Derivation and evaluation of a new extinction coefficient for use with the n-HUT snow emission model

In this study, snow slab data collected from the Arctic Snow Microstructure Experiment were used in conjunction with a six-directional flux coefficient model to calculate individual slab absorption and scattering coefficients. These coefficients formed the basis for a new semiempirical extinction coefficient model, using both frequency and optical diameter as input parameters, along with the complex dielectric constant of snow. Radiometric observations, at 18.7, 21.0, and 36.5 GHz at both horizontal polarization (H-Pol) and vertical polarization (V-Pol), and snowpit data collected as part of the Sodankylä Radiometer Experiment were used to compare and contrast the simulated brightness temperatures produced by the multi-layer Helsinki University of Technology snow emission model, utilizing both the original empirical model and the new semiempirical extinction coefficient model described here. The results show that the V-Pol RMSE and bias values decreased when using the semiempirical extinction coefficient; however, the H-Pol RMSE and bias values increased on two of the lower microwave bands tested. The unbiased RMSE was shown to decrease across all frequencies and polarizations when using the semiempirical extinction coefficient

Relationship between screen time and sleep among Finnish preschool children : results from the DAGIS study

Study objectives: To examine the associations between screen time, the time spent on different screen devices, and sleep in a sample of Finnish preschool children. Methods: The current study analyzed cross-sectional data from the DAGIS study carried out in Finland in 2015-2016 on 736 children aged 3-6 years. Parents reported in a 7-day diary the durations the child used screen devices daily, with separate details about watching TV or DVDs, using tablets or smartphones, and using computers. In addition, parents reported children's bedtimes and wake-up times, which were further used in calculating sleep duration. Parents answered questions regarding their child's sleep consistency. Statistical analyses included adjusted general linear modeling. Results: An hourly increase in total screen time was associated with 11 min later bedtime (p <0.001) and 10 min shorter sleep duration (p <0.001). More TV/DVD watching was associated with later bedtimes (p = 0.016) and a shorter sleep duration (p = 0.001). More smartphone/tablet use was associated with later bedtimes (p = 0.005), later wake-up times (p = 0.038), and weaker sleep consistency (p = 0.024). More computer use was associated with later bedtimes (p = 0.046). Results did not differ between genders. Conclusions: Increased screen time was associated with later bedtimes and shorter sleep duration among preschool children. Adverse associations with sleep outcomes were found for each screen device. Attention should be paid to promoting balanced use of screens and regular sleep habits in young children.Peer reviewe

Arctic Snow Microstructure Experiment for the development of snow emission modelling

The Arctic Snow Microstructure Experiment (ASMEx) took place in Sodankylä, Finland in the winters of 2013-2014 and 2014-2015. Radiometric, macro-, and microstructure measurements were made under different experimental conditions of homogenous snow slabs, extracted from the natural seasonal taiga snowpack. Traditional and modern measurement techniques were used for snow macro- and microstructure observations. Radiometric measurements of the microwave emission of snow on reflector and absorber bases were made at frequencies 18.7, 21.0, 36.5, 89.0 and 150.0 GHz, for both horizontal and vertical polarizations. Two measurement configurations were used for radiometric measurements: a reflecting surface and an absorbing base beneath the snow slabs. Simulations of brightness temperatures using two microwave emission models, Helsinki University of Technology (HUT) snow emission model and Microwave Emission Model of Layered Snowpacks (MEMLS), were compared to observed brightness temperatures. RMSE and bias were calculated; with the RMSE and bias values being smallest upon an absorbing base at vertical polarization. Simulations overestimated the brightness temperatures on absorbing base cases at horizontal polarization. With the other experimental conditions, the biases were small; with the exception of the HUT model 36.5 GHz simulation, which produced an underestimation for the reflector base cases. This experiment provides a solid framework for future research on the extinction of microwave radiation inside snow

Heme oxygenase-1 repeat polymorphism in septic acute kidney injury

Abstract Acute kidney injury (AKI) is a syndrome that frequently affects the critically ill. Recently, an increased number of dinucleotide repeats in the HMOX1 gene were reported to associate with development of AKI in cardiac surgery. We aimed to test the replicability of this finding in a Finnish cohort of critically ill septic patients. This multicenter study was part of the national FINNAKI study. We genotyped 300 patients with severe AKI (KDIGO 2 or 3) and 353 controls without AKI (KDIGO 0) for the guanine–thymine (GTn) repeat in the promoter region of the HMOX1 gene. The allele calling was based on the number of repeats, the cut off being 27 repeats in the S–L (short to long) classification, and 27 and 34 repeats for the S–M–L₂ (short to medium to very long) classification. The plasma concentrations of heme oxygenase-1 (HO-1) enzyme were measured on admission. The allele distribution in our patients was similar to that published previously, with peaks at 23 and 30 repeats. The S-allele increases AKI risk. An adjusted OR was 1.30 for each S-allele in an additive genetic model (95% CI 1.01–1.66; p = 0.041). Alleles with a repeat number greater than 34 were significantly associated with lower HO-1 concentration (p&lt;0.001). In septic patients, we report an association between a short repeat in HMOX1 and AKI risk