SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Average

291

Plastic pollution has been well documented in natural environments, including the open waters and sediments within lakes and rivers, the open ocean and even the air, but less attention has been paid to synthetic polymers in human consumables. Since multiple toxicity studies indicate risks to human health when plastic particles are ingested, more needs to be known about the presence and abundance of anthropogenic particles in human foods and beverages. This study investigates the presence of anthropogenic particles in 159 samples of globally sourced tap water, 12 brands of Laurentian Great Lakes beer, and 12 brands of commercial sea salt. Of the tap water samples analyzed, 81% were found to contain anthropogenic particles. The majority of these particles were fibers (98.3%) between 0.1-5 mm in length. The range was 0 to 61 particles/L, with an overall mean of 5.45 particles/L. Anthropogenic debris was found in each brand of beer and salt. Of the extracted particles, over 99% were fibers. After adjusting for particles found in lab blanks for both salt and beer, the average number of particles found in beer was 4.05 particles/L with a range of 0 to 14.3 particles/L and the average number of particles found in each brand of salt was 212 particles/kg with a range of 46.7 to 806 particles/kg. Based on consumer guidelines, our results indicate the average person ingests over 5,800 particles of synthetic debris from these three sources annually, with the largest contribution coming from tap water (88%).

Concepts: Water, Lake, Water pollution, Polymer, Average, Sea, Ocean, Great Lakes

277

To identify what features of online social networks can increase physical activity, we conducted a 4-arm randomized controlled trial in 2014 in Philadelphia, PA. Students (n = 790, mean age = 25.2) at an university were randomly assigned to one of four conditions composed of either supportive or competitive relationships and either with individual or team incentives for attending exercise classes. The social comparison condition placed participants into 6-person competitive networks with individual incentives. The social support condition placed participants into 6-person teams with team incentives. The combined condition with both supportive and competitive relationships placed participants into 6-person teams, where participants could compare their team’s performance to 5 other teams' performances. The control condition only allowed participants to attend classes with individual incentives. Rewards were based on the total number of classes attended by an individual, or the average number of classes attended by the members of a team. The outcome was the number of classes that participants attended. Data were analyzed using multilevel models in 2014. The mean attendance numbers per week were 35.7, 38.5, 20.3, and 16.8 in the social comparison, the combined, the control, and the social support conditions. Attendance numbers were 90% higher in the social comparison and the combined conditions (mean = 1.9, SE = 0.2) in contrast to the two conditions without comparison (mean = 1.0, SE = 0.2) (p = 0.003). Social comparison was more effective for increasing physical activity than social support and its effects did not depend on individual or team incentives.

Concepts: Comparison, Randomized controlled trial, Arithmetic mean, Average, Randomness, Control, Grammatical number, The A-Team

56

School closure policies are among the non-pharmaceutical measures taken into consideration to mitigate influenza epidemics and pandemics spread. However, a systematic review of the effectiveness of alternative closure policies has yet to emerge. Here we perform a model-based analysis of four types of school closure, ranging from the nationwide closure of all schools at the same time to reactive gradual closure, starting from class-by-class, then grades and finally the whole school. We consider policies based on triggers that are feasible to monitor, such as school absenteeism and national ILI surveillance system. We found that, under specific constraints on the average number of weeks lost per student, reactive school-by-school, gradual, and county-wide closure give comparable outcomes in terms of optimal infection attack rate reduction, peak incidence reduction or peak delay. Optimal implementations generally require short closures of one week each; this duration is long enough to break the transmission chain without leading to unnecessarily long periods of class interruption. Moreover, we found that gradual and county closures may be slightly more easily applicable in practice as they are less sensitive to the value of the excess absenteeism threshold triggering the start of the intervention. These findings suggest that policy makers could consider school closure policies more diffusely as response strategy to influenza epidemics and pandemics, and the fact that some countries already have some experience of gradual or regional closures for seasonal influenza outbreaks demonstrates that logistic and feasibility challenges of school closure strategies can be to some extent overcome.

Concepts: Epidemiology, Infectious disease, Influenza, Emergence, Average, Policy, Pandemic, Closure

31

The aim of the study was a detailed analysis of the sprinting activity of professional soccer players. The study involved 147 players who played in 10 matches of the 2008-2009 and 2010-2011 UEFA Europa League seasons. The number of performed sprints and total sprint distances covered by the players were examined using collected statistical material. Two types of sprints were distinguished based on their duration: S - short duration sprint (below 5 s) and L - long duration sprint (above 5 s). Additionally, sprints were classified according to their distance: 0-10 m, 10.1-20.0 m, and > 20 m, respectively. The analysis of the sprinting activity of soccer players also involved their respective positions of play. The study was carried out using Amisco Pro® (ver. 1.0.2, Nice, France), one of most comprehensive, up-to-date computer systems for match analysis.The statistical analysis revealed that the mean total sprint distance covered by players (≥ 24 km • h-1) amounted to 237 ± 123 m. With regard to the position of play, the forwards covered the longest sprint distance (345 ± 129 m), i.e. 9% longer than midfielders (313 ± 119 m), and over 100% longer than central midfielders (167 ± 87 m). The average number of sprints performed by the soccer players was 11.2 ± 5.3. It should also be emphasized that about 90% of sprints performed by professional soccer players were shorter than 5 s, while only 10% were longer than 5 s. Analysis of physical loads of soccer players during matches can be useful for individualization of training of soccer players' speed capabilities. It is an essential instrument of modern planning and application of training loads.

Concepts: Statistics, Arithmetic mean, Average, Running, UEFA Europa League, UEFA, UEFA Champions League, UEFA Intertoto Cup

28

Insurers, employers, and states increasingly encourage price transparency so that patients can compare health care prices across providers. However, the evidence on whether price transparency tools encourage patients to receive lower-cost care and reduce overall spending remains limited and mixed. We examined the experience of a large insured population that was offered a price transparency tool, focusing on a set of “shoppable” services (lab tests, office visits, and advanced imaging services). Overall, offering the tool was not associated with lower shoppable services spending. Only 12 percent of employees who were offered the tool used it in the first fifteen months after it was introduced, and use of the tool was not associated with lower prices for lab tests or office visits. The average price paid for imaging services preceded by a price search was 14 percent lower than that paid for imaging services not preceded by a price search. However, only 1 percent of those who received advanced imaging conducted a price search. Simply offering a price transparency tool is not sufficient to meaningfully decrease health care prices or spending.

Concepts: Health care, Health care provider, Health, Illness, Average, Employment, Price, Insurance

28

We show that one of the advantages of quorum-based decision-making is an ability to estimate the average value of a resource that fluctuates in quality. By using a quorum threshold, namely the number of ants within a new nest site, to determine their choice, the ants are in effect voting with their feet. Our results show that such quorum sensing is compatible with homogenization theory such that the average value of a new nest site is determined by ants accumulating within it when the nest site is of high quality and leaving when it is poor. Hence, the ants can estimate a surprisingly accurate running average quality of a complex resource through the use of extraordinarily simple procedures.

Concepts: Mathematics, Evaluation, Average, Moving average

28

Propagation patterns of animal acoustic signals provide insights into the evolution of signal design to convey signaler’s information to potential recipients. However, propagation properties of vertebrate calls have been rarely studied using natural calls from individuals; instead playback calls broadcast through loudspeakers have been used extensively, a procedure that may involve acoustical and physical features differing from natural sounds. Measurements of the transmission characteristics of natural advertisement calls, which are simple tonal sounds, of the Iberian midwife toad, Alytes cisternasii, were carried out, and the results were compared with previously published results broadcasting recorded calls of the same species. Measurements of sound pressure level (SPL) of calls from individual male A. cisternasii revealed that the call amplitude decreases at distances of 1-8 m from the source at rates averaging 1-5 dB above spherical transmission loss in an omni-directional pattern. A comparison between SPLs of natural calls in the current study and of playback calls from a previous study showed that patterns of propagation did not differ in average values, but variance was significantly higher for natural calls. Results suggest that using broadcast signals for transmission experiments may result in a simplification of the conditions in which actual animals communicate in nature.

Concepts: Acoustics, Average, Sound, Sound pressure, Microphone, Level, Broadcasting, Bioacoustics

28

Recent advances in the field of image processing have shown that level of noise highly affect the quality and accuracy of classification when working with mammographic images. In this paper, we have proposed a method that consists of two major modules: noise detection and noise filtering. For detection purpose, neural network is used which effectively detect the noise from highly corrupted images. Pixel values of the window and some other features are used as feature for the training of neural network. For noise removal, three filters are used. The weighted average value of these three filters is filled on noisy pixels. The proposed technique has been tested on salt & pepper and quantum noise present in mammogram images. Peak signal to noise ratio (PSNR) and structural similarity index measure (SSIM) are used for comparison of proposed technique with different existing techniques. Experiments shows that proposed technique produce better results as compare to existing methods.

Concepts: Arithmetic mean, Average, Mammography, Weighted mean, Signal-to-noise ratio, Image processing, Video quality, Peak signal-to-noise ratio

26

Abstract Introduction: We investigated the feasibility of using computer-assisted arm rehabilitation (CAAR) computer games in schools. Outcomes were children’s preference for single player or dual player mode, and changes in arm activity and kinematics. Method: Nine boys and two girls with cerebral palsy (6-12 years, mean 9 years) played assistive technology computer games in single-user mode or with school friends in an AB-BA design. Preference was determined by recording the time spent playing each mode and by qualitative feedback. We used the ABILHAND-kids and Canadian Occupational Performance Measure to evaluate activity limitation, and a portable laptop-based device to capture arm kinematics. Results: No difference was recorded between single-user and dual-user modes (median daily use 9.27 versus 11.2 min, p = 0.214). Children reported dual-user mode was preferable. There were no changes in activity limitation (ABILHAND-kids, p = 0.424; COPM, p = 0.484) but we found significant improvements in hand speed (p = 0.028), smoothness (p = 0.005) and accuracy (p = 0.007). Conclusion: School timetables prohibit extensive use of rehabilitation technology but there is potential for its short-term use to supplement a rehabilitation program. The restricted access to the rehabilitation games was sufficient to improve arm kinematics but not arm activity. Implications for Rehabilitation School premises and teaching staff present no obstacles to the installation of rehabilitation gaming technology. Twelve minutes per day is the average amount of time that the school time table permits children to use rehabilitation gaming equipment (without disruption to academic attendance). The use of rehabilitation gaming technology for an average of 12 minutes daily does not appear to benefit children’s functional performance, but there are improvements in the kinematics of children’s upper limb.

Concepts: Time, Mode, Median, Arithmetic mean, Mean, Average, Upper limb, Canadian model of occupational performance

24

In 2015, an average of 103 motor vehicle injury deaths, 121 suicides, and 49 homicides occurred each day. Motor vehicle injury deaths were more likely to occur on Saturdays and Sundays and least likely to occur on Tuesdays. The highest number of suicides occurred on Mondays and Tuesdays and the lowest on Saturdays. Homicides peaked on Sundays, followed by Saturdays; homicides were less likely to occur on weekdays.

Concepts: Death, Injury, Average, Suicide, Homicide