A CUSUM SCHEME BASED ON THE EXPONENTIAL DISTRIBUTION FOR SURVEDLLANCE OF RARE CONGENITAL MALFORMATIONS

A method of monitoring the incidence of malformations is described. It is suitable for systems where the number of births between successive malformations is known or can be estimated with reasonable accuracy. The method utilises a cusum technique based on the exponential distribution to detect an increase in the incidence of malformations above a baseline level. Adequate information to enable the implementation of the method is presented. The proposed method compares favourably with others such as the Poisson cusum and the modified sets technique.     

School Connectedness Buffers the Effects of Negative Family Relations and Poor Effortful Control on Early Adolescent Conduct Problems

This study examined the unique and interactive contributions of school connectedness, negative family relations, and effortful control to subsequent early adolescent conduct problems. Data were collected from 476 adolescents when they were initially in the 6th and 7th grades and again 1 year later. Results from hierarchical regression analyses showed that even after controlling for negative family relations, effortful control, baseline levels of conduct problems, and gender, school connectedness contributed to decreasing subsequent conduct problems. Examination of 2- and 3-way interactions indicated that high levels of school connectedness offset the adverse effects of negative family relations for boys and girls and the adverse effects of low levels of effortful control for girls. Findings underscore the role of school connectedness as a protective factor for early adolescent conduct problems.     

Inventory control for the supply chain: An adaptive control approach based on the identification of the lead-time

In this paper, an Internal Model Control (IMC) scheme is incorporated in production inventory control systems in a complete supply chain. This control scheme presents a good target inventory tracking under the perfect knowledge of the system. Furthermore, the inventory tracking and load disturbance rejection control problems can be tackled separately. However, the closed-loop performance of the IMC scheme may be degraded due to a mismatch between the modelled and actual delay or to the fact that delays may be time-varying. Thus, the IMC control scheme is enhanced in this work with a novel method for the online identification of lead times based on a multimodel scheme. In this way, all benefits of the IMC scheme can be exploited. A detailed discussion of the proposed production inventory system is provided including a stability and performance analysis as well as the identification capabilities of the algorithm. Several simulation examples illustrate the efficiency of the approach.     

Physical workload during firefighting in Chilean volunteers

The study was performed in a sample of 39 firemen. The state of health for each fire fighter was evaluated by means of a clinical examination and also through some specific exams. Aerobic capacity was estimated as an indicator of physical fitness. In each load, cardiac frequency and oxygen consumption were measured under a steady state condition. Additionally, body composition was calculated using a Tanita professional scale. Physical effort at work was determined by measuring cardiac frequency using a telemetric unit. Evaluations were carried out during night shifts, registering information under the following conditions: night shifts without emergency, fire simulation, training exercises and real fire fighting. In general terms, it is possible to state that fire fighters are healthy according to the result of the clinical examination. However, it is very important to highlight that 70% of the firemen consume alcohol and 80% were smokers. The average aerobic capacity of the sample was 2.6 l/min or 34.5 ml/kg/min. In terms of overweight and obesity, the body mass index was 25.7, whereas the percentage fat mass reached an average of 22.9 %. The cardiovascular load in the night shifts without emergencies did not surpass 40%, which in Chile is considered the highest limit for sustained work. However, during training, simulations and real fires, the firemen had higher cardiac frequencies, reaching peak levels close to 100% cardiovascular load.     

Two arguments for 'covert methods' in social research

In some 'covert' participant-observation studies, social researchers defend their omission of informed consent on the basis of a need to protect subjects from apprehension, nervousness, or even criminal prosecution. In other instances, researchers contend that deception is rampant in society, and that their methods are no more immoral than the behaviour that ordinarily prevails. These defenses of covert methods fail to appreciate the range of risks that may be involved, and in the latter case, fail to show that these methods are in fact morally indistinguishable from the 'deception' that people typically engage in. Ultimately, these proposed defenses of covert methods succeed only in arousing greater concern about informed consent in social research, and the researcher's privilege in bypassing it.     

The sexual division of labour: A qualitative analysis of social organisations in Peru

This is a study on participation in civil society organisations in Peru, which adopts a gender perspective to understand the dynamics of social welfare production in a family model, and in which there is also a preponderance of community intervention in the field of social protection. The study uses a qualitative methodology and an ethnographic analysis based on 21 organisations. The results indicate polarity of discourses between those who recognise gender differentiation and those who consider that there is gender equality. Despite the polarity, differences in roles, quantity and quality of services, leadership, involvement and motivation are shown. The differences identified vary according to the type of organisation, which shows the relationship between the organisations and the intervention in territories-regions.