The point of maximum curvature as a marker for physiological time series

We present a geometric analysis of the model of Stirling. In particular we analyze the curvature of a heart rate time series in response to a step like increment in the exercise intensity. We present solutions for the point of maximum curvature which can be used as a marker of physiological interest. This marker defines the point after which the heart rate no longer continues to rapidly rise and instead follows either a steady state or slow rise. These methods are then applied to find analytic solutions for a mono exponential model which is commonly used in the literature to model the response to a moderate exercise intensity. Numerical solutions are then found for the full model and parameter values presented in Stirling

Mathematical tools for identifying the fetal response to physical exercise during pregnancy

In the applied mathematics literature there exist a significant number of tools that can reveal the interaction between mother and fetus during rest and also during and after exercise. These tools are based on techniques from a number of areas such as signal processing, time series analysis, neural networks, heart rate variability as well as dynamical systems and chaos. We will briefly review here some of these methods, concentrating on a method of extracting the fetal heart rate from the mixed maternal-fetal heart rate signal, that is based on phase space reconstructio

Treatment approaches for dual diagnosis clients in England

Introduction - Dual diagnosis (DD, co-occurrence of substance use and mental health problems) prevalence data in England are limited to specific regions and reported rates vary widely. Reliable information on actual service provision for dual diagnosis clients has not been collated. Thus a national survey was carried out to estimate dual diagnosis prevalence in treatment populations and describe the service provision available for this client population in drug/alcohol (DAS) and mental health services (MHS). Design - A questionnaire was sent to managers of 706 DAS and 2374 MHS. Overall, 249 (39%) DAS and 493 (23%) MHS participated in the survey. Results - In both DAS and MHS, around 32% of clients were estimated to have dual diagnosis problems. However, fewer than 50% of services reported assessing clients for both problem areas. Regarding specific treatment approaches, most services (DAS: 88%, MHS: 87%) indicated working jointly with other agencies. Significantly fewer services used joint protocols (DAS: 55%, MHS: 48%) or shared care arrangements, including access to external drug/alcohol or mental health teams (DAS: 47%, MHS: 54%). Only 25% of DAS and 17% of MHS employed dual diagnosis specialists. Conclusions - Dual diagnosis clients constitute a substantial proportion of clients in both DAS and MHS in England. Despite recent policy initiatives, joint working approaches tend to remain unstructured

Update of MRST parton distributions.

We discuss the latest update of the MRST parton distributions in response to the most recent data. We discuss the areas where there are hints of difficulties in the global fit, and compare to some other updated sets of parton distributions, particularly CTEQ6. We briefly discuss the issue of uncertainties associated with partons

MRST global fit update.

We discuss the impact of the most recent data on the MRST global analysis - in particular the new high-ET jet data and their implications for the gluon and the new small x structure function data. In the light of these new data we also consider the uncertainty in predictions for physical quantities depending on parton distributions, concentrating on the W cross-section at hadron colliders

Acute maternal exercise during the third trimester of pregnancy, influence on foetal heart rate = Ejercicio físico durante el tercer trimestre de embarazo, influencia en la frecuencia cardiaca fetal

A substantial amount of research has investigated the influence of physical exercise during pregnancy on certain maternal and foetal parameters. Regarding the behaviour of the foetal heart rate (FHR) during the maternal exercise certain controversy exists; as several investigations have studied this parameter obtaining varied results. To test the hypotheses that the foetal heart rate (FHR) increases during maternal exercise, performed on a static bicycle during the third trimester. To know if the magnitude of the increase is related to gestational age or parity. This research involved a collaboration with the Gynaecology and Obstetrics Service of “Severo Ochoa” Hospital (Madrid) and Universidad Politécnica de Madrid (UPM). The approval of the Committee of Investigation as well as of the Ethical Commission of the Hospital was obtained. Twenty healthy pregnant women have been studied, in the last trimester. No women showed any medical complications in their pregnancy or contraindications for the practice of physical exercise. Informed consent was obtained. The exercise protocol consisted in the first part (rest), followed by a session of 20 minutes of moderate work (static bicycle exercise) and then rest until the FHR returned to the pre-exercise levels. Data for the evaluation of the FHR was obtained using an Electronic Foetal Monitor, Philips FM 20; and an Accurex Plus, Polar Electro OY was used for the control of the maternal heart rate. The clinical history of the pregnant women provided data about medical and personal factors. For the statistical analysis, Pearson correlation and Student’s t test for unpaired data were used. Our results show increases (11 - 36 beats/min, mean= 24 beats/min) of the FHR in all the studied cases. The gestational age shows no correlation with increments of FHR (Pearson 0.06) and there are larger increments of FHR in secundigravid (mean=152 ± 6.0 beats/min) than in primigravid (mean=147 ± 4.6 beats/min). Maternal aerobic and moderate exercise developing during last trimester increments FHR without harmful effects. These increments do not depend on the maternal age. Parity has influence on the level of increments of the FHR. Una cantidad importante de investigaciones han valorado la influencia del ejercicio físico durante el embarazo en ciertos parámetros fetales. En relación al comportamiento de la frecuencia cardiaca fetal (FCF) durante la realización del ejercicio existe cierta controversia, muchas investigaciones han estudiado este parámetro con resultados variados. El objetivo de este estudio fue comprobar la hipótesis de un aumento de la FCF durante la realización de ejercicio en bicicleta estática en el tercer trimestre de embarazo. También conocer si esos aumentos se relacionan con la edad gestacional o la paridad de la gestante. Este estudio se ha desarrollado mediante una colaboración entre el Servicio de Ginecología y Obstetricia del Hospital Severo Ochoa de Leganés y la Universidad Politécnica de Madrid. Se obtuvo la aprobación del Comité de Investigación así como de la Comisión Ética. Fueron estudiadas 20 gestantes en el último trimestre, sin complicaciones ni contraindicaciones médicas para el ejercicio, cada mujer firmó un consentimiento informado. El protocolo de ejercicio consistió en una primera parte de reposo, una sesión de 20 minutos de trabajo moderado en bicicleta estática y el reposo final con retorno a los niveles normales de FCF. Los datos correspondientes a la FCF se obtuvieron por medio de un Monitor Fetal Electrónico Philips FM 20, y un pulsómetro Accurex Plus, Polar Electro OY, fue usado para el control de la frecuencia cardiaca materna. La historia clínica de cada gestante aportó datos relativos a características médicas y personales. Para el análisis estadístico se utilizaron mecanismos descriptivos, el índice de correlación de Pearson y la t de Student para comparación de medias. Nuestros resultados muestran aumentos de la FCF de 11-36 lat/min (media de 24 lat/min). Los días de gestación no presentaron una correlación positiva con el nivel de los incrementos (Pearson 0.06). Hubo mayores aumentos en gestantes secundigrávidas (media=152 ± 6.0 lat/min) que en primigrávidas (media=147 ± 4.6 lat/min). El ejercicio aeróbico y moderado materno desarrollado durante el tercer trimestre de embarazo incrementa la FCF sin efectos perjudiciales. Los aumentos no dependen de la edad gestacional de la madre. La paridad de la gestante tiene influencia en el nivel de los incrementos

A model of heart rate kinetics in response to exercise

We present a mathematical model, in the form of two coupled ordinary differential equations, for the heart rate kinetics in response to exercise. Our heart rate model is an adaptation of the model of oxygen uptake kinetics of Stirling: a physiological justification for this adaptation, as well as the physiological basis of our heart rate model is provided. We also present the optimal fit of the heart rate model to a set of raw un averaged data for multiple constant intensity exercises for an individual at a particular level of fitness