Ten Simple Rules for Organizing an Unconference

This is an open access article distributed under the terms of the Creative Commons Attribution License.Peer Reviewe

A multiplex (m)RNA-profiling system for the forensic identification of body fluids and contact traces

In current forensic practice, information about the possible biological origin of forensic traces is mostly determined using protein-based presumptive testing. Recently, messenger RNA-profiling has emerged as an alternative strategy to examine the biological origin. Here we describe the development of a single multiplex mRNA-based system for the discrimination of the most common forensic body fluids as well as skin cells. A DNA/RNA co-isolation protocol was established that results in DNA yields equivalent to our standard in-house validated DNA extraction procedure which uses silica-based columns. An endpoint RT-PCR assay was developed that simultaneously amplifies 19 (m)RNA markers. This multiplex assay analyses three housekeeping, three blood, two saliva, two semen, two menstrual secretion, two vaginal mucosa, three general mucosa and two skin markers. The assay has good sensitivity as full RNA profiles for blood, semen and saliva were obtained when using >= 0.05 mu L body fluid starting material whereas full DNA profiles were obtained with >= 0.1 mu L. We investigated the specificity of the markers by analysing 15 different sets of each type of body fluid and skin with each set consisting of 8 individuals. Since skin markers have not been incorporated in multiplex endpoint PCR assays previously, we analysed these markers in more detail. Interestingly, both skin markers gave a positive result in samplings of the hands, feet, back and lips but negative in tongue samplings. Positive identification (regarding both DNA-and RNA-profiling) was obtained for specimens stored for many years, e.g. blood (28 years-old), semen (28 years-old), saliva (6 years-old), skin (10 years-old) and menstrual secretion (4 years-old). The described approach of combined DNA-and RNA-profiling of body fluids and contact traces assists in the interpretation of forensic stains by providing information about not only the donor(s) that contributed to the stain but also by indicating which cell types are present. (C) 2012 Elsevier Ireland Ltd. All rights reserved

Effect of nutrient sources on bench scale vinegar production using response surface methodology Efeito das fontes de nutrientes sobre a produção de vinagre em escala de bancada, usando-se a metodologia de superfície de resposta

The present work aims to evaluate on a bench scale, the effects of nitrogen and phosphorous nutrient source concentrations in vinegar production, a process that is used by small scale industries in the State of Paraiba. The response surface methodology has been utilized for modeling and optimization of the fermentation process. Initially a 2³ complete factorial design was used, where the effects of initial concentrations of ethyl alcohol, phosphorous and nitrogen sources were observed. After this analysis the concentration range of the nutrient variables were extended and a two level plus a star configuration factorial experimental design was performed. The experimental values are well represented by the linear and quadratic model equations obtained. The optimum concentration of ethanol was 4% in which the yield and the productivity of the acetic acid were maximized to the values of 70% and 0.87 g L-1 h-1 respectively, for a 24 hours fermentation period. The evaluation of the quadratic models showed that the yield of vinegar is maximized from 28.1 to 51.04% and the productivity from 0.69 to 1.29 g L-1 h-1 when the concentration of the nitrogen nutrient in the medium is increased from 0.2 to 2.3 g mL-1. Thus, at the optimized nitrogen nutrient concentration both the yield and the productivity of the vinegar are increased by 1.85 times.<br>Objetivou-se com o presente trabalho, estudar em escala de bancada, os efeitos de concentrações de fontes dos nutrientes nitrogênio e fósforo sobre a produção de vinagre de álcool, um processo muito utilizado nas indústrias de pequeno porte do Estado da Paraíba. A metodologia de superfície de resposta foi usada na modelagem e otimização de processo de fermentação acética. Inicialmente, a metodologia de planejamento fatorial completo 2³ foi utilizada, onde os efeitos das concentrações iniciais de etanol, de fontes de fósforo e de nitrogênio foram observados. Após esta análise as faixas das concentrações iniciais das variáveis de fontes de nutrientes foram ampliadas e o planejamento experimental fatorial do tipo 2² mais configuração estrela foi realizado. Os dados experimentais foram bem representados pelas equações de modelos linear e quadrático obtidos para os dois planejamentos experimentais. As avaliações dos modelos linear e quadrático mostraram que o rendimento de vinagre foi maximizado de 28,1 a 51,4% e a produtividade de 0,69 a 1,29 g L-1 h-1, quando a concentração da fonte do nutriente nitrogênio, no meio, foi aumentada de 0,2 a 2,3 g mL-1. Portanto, na concentração otimizada da fonte de nutriente nitrogênio, o rendimento e a produtividade aumentou 1,85 vezes