Denitrification in an oligotrophic estuary: a delayed sink for riverine nitrate

Estuaries are often seen as natural filters of riverine nitrate, but knowledge of this nitrogen sink in oligotrophic systems is limited. We measured spring and summer dinitrogen production (denitrification, anammox) in muddy and non-permeable sandy sediments of an oligotrophic estuary in the northern Baltic Sea, to estimate its function in mitigating the riverine nitrate load. Both sediment types had similar denitrification rates, and no anammox was detected. In spring at high nitrate loading, denitrification was limited by likely low availability of labile organic carbon. In summer, the average denitrification rate was similar to 138 mu mol N m(-2) d(-1). The corresponding estuarine nitrogen removal for August was similar to 1.2 t, of which similar to 93% was removed by coupled nitrification-denitrification. Particulate matter in the estuary was mainly phytoplankton derived (> 70% in surface waters) and likely based on the riverine nitrate which was not removed by direct denitrification due to water column stratification. Subsequently settling particles served as a link be tween the otherwise uncoupled nitrate in surface waters and benthic nitrogen removal. We suggest that the riverine nitrate brought into the oligotrophic estuary during the spring flood is gradually, and with a time delay, removed by benthic denitrification after being temporarily ` trapped' in phytoplankton particulate matter. The oligotrophic system is not likely to face eutrophication from increasing nitrogen loading due to phosphorus limitation. In response, coupled nitrification-denitrification rates are likely to stay constant, which might increase the future export of nitrate to the open sea and decrease the estuary's function as a nitrogen sink relative to the load.Peer reviewe

Grip on challenging behaviour: a multidisciplinary care programme for managing behavioural problems in nursing home residents with dementia. Study protocol

Contains fulltext : 97945.pdf (publisher's version ) (Open Access)BACKGROUND: Behavioural problems are common in nursing home residents with dementia and they often are burdensome for both residents and nursing staff. In this study, the effectiveness and cost-effectiveness of a new care programme for managing behavioural problems will be evaluated. METHODS/DESIGN: The care programme is based on Dutch national guidelines. It will consist of four steps: detection, analysis, treatment and evaluation. A stepped wedge design will be used. A total of 14 dementia special care units will implement the care programme. The primary outcome is behavioural problems. Secondary outcomes will include quality of life, prescription rate of antipsychotics, use of physical restraints and workload and job satisfaction of nursing staff. The effect of the care programme will be estimated using multilevel linear regression analysis. An economic evaluation from a societal perspective will also be carried out. DISCUSSION: The care programme is expected to be cost-effective and effective in decreasing behavioural problems, workload of nursing staff and in increasing quality of life of residents. TRIAL REGISTRATION: The Netherlands National Trial Register (NTR). Trial number: NTR 2141

The Course of Quality of Life and Its Predictors in Nursing Home Residents With Young-Onset Dementia

OBJECTIVE: To explore the course of quality of life (QoL) and possible resident-related predictors associated with this course in institutionalized people with young-onset dementia (YOD). DESIGN: An observational longitudinal study. SETTING AND PARTICIPANTS: A total of 278 residents with YOD were recruited from 13 YOD special care units in the Netherlands. METHODS: Secondary analyses were conducted with longitudinal data from the Behavior and Evolution in Young-ONset Dementia (BEYOND)-II study. QoL was assessed with proxy ratings, using the Quality of Life in Dementia (QUALIDEM) questionnaire at 4 assessment points over 18 months. Predictors included age, gender, dementia subtype, length of stay, dementia severity, neuropsychiatric symptoms, and psychotropic drug use at baseline. Multilevel modeling was used to adjust for the correlation of measurements within residents and clustering of residents within nursing homes. RESULTS: The total QUALIDEM score (range: 0-111) decreased over 18 months with a small change of 0.65 (95% confidence interval -1.27, -0.04) points per 6 months. An increase in several domains of QoL regarding care relationship, positive self-image, and feeling at home was seen over time, whereas a decline was observed in the subscales positive affect, social relations, and having something to do. Residents with higher levels of QoL and more advanced dementia at baseline showed a more progressive decline in QoL over time. Sensitivity analyses indicated a more progressive decline in QoL for residents who died during the follow-up. CONCLUSION AND IMPLICATIONS: This study shows that although overall QoL in nursing home residents with YOD was relatively stable over 18 months, there were multidirectional changes in the QoL subscales that could be clinically relevant. Higher levels of QoL and more advanced stages of dementia at baseline predicted a more progressive decline in QoL over time. More longitudinal studies are needed to verify factors influencing QoL in YOD

The Determinants of Quality of Life of Nursing Home Residents with Young-Onset Dementia and the Differences between Dementia Subtypes

Aims: The aims of this study are to (1) explore the determinants of quality of life (QoL) in nursing home residents with young-onset dementia (YOD), (2) investigate whether there are differences between dementia subtypes (Alzheimer dementia, vascular/mixed dementia, frontotemporal dementia, other) regarding these determinants, and (3) compare QoL profiles of YOD nursing home residents across dementia subtypes. Methods: This cross-sectional study included 207 nursing home residents. Multilevel modeling was used to determine the relationships between QoL and neuropsychiatric symptoms (NPS), dementia severity, psychotropic drug use (PDU), dementia subtype, age, and gender. Additional multilevel models were used to compare aspects of QoL between dementia subtypes. Results: Residents' QoL was negatively associated with advanced dementia, PDU, and NPS. In general, the relationships between the determinants and QoL were similar across the dementia subtypes. Aspects of QoL differed by dementia subtype. Residents with frontotemporal dementia showed less negative emotions, accepted more help and experienced better quality of relationships with professional caregivers, had a more positive self-image, felt more comfortable in the nursing home environment, and experienced lower quality of social relationships. Conclusions: Considering the high rates of NPS and PDU in YOD residents and their negative associations with QoL, we recommend emphasizing services to manage and reduce NPS and PDU in nursing home residents with YOD. Furthermore, our findings suggest accounting for differences in aspects of QoL by dementia subtype to address specific needs and thereby improve QoL. (C) 2017 The Author(s) Published by S. Karger AG, Base

Intramanual and intermanual transfer of the curvature aftereffect

The existence and transfer of a haptic curvature aftereffect was investigated to obtain a greater insight into neural representation of shape. The haptic curvature aftereffect is the phenomenon whereby a flat surface is judged concave if the preceding touched stimulus was convex and vice versa. Single fingers were used to touch the subsequently presented stimuli. A substantial aftereffect was found when the adaptation surface and the test surface were touched by the same finger. Furthermore, a partial, but significant transfer of the aftereffect was demonstrated between fingers of the same hand and between fingers of both the hands. These results provide evidence that curvature information is not only represented at a level that is directly connected to the mechanoreceptors of individual fingers but is also represented at a stage in the somatosensory cortex shared by the fingers of both the hands

Delirium

Depression is highly prevalent in nursing home residents with dementia. It is negatively associated with a resident’s well-being and daily functioning and can increase mortality and use of healthcare services. However, depression is under-recognized and undertreated in nursing homes. To improve depression management in residents with dementia, procedures are necessary for detecting and diagnosing depression and for psychosocial and pharmacological treatment strategies. Furthermore, monitoring the effects of any given treatment is highly important for improving depression management. This chapter describes a care program that encompasses procedures for a multidisciplinary approach to depression recognition and treatment in residents with dementia and that has been developed and shown to be effective in the nursing home setting. Additionally, the chapter goes into requirements for adequate depression management and implementing care programs in daily practice

Different methods to analyze stepped wedge trial designs revealed different aspects of intervention effects

OBJECTIVES: Within epidemiology, a stepped wedge trial design (i.e., a one-way crossover trial in which several arms start the intervention at different time points) is increasingly popular as an alternative to a classical cluster randomized controlled trial. Despite this increasing popularity, there is a huge variation in the methods used to analyze data from a stepped wedge trial design. STUDY DESIGN AND SETTING: Four linear mixed models were used to analyze data from a stepped wedge trial design on two example data sets. The four methods were chosen because they have been (frequently) used in practice. Method 1 compares all the intervention measurements with the control measurements. Method 2 treats the intervention variable as a time-independent categorical variable comparing the different arms with each other. In method 3, the intervention variable is a time-dependent categorical variable comparing groups with different number of intervention measurements, whereas in method 4, the changes in the outcome variable between subsequent measurements are analyzed. RESULTS: Regarding the results in the first example data set, methods 1 and 3 showed a strong positive intervention effect, which disappeared after adjusting for time. Method 2 showed an inverse intervention effect, whereas method 4 did not show a significant effect at all. In the second example data set, the results were the opposite. Both methods 2 and 4 showed significant intervention effects, whereas the other two methods did not. For method 4, the intervention effect attenuated after adjustment for time. CONCLUSION: Different methods to analyze data from a stepped wedge trial design reveal different aspects of a possible intervention effect. The choice of a method partly depends on the type of the intervention and the possible time-dependent effect of the intervention. Furthermore, it is advised to combine the results of the different methods to obtain an interpretable overall result