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Background: Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) have emerged as biomarkers for cerebral small vessel disease (SVD). We investigated their role in a hereditary SVD model, retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S). Methods: NfL and GFAP levels of 17 pre-symptomatic, 22 symptomatic RVCL-S mutation carriers and 69 controls were measured using a Simoa assay. We assessed the association of serum and cerebrospinal fluid (CSF) levels of NfL and GFAP with RVCL-S symptomatology and neuropsychological functioning. Results: Serum and CSF NfL levels were higher in symptomatic RVCL-S compared to controls ≥ 45 years (33.5 pg/mL vs. 9.2 pg/mL, p < 0.01; 8.5*102 pg/mL vs. 3.9*102 pg/mL, p < 0.01, respectively). Serum NfL levels were higher in symptomatic RVCL-S than pre-symptomatic carriers (33.5 pg/mL vs. 5.9 pg/mL, p = 0.02). Pre-symptomatic RVCL-S carriers had increased CSF NfL levels compared to controls < 45 years (5.2*102 pg/mL vs. 1.9*102 pg/mL, p < 0.01). No differences were found in GFAP levels across groups, but in RVCL-S carriers higher serum levels of both NfL and GFAP were linked to poorer global cognitive functioning (β[95%CI] = − 2.86 [− 5.58 to − 0.13], p = 0.04 and β[95%CI] = − 6.85 [− 11.54 to − 2.15], p = 0.01, respectively) and prolonged psychomotor test times (β[95%CI] = 6.71 [0.78–12.65], p = 0.03 and β[95%CI] = 13.84 [3.09–24.60], p = 0.01). Discussion: Higher levels of serum NfL and GFAP are associated with worse cognitive functioning in RVCL-S carriers and may serve as marker for disease progression. CSF NfL levels may serve as early marker as pre-symptomatic RVCL-S patients already show differences compared to young controls. [ABSTRACT FROM AUTHOR]

Common flood risk analyses often focus on direct impacts corresponding to the maximum depths of flood events. However, this information is not sufficient for risk communication, for the design of flood emergency plans and for the selection of risk management measures. For those issues, not only a static view of the maximum flood intensity is required, but also an understanding of the sequence of events from the rise of the threat to its recovery (including the action and reaction of actors). This paper discusses a new, additional approach to support flood risk management: the storyline approach, which serves to analyse the whole sequence of events during a flood. It starts from the initial rise of the flood threat, then describes the actual flooding and ends with the recovery from the flood impacts. It shows in a structured way the most important subsystems (water system, critical infrastructure system) and actors (water managers, local authorities, critical infrastructure operators, inhabitants) and their interactions. The application of the storyline approach to Dordrecht, the Netherlands, illustrates its use not only for flood event management, but also for the analysis of critical infrastructure vulnerability. The approach is designed to be applied in workshops with all relevant actors. The storylines support the communication of what might happen and help to develop consistent flood risk management strategies and emergency plans. [ABSTRACT FROM AUTHOR]

Evidence for the extent and nature of attentional impairment in premanifest and manifest Huntington's disease (HD) is inconsistent. Understanding such impairments may help to better understand early functional changes in HD and could have consequences concerning care for HD patients. We investigated attentional control in both early and premanifest HD. We studied 17 early HD subjects (mean age: 51 years), 12 premanifest HD subjects (mean age: 43 years), and 15 healthy controls (mean age: 51 years), using the sustained attention to response task (SART), a simple Go/No-go test reflecting attentional and inhibitory processes through reaction time (RT) and error rates. Simultaneously recorded EEG yielded P300 amplitudes and latencies. The early HD group made more Go errors ( p < 0.001) and reacted slower ( p < 0.005) than the other groups. The RT pattern during the SART was remarkably different for early HD subjects compared to the other two groups ( p < 0.005), apparent as significant post-error slowing. P300 data showed that for early HD the No-go amplitude was lower than for the other two groups ( p < 0.05). Subjects with early HD showed a reduced capacity to effectively control attention. They proved unable to resume the task directly after having made an error, and need more time to return to pre-error performance levels. No attentional control deficits were found for the premanifest HD group. [ABSTRACT FROM AUTHOR]

River-floodplain systems are amongst the most productive-but often severely impacted-aquatic systems worldwide. We explored the ecological response of fish to flow regime in a large river-floodplain system by studying the relationships between (1) discharge and inundated floodplain area, with a focus on spatial and temporal patterns in floodplain lake connectivity, and (2) flood volume and fisheries catch. Our results demonstrate a non-linear relationship between discharge and floodplain inundation with considerable hysteresis due to differences in inundation and drainage rate. Inundation extent was mostly determined by flood volume, not peak discharge. We found that the more isolated lakes (that is, lakes with a shorter connection duration to the river) are located at higher local elevation and at larger hydrological distance from the main rivers: geographical distance to the river appears a poor predictor of lake isolation. Although year-to-year fish catches in the floodplain were significantly larger with larger flood volumes in the floodplain, they were not in the main river, suggesting that mechanisms that increase catch, such as increased floodplain access or increased somatic growth, are stimulated by flooding in the floodplain, but not in the river. Fish species that profit from flooding belong to different feeding guilds, suggesting that all trophic levels may benefit from flooding. We found indications that the ecological functioning of floodplains is not limited to its temporary availability as habitat. Refugia can be present within the floodplain itself, which should be considered in the management of large rivers and their floodplain. [ABSTRACT FROM AUTHOR]

Monitoring of three-dimensional floodplain vegetation structure is essential for ecological studies, as well as for hydrodynamic modelling of rivers. Height and density of submerged vegetation and density of emergent vegetation are the key characteristics from which roughness parameters in hydraulic models are derived. Airborne laser scanning is a technique with broad applications in vegetation structure mapping, which therefore may be a promising tool in monitoring floodplain vegetation for river management applications. This paper first provides an introduction to the laser scanning technique, and reviews previous studies on the extraction of vegetation height and density of forests, low vegetation and meadows or unvegetated areas. Reliable predictions using laser scan data have been reported for forest height ( R 2=0.64–0.98), parameters related to forest density, such as stem number, stem diameter, biomass, timber volume or basal area ( R 2=0.42–0.93), and herbaceous vegetation height (summer condition; R 2=0.75–0.89). No empirical relations have been reported on density of herbaceous vegetation. Laser data of meadows and unvegetated areas show too much noise to predict vegetation structure correctly. In a case study for the lower Rhine river, the potential of laser scan mapping of vegetation structure was further explored for winter conditions. Three laser-derived metrics that are often reported in the literature have been applied to characterize local vertical distributions of laser reflections. The laser data clearly show the large structural differences both between and within vegetation units that currently are the basis of floodplain vegetation and roughness mapping. The results indicate that airborne laser scanning is a promising technique for extraction of 3D-structure of floodplain vegetation in winter, except for meadows and unvegetated areas. [ABSTRACT FROM AUTHOR]

The present compartmentalization layout within the river polders in the Dutch Rhine–Meuse delta is the result of abandonment and partial removal of secondary dikes and the construction of modern infrastructure embankments. These structures will guide the flow of water in case the polder would inundate. Through the application of a 2-D flood propagation model in the polder Land van Maas en Waal this study explores whether restoration or removal of old dike remnants would contribute to a reduction of the risk and damage during an inundation. A systematic set of 28 flood scenarios was simulated and for each scenario an additional damage and risk assessment was carried out. It is concluded that a simple removal or total restoration will not reduce flood damage, but that this must be achieved by a strategic compartment plan. With such a plan old dike remnants and present embankments can be used to keep water away from vulnerable and valuable areas for as long as possible and to guide the floodwater to areas that are considered less vulnerable. [ABSTRACT FROM AUTHOR]

Presents a study by the International Commission for the Hydrology of the Rhine basin which assessed the impact of climate change on the river flow conditions in the Rhine basin. Characteristics of the climate impact models used; Examination of the effects of the different modelling resolutions; Impact of climate change on the discharge regime of the Rhine.

In this study we evaluate the feasibility of measures that reflect different characteristics of motor activity and immobility in the objective quantification of hypokinesia. Because by definition hypokinesia can only be assessed over a period of time, continuous activity monitoring was used during 5 successive days in the home setting in 64 patients with Parkinson's disease (PD) and 104 healthy elderly subjects. In the patients we also evaluated the relation between the monitor measures and subjective measures of hypokinesia and age. Compared to the healthy elderly subjects, PD patients have a decreased activity level, increased proportion of time without movement, elevated mean duration of immobility, and decreased percentage of short-lasting immobility periods. Differences between both groups were most prominent for those measures that incorporate or reflect immobility. Moreover, in the PD patients the mean duration of immobility and percentage of short-lasting immobility periods show an apparent lack of relation with age and clinical ratings obtained from the UPDRS. In conclusion, our findings underscore the poor representation of hypokinesia in the UPDRS and value of objective quantification of this fundamental impairment of PD. [ABSTRACT FROM AUTHOR]

Because in the literature bradykinesia and hypokinesia are frequently confounded, we assessed the relation between these two fundamental aspects of altered movement and the influence of disease severity on these measures in 41 patients with Parkinson's disease (PD) and 24 age-matched healthy controls. Bradykinesia was measured with a test microcomputer interfaced with a response-board. Hypokinesia was assessed by activity monitoring at home over a period of 5 successive days. For each subject the choice reaction time and measures reflecting bradykinesia (tap rate, movement time) and hypokinesia (movement index, duration of immobility periods) were calculated. Patients with PD had a normal choice reaction time and a significantly impaired execution of voluntary movement and reduced amount of movement over time. Bradykinesia was clearly present in the less affected patients with PD, and worsened as the disease severity increased. Hypokinesia, however, emerged prominently only in the more affected patients. There was a striking lack of relation between the measures that reflect bradykinesia and hypokinesia. The use of levodopa or dopamine agonists did not confound these findings. Our findings show the very different character and course of two tiers of altered movement in patients with PD and question the causative mechanisms of both motor features in PD. A more precise use of the terms brady- and hypokinesia is a prerequisite for future studies that attempt to provide insight in the causative mechanisms of both motor features. [ABSTRACT FROM AUTHOR]

Deltas are low-relief landforms that are extremely vulnerable to sea-level rise. Impact assessments of relative sea-level rise in deltas primarily depend on elevation data accuracy and how well the vertical datum matches local sea level. Unfortunately, many major deltas are located in data-sparse regions, forcing researchers and policy makers to use low-resolution, global elevation data obtained from satellite platforms. Using a new, high-accuracy elevation model of the Vietnamese Mekong delta, we show that quality of global elevation data is insufficient and underscore the cruciality to convert to local tidal datum, which is often neglected. The novel elevation model shows that the Mekong delta has an extremely low mean elevation of ~0.8 m above sea level, dramatically lower than the earlier assumed ~2.6 m. Our results imply major uncertainties in sea-level rise impact assessments for the Mekong delta and deltas worldwide, with errors potentially larger than a century of sea-level rise. Assessments of sea level rise risks depend on elevation data. Here, the authors present a new dataset on the Mekong Delta which shows it to have a much lower elevation (0.82 m above sea level) than previously thought – underlying principles may also imply major elevation uncertainties in other deltas. [ABSTRACT FROM AUTHOR]