Sex Differences in Elite Swimming with Advanced Age Are Less Than Marathon Running

The sex difference in marathon performance increases with finishing place and age of the runner but whether this occurs among swimmers is unknown. The purpose was to compare sex differences in swimming velocity across world record place (1st–10th), age group (25–89 years), and event distance. We also compared sex differences between freestyle swimming and marathon running. The world\u27s top 10 swimming times of both sexes for World Championship freestyle stroke, backstroke, breaststroke, and butterfly events and the world\u27s top 10 marathon times in 5-year age groups were obtained. Men were faster than women for freestyle (12.4 ± 4.2%), backstroke (12.8 ± 3.0%), and breaststroke (14.5 ± 3.2%), with the greatest sex differences for butterfly (16.7 ± 5.5%). The sex difference in swimming velocity increased across world record place for freestyle (P \u3c 0.001), breaststroke, and butterfly for all age groups and distances (P  \u3c 0.001) because of a greater relative drop-off between first and 10th place for women. The sex difference in marathon running increased with the world record place and the sex difference for marathon running was greater than for swimming (P \u3c 0.001). The sex difference in swimming increased with world record place and age, but was less than for marathon running. Collectively, these results suggest more depth in women\u27s swimming than marathon running

Measure of Effectiveness for JSTARS Ground Moving Target Indicator: A Value Focused Thinking Approach

As the nature of warfare has shifted from a conventional approach to more guerilla type warfare, intelligence has become more important than at any other time in the history of the United States Military. With the stochastic nature of intelligence gathering, it is almost impossible to know with any degree of certainty where and when the next piece of information that could possibly change the course of the battle or war will be obtained. US intelligence gathering assets have long been plagued with using useless measures of performance rather than measures of effectiveness to determine their worth. This research uses a value focused thinking approach to determine the effectiveness of a specific capability or asset. Specifically, it looks at Ground Moving Target Indicator onboard the E-8C Joint Surveillance Target Attack Radar System. This research attempts to provide a model to a decision maker so he or she will know in advance the approximate value of information they will receive from a particular asset or capability before the asset is ever deployed into the area of responsibility

Men Are More Likely than Women to Slow in the Marathon

Studies on nonelite distance runners suggest that men are more likely than women to slow their pace in a marathon. Purpose: This study determined the reliability of the sex difference in pacing across many marathons and after adjusting women\u27s performances by 12% to address men\u27s greater maximal oxygen uptake and also incorporating information on racing experience. Methods: Data were acquired from 14 US marathons in 2011 and encompassed 91,929 performances. For 2929 runners, we obtained experience data from a race-aggregating Web site. We operationalized pace maintenance as the percentage change in pace observed in the second half of the marathon relative to the first half. Pace maintenance was analyzed as a continuous variable and as two categorical variables, as follows: maintain the pace, defined as slowing=30%. Results: The mean change in pace was 15.6% and 11.7% for men and women, respectively (P \u3c 0.0001). This sex difference was significant for all 14 marathons. The odds for women were 1.46 (95% confidence interval, 1.41–1.50; P \u3c 0.0001) times higher than men to maintain the pace and 0.36 (95% confidence interval, 0.34–0.38; P \u3c 0.0001) times that of men to exhibit marked slowing. Slower finishing times were associated with greater slowing, especially in men (interaction, P \u3c 0.0001). However, the sex difference in pacing occurred across age and finishing time groups. Making the 12% adjustment to women’s performances lessened the magnitude of the sex difference in pacing but not its occurrence. Although greater experience was associated with less slowing, controlling for the experience variables did not eliminate the sex difference in pacing. Conclusions: The sex difference in pacing is robust. It may reflect sex differences in physiology, decision making, or both

Buckling without bending: a new paradigm in morphogenesis

A curious feature of organ and organoid morphogenesis is that in certain cases, spatial oscillations in the thickness of the growing "film" are out-of-phase with the deformation of the slower-growing "substrate," while in other cases, the oscillations are in-phase. The former cannot be explained by elastic bilayer instability, and contradict the notion that there is a universal mechanism by which brains, intestines, teeth, and other organs develop surface wrinkles and folds. Inspired by the microstructure of the embryonic cerebellum, we develop a new model of 2d morphogenesis in which system-spanning elastic fibers endow the organ with a preferred radius, while a separate fiber network resides in the otherwise fluid-like film at the outer edge of the organ and resists thickness gradients thereof. The tendency of the film to uniformly thicken or thin is described via a "growth potential". Several features of cerebellum, +blebbistatin organoid, and retinal fovea morphogenesis, including out-of-phase behavior and a film thickness amplitude that is comparable to the radius amplitude, are readily explained by our simple analytical model, as may be an observed scale-invariance in the number of folds in the cerebellum. We also study a nonlinear variant of the model, propose further biological and bio-inspired applications, and address how our model is and is not unique to the developing nervous system.Comment: version accepted by Physical Review

Tracking Vector Magnetograms with the Magnetic Induction Equation

The differential affine velocity estimator (DAVE) developed in Schuck (2006) for estimating velocities from line-of-sight magnetograms is modified to directly incorporate horizontal magnetic fields to produce a differential affine velocity estimator for vector magnetograms (DAVE4VM). The DAVE4VM's performance is demonstrated on the synthetic data from the anelastic pseudospectral ANMHD simulations that were used in the recent comparison of velocity inversion techniques by Welsch (2007). The DAVE4VM predicts roughly 95% of the helicity rate and 75% of the power transmitted through the simulation slice. Inter-comparison between DAVE4VM and DAVE and further analysis of the DAVE method demonstrates that line-of-sight tracking methods capture the shearing motion of magnetic footpoints but are insensitive to flux emergence -- the velocities determined from line-of-sight methods are more consistent with horizontal plasma velocities than with flux transport velocities. These results suggest that previous studies that rely on velocities determined from line-of-sight methods such as the DAVE or local correlation tracking may substantially misrepresent the total helicity rates and power through the photosphere.Comment: 30 pages, 13 figure

Sediment Microbiomes Associated with Critical Habitat of the Juvenile American Horseshoe Crab; Limulus Polyphemus

Plumb Beach, Brooklyn, New York in USA is an important horseshoe crab breeding and nursery ground that has experienced substantial anthropogenic influence, including pollution, erosion and subsequent restoration. Since little is known about the relationship between sediment microbial communities and juvenile horseshoe crab survival, next generation sequencing was used to characterize and compare the sediment microbiome of three distinct areas of Plumb Beach:- a tidal creek with abundant juveniles, East Beach with moderate number of juveniles, and West Beach- a highly disturbed area where juvenile crabs are rarely seen. The microbiome of juvenile crab intestinal content (both dissected gut content and fecal flush content) from the tidal creek site was also examined. The results showed that in our 2017 survey, the overall dominant sediment orders at all beach sites were Vibrionales (30%), Flavobacteriales (22%) and Alteromonadales (21%). Although alpha diversity was similar among the three beach sites, Bray-Curtis distances assessed by Permanova revealed significant differences in Beta diversity, with a unique microbial assemblage found in the tidal creek. Both crab gut and fecal flush samples did not sequence well, showing low species diversity and very high variability. This study is the first to use next generation sequencing to characterize Plumb Beach sediment microbes and the first attempt to examine the gut microbiome of juvenile horseshoe crabs. This information will contribute to understanding the relationships between sediment microbial assemblages and juvenile crab populations within this important urban habitat

The problem of cooling an air-cooled cylinder on an aircraft engine

An analysis of the cooling problem has been to show by what means the cooling of an air-cooled aircraft engine may be improved. Each means of improving cooling is analyzed on the basis of effectiveness in cooling with respect to power for cooling. The altitude problem is analyzed for both supercharged and unsupercharged engines. The case of ground cooling is also discussed. The heat-transfer process from the hot gases to the cylinder wall is discussed on the basis of the fundamentals of heat transfer and thermodynamics. Adiabatic air-temperature rise at a stagnation point in compressible flow is shown to depend only on the velocity of flow

Aerodynamic characteristics of anemometer cups

The static lift and drag forces on three hemispherical and two conical cups were measured over a range of angles of attack from 0 degrees to 180 degrees and a range of Reynolds Numbers from very small up to 400,000. The problems of supporting the cup for measurement and the effect of turbulence were also studied. The results were compared with those of other investigators