emerges whereby organ-specific expression of Btnl molecules enables epithelial cells to actively shape the lifelong composition of their signature IEL compartments. Moreover, by identifying selection elements that regulate signature γδ IEL, our models also provide novel avenues to study the unique contributions of discreet IEL compartments to host immunity

Waiting time distribution in public health care: empirics and theory

Excessive waiting times for elective surgery have been a long-standing concern in many national healthcare systems in the OECD. How do the hospital admission patterns that generate waiting lists affect different patients? What are the hospitals characteristics that determine waiting times? By developing a model of healthcare provision and analysing empirically the entire waiting time distribution we attempt to shed some light on those issues. We first build a theoretical model that describes the optimal waiting time distribution for capacity constraint hospitals. Secondly, employing duration analysis, we obtain empirical representations of that distribution across hospitals in the UK from 1997–2005. We observe important differences on the ‘scale’ and on the ‘shape’ of admission rates. Scale refers to how quickly patients are treated and shape represents trade-offs across duration-treatment profiles. By fitting the theoretical to the empirical distributions we estimate the main structural parameters of the model and are able to closely identify the main drivers of these empirical differences. We find that the level of resources allocated to elective surgery (budget and physical capacity), which determines how constrained the hospital is, explains differences in scale. Changes in benefits and costs structures of healthcare provision, which relate, respectively, to the desire to prioritise patients by duration and the reduction in costs due to delayed treatment, determine the shape, affecting short and long duration patients differently

Perception and practice of Kangaroo Mother Care after discharge from hospital in Kumasi, Ghana: A longitudinal study

BACKGROUND: The practice of Kangaroo Mother Care (KMC) is life saving in babies weighing less than 2000 g. Little is known about mothers' continued unsupervised practice after discharge from hospitals. This study aimed to evaluate its in-hospital and continued practice in the community among mothers of low birth weight (LBW) infants discharged from two hospitals in Kumasi, Ghana. METHODS: A longitudinal study of 202 mothers and their inpatient LBW neonates was conducted from November 2009 to May 2010. Mothers were interviewed at recruitment to ascertain their knowledge of KMC, and then oriented on its practice. After discharge, the mothers reported at weekly intervals for four follow up visits where data about their perceptions, attitudes and practices of KMC were recorded. A repeated measure logistic regression analysis was done to assess variability in the binary responses at the various reviews visits. RESULTS: At recruitment 23 (11.4%, 95%CI: 7.4 to 16.6%) mothers knew about KMC. At discharge 95.5% were willing to continue KMC at home with 93.1% willing to practice at night. 95.5% thought KMC was beneficial to them and 96.0% beneficial to their babies. 98.0% would recommend KMC to other mothers with 71.8% willing to practice KMC outdoors.At first follow up visit 99.5% (181) were still practicing either intermittent or continuous KMC. This proportion did not change significantly over the four weeks (OR: 1.4, 95%CI: 0.6 to 3.3, p-value: 0.333). Over the four weeks, increasingly more mothers practiced KMC at night (OR: 1.7, 95%CI: 1.2 to 2.6, p = 0.005), outside their homes (OR: 2.4, 95%CI: 1.7 to 3.3, p < 0.001) and received spousal help (OR: 1.6, 95%CI: 1.1 to 2.4, p = 0.007). Household chores and potentially negative community perceptions of KMC did not affect its practice with odds of 0.8 (95%CI: 0.5 to 1.2, p = 0.282) and 1.0 (95%CI: 0.6 to 1.7, p = 0.934) respectively. During the follow-up period the neonates gained 23.7 sg (95%CI: 22.6 g to 24.7 g) per day. CONCLUSION: Maternal knowledge of KMC was low at outset. Once initiated mothers continued practicing KMC in hospital and at home with their infants gaining optimal weight. Continued KMC practice was not affected by perceived community attitudes