704 research outputs found
The impact of future sea-level rise on the global tides
Tides are a key component in coastal extreme water levels. Possible changes in the tides caused by mean sea-level rise (SLR) are therefore of importance in the analysis of coastal flooding, as well as many other applications. We investigate the effect of future SLR on the tides globally using a fully global forward tidal model: OTISmpi. Statistical comparisons of the modelled and observed tidal solutions demonstrate the skill of the refined model setup with no reliance on data assimilation. We simulate the response of the four primary tidal constituents to various SLR scenarios. Particular attention is paid to future changes at the largest 136 coastal cities, where changes in water level would have the greatest impact.
Spatially uniform SLR scenarios ranging from 0.5 to 10 m with fixed coastlines show that the tidal amplitudes in shelf seas globally respond strongly to SLR with spatially coherent areas of increase and decrease. Changes in the M2 and S2 constituents occur globally in most shelf seas, whereas changes in K1 and O1 are confined to Asian shelves. With higher SLR tidal changes are often not proportional to the SLR imposed and larger portions of mean high water (MHW) changes are above proportional. Changes in MHW exceed ±10% of the SLR at ~10% of coastal cities. SLR scenarios allowing for coastal recession tend increasingly to result in a reduction in tidal range. The fact that the fixed and recession shoreline scenarios result mainly in changes of opposing sign is explained by the effect of the perturbations on the natural period of oscillation of the basin. Our results suggest that coastal management strategies could influence the sign of the tidal amplitude change. The effect of a spatially varying SLR, in this case fingerprints of the initial elastic response to ice mass loss, modestly alters the tidal response with the largest differences at high latitudes
Expanding Thermal Plasma Deposition of a-Si:H Thin Films for Surface Passivation of c-Si Wafers,
We investigated the material properties of expanding thermal plasma deposited a-Si:H thin films, providing a record-low surface recombination velocity of 1.6 cm/s (at injection level of 1 1015 cm-3). a-Si:H thin films with different thicknesses have been deposited at a high deposition rate (1.2 nm/s) on both sides of low resistivity (1-5 Ohm cm), 260µm thick, n- and ptype c-Si FZ wafers. The material properties of a -Si:H films have been characterized by Fourier Transform Infrared diagnostic and Spectroscopic Ellipsometry. The surface passivation of the wafers has been determined by photoconductivity decay measurements of the effective carrier lifetime. The investigation points out that the growth of ETP a-Si:H films begins with the formation of a thin porous layer (<10 nm) with a refractive index of 3.9 (at 2 eV) and a microstructure parameter (R*) of 0.50. Despite the open network formation at the a-Si/c-Si interface, a 7 nm a-Si:H film achieves a recombination velocity as low as 12 cm/s (at 1·1015 cm-3 injection level on ntype wafers). The good passivation is probably due to the large hydrogen content of the a-Si:H film, which terminates dangling bonds present on the c-Si surface. After this initial growth, a dense a-Si:H network develops with a refractive index of 4.3 (at 2 eV) and R* = 0.03. The surface recombination velocity decresses linearly with the a-Si:H thickness, achieving a record value of 1.6 cm/s (at 1·1015 cm-3 injection level) for 90 nm thick a-Si film on n-type wafers. As compared to hot wire CVD and radiofrequency PECVD techniques, ETP is capable to deposit thin a-Si:H films with outstanding surface passivation at higher temperature (250° C) and higher deposition rate (1.2 nm/s). The stability in time of surface passivation has been investigated. Effective carrier lifetime is found to decrease following a stretched exponential. Photo-electronic properties of a-Si:H are know to relax in time in a similar fashion. These results therefore suggest a correlation between the photo-electronic roperties of the a-Si:H/c-Si interface and a-Si:H bulk material
Malnutrition is associated with dynamic physical performance
Background Malnutrition and poor physical performance are both conditions that increase in prevalence with age; however, their interrelation in a clinically relevant population has not been thoroughly studied. Aims This study aimed to determine the strength of the association between malnutrition and measures of both static and dynamic physical performance in a cohort of geriatric outpatients. Methods This cross-sectional study included 286 older adults (mean age 81.8, SD 7.2 years, and 40.6% male) who were referred to geriatric outpatient mobility clinics. The presence of malnutrition was determined using the Short Nutritional Assessment Questionnaire (SNAQ, cut-off ≥ 2 points). Measures of dynamic physical performance included timed up and go (TUG), 4-m walk test, and chair stand test (CST). Static performance encompassed balance tests and hand grip strength (HGS). Physical performance was standardized into sex-specific Z-scores. The association between malnutrition and each individual measure of physical performance was assessed using linear regression analysis. Results 19.9% of the cohort was identified as malnourished. Malnutrition was most strongly associated with CST and gait speed; less strong but significant associations were found between malnutrition and TUG. There was no significant association between malnutrition and HGS or balance. Discussion Physical performance was associated with malnutrition, specifically, dynamic rather than static measures. This may reflect muscle power being more impacted by nutritional status than muscle strength; however, this needs to be further addressed. Conclusions Malnutrition is associated with dynamic physical performance in geriatric outpatients, which should inform diagnosis and treatment/prevention strategies
Knee adduction moments are not increased in obese knee osteoarthritis patients during stair negotiation
Background: Negotiating stairs is an important activity of daily living that is also associated with large loads on the knee joint. In medial compartment knee osteoarthritis, the knee adduction moment during level walking is considered a marker for disease severity. It could be argued that the discriminative capability of this parameter is even better if tested in a strenuous stair negotiation task. Research question: What is the relation with knee osteoarthritis on the knee adduction moment during the stance phase of both stair ascent and descent in patients with and without obesity? Methods: This case control study included 22 lean controls, 16 lean knee osteoarthritis patients, and 14 obese knee osteoarthritis patients. All subjects ascended and descended a two-step staircase at a self-selected, comfortable speed. Three-dimensional motion analysis was performed to evaluate the knee adduction moment during stair negotiation. Results: Obese knee osteoarthritis patients show a prolonged stance time together with a more flattened knee adduction moment curve during stair ascent. Normalized knee adduction moment impulse, as well as the first and second peaks were not different between groups. During stair descent, a similar increase in stance time was found for both osteoarthritis groups. Significance: The absence of a significant effect of groups on the normalized knee adduction moment during stair negotiation may be explained by a lower ambulatory speed in the obese knee osteoarthritis group, that effectively lowers vertical ground reaction force. Decreasing ambulatory speed may be an effective strategy to lower knee adduction moment during stair negotiation
Inherited cavernous malformations of the central nervous system: clinical and genetic features in 19 Swiss families
Cavernous malformations (CCMs) are benign, well-circumscribed, and mulberry-like vascular malformations that may be found in the central nervous system in up to 0.5% of the population. Cavernous malformations can be sporadic or inherited. The common symptoms are epilepsy, hemorrhages, focal neurological deficits, and headaches. However, CCMs are often asymptomatic. The familiar form is associated with three gene loci, namely 7q21-q22 (CCM1), 7p13-p15 (CCM2), and 3q25.2-q27 (CCM3) and is inherited as an autosomal dominant trait with incomplete penetrance. The CCM genes are identified as Krit 1 (CCM1), MGC4607 (CCM2), and PDCD10 (CCM3). Here, we present the clinical and genetic features of CCMs in 19 Swiss families. Furthermore, surgical aspects in such families are also discusse
Diagnosis of diffuse idiopathic skeletal hyperostosis with chest computed tomography:inter-observer agreement
To evaluate and improve the interobserver agreement for the CT-based diagnosis of diffuse idiopathic skeletal hyperostosis (DISH). Six hundred participants of the CT arm of a lung cancer screening trial were randomly divided into two groups. The first 300 CTs were scored by five observers for the presence of DISH based on the original Resnick criteria for radiographs. After analysis of the data a consensus meeting was organised and the criteria were slightly modified regarding the definition of 'contiguous', the definition of 'flowing ossifications' and the viewing plane and window level. Subsequently, the second set of 300 CTs was scored by the same observers. kappa >= 0.61 was considered good agreement. The 600 male participants were on average 63.5 (SD 5.3) years old and had smoked on average 38.0 pack-years. In the first round kappa values ranged from 0.32 to 0.74 and 7 out of 10 values were below 0.61. After the consensus meeting the interobserver agreement ranged from 0.51 to 0.86 and 3 out of 10 values were below 0.61. The agreement improved significantly. This is the first study that reports interobserver agreement for the diagnosis of DISH on chest CT, showing mostly good agreement for modified Resnick criteria. . DISH is diagnosed on fluoroscopic and radiographic examinations using Resnick criteria . Evaluation of DISH on chest CT was modestly reproducible with the Resnick criteria . A consensus meeting and Resnick criteria modification improved inter-rater reliability for DISH . Reproducible CT criteria for DISH aids research into this poorly understood entity
The STUbL RNF4 regulates protein group SUMOylation by targeting the SUMO conjugation machinery
Cancer Signaling networks and Molecular Therapeutic
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