9 research outputs found
Vertical and lateral distribution of Foraminifera and Ostracoda in the East Frisian Wadden Sea - developing a transfer function for relative sea-level change
In light of rising sea levels and increased storm surge hazards, detailed information on relative sea-level (RSL) histories and local controlling mechanisms is required to support future projections and to better prepare for future coastal-protection challenges. This study contributes to deciphering Holocene RSL changes at the German North Sea coast in high resolution by developing a transfer function for RSL change. Recent associations of Foraminifera and Ostracoda from low intertidal to supratidal settings of the barrier island of Spiekeroog in combination with environmental parameters (granulomeny, C/N, total organic carbon, salinity) were investigated and quantified in elevation steps of 15 cm in order to generate a first transfer function (TF) of Holocene RSL change. In a future step, the TF can be applied to the stratigraphic record. Our data show a clear vertical zonation of foraminifer and ostracod taxa between the middle salt marsh and the tidal flat with very few individuals in the sand flat area, suggesting removal by the tidal current or poor preservation. Multivariate statistics identify the elevation, corresponding to the inundation frequency, as main driving factor. The smallest vertical error (49 cm) is associated with an entirely new approach of combining Foraminifera and Ostracoda for a TF. Advantages of the TF over classical RSL indicators such as basal and intercalated peats - beside the relatively narrow indicative meaning - include the possible application to a wide range of intertidal facies and that the resulting RSL curve does not depend on compaction-prone peats
Insights into Holocene relative seaâlevel changes in the southern North Sea using an improved microfaunaâbased transfer function
In light of global warming and rising relative sea level (RSL), detailed reconstructions of RSL histories and their controlling processes are essential in order to manage coastalâprotection challenges. This study contributes to unravelling Holocene RSL change on the East Frisian North Sea coast in high resolution and with a new approach for the German Bight. For the first time, a transfer function (vertical error: 29.7âcm â ~11% of the mean tidal range) for RSL change based on a combined training set of benthic foraminifers and ostracods from the backâbarrier tidal basin of Spiekeroog is applied to the Holocene record of the backâbarrier tidal basin of Norderney. The resulting RSL curve for the Norderney tidal basin is corrected for decompaction and shows a deceleration in RSL rise between 6000 and 5000âcalâbp. The smallest possible error envelope (~1âm) results from the good suitability of saltâmarsh layers between 5000 and 4000âcalâbp. The RSL curve provides an approach towards the closure of the common data gap of peatâbased curves for the southern North Sea related to a lack of basal peats in the youngest age range, and verifies regional differences in glacial isostatic adjustment.Volkswagen Foundation
http://dx.doi.org/10.13039/501100001663NiedersĂ€chsisches Ministerium fĂŒr Wissenschaft und Kultur
http://dx.doi.org/10.13039/50110001057
Oculomotor and Vestibular Findings in Gaucher Disease Type 3 and Their Correlation with Neurological Findings
ObjectivesTo evaluate the function of the oculomotor and vestibular systems and to correlate these findings with the clinical status of patients with Gaucher disease type 3 (GD3). The goal of this cross-sectional and longitudinal study was to find oculomotor biomarkers for future clinical trials.MethodsTwenty-six patients with GD3 were assessed for eligibility and 21 were able to perform at least one task. Horizontal and vertical reflexive saccades, smooth pursuit, gaze-holding, optokinetic nystagmus, and horizontal vestibulo-ocular reflex (VOR) were examined by video-oculography/video-head impulse test and compared concurrently with 33 healthy controls. The Scale for the Assessment and Rating of Ataxia (SARA), the modified Severity Scoring Tool (mSST), and Grooved Pegboard Test (GPT) were administered to assess overall neurological function. Eleven patients were also re-assessed after 1âyear.ResultsNine out of 17 patients exhibited gaze-holding deficits. One patient had upbeat nystagmus. Three patients presented with bilateral abducens palsy in combination with central oculomotor disorders, suggesting a bilateral involvement of the abducens nucleus. Horizontal angular VOR gain was reduced in all patients (0.66â±â0.37) compared with controls (1.1â±â0.11, pâ<â0.001). Most strongly correlated with clinical rating scales were peak velocity of downward saccades (SARA: Ïâ=ââ0.752, pâ<â0.0005; mSST: Ïâ=ââ0.611, pâ=â0.003; GPT: Ïâ=ââ0.649, pâ=â0.005) and duration of vertical saccades (SARA: Ïâ=â0.806, pâ<â0.001; mSST: Ïâ=â0.700, pâ<â0.0005; GPT: Ïâ=â0.558, pâ=â0.02) together with the VOR gain (SARA: Ïâ=ââ0.63, pâ=â0.016; mSST: Ïâ=ââ0.725, pâ=â0.003; GPT: Ïâ=ââ0.666, pâ=â0.004). Vertical smooth pursuit gain decreased significantly at follow-up.InterpretationThis study shows neuronal degeneration of the brainstem and cerebellum with combined involvement of both supranuclear and nuclear oculomotor structures and the vestibular system in GD3. We also identified oculomotor parameters that correlate with the neurological status and can be used as biomarkers in future clinical trials
Oculomotor and Vestibular Findings in Gaucher Disease Type 3 and Their Correlation with Neurological Findings
International audienceObjectives: To evaluate the function of the oculomotor and vestibular systems and to correlate these findings with the clinical status of patients with Gaucher disease type 3 (GD3). The goal of this cross-sectional and longitudinal study was to find oculomotor biomarkers for future clinical trials.Methods: Twenty-six patients with GD3 were assessed for eligibility and 21 were able to perform at least one task. Horizontal and vertical reflexive saccades, smooth pursuit, gaze-holding, optokinetic nystagmus, and horizontal vestibulo-ocular reflex (VOR) were examined by video-oculography/video-head impulse test and compared concurrently with 33 healthy controls. The Scale for the Assessment and Rating of Ataxia (SARA), the modified Severity Scoring Tool (mSST), and Grooved Pegboard Test (GPT) were administered to assess overall neurological function. Eleven patients were also re-assessed after 1 year.Results: Nine out of 17 patients exhibited gaze-holding deficits. One patient had upbeat nystagmus. Three patients presented with bilateral abducens palsy in combination with central oculomotor disorders, suggesting a bilateral involvement of the abducens nucleus. Horizontal angular VOR gain was reduced in all patients (0.66 ± 0.37) compared with controls (1.1 ± 0.11, p < 0.001). Most strongly correlated with clinical rating scales were peak velocity of downward saccades (SARA: Ï = â0.752, p < 0.0005; mSST: Ï = â0.611, p = 0.003; GPT: Ï = â0.649, p = 0.005) and duration of vertical saccades (SARA: Ï = 0.806, p < 0.001; mSST: Ï = 0.700, p < 0.0005; GPT: Ï = 0.558, p = 0.02) together with the VOR gain (SARA: Ï = â0.63, p = 0.016; mSST: Ï = â0.725, p = 0.003; GPT: Ï = â0.666, p = 0.004). Vertical smooth pursuit gain decreased significantly at follow-up.Interpretation: This study shows neuronal degeneration of the brainstem and cerebellum with combined involvement of both supranuclear and nuclear oculomotor structures and the vestibular system in GD3. We also identified oculomotor parameters that correlate with the neurological status and can be used as biomarkers in future clinical trials