5,677 research outputs found
Religiosity and Sexual Risk Behaviors Among Latina Adolescents: Trends from 1995 to 2008
Purpose: The purpose of this study was to determine trends in the influence of religiosity on sexual activity of Latina adolescents in the United States from 1995 to 2008 and to determine if differences existed between the Mexican American and other Latina groups.
Methods: The sample comprised the subset of unmarried, 15–21-year-old (mean 17 years) Latina female respondents in the 1995 (n=267), 2002 (n=306), and 2006–2008 (n=400) National Survey of Family Growth (NSFG) datasets. Associations between religiosity (importance of religion and service attendance) and history of ever having sex, number of sex partners, and age of sexual debut were investigated.
Results: Less than one half of Latinas in 1995 (44%) and in 2006–2008 (44%) reported that religion was very important to them, whereas in 2002, 50% reported it was important. Only in 1995 did Latinas who viewed religion as very important have a significantly lower level of sexual initiation. In 1995 and in 2006–2008, Latinas who held religion as very important had significantly fewer partners. In all three cohorts, the higher religious importance group had higher virgin survival rates. Across cohorts, approximately one third of respondents reported frequent religious attendance. In all cohorts, frequent attenders were less likely to have had sex, had fewer partners, and had older age at sexual debut. The survival rate as virgins for Mexican origin Latinas was higher in 1995 and 2002 compared to non-Mexican Latinas but was almost the same in 2006–2008.
Conclusions: Religiosity had a protective association with sexual activity among Latina adolescents. The association of importance of religion with sexual activity has diminished from 1995 to 2008, however, whereas the importance of service attendance has remained stable. The influence of religion was more apparent among the Latinas of Mexican origin, but this greater influence also diminished by 2006–2008
Transition from a phase-segregated state to single-phase incommensurate sodium ordering in Na_xCoO_2 with x \approx 0.53
Synchrotron X-ray diffraction investigations of two single crystals of
Na_xCoO_2 from different batches with composition x = 0.525-0.530 reveal
homogeneous incommensurate sodium ordering with propagation vector (0.53 0.53
0) at room-temperature. The incommensurate (qq0) superstructure exists between
220 K and 430 K. The value of q varies between q = 0.514 and 0.529, showing a
broad plateau at the latter value between 260 K and 360 K. On cooling, unusual
reversible phase segregation into two volume fractions is observed. Below 220
K, one volume fraction shows the well-known commensurate orthorhombic x = 0.50
superstructure, while a second volume fraction with x = 0.55 exhibits another
commensurate superstructure, presumably with a 6a x 6a x c hexagonal supercell.
We argue that the commensurate-to-incommensurate transition is an intrinsic
feature of samples with Na concentrations x = 0.5 + d with d ~ 0.03.Comment: Corrected/improved versio
Data Analysis Techniques for Fan Performance in Highly-Distorted Flows from Boundary Layer Ingesting Inlets
The design of a unique distortion-tolerant fan for a high-bypass ratio boundary-layer ingesting propulsion system has been completed and a rig constructed and tested in the NASA Glenn 8x6 wind tunnel. Processing the data from the experiment presented some interesting challenges because of the complexity of the experimental setup and the flow through the test rig. The experiment was run in three phases, each of which employed a unique complement of inlet throat and fan face instrumentation to avoid the blockage that would have resulted from simultaneously installing all of the rakes. The measurement from the individual test points were subsequently combined to compute the overall stage performance. A CFD model of the experiment was used to gain understanding of the flow field and to test some of the techniques proposed for interpolating and extrapolating the measurements into regions where measurements were not made. This capability became extremely useful when it was discovered that there was an unexpected total temperature distortion in the tunnel. The CFD model was modified by inserting a total temperature profile at the upstream boundary that mimicked the measured distortion where measurements were available and that CFD solution was used to investigate methods to infer the complete total temperature field at the fan face
Nitrogen and phosphorus budgets for Iowa and Iowa watersheds
https://ir.uiowa.edu/igs_tis/1046/thumbnail.jp
Nature of the spin dynamics and 1/3 magnetization plateau in azurite
We present a specific heat and inelastic neutron scattering study in magnetic
fields up into the 1/3 magnetization plateau phase of the diamond chain
compound azurite Cu(CO)(OH). We establish that the
magnetization plateau is a dimer-monomer state, {\it i.e.}, consisting of a
chain of monomers, which are separated by dimers on the
diamond chain backbone. The effective spin couplings K
and K are derived from the monomer and dimer
dispersions. They are associated to microscopic couplings K,
K and a ferromagnetic K, possibly as
result of orbitals in the Cu-O bonds providing the superexchange
pathways.Comment: 5 pages, 4 figure
Coupling of frustrated Ising spins to magnetic cycloid in multiferroic TbMnO3
We report on diffraction measurements on multiferroic TbMnO3 which
demonstrate that the Tb- and Mn-magnetic orders are coupled below the
ferroelectric transition TFE = 28 K. For T < TFE the magnetic propagation
vectors (tau) for Tb and Mn are locked so that tauTb = tauMn, while below TNTb
= 7 K we find that tauTb and tauMn lock-in to rational values of 3/7 b* and 2/7
b*, respectively, and obey the relation 3tauTb - tauMn = 1. We explain this
novel matching of wave vectors within the frustrated ANNNI model coupled to a
periodic external field produced by the Mn-spin order. The tauTb = tauMn
behavior is recovered when Tb magnetization is small, while the tauTb = 3/7
regime is stabilized at low temperatures by a peculiar arrangement of domain
walls in the ordered state of Ising-like Tb spins.Comment: 5 pages, 3 figure
Symmetry energy of dilute warm nuclear matter
The symmetry energy of nuclear matter is a fundamental ingredient in the
investigation of exotic nuclei, heavy-ion collisions and astrophysical
phenomena. New data from heavy-ion collisions can be used to extract the free
symmetry energy and the internal symmetry energy at subsaturation densities and
temperatures below 10 MeV. Conventional theoretical calculations of the
symmetry energy based on mean-field approaches fail to give the correct
low-temperature, low-density limit that is governed by correlations, in
particular by the appearance of bound states. A recently developed quantum
statistical (QS) approach that takes the formation of clusters into account
predicts symmetry energies that are in very good agreement with the
experimental data. A consistent description of the symmetry energy is given
that joins the correct low-density limit with quasiparticle approaches valid
near the saturation density.Comment: 4 pages, 2 figures, 1 tabl
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