The role of survival functions in competing risks

Competing risks data usually arises in studies in which the failure of an individual may be classified into one of k (k > 1) mutually exclusive causes of failure. When competing risks are present, there are two main differences with classical survival analysis: (i) survival functions are not mainly used to describe cause-specific failures and, (ii) classical estimation techniques may provide biased results. The main goal of this paper is to review, clarify and present the formulation of a competing risks model and the basic nonparametric estimation methods. We show why the use of survival functions in the competing risks framework may mislead the user, and we illustrate the presented methodologies by developing two examples from real data. The methods presented here can be implemented with several statistical packages, including R, SPSS and SAS: we give some highlights on how to perform a competing risks analysis with these software packages

QuEChERS-based analytical methods developed for LC-MS/MS multiresidue determination of pesticides in representative crop fatty matrices: Olives and sunflower seeds

Oilseed crops are greatly extended all over the world. Their high fat content can interfere during pesticide multiresidue analysis through liquid chromatography-tandem mass spectrometry (LC-MS/MS). This work aimed at overcoming this issue by developing and validating two QuEChERS-based methods for LC-MS/MS determination of 42 pesticides in two fatty food matrices: olives and sunflower seeds. Optimization of the extraction method was achieved following a 26-2 fractional factorial design in a highly cost-effective way. Validation of the multi-residue methods demonstrated improved limits of detection, below the established maximum residue levels (MRLs) for almost all compounds, good precision, and trueness, in compliance with SANTE guidelines. Application of these methods to the analysis of real samples from the Iberian Peninsula showed the presence of some pesticides of relevant environmental concern, including four compounds contained in the Pesticide Action Network International list of highly hazardous pesticides, found at levels between 0.03 ng/g and 104 ng/g

Human or Computer Assisted Interactive Transcription: Automated Text Recognition, Text Annotation, and Scholarly Edition in the Twenty-First Century

Computer assisted transcription tools can speed up the initial process of reading and transcribing texts. At the same time, new annotation tools open new ways of accessing the text in its graphical form. The balance and value of each method still needs to be explored. STATE, a complete assisted transcription system for ancient documents, was presented to the audience of the 2013 International Medieval Congress at Leeds. The system offers a multimodal interaction environment to assist humans in transcribing ancient documents: the user can type, write on the screen with a stylus, or utter a word. When one of these actions is used to correct an erroneous word, the system uses this new information to look for other mistakes in the rest of the line. The system is modular, composed of different parts: one part creates projects from a set of images of documents, another part controls an automatic transcription system, and the third part allows the user to interact with the transcriptions and easily correct them as needed. This division of labour allows great flexibility for organising the work in a team of transcribers.Las herramientas de ayuda a la transcripción automática pueden acelerar el proceso inicial de la lectura y transcripción de textos. Al mismo tiempo, las nuevas herramientas de anotación aportan nuevas formas de acceder al texto en su forma original gráfica. Sin embargo, todavía es necesario evaluar las bondades y capacidades de los distintos métodos. STATE, un completo sistema de asistencia a la transcripción de documentos antiguos, se presentó a la audiencia del International Medieval Congress de 2013 celebrado en Leeds. El sistema ofrece un entorno de interacción multimodal para ayudar a las personas en la transcripción de documentos antiguos: el usuario puede teclear, escribir en la pantalla con un lápiz óptico o corregir usando la voz. Cada vez que el usuario cambia de esta forma una palabra, el sistema utiliza la corrección para buscar errores en el resto de la línea. El sistema está dividido en diferentes módulos: uno crea proyectos a partir de un conjunto de imágenes de documentos, otro módulo controla el sistema de transcripción automática, y un tercer módulo permite al usuario interactuar con las transcripciones y corregirlas fácilmente cuando sea necesario. Esta división de las tareas permite una gran flexibilidad para organizar el trabajo de los transcriptores en equipo

Competing risks methods

Competing risks data usually arises in studies in which the failure of an individual may be classified into one of k (k > 1) mutually exclusive causes of failure. When competing risks are present, classical survival analysis techniques may not be appropriate to use. The main goal of this paper is to review the specific methods to deal with competing risks. To this aim, we first focus on how to specify a competing risks model, which is the structure of observed data in this framework, and how components of the model are estimated from a given random sample. In addition, we discuss how to correctly interpret probabilities in the presence of competing risks, and regression models are considered in detail. To conclude, we illustrate the problem with data from a bladder cancer study

Coordinación de competencias de tratamiento de señal y comunicaciones en estudios de Telecomunicación en EPS-UA

Los objetivos del presente trabajo son el seguimiento, la coordinación, la evaluación y la mejora en la distribución de competencias de las asignaturas obligatorias de los cursos primero, segundo y tercero del Grado en Ingeniería en Sonido e Imagen en Telecomunicación y una asignatura obligatoria del Máster en Ingeniería de Telecomunicación. La red tiene carácter transversal y se centra en materias de tratamiento de señal y comunicaciones de estudios de Telecomunicación en la Escuela Politécnica Superior de la Universidad de Alicante. Para alcanzar los objetivos se plantea llevar a cabo una colaboración de la que formen parte las subdirecciones de las titulaciones, la dirección del departamento y las profesoras y los profesores de las asignaturas relacionadas con las competencias de tratamiento de señal y comunicaciones en el Grado y Máster Universitario de estudios de Telecomunicación en la Escuela Politécnica Superior. En el proceso se elaboraron documentos para facilitar la puesta en común y la concreción de acuerdos de mejora

Exome sequencing reveals a high genetic heterogeneity on familial Hirschsprung disease

published_or_final_versio

Family presence during resuscitation: Validation of the risk–benefit and self-confidence scales for student nurses

© 2016, © The Author(s) 2016. Background. There is increasing debate about the advantages and disadvantages of family-witnessed resuscitation. Research about the views of healthcare providers depends upon reliable tools to measure their perceptions. Two tools have been developed for use with nurses (26-item cost-benefit tool, 17-item self-confidence tool). Objectives. Firstly, to validate these tools for use with student nurses in the UK. Secondly, to report on the perceived risks and benefits reported by student nurses, and their self-confidence in dealing with this situation. Methods. A sample of 79 student nurses were invited to complete the tools. Item-total correlations and Cronbach’s α were used to determine internal consistency. Factor analysis was computed to assess construct validity. The correlation between the two scales was explored. Results. 69 students completed a questionnaire. Very few had experience of family-witnessed resuscitation. Mean total scores were 3.16 (standard deviation 0.37; range 2.04–4.12) on the risk-benefit scale and 3.14 (standard deviation 0.66; range 1.94–4.82) on the self-confidence scale. Four of the original items were removed from the risk-benefit scale (Cronbach's α 0.86; 95% confidence interval ≥0.82). None were removed from the self-confidence scale (Cronbach's α 0.93; 95% confidence interval ≥0.91). There was a significant correlation between the two scales (r = 0.37, p = 0.002). Conclusions. There is growing evidence that these tools are valid and reliable for measuring student nurses’ perceptions about family-witnessed resuscitation

Emotion, verbal context and facial expression perception: Tell me who you are and I will tell you how I perceive you

La percepción de la expresión facial en un contexto verbal facilita la activación del conocimiento conceptual a través del cual es interpretada. Con el objetivo de analizar cómo la emoción, a través del contexto verbal, modula la percepción de la expresión facial en sus niveles de valencia, activación y control, se realizó un primer experimento en el que se generó el contexto verbal mediante palabras de contenido emocional (positivo, negativo), antes del reconocimiento de una expresión mixta de alegría y tristeza. En un segundo experimento, manteniendo neutros tanto contexto verbal como expresión facial, se indujo un estado afectivo positivo o negativo, antes o después de la codificación del contexto verbal. En el primer experimento, la condición de contexto verbal positivo facilitó que la cara mixta de alegría se percibiera con una expresión de mayor seguridad/confianza (control) respecto a la cara mixta de tristeza. En el segundo experimento, la emoción positiva inducida de manera previa a la codificación del contexto verbal, generó que la cara se percibiera con una expresión de mayor activación, respecto a cuando la emoción fue negativa. Se discuten los resultados a partir del modelo constructivista de la emoción