A global climatology of polar lows investigated for local differences and wind-shear environments

Polar lows are intense mesoscale cyclones developing in marine polar air masses. This study presents a new global climatology of polar lows based on the ERA5 reanalysis for the years 1979–2020. Criteria for the detection of polar lows are derived based on a comparison of five polarlow archives with cyclones derived by a mesoscale tracking algorithm. The characteristics associated with polar lows are considered by the following criteria: (i) intense cyclone (large relative vorticity), (ii) mesoscale (small vortex diameter), and (iii) development in the marine polar air masses (a combination of low potential static stability and low potential temperature at the tropopause). Polar lows develop in all marine areas adjacent to sea ice or cold landmasses, mainly in the winter half year. The length and intensity of the season are regionally dependent. The highest density appears in the Nordic Seas. For all ocean sub-basins, forward-shear polar lows are the most common, whereas weak-shear polar lows and those propagating towards warmer environments are second and third most frequent, depending on the area. Reverse-shear polar lows and those propagating towards colder environments are rather seldom, especially in the Southern Ocean. Generally, polar lows share many characteristics across ocean basins and wind-shear categories. The most remarkable difference is that forward-shear polar lows often occur in a stronger vertical wind shear, whereas reverse-shear polar lows feature lower static stability. Hence, the contribution to a fast baroclinic growth rate is slightly different for the shear categories

Demographics and Physical Activity Levels of eSports Athletes at The University of Akron

Esports is rapidly growing and gaining popularity, however there is a lack of research regarding physical activity levels of eSport athletes, especially those at the collegiate level. This study summarizes the current research and findings related to exercise, overall health, and video game performance. All varsity eSport athletes for The University of Akron varsity team were “participants” in this study. A survey tool was designed through Qualtrics (Qualtrics 2020© Provo, UT), an online survey instrument, to assess current physical activity levels, preferences and tolerance for exercise intensity, and perceptions about how physical activity affects gaming performance. This survey was distributed to The University of Akron eSports varsity team. However, due to the Coronavirus COVID-19 pandemic of 2020, the results were unable to be collected and analyzed. This survey instrument can serve as a baseline for further research on this topic, particularly concerning eSports training programs

The global atmospheric energy transport analysed by a wavelength-based scale separation

Source at https://www.weather-climate-dynamics.net/.The global atmospheric circulation is fundamental for the local weather and climate by redistributing energy and moisture. To the present day, there is a knowledge gap at which spatial scales the energy and its components are transported. Therefore, we separate the meridional atmospheric energy transport in the ERA5 reanalysis by the spatial scales, the quasi-stationary and transient flow patterns, and the latent and dry-static component. We focus on the annual and seasonal mean in the transport components as well as their inter-annual variability. Motivated by similarities across latitudes in the atmospheric transport spectra when displayed as function of wavelength, we refine the existing scale separation method to be based on wavelength instead of wavenumber. This reveals advantageous, as the following conclusions can be drawn, which are fairly similar in the two hemispheres. Transport by synoptic waves, defined at wavelengths between 2,000 and 8,000 km, is the largest contributor to extra-tropical energy and moisture transport, is mainly of transient character, and is little influenced by seasonality. In contrast, the transport by planetary waves, larger than 8,000 km, highly depends on the season and has two distinct characteristics. (1) In the extra-tropical winter, planetary waves are of major importance due to transport of dry-static energy. This planetary transport feature the largest inter-annual variability, and is mainly quasi-stationary in the Northern Hemisphere, but transient in its southern counterpart. (2) In the subtropical summer, quasi-stationary planetary waves are the most important transport component mainly due to advection of moisture, which is associated with monsoons. In contrast to transport by planetary and synoptic waves, only a negligible amount of energy is transported by mesoscale eddies (< 2,000 km)

On strongly walk regular graphs,triple sum sets and their codes

Strongly walk-regular graphs (SWRGs) can be constructed as coset graphs of the duals of projective three-weight codes whose weights satisfy a certain equation. We provide classifications of the feasible parameters of these codes in the binary and ternary case for medium size code lengths. For the binary case, the divisibility of the weights of these codes is investigated and several general results are shown. It is known that an SWRG has at most 4 distinct eigenvalues $k > \theta_1 > \theta_2 > \theta_3$. For an $s$-SWRG, the triple $(\theta_1, \theta_2, \theta_3)$ satisfies a certain homogeneous polynomial equation of degree $s - 2$ (Van Dam, Omidi, 2013). This equation defines a plane algebraic curve; we use methods from algorithmic arithmetic geometry to show that for $s = 5$ and $s = 7$, there are only the obvious solutions, and we conjecture this to remain true for all (odd) $s \ge 9$.Comment: 42 page

On strongly walk regular graphs, triple sum sets and their codes

Strongly walk-regular graphs (SWRGs) can be constructed as coset graphs of the duals of projective three-weight codes whose weights satisfy a certain equation. We provide classifications of the feasible parameters of these codes in the binary and ternary case for medium size code lengths. For the binary case, the divisibility of the weights of these codes is investigated and several general results are shown. It is known that an SWRG has at most 4 distinct eigenvalues $k > \theta_1 > \theta_2 > \theta_3$. For an $s$-SWRG, the triple $(\theta_1, \theta_2, \theta_3)$ satisfies a certain homogeneous polynomial equation of degree $s - 2$ (Van Dam, Omidi, 2013). This equation defines a plane algebraic curve; we use methods from algorithmic arithmetic geometry to show that for $s = 5$ and $s = 7$, there are only the obvious solutions, and we conjecture this to remain true for all (odd) $s \ge 9$.Comment: 42 page

Changes in atmospheric latent energy transport into the Arctic: Planetary versus synoptic scales

Atmospheric meridional energy transport into the Arctic plays an important role in Arctic weather and climate. The transport of latent energy in the form of water vapour strongly influences the Arctic atmosphere. The transport is achieved by circulation mechanisms on various scales and is largely comprised of extreme transport events. Here, we use a Fourier-based method of dividing the latent energy transport into spatial scales and investigate the extent to which extreme events in latent energy transport on planetary and synoptic scales have changed over the past four decades, and how they influence the Arctic winter temperatures. We find that wintertime extreme transport events on planetary scales are associated with warm temperature anomalies across the entire Arctic, while the extreme events on synoptic scales have less impact on the Arctic temperatures. We show that over the past four decades, there has been a significant increase in the wintertime latent energy transport by planetary-scale systems, and a decrease in synoptic-scale transport. This shift may have contributed to the amplified warming observed in the Arctic winter over the past decades

The Influence of Setting on Care Coordination for Childhood Asthma

Asthma affects 7.1 million children in the United States, disproportionately burdening African American and Latino children. Barriers to asthma control include insufficient patient education and fragmented care. Care coordination represents a compelling approach to improve quality of care and address disparities in asthma. The sites of The Merck Childhood Asthma Network Care Coordination Programs implemented different models of care coordination to suit specific settings—school district, clinic or health care system, and community—and organizational structures. A variety of qualitative data sources were analyzed to determine the role setting played in the manifestation of care coordination at each site. There were inherent strengths and challenges of implementing care coordination in each of the settings, and each site used unique strategies to deliver their programs. The relationship between the lead implementing unit and entities that provided (1) access to the priority population and (2) clinical services to program participants played a critical role in the structure of the programs. The level of support and infrastructure provided by these entities to the lead implementing unit influenced how participants were identified and how asthma care coordinators were integrated into the clinical care team.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113262/1/MCAN_Settings_Manuscript_20150708.docxhttp://deepblue.lib.umich.edu/bitstream/2027.42/113262/3/MCAN_Settings_Manuscript_20150708.pdfDescription of MCAN_Settings_Manuscript_20150708.docx : Main ArticleDescription of MCAN_Settings_Manuscript_20150708.pdf : Main Article with Title Page and Abstrac

Evaluation of a sub-kilometre NWP system in an Arctic fjord-valley system in winter

Terrain challenges the prediction of near-surface atmospheric conditions, even in kilometre-scale numerical weather prediction (NWP) models. In this study, the ALADIN-HIRLAM NWP system with 0.5 km horizontal grid spacing and an increased number of vertical levels is compared to the 2.5-km model system similar to the currently operational NWP system at the Norwegian Meteorological Institute. The impact of the increased resolution on the forecasts’ ability to represent boundary-layer processes is investigated for the period from 12 to 16 February 2018 in an Arctic fjord-valley system in the Svalbard archipelago. Model simulations are compared to a wide range of observations conducted during a field campaign. The model configuration with sub-kilometre grid spacing improves both the spatial structure and overall verification scores for the near-surface temperature and wind forecasts compared to the 2.5-km experiment. The subkilometre experiment successfully captures the wind channelling through the valley and the temperature field associated with it. In a situation of a cold-air pool development, the sub-kilometre experiment has a particularly high near-surface temperature bias at low elevations. The use of measurement campaign data, however, reveals some encouraging results, e.g. the sub-kilometre system has a more realistic vertical profile of temperature and wind speed, and the surface temperature sensitivity to the net surface energy is closer to the observations. This work demonstrates the potential of sub-kilometre NWP systems for forecasting weather in complex Arctic terrain, and also suggests that the increase in resolution needs to be accompanied with further development of other parts of the model system

Long-Term Clinical Outcomes With Sirolimus-Eluting Coronary Stents Five-Year Results of the RAVEL Trial

ObjectivesThis study examined the clinical outcomes at 5 years in RAVEL (A Randomized Comparison of a Sirolimus-Eluting Stent With a Standard Stent for Coronary Revascularization), the first controlled trial of drug-eluting stents.BackgroundThe 6-month rate of angiographic coronary restenosis has been markedly lowered by sirolimus-eluting stents (SES). The long-term performance of drug-eluting stents, however, is under close scrutiny.MethodsThe trial included 238 patients (mean age 60.7 ± 10.4 years, 76% men) with a single, de novo native coronary artery lesion, randomly assigned to treatment with SES versus bare-metal stents (BMS). Rates of major adverse cardiac events (MACE), defined as all-cause mortality, myocardial infarction, and percutaneous or surgical revascularization up to 5 years of follow-up, and rates of stent thrombosis were compared between the 2 treatment groups.ResultsComplete datasets were available in 92.5% of patients treated with SES and 89.1% of patients assigned to BMS. The 1-, 3-, and 5-year rates of survival free from target lesion revascularization (TLR) were, respectively, 99.2%, 93.8%, and 89.7% in the SES group versus 75.9%, 75.0%, and 74.0% in the control group (p < 0.001; log-rank). Rates of all MACE at 5 years were 25.8% in patients treated with SES versus 35.2% in patients assigned to BMS (p = 0.03; log-rank). Rates of stent thrombosis, per protocol or by the Academic Research Consortium definitions, were similar in both groups.ConclusionsThe 5-year rate of TLR associated with SES was significantly lower than that with BMS. There was no apparent adverse effect associated with the use of SES, although the trial was not powered to examine uncommon complications

The speciation and genotyping of Cronobacter isolates from hospitalised patients

The World Health Organization (WHO) has recognised all Cronobacter species as human pathogens. Among premature neonates and immunocompromised infants, these infections can be life-threatening, with clinical presentations of septicaemia, meningitis and necrotising enterocolitis. The neurological sequelae can be permanent and the mortality rate as high as 40 – 80 %. Despite the highlighted issues of neonatal infections, the majority of Cronobacter infections are in the elderly population suffering from serious underlying disease or malignancy and include wound and urinary tract infections, osteomyelitis, bacteraemia and septicaemia. However, no age profiling studies have speciated or genotyped the Cronobacter isolates. A clinical collection of 51 Cronobacter strains from two hospitals were speciated and genotyped using 7-loci multilocus sequence typing (MLST), rpoB gene sequence analysis, O-antigen typing and pulsed- field gel electrophoresis (PFGE). The isolates were predominated by C. sakazakii sequence type 4 (63 %, 32/51) and C. malonaticus sequence type 7 (33 %, 17/51). These had been isolated from throat and sputum samples of all age groups, as well as recal and faecal swabs. There was no apparent relatedness between the age of the patient and the Cronobacter species isolated. Despite the high clonality of Cronobacter , PFGE profiles differentiated strains across the sequence types into 15 pulsotypes. There was almost complete agreement between O-antigen typing and rpoB gene sequence analysis and MLST profiling. This study shows the value of applying MLST to bacterial population studies with strains from two patient cohorts, combined with PFGE for further discrimination of strains