1,101 research outputs found
Deep circulation in the Lau Basin and Havre Trough of the western South Pacific Ocean from floats and hydrography
A system of meridional ridges in the western South Pacific Ocean frame the Lau Basin and Havre Trough, and form a barrier to direct communication between the far western South Pacific basins and the interior South Pacific Ocean. The eastern side of this system comprises the Tonga and Kermadec Ridges, the location of the main deep western boundary current entering the Pacific Ocean. Observations from floats released in the Lau Basin as part of the RIDGE2000 program suggested the presence of a western boundary current along the Lau Ridge exiting into the North Fiji Basin. Those observations, together with Argo sub-surface float data and repeat hydrographic sections, confirm and expand the boundary current observations along the Lau Ridge throughout the Lau Basin and into the Havre Trough, along the Colville Ridge. The observations also reveal two previously unrecognized westward flowing jets bisecting the Lau Basin and Havre Trough. Using an extension to the classic Stommel-Arons abyssal circulation model, the predicted strength and location of these boundary currents and their bifurcation is compared with the float observations. The model provides a simplified view of the dynamics controlling the boundary current structure in the deep basins. A comparison of transport within the western boundary current derived from float data, hydrographic sections, and the idealized analytical model indicates that roughly 4 Sv (below 1,000 db) is transported northward through the Lau Basin, exiting into the North Fiji Basin
Entwicklung von Überzeugungen angehender Lehrkräfte zu digitalen Werkzeugen und digitalem Feedback
Überzeugungen gelten als ein wichtiger Bestandteil der professionellen Handlungskompetenz von Lehrkräften, da sie als Grundlage für die Gestaltung von Unterricht angesehen werden können (Skott, 2015). In dem hier
beschriebenen Projekt betrachten wir Überzeugungen als eine individuelle Aussage einer Person zu einem Gegenstand oder Sachverhalt, die die Art und Weise prägt, wie sie Informationen erhält und in einer bestimmten Situation handelt. Überzeugungen können somit als Filter verstanden werden, die das (zukünftige) Handeln von (angehenden) Lehrkräften beeinflussen (Levin, 2015)
Längsschnittstudie zum Verlauf motorischer Fähigkeiten von Grundschulkindern in Abhängigkeit auffälliger motorischer Leistungen der Fein- und Grobmotorik
Theoretischer Hintergrund: Die motorische Leistungsfähigkeit (MLF) spielt eine zentrale Rolle in der Kindesentwicklung. Über
den Verlauf der MLF über die Grundschulzeit in Abhängigkeit auffälliger motorischer Leistungen im Vorschulalter liegen nur wenige Befunde vor.
Fragestellung: Liegen unterschiedliche Entwicklungsverläufe derMLF bei Kindern mitmotorisch auffälligen Leistungen in der Fein- und Grobmotorik
vor? Methode: Innerhalb einer Längsschnittstudie wurden die motorischen Dimensionen Kraft, Ausdauer, Schnelligkeit, Koordination und Beweglichkeit
von Grundschulkindern (N=424) jährlich untersucht und mittels Varianzanalyse mit Messwiederholung geprüft. Ergebnisse: Kinder, die vor
Schuleintritt grob- oder feinmotorische Auffälligkeiten (9-15 %) aufwiesen, blieben in ihrer motorischen Entwicklung deutlich hinter motorisch
unauffälligen Kindern zurück. Diskussion und Schlussfolgerung: In der Folge können sich erhebliche Einschränkungen für die Alltagsmotorik und das
Erlernen komplexer Bewegungen ergeben. Um gleiche motorische Startbedingungen für die betroffenen Kinder herzustellen, stellt die Erweiterung
der bewegungsbezogenen Förderung der MLF vor Schulbeginn einen notwendigen Ansatz dar.Theoretical Background: Motor performance is an important matter in the health-related development of children, particularly for
perception and for establishing a personal and material environment using physical activity. Developmental coordination disorders in preschoolaged
children may relate to lower levels of fine and gross motor development. Short-term longitudinal studies revealed that preschoolers with motor
deficits fall behind in their overall motor performance during the 1st and 2nd grades of primary school. Moreover, the years at primary school are a
meaningful stage in life for children because of its rapid progression in motor-learning capability. Objective: Regarding children in primary school,
little is known about the effects of developmental coordination disorders on the grade-related progression of basic motor abilities (i.e., flexibility,
strength, endurance, speed of movement, coordination). This study analyzes the motor performance development of children over the period of
primary school. Method: Using a longitudinal study design (KOMPASS-2 Study), we examined motor ability development in a sample of N = 424
primary school-aged children (n = 218 girls, 51.4%). To assess levels of motor abilities, we used the German Motor Test (DMT 6-18). Based on
standard screening for school entry, children were separated into two groups based on the status of their fine and gross motor development.
Changes inmotor ability levels were analyzed via robust repeated measures analyses of variance (rmANOVA) regarding developmental group effects,
school timeframe effects, and interaction effects. Results: 9% (n = 39) of the children were classified with a gross motor disorder, and 15% (n = 62)
of the children were classified with a fine motor disorder. The statistical analyses with rmANOVA demonstrated that children with developmental
coordination disorders regarding gross or fine motor developmental status showed lower motor-ability levels on all test tasks compared to children
without disorders. Particularly gross-motor disordered children achieved significantly lower motor-ability levels regarding coordination under time
constraint (jumping sideways) and coordination during dynamic precision tasks (backward balancing). However, motor-ability levels increased
significantly over time for both developmental status groups. Discussion and conclusion: Children with developmental coordination disorders may
experience substantial restrictions to meeting daily physical activities and motor learning of complex movements. To create equal motor
developmental conditions for children just starting school, it is necessary to promote physical activity in general. Interventions should regard a set of
coordination tasks that require children’s attention and speed during movement. Measuring the motor abilities of primary-school-aged children
once a year should be an integral part of communal health monitoring
Modulation of the sympathetic nervous system by renal denervation prevents reduction of aortic distensibility in atherosclerosis prone ApoE-deficient rats
Apolipoprotein E-deficient (ApoE(-/-)) rodents spontaneously develop severe hypercholesterolemia and increased aortic stiffness, both accepted risk factors for cardiovascular morbidity and mortality in humans. In patients with resistant hypertension renal denervation (RDN) may improve arterial stiffness, however the underlying mechanisms are incompletely understood. This study investigates the impact of RDN on aortic compliance in a novel atherosclerosis prone ApoE(-/-)-rat model.Methods
Normotensive, 8 weeks old ApoE−/− and Sprague–Dawley (SD) rats were subjected to bilateral surgical RDN (n = 6 per group) or sham operation (n = 5 per group) and fed with normal chow for 8 weeks. Compliance of the ascending aorta was assessed by magnetic resonance imaging. Vasomotor function was measured by aortic ring tension recordings. Aortic collagen content was quantified histologically and plasma aldosterone levels were measured by enzyme-linked immunosorbent assay (ELISA).Results
After 8 weeks, ApoE−/−-sham demonstrated a 58 % decrease in aortic distensibility when compared with SD-sham (0.0051 ± 0.0011 vs. 0.0126 ± 0.0023 1/mmHg; p = 0.02). This was accompanied by an impaired endothelium-dependent relaxation of aortic rings and an increase in aortic medial fibrosis (17.87 ± 1.4 vs. 12.27 ± 1.1 %; p = 0.006). In ApoE−/−-rats, RDN prevented the reduction of aortic distensibility (0.0128 ± 0.002 vs. 0.0051 ± 0.0011 1/mmHg; p = 0.01), attenuated endothelial dysfunction, and decreased aortic medial collagen content (12.71 ± 1.3 vs. 17.87 ± 1.4 %; p = 0.01) as well as plasma aldosterone levels (136.33 ± 6.6 vs. 75.52 ± 8.4 pg/ml; p = 0.0003). Cardiac function and metabolic parameters such as hypercholesterolemia were not influenced by RDN.Conclusion
ApoE−/−-rats spontaneously develop impaired vascular compliance. RDN improves aortic distensibility and attenuated endothelial dysfunction in ApoE−/−-rats. This was associated with a reduction in aortic fibrosis formation, and plasma aldosterone levels
Modulation of the sympathetic nervous system by renal denervation prevents reduction of aortic distensibility in atherosclerosis prone ApoE-deficient rats
Apolipoprotein E-deficient (ApoE(-/-)) rodents spontaneously develop severe hypercholesterolemia and increased aortic stiffness, both accepted risk factors for cardiovascular morbidity and mortality in humans. In patients with resistant hypertension renal denervation (RDN) may improve arterial stiffness, however the underlying mechanisms are incompletely understood. This study investigates the impact of RDN on aortic compliance in a novel atherosclerosis prone ApoE(-/-)-rat model.Methods
Normotensive, 8 weeks old ApoE−/− and Sprague–Dawley (SD) rats were subjected to bilateral surgical RDN (n = 6 per group) or sham operation (n = 5 per group) and fed with normal chow for 8 weeks. Compliance of the ascending aorta was assessed by magnetic resonance imaging. Vasomotor function was measured by aortic ring tension recordings. Aortic collagen content was quantified histologically and plasma aldosterone levels were measured by enzyme-linked immunosorbent assay (ELISA).Results
After 8 weeks, ApoE−/−-sham demonstrated a 58 % decrease in aortic distensibility when compared with SD-sham (0.0051 ± 0.0011 vs. 0.0126 ± 0.0023 1/mmHg; p = 0.02). This was accompanied by an impaired endothelium-dependent relaxation of aortic rings and an increase in aortic medial fibrosis (17.87 ± 1.4 vs. 12.27 ± 1.1 %; p = 0.006). In ApoE−/−-rats, RDN prevented the reduction of aortic distensibility (0.0128 ± 0.002 vs. 0.0051 ± 0.0011 1/mmHg; p = 0.01), attenuated endothelial dysfunction, and decreased aortic medial collagen content (12.71 ± 1.3 vs. 17.87 ± 1.4 %; p = 0.01) as well as plasma aldosterone levels (136.33 ± 6.6 vs. 75.52 ± 8.4 pg/ml; p = 0.0003). Cardiac function and metabolic parameters such as hypercholesterolemia were not influenced by RDN.Conclusion
ApoE−/−-rats spontaneously develop impaired vascular compliance. RDN improves aortic distensibility and attenuated endothelial dysfunction in ApoE−/−-rats. This was associated with a reduction in aortic fibrosis formation, and plasma aldosterone levels
Direct Estimate of Lateral Eddy Diffusivity Upstream of Drake Passage
The first direct estimate of the rate at which geostrophic turbulence mixes tracers across the Antarctic Circumpolar Current is presented. The estimate is computed from the spreading of a tracer released upstream of Drake Passage as part of the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES). The meridional eddy diffusivity, a measure of the rate at which the area of the tracer spreads along an isopycnal across the Antarctic Circumpolar Current, is 710 ± 260 m[superscript 2] s[superscript −1] at 1500-m depth. The estimate is based on an extrapolation of the tracer-based diffusivity using output from numerical tracers released in a one-twentieth of a degree model simulation of the circulation and turbulence in the Drake Passage region. The model is shown to reproduce the observed spreading rate of the DIMES tracer and suggests that the meridional eddy diffusivity is weak in the upper kilometer of the water column with values below 500 m[superscript 2] s[superscript −1] and peaks at the steering level, near 2 km, where the eddy phase speed is equal to the mean flow speed. These vertical variations are not captured by ocean models presently used for climate studies, but they significantly affect the ventilation of different water masses.National Science Foundation (U.S.) (Award OCE-1233832)National Science Foundation (U.S.) (Award OCE-1232962)National Science Foundation (U.S.) (Award OCE-1048926
Serum amyloid A: high-density lipoproteins interaction and cardiovascular risk
Aims High-density lipoproteins (HDLs) are considered as anti-atherogenic. Recent experimental findings suggest that their biological properties can be modified in certain clinical conditions by accumulation of serum amyloid A (SAA). The effect of SAA on the association between HDL-cholesterol (HDL-C) and cardiovascular outcome remains unknown. Methods and results We examined the association of SAA and HDL-C with mortality in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study, which included 3310 patients undergoing coronary angiography. To validate our findings, we analysed 1255 participants of the German Diabetes and Dialysis study (4D) and 4027 participants of the Cooperative Health Research in the Region of Augsburg (KORA) S4 study. In LURIC, SAA concentrations predicted all-cause and cardiovascular mortality. In patients with low SAA, higher HDL-C was associated with lower all-cause and cardiovascular mortality. In contrast, in patients with high SAA, higher HDL-C was associated with increased all-cause and cardiovascular mortality, indicating that SAA indeed modifies the beneficial properties of HDL. We complemented these clinical observations by in vitro experiments, in which SAA impaired vascular functions of HDL. We further derived a formula for the simple calculation of the amount of biologically ‘effective' HDL-C based on measured HDL-C and SAA from the LURIC study. In 4D and KORA S4 studies, we found that measured HDL-C was not associated with clinical outcomes, whereas calculated ‘effective' HDL-C significantly predicted better outcome. Conclusion The acute-phase protein SAA modifies the biological effects of HDL-C in several clinical conditions. The concomitant measurement of SAA is a simple, useful, and clinically applicable surrogate for the vascular functionality of HD
Relations between lipoprotein(a) concentrations, LPA genetic variants, and the risk of mortality in patients with established coronary heart disease: a molecular and genetic association study
Background:
Lipoprotein(a) concentrations in plasma are associated with cardiovascular risk in the general population. Whether lipoprotein(a) concentrations or LPA genetic variants predict long-term mortality in patients with established coronary heart disease remains less clear.
Methods:
We obtained data from 3313 patients with established coronary heart disease in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. We tested associations of tertiles of lipoprotein(a) concentration in plasma and two LPA single-nucleotide polymorphisms ([SNPs] rs10455872 and rs3798220) with all-cause mortality and cardiovascular mortality by Cox regression analysis and with severity of disease by generalised linear modelling, with and without adjustment for age, sex, diabetes diagnosis, systolic blood pressure, BMI, smoking status, estimated glomerular filtration rate, LDL-cholesterol concentration, and use of lipid-lowering therapy. Results for plasma lipoprotein(a) concentrations were validated in five independent studies involving 10 195 patients with established coronary heart disease. Results for genetic associations were replicated through large-scale collaborative analysis in the GENIUS-CHD consortium, comprising 106 353 patients with established coronary heart disease and 19 332 deaths in 22 studies or cohorts.
Findings:
The median follow-up was 9·9 years. Increased severity of coronary heart disease was associated with lipoprotein(a) concentrations in plasma in the highest tertile (adjusted hazard radio [HR] 1·44, 95% CI 1·14–1·83) and the presence of either LPA SNP (1·88, 1·40–2·53). No associations were found in LURIC with all-cause mortality (highest tertile of lipoprotein(a) concentration in plasma 0·95, 0·81–1·11 and either LPA SNP 1·10, 0·92–1·31) or cardiovascular mortality (0·99, 0·81–1·2 and 1·13, 0·90–1·40, respectively) or in the validation studies.
Interpretation:
In patients with prevalent coronary heart disease, lipoprotein(a) concentrations and genetic variants showed no associations with mortality. We conclude that these variables are not useful risk factors to measure to predict progression to death after coronary heart disease is established.
Funding:
Seventh Framework Programme for Research and Technical Development (AtheroRemo and RiskyCAD), INTERREG IV Oberrhein Programme, Deutsche Nierenstiftung, Else-Kroener Fresenius Foundation, Deutsche Stiftung für Herzforschung, Deutsche Forschungsgemeinschaft, Saarland University, German Federal Ministry of Education and Research, Willy Robert Pitzer Foundation, and Waldburg-Zeil Clinics Isny
Identifying rare variants from exome scans: the GAW17 experience
Genetic Analysis Workshop 17 (GAW17) provided a platform for evaluating existing statistical genetic methods and for developing novel methods to analyze rare variants that modulate complex traits. In this article, we present an overview of the 1000 Genomes Project exome data and simulated phenotype data that were distributed to GAW17 participants for analyses, the different issues addressed by the participants, and the process of preparation of manuscripts resulting from the discussions during the workshop
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