Systems theoretic methods in decoding

In this paper we show how ideas based on system theoretic modeling of linear behaviors may be used for decoding of linear codes. In particular we show how Sudan's bivariate interpolation approach to list decoding of RS codes allows a system theoretic interpretation

Proper elimination of latent variables

We consider behaviors in which we distinguish two types of variables, manifest variables, the variables that are of interest to the user and latent variables, the variables that are introduced to obtain a first representation. The problem is to find a representation of the manifest behavior, that is, we want to eliminate the latent variables. If the original behavior can be represented by linear differential equations with constant coefficients, then under certain conditions the same is true for the manifest behavior. In this note we formulate and study these conditions. The results are illustrated by means of some examples. As an application we study behaviors in image representation

Contact tracing for vancomycin-resistant Enterococcus faecium (VRE):evaluation of the Dutch policy of quintuple screening cultures

Detection of vancomycin-resistant Enterococcus faecium (VRE) is hampered by low sensitivity of rectal swab cultures. This study aimed to define the number of screening cultures needed to increase sensitivity to detect VRE transmission, and to determine time from presumed exposure to detectable colonization. In a tertiary care setting, we retrospectively analyzed data from 9 VRE outbreaks. As a proxy or estimation for time to detectable colonization, the time between first positive culture of the presumed index patient and that of their contacts was determined. Only 64% of secondary cases were positive in the first out of five cultures. By using the first three out of five rectal swabs, 89% (95%CI: 78–95%) of all secondary cases would have been identified. The median number of days between the positive culture of the index patient and the first positive culture of secondary cases was 9 days. Eleven percent of secondary cases would have been missed if only three rectal samples would have been obtained. Furthermore, our results show that one or more rectal swabs taken around day 9 after presumed exposure should at least be included in the screening approach. In our setting, obtaining a fourth and a fifth rectal swab showed a relevant additional value compared to only one to three swabs. Our findings are useful for determining the most effective VRE contact tracing approach to prevent transmission.</p

The Effect of Sugar-Free Versus Sugar-Sweetened Beverages on Satiety, Liking and Wanting: An 18 Month Randomized Double-Blind Trial in Children

BACKGROUND: Substituting sugar-free for sugar-sweetened beverages reduces weight gain. A possible explanation is that sugar-containing and sugar-free beverages cause the same degree of satiety. However, this has not been tested in long-term trials. METHODS: We randomized 203 children aged 7-11 years to receive 250 mL per day of an artificially sweetened sugar-free beverage or a similarly looking and tasting sugar-sweetened beverage. We measured satiety on a 5-point scale by questionnaire at 0, 6, 12 and 18 months. We calculated the change in satiety from before intake to 1 minute after intake and 15 minutes after intake. We then calculated the odds ratio that satiety increased by 1 point in the sugar-group versus the sugar-free group. We also investigated how much the children liked and wanted the beverages. RESULTS: 146 children or 72% completed the study. We found no statistically significant difference in satiety between the sugar-free and sugar-sweetened group; the adjusted odds ratio for a 1 point increase in satiety in the sugar group versus the sugar-free group was 0.77 at 1 minute (95% confidence interval, 0.46 to 1.29), and 1.44 at 15 minutes after intake (95% CI, 0.86 to 2.40). The sugar-group liked and wanted their beverage slightly more than the sugar-free group, adjusted odds ratio 1.63 (95% CI 1.05 to 2.54) and 1.65 (95% CI 1.07 to 2.55), respectively. CONCLUSIONS: Sugar-sweetened and sugar-free beverages produced similar satiety. Therefore when children are given sugar-free instead of sugar-containing drinks they might not make up the missing calories from other sources. This may explain our previous observation that children in the sugar-free group accumulated less body fat than those in the sugar group.<br /

Risk Factors and Transmission of Healthcare-Related Pathogens

The literature reviews and observational studies in this thesis are about the role of epidemiology in describing, identifying and controlling transmission of healthcare-related pathogens. The ultimate goal of conducting these studies is to optimize care and to provide safer care for p

More than words: Recognizing speech of people with Parkinson's disease

Parkinson’s disease (PD) is the fastest-growing neurological disorder in the world, with approximately 10 million people currently living with the diagnosis. Hypokinetic dysarthria (HD) is one of the symptoms that appear in early stages of the disease progression. The main aim of this dissertation is to gain insights into listeners’ impressions of dysarthric speech and to uncover acoustic correlates of those impressions. We do this by exploring two sides of communication: speech production of people with PD, and listeners’ recognition of speech of people with PD. Therefore, the studies in this dissertation approach the topic of speech changes in PD from both the speakers' side - via acoustic analysis of speech, and the listeners' side - via experiments exploring the influence of expertise and language background on recognition of speech of people with PD. Moreover, to obtain a more comprehensive picture of these perspectives, the studies of this dissertation are multifaceted, explore cross-linguistic aspects of dysarthric speech recognition and include both cross-sectional and longitudinal designs. The results demonstrate that listeners' ability to recognize speech of people with PD as unhealthy is rooted in the acoustic changes in speech, not in its content. Listeners’ experience in the fields of speech and language therapy or speech sciences affect dysarthric speech recognition. The results also suggest that tracking speech parameters is a useful tool for monitoring the progression and/or development of dysarthria and objectively evaluating long-term effects of speech therapy

Coordination and timing of speech gestures in Parkinson’s disease

Many individuals with Parkinson's disease (PD) experience articulatory difficulties, which often have a considerable impact on their quality of life. It is currently poorly understood which mechanisms underlie these articulatory difficulties. In order to learn more about these mechanisms, this dissertation examined the coordination and timing of speech gestures in PD speech. Both these aspects are intrinsic to articulation, but at current it is unknown how they relate to the articulatory difficulties observed in PD speech. The studies in this dissertation address this issue using state-of-the-art methods. In the first study of this thesis, the effect of levodopa on vowel articulation in PD was examined. The results from this study suggest that articulation of vowels is not influenced by levodopa. In the following two studies, spatial and temporal aspects of speech gestures have been examined. The results from these studies suggest that the timing of speech gestures, and also the coupling between speech gestures is impaired in PD. In the final study of this dissertation, the prevalence and nature of tongue tremor in individuals with PD were investigated. Using a computer algorithm, we found different types of tongue tremor in our data, which we believe may affect the timing of speech gestures. Together, the studies in this dissertation show that coordination and timing are indeed impaired in the speech of (at least some) individuals with PD. We believe that this impairment may be caused by the presence of malfunctioning regulatory mechanisms in PD speech

Exploring the role of the microbiota: in defence against Clostridioides difficile and multidrug resistant Gram-negatives

Antibiotics provided humanity resilience to the majority of bacterial infections. An important trade-off is the emergence of antimicrobial resistance, and a diminished and perturbed microbiota, resulting in an increased susceptibility for Clostridioides difficile infections. For both C. difficile and multidrug resistant micro-organisms (MDRO), asymptomatic colonisation of the gut plays an important role in the development of infection. The aim of this thesis is to better understand the role of the microbiota in defence against infections with C. difficile and MDRO. The first part describes the epidemiology and detection of asymptomatically colonized individuals. It concludes that though asymptomatic colonization of MDRO and C. difficile can become a nidus for nosocomial (hospital) infection and transmission, its prevalence is still low in the Netherlands. The second part of this thesis focuses on eradication and/or treatment of these micro-organisms with ‘fecal microbiota transplantation’ of healthy donor feces. It describes the establishment of the Netherlands Donor Feces Bank, and the research, experiences and successes of FMT in the treatment of patients with recurrent C. difficile infections and MDRO. The experience of this thesis may help the establishment, utilization, standardization and maturation of stool banks and research institutes of the next-generation of microbiota modifying therapies. </p