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Extreme H isotopic anomalies in chondritic organic matter
Extract from introduction: We have conducted ionprobe (IMS6f and NanoSIMS) imaging studies of various samples for H, D, C, 14N and 15N. These will ultimately be correlated with micro-analytic techniques such as FIB/TEM or STXM/XANES. We analyzed matrix fragments from Bells (CM2), Al Rais (CR2) and Tagish Lake (unique) [2], high purity insoluble organic matter (IOM) [3] extracted from EET92042 (“EET”, CR2), Bells, Murchison (CM2), Allende (CV3), Krymka (LL3.1) and, for comparison, 3 IDPs
Investigation of generic hub fairing and pylon shapes to reduce hub drag
Reported are investigations of fairing configurations pointed toward substantially reducing hub drag. Experimental investigations have shown the importance of hub-fairing camber, lower-surface curvature, and relative size of the drag. The significance of pylon and hub fairings in combination have also been shown. Model test data presented here documented these findings, and also showed the effect of gaps and hub-fairing inclination angle on drag. From a drag standpoint, the best hub fairing had a circular arc, upper-surface curvature, a flat bottom surface, and 8.75% camber
Late time evolution of brane gas cosmology and compact internal dimensions
We study the late-time behavior of a universe in the framework of brane gas
cosmology. We investigate the evolution of a universe with a gas of
supergravity particles and a gas of branes. Considering the case when different
dimensions are anisotropically wrapped by various branes, we have derived
Friedman-like equations governing the dynamics of wrapped and unwrapped
subvolumes. We point out that the compact internal dimensions are wrapped by
three or higher dimensional branes.Comment: 16 pages, typos, references, comment on the possibility of
stabilizing the internal dimensions with fluxe
Understanding Perceptions of Problematic Facebook Use: When People Experience Negative Life Impact and a Lack of Control
While many people use social network sites to connect with friends and
family, some feel that their use is problematic, seriously affecting their
sleep, work, or life. Pairing a survey of 20,000 Facebook users measuring
perceptions of problematic use with behavioral and demographic data, we
examined Facebook activities associated with problematic use as well as the
kinds of people most likely to experience it. People who feel their use is
problematic are more likely to be younger, male, and going through a major life
event such as a breakup. They spend more time on the platform, particularly at
night, and spend proportionally more time looking at profiles and less time
browsing their News Feeds. They also message their friends more frequently.
While they are more likely to respond to notifications, they are also more
likely to deactivate their accounts, perhaps in an effort to better manage
their time. Further, they are more likely to have seen content about social
media or phone addiction. Notably, people reporting problematic use rate the
site as more valuable to them, highlighting the complex relationship between
technology use and well-being. A better understanding of problematic Facebook
use can inform the design of context-appropriate and supportive tools to help
people become more in control.Comment: CHI 201
A transdiagnostic systematic review and meta-analysis of ketamine's anxiolytic effects
Background:Ketamine may be effective in treating symptoms of anxiety, but the time profile of ketamine’s anxiolytic effect is ill-defined. This systematic review and meta-analysis investigated the anxiolytic effect of ketamine at different time points across a range of clinical settings.Methods:Electronic databases were searched to capture randomised control trials measuring the anxiolytic effects of ketamine in contexts including mood disorders, anxiety disorders and chronic pain. Meta-analyses were conducted using a random-effects model. The correlations between (1) improvements in mean anxiety and depression scores, and (2) peak dissociation and improvements in mean anxiety scores were also assessed.Results:In all, 14 studies met inclusion criteria. Risk of bias was high in 11 studies. Ketamine significantly reduced anxiety scores compared to placebo at acute (<12 h; standard mean difference (SMD): −1.17, 95% confidence interval (CI) [−1.89, −0.44], p < 0.01), subacute (24 h; SMD: −0.44, 95% CI [−0.65, −0.22], p < 0.01) and sustained (7–14 days; SMD: −0.40, 95% CI [−0.63, −0.17], p < 0.01) time points. Exploratory analyses revealed improvements in anxiety and depression symptoms correlated at both subacute (R2 = 0.621, p = 0.035) and sustained time points (R2 = 0.773, p = 0.021). The relationship between peak dissociation and improvement in anxiety was not significant.Conclusions:Ketamine appears to offer rapid and sustained anxiety symptom relief across a range of clinical settings, with anxiolytic effects occurring within the first 12 h of administration and remaining effective for 1–2 weeks. Future studies could explore the effects of ketamine maintenance therapy on anxiety symptoms
Galaxy Cluster Pressure Profiles as Determined by Sunyaev Zel'dovich Effect Observations with MUSTANG and Bolocam I: Joint Analysis Technique
We present a technique to constrain galaxy cluster pressure profiles by
jointly fitting Sunyaev-Zel'dovich effect (SZE) data obtained with MUSTANG and
Bolocam for the clusters Abell 1835 and MACS0647. Bolocam and MUSTANG probe
different angular scales and are thus highly complementary. We find that the
addition of the high resolution MUSTANG data can improve constraints on
pressure profile parameters relative to those derived solely from Bolocam. In
Abell 1835 and MACS0647, we find gNFW inner slopes of and , respectively when
and are constrained to 0.86 and 4.67 respectively. The fitted
SZE pressure profiles are in good agreement with X-ray derived pressure
profiles.Comment: 12 pages, 12 figures. Submitted to Ap
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