Archetype analysis and the PHATE algorithm as methods to describe and visualize pregnant women's levels of physical activity knowledge.

The knowledge of physical activity (PA) recommended for pregnant women and practical application of it has positive impact on the outcome. Nevertheless, it is estimated that in high-income countries over 40% of pregnant women are insufficiently physically active. One of the reasons is insufficient knowledge pregnant women have about allowed effort during pregnancy and both recommended and not recommended physical activities. Description of knowledge about physical activity the women have and distinguishing patterns of their knowledge is becoming an increasingly important issue. A common approach to handle survey data that reflect knowledge involves clustering methods or Principal Component Analysis (PCA). Nevertheless, new procedures of data analysis are still being sought. Using survey data collected by the Institute of Mother and Child Archetypal analysis has been applied to detect levels of knowledge reflected by answers given in a questionnaire and to derive patterns of knowledge contained in the data. Next, PHATE (Potential of Heat-diffusion for Affinity-based Trajectory Embedding) algorithm has been used to visualize the results and to get a deeper insight into the data structure. The results were compared with picture derived from PCA. Three archetypes representing three patterns of knowledge have been distinguished and described. The presentation of complex data in a low dimension was obtained with help of PHATE. The formations revealed by PHATE have been successfully described in terms of knowledge levels reflected by the survey. Finally, comparison of PHATE with PCA has been shown. Archetype analysis combined with PHATE provides novel opportunities in examining nonlinear structure of survey data and allows for visualization that captures complex relations in the data. PHATE has made it possible to distinguish sets of objects that have common features but were captured neither by Archetypal analysis nor PCA. Moreover, for our data, PHATE provides an image of data structure which is more detailed than interpretation of PCA.

Archetypal Analysis and DEA Model, Their Application on Financial Data and Visualization with PHATE.

One of the goals of macroeconomic analysis is to rank and segment enterprises described by many financial indicators. The segmentation can be used for investment strategies or risk evaluation. The aim of this research was to distinguish groups of similar objects and visualize the results in a low dimensional space. In order to obtain clusters of similar objects, the authors applied a DEA BCC model and archetypal analysis for a set of companies described by financial indicators and listed on the Warsaw Stock Exchange. The authors showed that both methods give consistent results. To get a better insight into the data structure as well as a visualization of the similarities between objects, the authors used a new approach called the PHATE algorithm. It allowed the results of DEA and archetypal analysis to be visualized in a low dimensional space.

The protocol for a randomised-controlled trial of the evaluation of the tolerance and safety of early enteral nutrition in children after percutaneous endoscopic gastrostomy placement. (protocol version 09.01.2015).

BACKGROUND: The appropriate time to initiate enteral nutrition after the placement of a percutaneous endoscopic gastrostomy (PEG) tube has been an area of limited research. There are no sufficient randomised prospective controlled trials in the paediatric population comparing the safety and tolerance of early feeding (3 h) after PEG placement. In order to reduce the period of fasting, inadequate nutritional support, and hospitalisation time, we decided to devise this study. METHODS/DESIGN: This study is a multicentre, randomised, open-label trial designed to evaluate the tolerance and safety of early enteral nutrition after PEG placement in children. Patients are randomised to receive the first feeding bolus with a polymeric diet (1 kcal/ml) via a feeding tube 3 h after the PEG placement (group I - early enteral feeding) or 8 h after the procedure (group II - late enteral feeding). The key objective of the study is to compare the tolerance and safety of the early- and late-feeding modes after PEG placement in children. The primary endpoint is the number of patients who will achieve full feed (total fluid and caloric requirements) within 48 h of the first feeding bolus. The secondary endpoints are: the number of early and late complications, the duration of hospitalisation after PEG placement, gastric residuals (ml) total in the period up to 48 h since the first feeding bolus. DISCUSSION: To our knowledge this is the first study in paediatric patients to evaluate the tolerance and safety of early enteral nutrition after PEG placement. The goal is to establish an optimum standard procedure in the group of paediatric patients qualified for the PEG insertion procedure in Poland. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT02777541 , registration date 05/18/2016.