2,260 research outputs found
Introducing oral tobacco for tobacco harm reduction: what are the main obstacles?
With the number of smokers worldwide currently on the rise, the regular failure of smokers to give up their tobacco addiction, the direct role of smoke (and, to a much lesser extent, nicotine) in most tobacco-related diseases, and the availability of less toxic (but still addictive) oral tobacco products, the use of oral tobacco in lieu of smoking for tobacco harm reduction (HR) merits assessment
Size-scaling of clump instabilities in turbulent, feedback regulated disks
We explore the scaling between the size of star-forming clumps and rotational
support in massively star-forming galactic disks. The analysis relies on
simulations of a clumpy galaxy at and the observed DYNAMO sample of rare
clumpy analogs at to test a predictive clump size scaling
proposed by \citet{Fisher2017ApJ...839L...5F} in the context of the Violent
Disk Instability (VDI) theory. We here determine the clump sizes using a
recently presented 2-point estimator, which is robust against resolution/noise
effects, hierarchical clump substructure, clump-clump overlap and other
galactic substructure. After verifying Fisher's clump scaling relation for the
DYNAMO observations, we explore whether this relation remains characteristic of
the VDI theory, even if realistic physical processes, such as local asymetries
and stellar feedback, are included in the model. To this end, we rely on
hydrodynamic zoom-simulations of a Milky Way-mass galaxy with four different
feedback prescriptions. We find that, during its marginally stable epoch at
, this mock galaxy falls on the clump scaling relation, although its
position on this relation depends on the feedback model. This finding implies
that Toomre-like stability considerations approximately apply to large
() instabilities in marginally stable turbulent disks,
irrespective of the feedback model, but also emphasizes that the global clump
distribution of a turbulent disk depends strongly on feedback.Comment: Accepted by ApJ, no changes made. 11 pages, 4 figure
Voting on Cyclic Orders, Group Theory, and Ballots
A cyclic order may be thought of informally as a way to seat people around a
table, perhaps for a game of chance or for dinner. Given a set of agents such
as , we can formalize this by defining a cyclic order as a
permutation or linear order on this finite set, under the equivalence relation
where is identified with both and . As with other collections of sets with some structure, we might want
to aggregate preferences of a (possibly different) set of voters on the set of
possible ways to choose a cyclic order.
However, given the combinatorial explosion of the number of full rankings of
cyclic orders, one may not wish to use the usual voting machinery. This raises
the question of what sort of ballots may be appropriate; a single cyclic order,
a set of them, or some other ballot type? Further, there is a natural action of
the group of permutations on the set of agents. A reasonable requirement for a
choice procedure would be to respect this symmetry (the equivalent of
neutrality in normal voting theory).
In this paper we will exploit the representation theory of the symmetric
group to analyze several natural types of ballots for voting on cyclic orders,
and points-based procedures using such ballots. We provide a full
characterization of such procedures for two quite different ballot types for
, along with the most important observations for .Comment: 29 pages, to be published in conference proceedings from AMS Special
Session on The Mathematics of Decisions, Elections and Games, 202
The stellar mass - size relation for cluster galaxies at z=1 with high angular resolution from the Gemini/GeMS multi-conjugate adaptive optics system
We present the stellar mass - size relation for 49 galaxies within the =
1.067 cluster SPT-CL J05465345, with FWHM 80-120 mas -band data from the Gemini multi-conjugate adaptive optics system
(GeMS/GSAOI). This is the first such measurement in a cluster environment,
performed at sub-kpc resolution at rest-frame wavelengths dominated by the
light of the underlying old stellar populations. The observed stellar mass -
size relation is offset from the local relation by 0.21 dex, corresponding to a
size evolution proportional to , consistent with the literature.
The slope of the stellar mass - size relation = 0.74 0.06,
consistent with the local relation. The absence of slope evolution indicates
that the amount of size growth is constant with stellar mass. This suggests
that galaxies in massive clusters such as SPT-CL J05465345 grow via
processes that increase the size without significant morphological
interference, such as minor mergers and/or adiabatic expansion. The slope of
the cluster stellar mass - size relation is significantly shallower if measured
in /ACS imaging at wavelengths blueward of the Balmer break, similar to
rest-frame UV relations at = 1 in the literature. The stellar mass - size
relation must be measured at redder wavelengths, which are more sensitive to
the old stellar population that dominates the stellar mass of the galaxies. The
slope is unchanged when GeMS -band imaging is degraded to the resolution
of -band HST/NICMOS resolution but dramatically affected when degraded to
-band Magellan/FourStar resolution. Such measurements must be made with AO
in order to accurately characterise the sizes of compact, = 1 galaxies.Comment: 24 pages, 13 figures, 3 tables. Accepted for publication in MNRAS.
Typos corrected, DOI adde
Structural Equation Modeling to Detect Correlates of Childhood Vaccination: A Moderated Mediation Analysis
OBJECTIVES: This study used a health belief theory derived framework and structural equation model to examine moderators, mediators, and direct and indirect predictors of childhood vaccination.
METHODS: A secondary analysis was conducted using data collected from a cross-sectional survey of a random sample of 1599 parents living in urban and rural areas of Mysore district, India. Applying two-stage probability proportionate-to-size sampling, adolescent girls attending 7th through 10th grades in 23 schools were selected to take home a questionnaire to be answered by their parents to primarily assess HPV vaccine intentions. Parents were also asked whether their children had received one dose of Bacillus Calmette-Guérin; three doses of Diphtheria, Pertussis, Tetanus; three doses of oral Polio vaccine; and one dose of Measles vaccine. In addition, parents were asked about their attitudes towards childhood vaccination.
RESULTS: Out of the 1599 parents, 52.2% reported that their children had received all the routine vaccines (fully vaccinated); 42.7% reported their children had missed at least one routine vaccine, and 5.2% reported that their children had missed all routine vaccinations. Perceptions about the benefits/facilitators to childhood vaccination significantly predicted the full vaccination rate (standardized regression coefficient (β) = 0.29) directly and mediated the effect of parental education (β = 0.11) and employment (β = -0.06) on the rate of full vaccination. Parental education was significantly associated indirectly with higher rates of full vaccination (β = 0.11). Parental employment was significantly associated indirectly with decreasing rates of full vaccination (β = -0.05). Area of residence moderated the role of religion (β = 0.24) and the \u27number of children\u27 in a family (β = 0.33) on parental perceptions about barriers to childhood vaccination. The model to data fit was acceptable (Root Mean Square Error of Approximation = 0.02, 95% CI 0.018 to 0.023; Comparative Fit Index = 0.92; Tucker-Lewis Index = 0.91).
CONCLUSIONS: Full vaccination rate was relatively low among children in Mysore, especially among parents who were unsure about the benefits of routine vaccination and those with low educational levels. Interventions increasing awareness of the benefits of childhood vaccination that target rural parents with lower levels of education may help increase the rate of full childhood vaccination in India
Balneologische Mittheilung aus Hapsal. 4, Das Hapsaler Meer
https://www.ester.ee/record=b4485488*es
De morbo: Sinni wil (blaue Blatter) nominato, carbunculo quodam Esthoniae rusticis endemio : dissertatio inauguralis
http://tartu.ester.ee/record=b1714828~S1*es
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