708 research outputs found
From 4-H International Youth Exchange to Global Citizen: Common Pathways of Ten Past Program Participants
This qualitative study examined the life course of ten adults who participated as youth in the 4-H International Exchange program. The purpose of this research was to explore the pathways that led each participant to their exchange experience as a youth and how that experience set the stage for further development into an adulthood marked by cultural interest, awareness, competence and global citizenship. Using a grounded theory approach the data were analyzed through selective, open, and axial codings that elucidated a series of key events, opportunities, and qualities that form a common pathway among all participants. The results of this research contribute to the articulation of a theory of change upon which international youth exchange programs can be effectively developed and enhanced. Specific recommendations for international youth exchange programs are presented
From 4-H International Youth Exchange to Global Citizen: Common Pathways of Ten Past Program Participants
This qualitative study examined the life course of ten adults who participated as youth in the 4-H International Exchange program. The purpose of this research was to explore the pathways that led each participant to their exchange experience as a youth and how that experience set the stage for further development into an adulthood marked by cultural interest, awareness, competence and global citizenship. Using a grounded theory approach the data were analyzed through selective, open, and axial codings that elucidated a series of key events, opportunities, and qualities that form a common pathway among all participants. The results of this research contribute to the articulation of a theory of change upon which international youth exchange programs can be effectively developed and enhanced. Specific recommendations for international youth exchange programs are presented
Competition between Magnetic and Structural Transition in CrN
CrN is observed to undergo a paramagnetic to antiferromagnetic transition
accompanied by a shear distortion from cubic NaCl-type to orthorhombic
structure. Our first-principle plane wave and ultrasoft pseudopotential
calculations confirm that the distorted antiferromagnetic phase with spin
configuration arranged in double ferromagnetic sheets along [110] is the most
stable. Antiferromagnetic ordering leads to a large depletion of states around
Fermi level, but it does not open a gap. Simultaneous occurence of structural
distortion and antiferromagnetic order is analyzed.Comment: 10 pages, 10 figure
Thermodynamics of 3+ metal cation containing systems
xi, 149 leaves : ill. ; 29 cm.Measurements of relative densities and relative massic heat capacities have been made for several aqueous rare earth chloride and perchlorate systems. Densities and relative massic heat capacities of acidified aqueous perchlorates of yttrium, ytterbium, dysprosium, and samarium as well as the chlorides of yttrium, ytterbium, dysprosium, samarium and gadolinium have been measured at the temperatures 288.15, 298.15, 313.5 and 328.15 K. Using the density and massic heat capacity data, apparent molar volumes and apparent molar heat capacities have been calculated. These data have been modeled using the Pitzer ion interaction approach as well as the Helgeson, Kirkham and Flowers equations of state. Apparent molar volumes and apparent molar heat capacities previously presented in the literature have been compared to the data presented here. single ion apparent molar volume and apparent molar heat capacity contributions were calculated. Infinite dilution properties have been compared to existing models used to predict infinite dilution properties. Densities of aqueous perchloric acid and ytterbium perchlorate at the temperatures from 348.15 to 423.15 K and at pressured from 10.00 to 30.00 MPa were measured. Apparante molar volumes were calculated from the density measurements. The apparent molar volume data were modeled using Pitzer ion interaction theory as well as HKF equations of state. Models presented are compared to existing models
Magnetic stress as a driving force of structural distortions: the case of CrN
We show that the observed transition from rocksalt to orthorhombic P
symmetry in CrN can be understood in terms of stress anisotropy. Using local
spin density functional theory, we find that the imbalance between stress
stored in spin-paired and spin-unpaired Cr nearest neighbors causes the
rocksalt structure to be unstable against distortions and justifies the
observed antiferromagnetic ordering. This stress has a purely magnetic origin,
and may be important in any system where the coupling between spin ordering and
structure is strong.Comment: 4 pages (two columns) 4 figure
The complex TIE between macrophages and angiogenesis
Macrophages are primarily known as phagocytic immune cells, but they also play a role in diverse processes, such as morphogenesis, homeostasis and regeneration. In this review, we discuss the influence of macrophages on angiogenesis, the process of new blood vessel formation from the pre-existing vasculature. Macrophages play crucial roles at each step of the angiogenic cascade, starting from new blood vessel sprouting to the remodelling of the vascular plexus and vessel maturation. Macrophages form promising targets for both pro- and anti-angiogenic treatments. However, to target macrophages, we will first need to understand the mechanisms that control the functional plasticity of macrophages during each of the steps of the angiogenic cascade. Here, we review recent insights in this topic. Special attention will be given to the TIE2-expressing macrophage (TEM), which is a subtype of highly angiogenic macrophages that is able to influence angiogenesis via the angiopoietin-TIE pathway
Impact of generic alendronate cost on the cost-effectiveness of osteoporosis screening and treatment
Introduction: Since alendronate became available in generic form in the Unites States in 2008, its price has been decreasing. The objective of this study was to investigate the impact of alendronate cost on the cost-effectiveness of osteoporosis screening and treatment in postmenopausal women. Methods: Microsimulation cost-effectiveness model of osteoporosis screening and treatment for U.S. women age 65 and older. We assumed screening initiation at age 65 with central dual-energy x-ray absorptiometry (DXA), and alendronate treatment for individuals with osteoporosis; with a comparator of "no screening" and treatment only after fracture occurrence. We evaluated annual alendronate costs of 800; outcome measures included fractures; nursing home admission; medication adverse events; death; costs; quality-adjusted life-years (QALYs); and incremental cost-effectiveness ratios (ICERs) in 2010 U.S. dollars per QALY gained. A lifetime time horizon was used, and direct costs were included. Base-case and sensitivity analyses were performed. Results: Base-case analysis results showed that at annual alendronate costs of 400 through 714 per QALY gained through 50,000/QALY at all alendronate costs evaluated. Conclusions: Osteoporosis screening followed by alendronate treatment is effective and highly cost-effective for postmenopausal women across a range of alendronate costs, and may be cost-saving at annual alendronate costs of $200 or less. © 2012 Nayak et al
Participatory Process for Implementing a Colorectal Cancer Screening Intervention: an Action Plan for Local Sustainability
Background: Rigid protocols can hamper translation of evidence-based interventions from research to real-world settings. This investigation aimed to develop procedures for modifying the study protocol of a community-based participatory research (CBPR) project and to analyze the theoretical constructs that underlie this process.
Methods: The research project is a dissemination and implementation study of the Educational Program to Increase Colorectal Cancer Screening (EPICS), an evidence-based intervention targeting African Americans in the United States. The study is being conducted in a partnership with community coalitions in 15 different cities. Each site initially presented unique issues that required modification of the study protocol.
Results: In order to honor underlying CBPR theory, it was necessary to negotiate protocol changes with the community coalition at each site, while insuring preservation of the core elements of the intervention.
Conclusions: We discuss the ways in which this represents a narrowing of the gap between CBPR and traditional research approaches
Magnetic correlations and quantum criticality in the insulating antiferromagnetic, insulating spin liquid, renormalized Fermi liquid, and metallic antiferromagnetic phases of the Mott system V_2O_3
Magnetic correlations in all four phases of pure and doped vanadium
sesquioxide V_2O_3 have been examined by magnetic thermal neutron scattering.
While the antiferromagnetic insulator can be accounted for by a Heisenberg
localized spin model, the long range order in the antiferromagnetic metal is an
incommensurate spin-density-wave, resulting from a Fermi surface nesting
instability. Spin dynamics in the strongly correlated metal are dominated by
spin fluctuations in the Stoner electron-hole continuum. Furthermore, our
results in metallic V_2O_3 represent an unprecedentedly complete
characterization of the spin fluctuations near a metallic quantum critical
point, and provide quantitative support for the SCR theory for itinerant
antiferromagnets in the small moment limit. Dynamic magnetic correlations for
energy smaller than k_BT in the paramagnetic insulator carry substantial
magnetic spectral weight. However, the correlation length extends only to the
nearest neighbor distance. The phase transition to the antiferromagnetic
insulator introduces a sudden switching of magnetic correlations to a different
spatial periodicity which indicates a sudden change in the underlying spin
Hamiltonian. To describe this phase transition and also the unusual short range
order in the paramagnetic state, it seems necessary to take into account the
orbital degrees of freedom associated with the degenerate d-orbitals at the
Fermi level in V_2O_3.Comment: Postscript file, 24 pages, 26 figures, 2 tables, accepted by Phys.
Rev.
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