5,290 research outputs found
Investigation of phonon behavior in Pr2NiMnO6 by micro-Raman spectroscopy
The temperature dependence of phonon excitations and the presence of spin
phonon coupling in polycrystalline Pr2NiMnO6 samples were studied using
micro-Raman spectroscopy and magnetometry. Magnetic properties show a single
ferromagnetic-to-paramagnetic transition at 228 K and a saturation
magnetization close to 4.95 \muB/f.u.. Three distinct Raman modes at 657, 642,
and 511 cm-1 are observed. The phonon excitations show a clear hardening due to
anharmonicity from 300 K down to 10 K. Further, temperature dependence of the
657 cm-1 mode shows only a small softening. This reflects the presence of a
relatively weak spin-phonon coupling in Pr2NiMnO6 contrary to other double
perovskites previously studied.Comment: 10 pages, 4 fig
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"Call a Teenager… That's What I Do!" - Grandchildren Help Older Adults Use New Technologies: Qualitative Study.
BackgroundAlthough family technical support seems intuitive, there is very little research exploring this topic.ObjectiveThe objective of this study was to conduct a subanalysis of data collected from a large-scale qualitative project regarding older adults' experiences in using health information technology. Specifically, the subanalysis explored older adults' experiences with technology support from family members to inform strategies for promoting older adults' engagement with new health technologies. Although the primary analysis of the original study was theoretically driven, this paper reports results from an inductive, open-coding analysis.MethodsThis is a subanalysis of a major code identified unexpectedly from a qualitative study investigating older adults' use experience of a widespread health technology, the patient portal. A total of 24 older patients (≥65 years) with multiple chronic conditions (Charlson Comorbidity Index >2) participated in focus groups conducted at the patients' primary clinic. While conducting the primary theoretically driven analysis, coders utilized an open-coding approach to ensure important ideas not reflected in the theoretical code book were captured. Open coding resulted in 1 code: family support. This subanalysis further categorized family support by who provided tech support, how tech support was offered, and the opinions of older participants about receiving family tech support.ResultsThe participants were not specifically asked about family support, yet themes around family assistance and encouragement for technology emerged from every focus group. Participants repeatedly mentioned that they called their grandchildren and adult children if they needed help with technology. Participants also reported that family members experienced difficulty when teaching technology use. Family members struggled to explain simple technology tasks and were frustrated by the slow teaching process.ConclusionsThe results suggest that older adults ask their family members, particularly grandchildren, to support them in the use of new technologies. However, family may experience difficulties in providing this support. Older adults will be increasingly expected to use health technologies, and family members may help with tech support. Providers and health systems should consider potential family support and engagement strategies to foster adoption and use among older patients
Predators reduce extinction risk in noisy metapopulations
Background
Spatial structure across fragmented landscapes can enhance regional population persistence by promoting local “rescue effects.” In small, vulnerable populations, where chance or random events between individuals may have disproportionately large effects on species interactions, such local processes are particularly important. However, existing theory often only describes the dynamics of metapopulations at regional scales, neglecting the role of multispecies population dynamics within habitat patches.
Findings
By coupling analysis across spatial scales we quantified the interaction between local scale population regulation, regional dispersal and noise processes in the dynamics of experimental host-parasitoid metapopulations. We find that increasing community complexity increases negative correlation between local population dynamics. A potential mechanism underpinning this finding was explored using a simple population dynamic model.
Conclusions
Our results suggest a paradox: parasitism, whilst clearly damaging to hosts at the individual level, reduces extinction risk at the population level
Letter from Bear, et al to Representative Burdick Regarding Property Laws, Undated
This undated resolution signed by Joe B. Bear, Adlai Stevenson, Alfred S. Smith, Jackson Dancing Bull, and Francis Stevenson concerns property issues related to the Three Affiliated Tribes of the Fort Berthold Reservation. The resolution states that the members of the Fort Berthold Americans Inc. do not agree with a law which would regard native property as a collective movement that denies property ownership.
See also:
Letter from Adlai Stevenson to Representative Burdick Regarding Lemke Bill, April 3, 1944https://commons.und.edu/burdick-papers/1212/thumbnail.jp
Influence of lattice distortion on the Curie temperature and spin-phonon coupling in LaMnCoO
Two distinct ferromagnetic phases of LaMnCoO having
monoclinic structure with distinct physical properties have been studied. The
ferromagnetic ordering temperature is found to be different
for both the phases. The origin of such contrasting characteristics is assigned
to the changes in the distance(s) and angle(s) between Mn - O - Co resulting
from distortions observed from neutron diffraction studies. Investigations on
the temperature dependent Raman spectroscopy provide evidence for such
structural characteristics, which affects the exchange interaction. The
difference in B-site ordering which is evident from the neutron diffraction is
also responsible for the difference in . Raman scattering
suggests the presence of spin-phonon coupling for both the phases around the
. Electrical transport properties of both the phases have been
investigated based on the lattice distortion.Comment: 9 figure
More than just tracking time: Complex measures of user engagement with an internet-based health promotion intervention
BACKGROUND: There has been a rise in internet-based health interventions without a concomitant focus on new methods to measure user engagement and its effect on outcomes. We describe current user tracking methods for internet-based health interventions and offer suggestions for improvement based on the design and pilot testing of healthMpowerment.org (HMP).
METHODS: HMP is a multi-component online intervention for young Black men and transgender women who have sex with men (YBMSM/TW) to reduce risky sexual behaviors, promote healthy living and build social support. The intervention is non-directive, incorporates interactive features, and utilizes a point-based reward system. Fifteen YBMSM/TW (age 20-30) participated in a one-month pilot study to test the usability and efficacy of HMP. Engagement with the intervention was tracked using a customized data capture system and validated with Google Analytics. Usage was measured in time spent (total and across sections) and points earned.
RESULTS: Average total time spent on HMP was five hours per person (range 0-13). Total time spent was correlated with total points earned and overall site satisfaction.
CONCLUSION: Measuring engagement in internet-based interventions is crucial to determining efficacy. Multiple methods of tracking helped derive more comprehensive user profiles. Results highlighted the limitations of measures to capture user activity and the elusiveness of the concept of engagement
Cosmological performance of SKA H i galaxy surveys
The Square Kilometre Array (SKA) will conduct the biggest spectroscopic galaxy survey ever, by detecting the 21 cm emission line of neutral hydrogen (
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