3,232 research outputs found
Influence of a humidor on the aerodynamics of baseballs
We investigate whether storing baseballs in a controlled humidity environment
significantly affects their aerodynamic properties. To do this, we measure the
change in diameter and mass of baseballs as a function of relative humidity
(RH) in which the balls are stored. We then model trajectories for pitched and
batted baseballs to assess the difference between those stored at 30% RH versus
50% RH. The results show that a drier baseball may be expected to curve
slightly more than a humidified one for a given pitch velocity. We also find
that the aerodynamics alone would add ~2 feet to the distance a moister ball is
hit. However, this is compensated by a ~6 foot reduction in batted distance due
to the well known change in coefficient of restitution of the ball. We discuss
consequences of these results for baseball played at Coors Field in Denver,
where baseballs have been stored in a humidor at 50% RH since 2002.Comment: 21 pages, 7 figures, modified and re-posted 2/2
Association of FTO With Obesity-Related Traits in the Cebu Longitudinal Health and Nutrition Survey (CLHNS) Cohort
OBJECTIVE—The underlying genetic component of obesity-related traits is not well understood, and there is limited evidence to support genetic association shared across multiple studies, populations, and environmental contexts. The present study investigated the association between candidate variants and obesity-related traits in a sample of 1,886 adult Filipino women from the Cebu Longitudinal Health and Nutrition Survey (CLHNS) cohort
Fano effect in a ring-dot system with tunable coupling
Transport measurements are presented on a quantum ring that is tunnel-coupled
to a quantum dot. When the dot is in the Coulomb blockade regime, but strongly
coupled to the open ring, Fano line shapes are observed in the current through
the ring, when the electron number in the dot changes by one. The symmetry of
the Fano resonances is found to depend on the magnetic flux penetrating the
area of the ring and on the strength of the ring-dot coupling. At temperatures
above T=0.65 K the Fano effect disappears while the Aharonov-Bohm interference
in the ring persists up to T=4.2 K. Good agreement is found between these
experimental observations and a single channel scattering matrix model
including decoherence in the dot.Comment: 9 pages, 6 figure
Pathways to online infidelity: the roles of perceived online dating success, perceived availability of alternative partners, and mate value discrepancy
Data availability: The data associated with the present paper is available upon request by contacting Dr. Bruna Nascimento at [email protected] information is available online at: https://link.springer.com/article/10.1007/s12144-023-05345-y#Sec18 .Copyright © The Author(s) 2023. Online dating applications have become increasingly popular in recent years and a common way for relationship initiation. However, the potential implications of online dating applications for long-term relationships are not well-understood. To further the literature in this field, this study aimed to examine the association between perceived online dating success and online infidelity-related behaviours by considering two possible indirect paths through perceived number of alternative partners or mate value discrepancy (i.e., mate value relative to one’s partner) and attention to alternatives. A total of 338 individuals that were currently in an exclusive long-term relationship participated in this study. A serial mediation analysis with two parallel paths revealed that perceived online dating success is associated with higher perceived availability of alternative partners and higher mate value relative to one’s partner, both of which are associated with attention to alternatives that, in turn, increases engagement in online infidelity-related behaviours. No direct association between perceived online dating success and online infidelity-related behaviours was found
Stunting of children under two from repeated pregnancy among young mothers
Repeated pregnancy leaves young mothers nutritionally deprived which may in turn lead to poor infant growth. We measure the occurrence and persistence of stunting among offspring of young mothers who experienced repeated pregnancies using data from the Cebu Longitudinal Health and Nutrition Survey. We selected mothers aged 14–24 years (n = 1,033) with singleton birth. We determined the length-for-age z scores (LAZ) at 12 and 24 months of the index child using the World Health Organisation 2007 growth standard. We fitted LAZ, stunting occurrence (i.e. LAZ < − 2) and persistence from 12 to 24 months into regression models and tested for the mediating effect of low birthweight and feeding practices. In these models, repeated pregnancy was analysed in an ordinal approach using number of past pregnancies of young mothers at birth of the index child. Compared to infants born to young mothers aged 14–24 years who had no previous pregnancies, those born to young mothers with repeated pregnancies have at least 0.15 (95% CI − 0.23, − 0.08) LAZ lower and are at higher chance of stunting by at least 40% (95% CI 1.19, 1.67) at 12 and 24 months. Similar cohorts of infants showed an elevated risk of persistent stunting from 12 through 24 months with a relative risk ratio of 1.51 (95% CI 1.21, 1.88). Optimal feeding practices substantially mediated stunting outcomes by further reducing the effects of repeated pregnancy to stunting occurrence and persistence by 19.95% and 18.09% respectively. Mediation tests also showed low birthweight in the causal pathway between repeated pregnancy and stunting. Repeated pregnancy in young mothers is a predictor of stunting among children under 2 years. Secondary pregnancy prevention measures and addressing suboptimal feeding practices are beneficial to mitigate the negative impact of repeated adolescent pregnancy on children
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