Ensayo clínico controlado y aleatorizado para determinar los efectos del uso de pelotas de parto durante el trabajo de parto

Objetivo. Determinar los efectos del uso de la pelota de parto (PdP) durante el trabajo de parto en relación al tiempo de dilatación y expulsivo, la integridad perineal, la percepción de la intensidad del dolor y la seguridad. Método. Ensayo clínico controlado y aleatorizado. Participantes: nulíparas de 18 a 35 años, bajo riesgo, a término. Intervención: realización de movimientos sentadas sobre PdP durante el parto. Variables resultado: tiempo de dilatación y expulsivo; integridad perineal; percepción del dolor, recuerdo del dolor en el puerperio y pre-post intervención; tipo de parto; motivo de distocia; Apgar; ingreso en UCI neonatal. Análisis: comparación de grupos: t-Student para variables contínuas y Ji-cuadrado para categóricas. Significación p≤0,05. Resultados. 58 participantes (34 grupo experimental y 24 grupo control). El tiempo de dilatación y expulsivo, y la integridad perineal fue similar entre grupos. A los 4 cm el grupo experimental refirió menos dolor que el grupo control; 6,9 puntos vs 8,2 (p = 0,039). La diferencia en la percepción del dolor recordada en el puerperio inmediato fue de 1,48 puntos mayor en el grupo control (p = 0,003). La medición del dolor en el grupo experimental antes del uso de la PdP fue de 7,45 puntos y tras la intervención de 6,07 puntos (p < 0,001). En las variables relacionadas con la seguridad no hubo diferencias entre los grupos. Conclusión. El uso de pelotas de parto disminuye la percepción del dolor de parto y es segura.

An evolutive approach for the delineation of local labour markets

This paper presents a new approach to the delineation of local labour markets based on evolutionary computation. The main objective is the regionalisation of a given territory into functional regions based on commuting flows. According to the relevant literature, such regions are defined so that (a) their boundaries are rarely crossed in daily journeys to work, and (b) a high degree of intra-area movement exists. This proposal merges municipalities into functional regions by maximizing a fitness function that measures aggregate intra-region interaction under constraints of inter-region separation and minimum size. Real results are presented based on the latest database from the Census of Population in the Region of Valencia. Comparison between the results obtained through the official method which currently is most widely used (that of British Travel-to-Work Areas) and those from our approach is also presented, showing important improvements in terms of both the number of different market areas identified that meet the statistical criteria and the degree of aggregate intra-market interaction.

A memetic algorithm for the delineation of local labour markets

Given a territory composed of basic geographical units, the delineation of local labour market areas (LLMAs) can be seen as a problem in which those units are grouped subject to multiple constraints. In previous research, standard genetic algorithms were not able to find valid solutions, and a specific evolutionary algorithm was developed. The inclusion of multiple ad hoc operators allowed the algorithm to find better solutions than those of a widely-used greedy method. However, the percentage of invalid solutions was still very high. In this paper we improve that evolutionary algorithm through the inclusion of (i) a reparation process, that allows every invalid individual to fulfil the constraints and contribute to the evolution, and (ii) a hillclimbing optimisation procedure for each generated individual by means of an appropriate reassignment of some of its constituent units. We compare the results of both techniques against the previous results and a greedy method.