Volume 3 Issue 4
Authors: G. Koloutsos; B. Christoforidou; K. Kontos; G. Kechagias; K. Andoniades; C. Tsompanidou; K. Vahtsevanos; K. Paraskevopoulos; P. Xirou; K. Kitikidou; A. Ntomouchtsis
Abstract: Having at our disposal a dataset of 186 lip cancer cases in Greece, we attempt to interpret them by applying four different statistical methods: Generalized Linear Model (GLM), Markov Chain Monte Carlo (MCMC), Cox proportional hazards model and Bayes factor. The likelihood score equations from GLM exerted estimators with bounded influence, so that the resulting estimators were robust against outliers while maintaining high efficiency in the absence of outliers. Batch means method of estimating the variance of the asymptotic normal distribution, used in MCMC, gave strong consistency when it was applied to our data. A Cox proportional hazards model done with a weighted expectation-maximization gave efficient parameter estimates. Finally, using Bayes factor to the prior distributions for the parameters in compared regression models was proved to be highly sensitive.
Keywords: Bayes Factor; Cox Regression; Generalized Linear Model; Lip cancer; Markov Chain Monte Carlo
Authors: Sara Silva; Fátima Moreira; Filomena Soares; Ana Paula Pereira; Sandra Costa
Abstract: Children with autism spectrum disorders (ASD) may present some difficulties in developing social behaviours, communicating with others and acquiring cognitive skills. In this study, we test the introduction of a robot Lego Mindstorms NXT as a mediator and/or positive reinforcement in the intervention of children with ASD in triadic interventions. The goal was to improve their academic skills and to transfer the acquired skills to their daily lives. Three case studies with 8-13 years old children are presented and discussed. The explored target skills were the concept of quantity, colour awareness and a gesture to make a request. Parents had an active participatory role in this study, especially in the Skill Transfer Phase.
Keywords: Autism Spectrum Disorders; Assistive Robotics; Social Interaction; Lego Mindstorms NXT
Authors: Abayomi Odekunle; Andrew Adogwa; Venkatesan Sundaram; Isanna Gibbons
Abstract: The study was done to compare the cytoarchitecture of two species of bats to ascertain whether echolocation has a bearing on the development of the inferior colliculus. Six bats each of Noctilio leporinus and Phyllostomus hastatus were used for the study. The brains of these bats were processed by double embedding, serially sectioned at 10μm and stained with cresyl fast violet. The inferior colliculus measured 1200 ± 90μm in length in N. leporinus bat and 1120± 63 μm in P. hastatus bat. The inferior colliculus of the bats is subdivided into three parts: dorsomedial, ventromedial and the peripheral. Two types of cells are most common in the inferior colliculus of the bats: multipolar and oval. The inferior colliculus is very large in the two species of bats compared to other animals which do not echolocate and which may not have as good a sense of hearing as the bat. It is larger in the N. leporinus than in the P. hastatus bat suggesting that N. leporinus depends more on echolocation than P. hastatus. The large inferior colliculus in these bats may be related to an acute sense of hearing in these animals.
Keywords: Inferior Colliculus; Cytoarchitecture; Bats
Authors: Ismail Saadoun; Ahlam Dawagreh; Ziad Jaradat; Qotaiba Ababneh
Abstract: The purpose of this study was to determine the influence of growth conditions and medium composition on the pectinase enzyme production by Streptomyces sp. Production of pectinase by a Streptomyces strain (J9) was detected on pectin agar medium after 4 days of incubation at 28°C which exhibited a clear zone of 12 mm around the colony. Pectinase production was assayed by measuring the amount of reducing groups (D–galacturonic acid) liberated from the substrate in μmol/ml/min using the dinitrosalicylic acid assay method. The highest crude enzyme relative activity (>80%) was observed after 2 days of incubation at pH 6 and 35°C. Strain J9 produced higher amount of crude pectinase when pectin and peptone were used as carbon and nitrogen sources, respectively. Crude pectinase was maximally active at day 4 (1122 U/L) and day 5 (923 U/L) when apple and orange pomaces were used as a sole carbon source, respectively. The findings of this investigation form an avenue for production of pectinase enzyme from Streptomyces strain (J9) to be used for commercial fruit clarification and for production of transgenic plants with extended shelf life as pectinase genes cloned from this active strain.
Keywords: Conditions; Culture; Fruit Pomace; Pectinase; Streptomyces sp.
Authors: A. Ted Watson; Jinsoo Uh
Abstract: Hydraulic permeability of cancellous bone is an important property for modeling bone and fluid response to mechanical stimuli. It can play a role in design of bone substitutes and cementation procedures. However, this property is poorly understood. Published experimental studies have reported large variations in property values, and there remains no reliable method for predicting the permeability from other observations or measurements. Consideration of spatial variations in properties within laboratory samples raises significant issues regarding the efficacy of permeability determinations from conventional experiments. We use magnetic resonance imaging (MRI) to probe fluid flow and fluid residence at a much finer scale than can be assessed with conventional experiments. We use this information to resolve spatial distributions of porosity and permeability on a bone sample.
Keywords: Hydraulic Permeability; Cancellous Bone; Magnetic Resonance Imaging; Spatially Distributed Properties