Time series analysis in road safety research using state space methods

Koopman, S.J. [Promotor]Montfort, C.A.G.M. van [Copromotor

Freshwater fishes of Shipstern Nature Reserve

A survey of fishes in and around Shipstern Nature Reserve in Northern Belize, Central America, was carried out over a period of eight months, from February to September 1990. Its purpose was to establish a preliminary list of the fishes of Shipstern Nature Reserve, including descriptions, distribution and collecting data and additionally to describe some of the habitats in which the fishes were found. This study focuses on fishes considered to be freshwater species. These occurred for the greater part in brackish habitats. Nevertheless, a few fish considered as marine species were caught in the waters of the reserve and these equally received attention. Findings include 15 species of fresh or brackish water and 3 marine species. Two species are of particular interest: Cyprinodon variegatus (Cyprinodontidae) is a new species for the Belizean fauna, while Rivulus ocellatus (Rivulidae), which was recorded from Twin Cays on the barrier reef (Davis et al., 1990), is now also confirmed for a mainland coastal habitats

Model-based measurement of latent risk in time series with applications

Risk is at the center of many policy decisions in companies, governments and other institutions. The risk of road fatalities concerns local governments in planning counter- measures, the risk and severity of counterparty default concerns bank risk managers on a daily basis and the risk of infection has actuarial and epidemiological consequences. However, risk can not be observed directly and it usually varies over time. Measuring risk is therefore an important exercise. In this paper we introduce a general multivariate framework for the time series analysis of risk that is modelled as a latent process. The latent risk time series model extends existing approaches by the simultaneous modelling of (i) the exposure to an event, (ii) the risk of that event occurring and (iii) the severity of the event. First, we discuss existing time series approaches for the analysis of risk which have been applied to road safety, actuarial and epidemiological problems. Seco! nd, we present a general model for the analysis of risk and discuss its statistical treatment based on linear state space methods. Third, we apply the methodology to time series of insurance claims, credit card purchases and road safety. It is shown that the general methodology can be effectively used in the assessment of risk

Persistent Pollutants in Audouin's Gull (Larus audouinii) in the Western Mediterranean: A Case-study with Wide Implications?

The possibility of persistent pollutants playing an adverse role in the reproductive success of Audouin's Gull in the western Mediterranean was examined through chemical analyses of 7 eggs of this species that did not hatch. Residues of organochlorine compounds and mercury were found. The conclusion has been reached that a further increase of present levels of DDE may well lead to a decline of the reproductive success of the species in the western Mediterranean, especially in the northern part. These observations, although limited, could have implications for further species as is already indicated by other work cite

Persistent Pollutants in Audouin's Gull (Larus audouinii) in the Western Mediterranean: A Case-study with Wide Implications?

The possibility of persistent pollutants playing an adverse role in the reproductive success of Audouin's Gull in the western Mediterranean was examined through chemical analyses of 7 eggs of this species that did not hatch. Residues of organochlorine compounds and mercury were found. The conclusion has been reached that a further increase of present levels of DDE may well lead to a decline of the reproductive success of the species in the western Mediterranean, especially in the northern part. These observations, although limited, could have implications for further species as is already indicated by other work cite

Information fusion of GNSS sensor readings, field notes, and expert's a priori knowledge

Documenting machinery movements by using positioning technologies, such as global navigation satellite systems (GNSS), is essential to understand and further improve construction processes. However, before measurements can be meaningfully analysed the documented movements should be filtered to exclude outliers. Eliminating outliers manually is a time-demanding process, while automatic filtering can be inaccurate. In particular, path elements may get lost if machine-specific movements are misconceived as noisy data. As a trade-off, we propose an information fusion approach to filter paths of construction machines in a semi-automatic way. The approach allows an expert to relate “hard” sensor and “soft” field records with his or her expectations about how machines can move in real construction projects. Specially developed open-source software illustrates the proposed approach for filtering the documented paths of machines involved in road paving projects. The initial testing of the developed software showed its suitability to filter outliers in GNSS data and identified possibilities for further improvements

Cholestase bij pasgeborenen als gevolg van parenterale voeding

Toediening van totale parenterale voeding (TPN) aan pasgeborenen is geassocieerd met het ontstaan van cholestase. Ondanks intensief onderzoek zijn de pathofysiologische mechanismen slechts gedeeltelijk opgehelderd. In dit artikel wordt ingegaan op de huidige inzichten in de risicofactoren die geassocieerd zijn met TPN-cholestase bij pasgeborenen, de specifieke bestanddelen en deficiënties van TPN die cholestase kunnen veroorzaken, de mogelijke relatie met de ‘fysiologische cholestase van de pasgeborene’, die de pasgeborene kwetsbaarder maakt voor potentieel hepatotoxische stoffen, en de transportsystemen in de levercelmembraan die betrokken zijn bij galvorming. De hypothese dat ‘cholestatische galzuren’ een rol spelen in de etiologie van TPN-cholestase en de therapeutische mogelijkheden worden besproken.Administration of total parenteral nutrition (TPN) to neonates is associated with the occurrence of cholestasis. Despite intensive research, the pathophysiological mechanisms have not been elucidated. In this review we describe the present insights into the risk factors for the development of TPN-associated cholestasis, the specific components or lack of components (deficiencies) in TPN that can cause cholestasis, the possible correlation with 'physiologic cholestasis of the neonate', which makes the infant more susceptible for potentially hepatotoxic compounds, and the transport systems in the liver cell membrane which are involved in bile formation. The hypothesis that 'cholestatic bile salts' play a role in the etiology of TPN-related cholestasis and the therapeutic options will be discussed.</p

Long-term Outcome Following Thrombembolectomy in the Upper Extremity

AbstractObjectivesTo evaluate short- and long-term mortality and morbidity in patients that were treated for acute upper extremity ischemia.DesignSingle center retrospective study.PatientsA consecutive series of 148 patients who were admitted with a diagnosis of acute ischemia of the upper extremity during an 11-year period.MethodsAll charts were reviewed retrospectively and 96% of all survivors participated in clinical follow-up.ResultsThe median age was 78 years and 64% of patients were females. The 30-day mortality was 8% and the overall 5-year survival 37%. The observed mortality during the follow-up period was significantly higher than expected. Survival was not significantly different in patients who received anticoagulant drugs following discharge from the hospital. The duration of ischemia did not significantly influence long-term arm-function.ConclusionsAcute embolic episodes in the upper extremity primarily occur in elderly and the peri-operative mortality is high. Mortality following discharge from the hospital remains significantly higher than that of the background population

Validating ATLAS: A regional-scale high-throughput tracking system

Fine-scale tracking of animal movement is important to understand the proximate mechanisms of animal behaviour. The reverse-GPS system—ATLAS—uses inexpensive (~€25), lightweight (90% at 15 of 16 stationary sites. Tags on birds (1/6 Hz) on the Griend mudflat had a mean fix rate of 51%, yielding an average sampling rate of 0.085 Hz. Fix rates were higher in more central parts of the receiver array. ATLAS provides accurate, regional-scale tracking with which hundreds of relatively small-bodied species can be tracked simultaneously for long periods of time. Future ATLAS users should consider the height of receivers, their spatial arrangement, density and the movement modes of their study species (e.g. ground-dwelling or flying)