Robust estimation of stationary continuous-time ARMA models via indirect inference

In this paper we present a robust estimator for the parameters of a continuous-time ARMA(p,q) (CARMA(p,q)) process sampled equidistantly which is not necessarily Gaussian. Therefore, an indirect estimation procedure is used. It is an indirect estimation because we first estimate the parameters of the auxiliary AR(r) representation ($r\geq 2p-1$) of the sampled CARMA process using a generalized M- (GM-)estimator. Since the map which maps the parameters of the auxiliary AR(r) representation to the parameters of the CARMA process is not given explicitly, a separate simulation part is necessary where the parameters of the AR(r) representation are estimated from simulated CARMA processes. Then, the parameter which takes the minimum distance between the estimated AR parameters and the simulated AR parameters gives an estimator for the CARMA parameters. First, we show that under some standard assumptions the GM-estimator for the AR(r) parameters is consistent and asymptotically normally distributed. Next, we prove that the indirect estimator is consistent and asymptotically normally distributed as well using in the simulation part the asymptotically normally distributed LS-estimator. The indirect estimator satisfies several important robustness properties such as weak resistance, $\pi_{d_n}$-robustness and it has a bounded influence functional. The practical applicability of our method is demonstrated through a simulation study with replacement outliers and compared to the non-robust quasi-maximum-likelihood estimation method

The impact of regulation, ownership and business culture on managing corporate risk within the water industry

Although the specifics of water utility ownership, regulation and management culture have been explored in terms of their impact on economic and customer value, there has been little meaningful engagement with their influence on the risk environment and risk management. Using a literature review as the primary source of information, this paper maps the existing knowledge base onto two critical questions: what are the particular features of regulation, ownership and management culture which influence the risk dynamic, and what are the implications of these relationships in the context of ambitions for resilient organizations? In addressing these queries, the paper considers the mindful choices and adjustments a utility must make to its risk management strategy to manage strategic tensions between efficiency, risk and resilience. The conclusions note a gap in understanding of the drivers required for a paradigm shift within the water sector from a re-active to a pro-active risk management culture. A proposed model of the tensions between reactive risk management and pro-active, adaptive risk management provides a compelling case for measured risk management approaches which are informed by an appreciation of regulation, ownership and business culture. Such approaches will support water authorities in meeting corporate aspirations to become "high reliability" services while retaining the capacity to out-perform financial and service level targets

Purification of Mg2+-dependent phosphatidate phosphohydrolase from rat liver: new steps and aspects

A new procedure for the partial purification of Mg2+-dependent, N-ethylmaleimide-sensitive phosphatidate phosphohydrolase (Mg2+-PAP; EC 3.1.3.4) from rat liver cytosol is described, using protein precipitation with MgCl2, gel filtration on Sephacryl S-400, chromatography on DEAE-cellulose and affinity chromatography on calmodulin-agarose. From the parallel change in staining intensity and in the level of the specific activity of enzyme fractions, a relationship between a 90-kDa SDS gel band, identified as the beta-isoform of the 90-kDa heat shock protein, and Mg2+-PAP could be detected

Understanding patient choices for attending sexually transmitted infection testing services: a qualitative study

Objectives: To establish which aspects of sexually transmitted infection (STI) testing services are important to STI testing service users. Methods: 10 focus groups consisting of previous or existing users of STI testing services were conducted in community settings in the south east of England. Groups were quota sampled based on age, gender and sexual orientation. Data were analysed using Framework Analysis. Results: 65 respondents (58% men) participated. Perceived expertise of staff was the key reason for attendance at genitourinary medicine services rather than general practice. Although some respondents voiced a willingness to test for STIs within general practice, the apparent limited range of tests available in general practice and the perceived lack of expertise around sexual health appeared to discourage attendance at general practice. The decision of where to test for STIs was also influenced by past experience of testing, existing relationships with general practice, method of receiving test results and whether the patient had other medical conditions such as HIV. Conclusions: No one type of STI testing service is suitable for all patients. This is recognised by policymakers, and it now requires commissioners and providers to make services outside of genitourinary medicine clinics more acceptable and attractive to patients, in particular to address the perceived lack of expertise and limited range of STIs tests available at alternative testing sites

Assessing user preferences for sexually transmitted infection testing services: a discrete choice experiment

Objective: To assess user preferences for different aspects of sexually transmitted infection (STI) testing services. Design: A discrete choice experiment. Setting: 14 centres offering tests for STIs in East Sussex, England. Participants: People testing for STIs. Main outcome measure: (Adjusted) ORs in relation to preferred service characteristics. Results: 3358 questionnaires were returned; mean age 26 (SD 9.4) years. 70% (2366) were recruited from genitourinary medicine (GUM) clinics. The analysis suggested that the most important characteristics to users were whether 'staff had specialist STI knowledge' compared with 'staff without it' (OR 2.55; 95% CI 2.47 to 2.63) and whether 'tests for all STIs' were offered rather than 'some' (OR 2.19; 95% CI 2.12 to 2.25). They remained the most important two service characteristics despite stratifying the analysis by variables such as age and sex. Staff levels of expertise were viewed as particularly important by people attending CASH centres, women and non-men who have sex with men. A 'text or call to a mobile phone' and 'dropping in and waiting' were generally the preferred methods of results reporting and appointment system, respectively. Conclusions: This study suggests that people testing for STIs place particular importance on testing for all infections rather than some and staff with specialist STI knowledge. Thus, targets based purely on waiting up to 48 h for an appointment are misguided from a user perspectiv

Financial networks and the globalization of transnational corporations: the case of educational services

In this article, I advance understandings of the intersection between financial and educational services from an economic geographical perspective by examining the importance of financial networks in shaping the internationalization activities of for- profit business education service firms. By combining relational approaches to the globalization of transnational corporations (TNCs) with work on monetary networks I argue that extra-firm networks with financial services are an important element in understanding how, where and why business education service firms internationalize. Theoretically, this argument responds to calls for firm finances to be more fully incorporated into understandings of wider economic geographies and, in particular, addresses the neglect of finance in extant understandings of the internationalization of TNCs. Empirically, I position educational services as an overlooked business services sector that deserves greater attention within economic geography

Pedagogies of belonging in an anxious world: A collaborative autoethnography of four practitioners

The concept of belonging has found prominence in higher education learning environments, as the COVID-19 pandemic continues to have an unprecedented impact on educational provision. In times of disruption, alienation and isolation, the most basic of our psychological and physiological needs have come to be almost universally recognised as critical factors that must be considered and examined. Experiencing belonging is integral to human existence, and knowing where, with whom, and how we belong, is a salient driver for learning and self-actualisation. We recognise there are a number of ways to frame and approach the idea of belonging in the educational experience. We also recognise that there are multiple understandings of what belonging means and therefore how it is enacted within the curricula and the “classroom” in its varying forms - physical, online, digital, work-based. This Editorial takes a critical perspective to our own intellectual standpoint in relation to pedagogies of belonging. As co-editors, we have outlined our respective conceptions and experiences of belonging as a collaborative autoethnography, capturing our individual views of pedagogies of belonging in a collaborative context. Our collaboration has allowed us to situate ourselves both theoretically and practically, as well as ontologically, and advance our understanding of practices that promote student belonging in all its possible forms within the higher education experience. We suggest that the possibilities for belonging offered by interdisciplinary and transdisciplinary approaches are ripe for inquiry, and the place of non-traditional, Indigenous, iterative and emergent methodologies to examine belonging requires further exploration

Firm finances, weather derivatives and geography

This paper considers some intellectual, practical and political dimensions of collaboration between human and physical geographers exploring how firms are using relatively new financial products – weather derivatives – to displace any costs of weather-related uncertainty and risk. The paper defines weather derivatives and indicates how they differ from weather insurance products before considering the geo-political, cultural and economic context for their creation. The paper concludes by reflecting on the challenges of research collaboration across the human–physical geography divide and suggests that while such initiatives may be undermined by a range of institutional and intellectual factors, conversations between physical and human geographers remain and are likely to become increasingly pertinent. The creation of a market in weather derivatives raises a host of urgent political and regulatory questions and the confluence of natural and social knowledges, co-existing within and through the geography academy, provides a constructive and creative basis from which to engage with this new market and wider discourses of uneven economic development and climate change