Mathematical model and simulation of the progression of cutaneous T-cell lymphoma

A simple mathematical model and simulation of the progression of cancer with particular emphasis on Cutaneous T Cell Lymphoma was investigated. The mathematical model consists of a set of differential equations that first satisfies the homeostasis levels of the different components present and second predicts the dynamics during a diseased or unhealthy condition. The simulation was done using a FORTRAN program for integrating the differential equations. Simulation of the immune system is important in evaluating the usefulness of particular sorts of biologically targeted therapies and in selecting the most promising treatment strategies for clinical trials. In particular, the effects of leukapheresis and photopheresis in the treatment of CTCL was investigated using the model and available data. Simulation is also important for testing the effectiveness of new drugs on the system

Identifying the characteristics of support Australian university teachers use in their design work: Implications for the learning design field

© 2018 Australasian Journal of Educational Technology. Quality teaching is a strategic objective for universities; thus, there is an expectation that university teachers design high quality learning experience for their students. The field of learning design has developed over the past 15 years as a way to support teachers in their design work. There has been significant research and development work that has focused on creating support tools to help teachers plan, develop and deliver learning experiences. However, little is known about what supports teachers access and use when they design and overall how teachers undertake their design work. This paper presents the findings from a qualitative study that investigated the types of supports 30 teachers from 16 Australian universities reported using in their design work. Data was collected from semi-structured interviews, and the results show that participants accessed a variety of supports depending on their design need. The kind of support participants accessed in their design work were colleagues, literature, workshops and seminars, conferences, institutional support services, and enrolment in postgraduate study. How participants explained using these supports can be characterised as varied, personalised, dynamic and networked. Based on these results, implications for the learning design field are discussed with recommendations for future research

Efficiency of microfinance institutions : analysis of Southern African Development Community (SADC) member countries

Microfinance is seen as an important tool for financial inclusion and the fight against poverty because it has both a social and financial focus. The main objective of this paper is to evaluate the financial and social efficiency of 18 microfinance institutions (MFIs) in the year 2016 from 8 member countries of the Southern African Development Community (SADC). The methodology chosen is the data envelopment analysis (DEA) with variable returns to scale (VRS) using an input-oriented production approach. The results indicate higher scores of financial efficiency than social efficiency. This may suggest that microfinance institutions adopt a more institutionalist approach over the welfarist approach. We also find evidence that providing financial services to women or the entire disadvantaged population is profitable. However, non-bank financial institutions (NBFIs) and non-governmental organizations (NGOs) are more efficient in this regard than credit unions or banksinfo:eu-repo/semantics/publishedVersio

Human dermal exposure to galaxolide from personal care products

Musks are synthetic fragrances applied on personal care and household products as fixatives, by retarding the release of other fragrances with higher volatility. Galaxolide is the most used polycyclic musk since the 90th decade, and it has been detected in several environmental and biological matrices, particularly in human tissues and fluids. For exposure assessment purposes, large-monitoring data need to be obtained and rapid but reliable analytical techniques are requested. The main objective of this study is to develop and validate a new and fast analytical methodology to quantify galaxolide in personal care products and to apply this method to real matrices like skin care products (creams and lotions), shower products (soap bar), hair care products (shampoo and hair conditioner) and oral care products (toothpaste), to evaluate the human dermal exposure risk. A dispersive solid-phase extraction is proposed, using QuEChERS methodology, followed by HPLC with fluorescence detection. Some extraction parameters were studied, like the ratio of sample/solvent amounts, the homogenization time, the salt addition effect and the used sorbents. The validation parameters of the developed method were the following: a linearity range of 0.005-1.002 mg kg⁻¹ sample, a limit of detection of 0.001 mg kg⁻¹ sample, repeatability between 0.7% and 11.3% (variation coefficient of six standard injections), an intermediate precision of 2.5% (variation coefficient of six independent analysis of the same sample), mean recoveries ranging from 65% (soap bar) to 95% (body cream) and 3% of global uncertainty in most of the working range. The time of analysis, including the extraction steps, is 60 min, allowing a throughput of 4 samples h⁻¹ . Galaxolide was detected in all of the seven analysed products in concentrations ranging from 0.04 ± 0.01 mg kg⁻¹ sample (toothpaste) to 280.78 ± 8.19 mg kg⁻¹ sample (perfumed body cream), which may correspond to a significant estimated daily human dermal exposure of 904 μg day⁻¹.info:eu-repo/semantics/publishedVersio

On the precision and accuracy of the acoustic birefringence technique for stress evaluation

This paper presents a numerical procedure for estimation of the precision and accuracy of the acoustic birefringence technique as used in the Instituto de Engenharia Nuclear (IEN) for evaluation of residual and applied stresses in structures and components, mainly of the nuclear power industry. This procedure shall be incorporated to the signal processing module of the ultrasonic system used at IEN’s Ultrasonic Laboratory to account in an automatic and systematic way for the uncertainties in the input data and their propagation throughout the calculations. The acoustic birefringence is generally defined from the speeds of two mutually orthogonal volumetric waves of normal incidence, but when the use of a pulse-echo measurement system is feasible, the birefringence can be defined directly from the time-of-flight of the waves, since they travel the same physical space. The times-of-flight of the waves can thus be regarded as the primary variables of interest. They are estimated by coupling the mathematical techniques of cross correlation and data interpolation, whereas the material’s acoustoelastic constant is determined via a weighted linear regression. An Excel spreadsheet performs all calculations taking into account the uncertainties and the number of significant digits in the results. As an example of the procedure developed, the estimation of the precision and accuracy in the evaluation of the stresses acting in a beam under bending is presented. The analytical solution derived from the strength of materials theory was used as the reference value for accuracy estimation purpos

Distribution of the members of Anopheles gambiae and pyrethroid knock-down resistance gene (kdr) in Guinea-Bissau, West Africa

Une étude entomologique a été réalisée en 2002 dans quatre localités couvrant différents faciès écologiques de la Guinée Bissau : Buba Tombao (forêt), Gabu (savane), Cacheu (mangrove) et Bissau (urbain) afin i) d'étudier la distribution des membres du complexe Anopheles gambiae (Diptera: Culicidae) ii) d'évaluer le statut de résistance de ces vecteurs du paludisme aux insecticides (perméthrine 0.75%, DDT 4%) et enfin iii) de rechercher la présence et la distribution de la mutation kdr au sein de ces populations. Les femelles de moustiques adultes issues de captures matinales à l'intérieur des maisons ont été testées suivant les procédures OMS (kit de bio essai et papier imprégné) afin d'évaluer leur statut de résistance aux insecticides. Les spécimens testés ont été identifiés et caractérisés pour la présence de la mutation kdr par PCR. En Guinée Bissau, dans les localités étudiées, le complexe An. gambiae est dominé par An. gambiae s.s. (avec les deux formes moléculaires S et M représentées) vivant en sympatrie sur le littoral avec une faible proportion d'An. melas. Les populations d'An. gambiae s.s. exposées aux deux insecticides se sont révélées sensibles quelle que soit leur provenance. La mutation kdr Leu-Phe a été détectée en de très faibles fréquences seulement dans deux localités situées respectivement en zone urbaine (Bissau) et en savane (Gabu). Cette mutation est présente uniquement dans la forme moléculaire S à Gabu (avec une fréquence allélique de 0.14) et dans les deux formes moléculaires M et S à Bissau avec des fréquences alléliques respectives de 0.06 et de 0.02. Ces résultats suggèrent que les populations d'An. gambiae s.s., vecteur le plus fréquent du paludisme en Guinée Bissau, demeurent encore sensibles aux pyréthrinoides et au DDT 4%. Ce statut de sensibilité ainsi que la fréquence des gènes de résistance tel que le kdr doivent être surveillés dans le futur particulièrement dans les zones urbaine et de savane soumises à une utilisation intensive d'insecticides. (Résumé d'auteur