Parametric estimation for ARFIMA models via spectral methods

Given a fractional integrated, autoregressive, moving average,ARFIMA (p, d, q) process, the simultaneous estimation of the short and long memory parameters can be achieved by maximum likelihood estimators. In this paper, following a two-step algorithm, the coefficients are estimated combining the maximum likelihood estimators with the general orthogonal decomposition of stochastic processes. In particular, the principal component analysis of stochastic processes is exploited to estimate the short memory parameters, which are plugged into the maximum likelihood function to obtain the fractional differencingd.     

The Effect of Grandparental Support on Mothers’ Labour Market Participation: An Instrumental Variable Approach

Childcare arrangements are key in women’s ability to juggle motherhood and work outside the home. As such, the study of access to childcare and its use is of great policy relevance. We focus on a particular kind of informal childcare, the one provided by grandparents. Empirically, assessing the effect of grandparental childcare is not an easy task due to unobserved preferences. In light of the potential outcome framework, we interpret the biases resulting from unobserved preferences as arising from the non-compliance of mothers to the availability of grandparents and from preferences of grandparents for activities other than childcare. Using an instrumental variable approach on Italian data, we find that the effect of grandparental childcare on mothers’ labour supply is positive, statistically significant and economically relevant. The effect is stronger for less educated mothers, with young children and living in northern and central Italy.     

Midwifery as established sect: an expanded application of the church–sect continuum

Based on church–sect theory, this paper asserts that midwifery is much like an established sect in relation to its church equivalent: Western medicine. We find that midwifery can endure in this form – as both protest movement and established institution – because of its ability to maintain its central oppositional values while being accepted as a legitimate, if marginalized, profession. Using interview data from 25 Florida midwives, we draw an analogy between the liminal status of midwifery and three of the most important characteristics of the established sect: limited institutionalization, acceptance and opposition, and a unique value set. This comparison sheds light on both church–sect theory and midwifery, which also leads us to suggest that similar analogies be used for analysis across other sub-fields in sociology.     

The Use of Risk Assessment to Decide the Control Strategy for Bluetongue in Italian Ruminant Populations

The affiliation, assessment and management of risks is a traditional part of veterinary medicine. In the past, veterinary services involved in this type of activity usually assessed risks qualitatively. However, since the 1990s, quantitative methods have become increasingly important. The establishment of the World Trade Organization in 1994, and the promulgation of its Agreement on the Application of Sanitary and Phytosanitary Measures (the "SPS Agreement") led to an increased application of import risk analysis and to significant improvements in the methodology of risk analysis as applied to international trade policy for animals and animal products. However, there was very little development of risk analysis in veterinary fields other than international trade and management of health risks to consumers of animal products and little has been published on its use in the choice and definition of control or prophylaxis strategies for animal diseases. This article describes a quantitative risk assessment, which was undertaken in Italy to help choose an appropriate national response strategy following an incursion of bluetongue, an infectious disease of sheep and goats. The results obtained in this study support the use of risk analysis as a tool to assist in choosing an appropriate animal disease management strategy. The use of risk analysis in the evaluation of disease management strategies also offers advantages in international trade. It makes easier the comparison of different strategies applied in the various countries, and thus facilitates the assessment of equivalence of the guarantees provided by different strategies.     

Abusing victims: detention of child sexual abuse victims in secure accommodation

Sexually abused children and adolescents, in limbo between revelation of abuse and trial of an alleged offender, or in emotional turmoil after such abuse, need special care and support. Evidence indicates that a number of such children are held in local authority secure centres, on various grounds: to protect them from further sexual assaults by an adult offender; because of their persistent absconding from non-secure residential centres; and because of their disturbed behaviour (including suicidal behaviours), which may have been caused by the assault. Victims of sexual abuse are held with juveniles on remand for serious crimes (including rape and murder), or (because they are too young for youth detention centres) with young adolescents who are held in detention following conviction for such crimes. Evidence is produced from case histories, and from a survey of 15 of the 27 secure detention centres for children and young people in England, that the mix of abused, disturbed and very aggressive children is highly problematic. In worst case scenarios, victims of child sexual abuse are sexually assaulted by juvenile rapists with whom they are housed. © 1998 John Wiley & Sons, Ltd.     

Selection of a voice for a speech signal for personalized warnings: the effect of speaker's gender and voice pitch

There is an increasing interest in multimodal technology-based warnings, namely those conveying speech-warning statements. This type of warning may be tailored to the situation as well as to the target user's characteristics. However, more information is needed on how to design these warnings in a way that ensures intelligibility, promotes compliance and reduces the potential for annoyance. In this context, this paper reports an exploratory study whose main purpose was to assist the selection of a synthesized voice for a subsequent compliance study with personalized (i.e., using the person's name) technology-based warnings using Virtual Reality. Participants were requested to listen to speech signals, gathered from a speech synthesizer and post-processed in order to change the pitch perception, and then these were evaluated by fulfilling the MOS-X questionnaire. After that, the participants ranked the voices according to their preference. The effects of the speaker's gender and voice pitch, on both ratings and ranking were assessed. The preference of the male and female listeners for a talker's voice gender was also investigated. The results show that participants mostly prefer as first choice the high-pitched female voice, which also gathered the highest overall score in the MOS-X questionnaire. No significant influence of the participants' gender was found on the assessed measures.