4,742 research outputs found
It takes a village to break up a match: a systemic analysis of formal youth mentoring relationship endings
BACKGROUND
Although early closure of formal youth mentoring relationships has recently begun to receive some attention, more information about factors that contribute to premature endings, and how those factors interact, is needed so that empirically-based program practices can be developed and disseminated to prevent such endings and to ensure that youth reap the benefits mentoring can provide.
OBJECTIVE
This qualitative interview study applies a systemic model of youth mentoring relationships (Keller in J Prim Prev 26:169â188, 2005a) to the study of mentoring relationship endings in community-based mentoring matches to understand why these matches ended.
METHOD
Mentors, parents/guardians and program staff associated with 36 mentoring matches that had ended were interviewed about their experiences of these relationships and their understanding of why they had ended. Thematic analysis of the interview transcripts and mentoring program case notes for each match followed by systemic modeling of the relationships yielded three major findings.
RESULTS
A strong mentorâyouth relationship is necessary but not sufficient for match longevity. The mentorâyouth relationship, even when relatively strong, is unlikely to withstand disruptions in other relationships in the system. Agency contextual factors, such as program practices and policies and staffing patterns, have a critical role to play in sustaining mentoring matches, as they directly influence all of the relationships in the mentoring system.
CONCLUSION
These findings highlight the importance of considering not just the mentoring dyad but also the parent/guardian and program context when trying to prevent match closures. They also point to several program practices that may support longer mentoring relationships.Accepted manuscrip
Optimal MRI sequences for 68Ga-PSMA-11 PET/MRI in evaluation of biochemically recurrent prostate cancer.
BackgroundPET/MRI can be used for the detection of disease in biochemical recurrence (BCR) patients imaged with 68Ga-PSMA-11 PET. This study was designed to determine the optimal MRI sequences to localize positive findings on 68Ga-PSMA-11 PET of patients with BCR after definitive therapy. Fifty-five consecutive prostate cancer patients with BCR imaged with 68Ga-PSMA-11 3.0T PET/MRI were retrospectively analyzed. Mean PSA was 7.9 ± 12.9 ng/ml, and mean PSA doubling time was 7.1 ± 6.6 months. Detection rates of anatomic correlates for prostate-specific membrane antigen (PSMA)-positive foci were evaluated on small field of view (FOV) T2, T1 post-contrast, and diffusion-weighted images. For prostate bed recurrences, the detection rate of dynamic contrast-enhanced (DCE) imaging for PSMA-positive foci was evaluated. Finally, the detection sensitivity for PSMA-avid foci on 3- and 8-min PET acquisitions was compared.ResultsPSMA-positive foci were detected in 89.1% (49/55) of patients evaluated. Small FOV T2 performed best for lymph nodes and detected correlates for all PSMA-avid lymph nodes. DCE imaging performed the best for suspected prostate bed recurrence, detecting correlates for 87.5% (14/16) of PSMA-positive prostate bed foci. The 8-min PET acquisition performed better than the 3-min acquisition for lymph nodes smaller than 1 cm, detecting 100% (57/57) of lymph nodes less than 1 cm, compared to 78.9% (45/57) for the 3-min acquisition.ConclusionPSMA PET/MRI performed well for the detection of sites of suspected recurrent disease in patients with BCR. Of the MRI sequences obtained for localization, small FOV T2 images detected the greatest proportion of PSMA-positive abdominopelvic lymph nodes and DCE imaging detected the greatest proportion of PSMA-positive prostate bed foci. The 8-min PET acquisition was superior to the 3 min acquisition for detection of small lymph nodes
Periodontal Disease in Five and Six Year Old Children
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141478/1/jper0019.pd
Gyrotronâbackwardâwaveâoscillator experiments utilizing a high current, high voltage, microsecond electron accelerator
We report the first gyrotronâbackwardâwaveâoscillator experiments to produce high power (tube power of âŒ1â8 MW), longâpulse (0.3â1.2 ÎŒs) microwaves at high currents (0.1â2 kA) and high voltages (650â750 kV). Experiments were performed in the TE11 fundamental backwardâwave mode, with efficiencies of âŒ1%â2%. Mode competition was observed which is believed to originate from the TE21 absolute instability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70862/2/JAPIAU-72-4-1221-1.pd
Implementing a Comprehensive Hiring Strategy to Enhance Research Activity: The MizzouForward Initiative
Ultrafast elemental and oxidation-state mapping of hematite by 4D electron microscopy
This work was supported by the Air Force Office of Scientific Research (FA9550-11-1-0055) in the Gordon and Betty Moore Center for Physical Biology at the California Institute of Technology.We describe a new methodology that sheds light on the fundamental electronic processes that occur at the subsurface regions of inorganic solid photocatalysts. Three distinct kinds of microscopic imaging are used that yield spatial, temporal and energy-resolved information. We also carefully consider the effect of photon-induced near-field electron microscopy (PINEM), first reported by Zewail et al. in 2009. The value of this methodology is illustrated by studying afresh a popular and viable photocatalyst, hematite, α-Fe2O3, that exhibits most of the properties required in a practical application. By employing high-energy electron-loss signals (of several hundred eV), coupled to femtosecond temporal resolution as well as ultrafast energy-filtered transmission electron microscopy in 4D, we have, inter alia, identified Fe4+ ions that have a lifetime of a few picoseconds, as well as associated photoinduced electronic transitions and charge transfer processes.PostprintPeer reviewe
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