An overview of barrier winds off southeastern Greenland during the Greenland Flow Distortion experiment

During the Greenland Flow Distortion experiment, barrier flow was observed by an instrumented aircraft on 1, 2, 5 and 6 March 2007 off southeastern Greenland. During this time period the barrier flow increased from a narrow jet, ~15 m s-1, to a jet filling almost the whole of the Denmark Strait with maximum wind speed exceeding 40 m s-1. Dropsonde observations show that the barrier flow was capped by a sharp temperature inversion below mountain height. Below the inversion was a cold and dry jet, with a larger northerly wind component than that of the flow above, which was also warmer and more moist. Thus, the observations indicate two air masses below mountain height: a cold and dry barrier jet of northern origin and, above this, a warmer and moister air mass that was of cyclonic origin. Numerical simulations emphasize the non-stationarity of the Greenland barrier flow and its dependence on the synoptic situation in the Greenland--Iceland region. They show that the barrier jet originated north of the Denmark Strait and was drawn southward by a synoptic-scale cyclone, with the strength and location of the maximum winds highly dependent on the location of the cyclone relative to the orography of Greenland. Experiments without Greenland's orography suggest a ~20 m s-1 enhancement of the low-level peak wind speeds due to the presence of the barrier. Thus, the Greenland barrier flows are not classic geostrophically balanced barrier flows but have a significant ageostrophic component and are precisely controlled by synoptic-scale systems

Cytotoxicity and non-specific cellular uptake of bare and surface-modified upconversion nanoparticles in human skin cells

The cytotoxicity and non-specific cellular uptake of the most popular composition of upconversion nanoparticle (UCNP), NaYF4:Yb3+:Er3+, is reported using normal human skin cells, including dermal fibroblasts and immortalized human epidermal linear keratinocytes (HaCaT). A new hydrophilization reaction of as-synthesized UCNPs based on tetramethylammonium hydroxide (TMAH) enabled evaluation of the intrinsic cytotoxicity of bare UCNPs. The cytotoxicity effects of the UCNP surface-coating and polystyrene host were investigated over the concentration range 62.5–125 μg/mL with 24-h incubation, using a MTT test and optical microscopy. The fibroblast viability was not compromised by UCNPs, whereas the viability of keratinocytes varied from 52% ± 4% to 100% ± 10% than the control group, depending on the surface modification. Bare UCNPs reduced the keratinocyte viability to 76% ± 3%, while exhibiting profound non-specific cellular uptake. Hydrophilic poly(D,L-lactide)- and poly(maleic anhydride-alt-1-octadecene)-coated UCNPs were found to be least cytotoxic among the polymer-coated UCNPs, and were readily internalized by human skin cells. Polystyrene microbeads impregnated with UCNPs remained nontoxic. Surprisingly, no correlation was found between UCNP cytotoxicity and the internalization level in cells, although the latter ranged broadly from 0.03% to 59%, benchmarked against 100% uptake level of TMAH-UCNPs. [Figure not available: see fulltext.

Stability of the associations between early life risk indicators and adolescent overweight over the evolving obesity epidemic.

BACKGROUND: Pre- and perinatal factors and preschool body size may help identify children developing overweight, but these factors might have changed during the development of the obesity epidemic. OBJECTIVE: We aimed to assess the associations between early life risk indicators and overweight at the age of 9 and 15 years at different stages of the obesity epidemic. METHODS: We used two population-based Northern Finland Birth Cohorts including 4111 children born in 1966 (NFBC1966) and 5414 children born in 1985-1986 (NFBC1986). In both cohorts, we used the same a priori defined prenatal factors, maternal body mass index (BMI), birth weight, infant weight (age 5 months and 1 year), and preschool BMI (age 2-5 years). We used internal references in early childhood to define percentiles of body size (90) and generalized linear models to study the association with overweight, according to the International Obesity Taskforce (IOTF) definitions, at the ages of 9 and 15 years. RESULTS: The prevalence of overweight at the age of 15 was 9% for children born in 1966 and 16% for children born in 1986. However, medians of infant weight and preschool BMI changed little between the cohorts, and we found similar associations between maternal BMI, infant weight, preschool BMI, and later overweight in the two cohorts. At 5 years, children above the 90th percentile had approximately a 12 times higher risk of being overweight at the age of 15 years compared to children below the 50th percentile in both cohorts. CONCLUSIONS: The associations between early body size and adolescent overweight showed remarkable stability, despite the increase in prevalence of overweight over the 20 years between the cohorts. Using consequently defined internal percentiles may be a valuable tool in clinical practice

Preschool weight and body mass index in relation to central obesity and metabolic syndrome in adulthood.

BACKGROUND: If preschool measures of body size routinely collected at preventive health examinations are associated with adult central obesity and metabolic syndrome, a focused use of these data for the identification of high risk children is possible. The aim of this study was to test the associations between preschool weight and body mass index (BMI) and adult BMI, central obesity and metabolic alterations. METHODS: The Northern Finland Birth Cohort 1966 (NFBC1966) (N = 4111) is a population-based cohort. Preschool weight (age 5 months and 1 year) and BMI (age 2-5 years) were studied in relation to metabolic syndrome as well as BMI, waist circumference, lipoproteins, blood pressure, and fasting glucose at the age of 31 years. Linear regression models and generalized linear regression models with log link were used. RESULTS: Throughout preschool ages, weight and BMI were significantly linearly associated with adult BMI and waist circumference. Preschool BMI was inversely associated with high-density lipoprotein levels from the age of 3 years. Compared with children in the lower half of the BMI range, the group of children with the 5% highest BMI at the age of 5 years had a relative risk of adult obesity of 6.2(95% CI:4.2-9.3), of adult central obesity of 2.4(95% CI:2.0-2.9), and of early onset adult metabolic syndrome of 2.5(95% CI:1.7-3.8). CONCLUSIONS: High preschool BMI is consistently associated with adult obesity, central obesity and early onset metabolic syndrome. Routinely collected measures of body size in preschool ages can help to identify children in need of focused prevention due to their increased risk of adverse metabolic alterations in adulthood

Quality Control-Driven Image Segmentation Towards Reliable Automatic Image Analysis in Large-Scale Cardiovascular Magnetic Resonance Aortic Cine Imaging

“The final authenticated version is available online at https://doi.org/10.1007/978-3-030-32245-8_83.”© 2019, Springer Nature Switzerland AG. Recent progress in fully-automated image segmentation has enabled efficient extraction of clinical parameters in large-scale clinical imaging studies, reducing laborious manual processing. However, the current state-of-the-art automatic image segmentation may still fail, especially when it comes to atypical cases. Visual inspection of segmentation quality is often required, thus diminishing the improvements in efficiency. This drives an increasing need to enhance the overall data processing pipeline with robust automatic quality scoring, especially for clinical applications. We present a novel quality control-driven (QCD) framework to provide reliable segmentation using a set of different neural networks. In contrast to the prior segmentation and quality scoring methods, the proposed framework automatically selects the optimal segmentation on-the-fly from the multiple candidate segmentations available, directly utilizing the inherent Dice similarity coefficient (DSC) predictions. We trained and evaluated the framework on a large-scale cardiovascular magnetic resonance aortic cine image sequences from the UK Biobank Study. The framework achieved segmentation accuracy of mean DSC at 0.966, mean prediction error of DSC within 0.015, and mean error in estimating lumen area ≤17.6 mm2 for both ascending aorta and proximal descending aorta. This novel QCD framework successfully integrates the automatic image segmentation along with detection of critical errors on a per-case basis, paving the way towards reliable fully-automatic extraction of clinical parameters for large-scale imaging studies

"Open Innovation" and "Triple Helix" Models of Innovation: Can Synergy in Innovation Systems Be Measured?

The model of "Open Innovations" (OI) can be compared with the "Triple Helix of University-Industry-Government Relations" (TH) as attempts to find surplus value in bringing industrial innovation closer to public R&D. Whereas the firm is central in the model of OI, the TH adds multi-centeredness: in addition to firms, universities and (e.g., regional) governments can take leading roles in innovation eco-systems. In addition to the (transversal) technology transfer at each moment of time, one can focus on the dynamics in the feedback loops. Under specifiable conditions, feedback loops can be turned into feedforward ones that drive innovation eco-systems towards self-organization and the auto-catalytic generation of new options. The generation of options can be more important than historical realizations ("best practices") for the longer-term viability of knowledge-based innovation systems. A system without sufficient options, for example, is locked-in. The generation of redundancy -- the Triple Helix indicator -- can be used as a measure of unrealized but technologically feasible options given a historical configuration. Different coordination mechanisms (markets, policies, knowledge) provide different perspectives on the same information and thus generate redundancy. Increased redundancy not only stimulates innovation in an eco-system by reducing the prevailing uncertainty; it also enhances the synergy in and innovativeness of an innovation system.Comment: Journal of Open Innovations: Technology, Market and Complexity, 2(1) (2016) 1-12; doi:10.1186/s40852-016-0039-

A survey of oral health in a Sudanese population

10.1186/1472-6831-12-5BMC Oral Health121

Vaccines against toxoplasma gondii : challenges and opportunities

Development of vaccines against Toxoplasma gondii infection in humans is of high priority, given the high burden of disease in some areas of the world like South America, and the lack of effective drugs with few adverse effects. Rodent models have been used in research on vaccines against T. gondii over the past decades. However, regardless of the vaccine construct, the vaccines have not been able to induce protective immunity when the organism is challenged with T. gondii, either directly or via a vector. Only a few live, attenuated T. gondii strains used for immunization have been able to confer protective immunity, which is measured by a lack of tissue cysts after challenge. Furthermore, challenge with low virulence strains, especially strains with genotype II, will probably be insufficient to provide protection against the more virulent T. gondii strains, such as those with genotypes I or II, or those genotypes from South America not belonging to genotype I, II or III. Future studies should use animal models besides rodents, and challenges should be performed with at least one genotype II T. gondii and one of the more virulent genotypes. Endpoints like maternal-foetal transmission and prevention of eye disease are important in addition to the traditional endpoint of survival or reduction in numbers of brain cysts after challenge

Stimulus Dependence of Barrel Cortex Directional Selectivity

Neurons throughout the rat vibrissa somatosensory pathway are sensitive to the angular direction of whisker movement. Could this sensitivity help rats discriminate stimuli? Here we use a simple computational model of cortical neurons to analyze the robustness of directional selectivity. In the model, directional preference emerges from tuning of synaptic conductance amplitude and latency, as in recent experimental findings. We find that directional selectivity during stimulation with random deflection sequences is strongly dependent on the mean deflection frequency: Selectivity is weakened at high frequencies even when each individual deflection evokes strong directional tuning. This variability of directional selectivity is due to generic properties of synaptic integration by the neuronal membrane, and is therefore likely to hold under very general physiological conditions. Our results suggest that directional selectivity depends on stimulus context. It may participate in tasks involving brief whisker contact, such as detection of object position, but is likely to be weakened in tasks involving sustained whisker exploration (e.g., texture discrimination)