9,693 research outputs found
Management of an Accessory Bile Duct Leak Following Pancreaticoduodenectomy: A Novel Approach Utilizing a Percutaneous and Endoscopic Rendezvous.
Biliary leaks are uncommon but morbid complications of pancreaticoduodenectomies, which have historically been managed with percutaneous drainage, reoperation, or a combination of both. We report a de novo percutaneous-endoscopic hepaticojejunostomy from an anomalous right hepatic duct injured during pancreaticoduodenectomy to the afferent bowel limb. The percutaneous-endoscopic hepaticojejunostomy was stented to allow for tract formation with successful stent removal after 5.5 months. One year after the creation of the percutaneous-endoscopic hepaticojejunostomy, the patient remains clinically well without evidence of biliary leak or obstruction
The miscarriage circle of care:towards leveraging online spaces for social support
BACKGROUND: Lack of social support during and after miscarriage can greatly affect mental wellbeing. With miscarriages being a common experience, there remains a discrepancy in the social support received after a pregnancy is lost. METHOD: 42 people who had experienced at least one miscarriage took part in an Asynchronous Remote Community (ARC) study. The study involved 16 activities (discussions, creative tasks, and surveys) in two closed, secret Facebook groups over eight weeks. Descriptive statistics were used to analyse quantitative data, and content analysis was used for qualitative data. RESULTS: There were two main miscarriage care networks, formal (health care providers) and informal (friends, family, work colleagues). The formal care network was the most trusted informational support source, while the informal care network was the main source of tangible support. However, often, participants’ care networks were unable to provide sufficient informational, emotional, esteem, and network support. Peers who also had experienced miscarriage played a crucial role in addressing these gaps in social support. Technology use varied greatly, with smartphone use as the only common denominator. While there was a range of online support sources, participants tended to focus on only a few, and there was no single common preferred source. DISCUSSION: We propose a Miscarriage Circle of Care Model (MCCM), with peer advisors playing a central role in improving communication channels and social support provision. We show how the MCCM can be used to identify gaps in service provision and opportunities where technology can be leveraged to fill those gaps
Characterizations of tropospheric turbulence and stability layers from aircraft observations
[1] Velocity, temperature, and specific humidity data collected by aircraft at 20-Hz resolution are analyzed for stability and turbulence parameters. Over 100 vertical profiles (mostly over the ocean) with a total of over 300 km in vertical airspace sampled are used. The compiled statistics show that anisotropy in the velocity fluctuations prevail down to the smallest spatial separations measured. A partitioning of convective versus dynamical instability indicates that in the free troposphere, the ratio of shear-produced turbulence to convectively produced turbulence increases from roughly 2:1 for weak turbulence (ϵ 10⁻⁴ m² s⁻³). For the boundary layer, this ratio is close to 1:1 for weak turbulence and roughly 2:1 for strong turbulence. There is also a correlation between the strength of the vertical shear in horizontal winds and the turbulence intensity. In the free troposphere the turbulence intensity is independent of the degree of static stability, whereas in the boundary layer the turbulence intensity increases with a fall in static stability. Vertical humidity gradients correlate with static stability for strong humidity gradients, which supports the basic notion that stable layers impede vertical mixing of trace gases and aerosols. Vertical shear correlates with vertical humidity gradient, so it appears that the effect of differential advection creating tracer gradients dominates the effect of differential advection destroying tracer gradients through shear-induced turbulence.United States. National Aeronautics and Space Administration (Grant NCC1-415)United States. National Aeronautics and Space Administration (Grant NAG1-2306
SPITZER: Accretion in Low Mass Stars and Brown Dwarfs in the Lambda Orionis Cluster
We present multi-wavelength optical and infrared photometry of 170 previously
known low mass stars and brown dwarfs of the 5 Myr Collinder 69 cluster (Lambda
Orionis). The new photometry supports cluster membership for most of them, with
less than 15% of the previous candidates identified as probable non-members.
The near infrared photometry allows us to identify stars with IR excesses, and
we find that the Class II population is very large, around 25% for stars (in
the spectral range M0 - M6.5) and 40% for brown dwarfs, down to 0.04 Msun,
despite the fact that the H(alpha) equivalent width is low for a significant
fraction of them. In addition, there are a number of substellar objects,
classified as Class III, that have optically thin disks. The Class II members
are distributed in an inhomogeneous way, lying preferentially in a filament
running toward the south-east. The IR excesses for the Collinder 69 members
range from pure Class II (flat or nearly flat spectra longward of 1 micron), to
transition disks with no near-IR excess but excesses beginning within the IRAC
wavelength range, to two stars with excess only detected at 24 micron.
Collinder 69 thus appears to be at an age where it provides a natural
laboratory for the study of primordial disks and their dissipation.Comment: ApJ, in pres
Past and future of a century old Citrus tristeza virus collection: a California citrus germplasm tale.
Citrus tristeza virus (CTV) isolates collected from citrus germplasm, dooryard and field trees in California from 1914 have been maintained in planta under quarantine in the Citrus Clonal Protection Program (CCPP), Riverside, California. This collection, therefore, represents populations of CTV isolates obtained over time and space in California. To determine CTV genetic diversity in this context, genotypes of CTV isolates from the CCPP collection were characterized using multiple molecular markers (MMM). Genotypes T30, VT, and T36 were found at high frequencies with T30 and T30+VT genotypes being the most abundant. The MMM analysis did not identify T3 and B165/T68 genotypes; however, biological and phylogenetic analysis suggested some relationships of CCPP CTV isolates with these two genotypes. Phylogenetic analysis of the CTV coat protein (CP) gene sequences classified the tested isolates into seven distinct clades. Five clades were in association with the standard CTV genotypes T30, T36, T3, VT, and B165/T68. The remaining two identified clades were not related to any standard CTV genotypes. Spatiotemporal analysis indicated a trend of reduced genotype and phylogenetic diversity as well as virulence from southern California (SC) at early (1907-1957) in comparison to that of central California (CC) isolates collected from later (1957-2009) time periods. CTV biological characterization also indicated a reduced number and less virulent stem pitting (SP) CTV isolates compared to seedling yellows isolates introduced to California. This data provides a historical insight of the introduction, movement, and genetic diversity of CTV in California and provides genetic and biological information useful for CTV quarantine, eradication, and disease management strategies such as CTV-SP cross protection
New Low-Mass Members of the Taurus Star-Forming Region
Briceno et al. recently used optical imaging, data from the Two-Micron
All-Sky Survey (2MASS), and follow-up spectroscopy to search for young low-mass
stars and brown dwarfs in 8 square degrees of the Taurus star-forming region.
By the end of that study, there remained candidate members of Taurus that
lacked the spectroscopic observations needed to measure spectral types and
determine membership. In this work, we have obtained spectroscopy of the 22
candidates that have A_V<=8, from which we find six new Taurus members with
spectral types of M2.75 through M9. The new M9 source has the second latest
spectral type of the known members of Taurus (~0.02 M_sun). Its spectrum
contains extremely strong emission in H_alpha (W~950 A) as well as emission in
He I 6678 A and the Ca II IR triplet. This is the least massive object known to
exhibit emission in He I and Ca II, which together with the strong H_alpha are
suggestive of intense accretion.Comment: to be published in The Astrophysical Journal, 13 pages, 6 figures,
also found at http://cfa-www.harvard.edu/sfgroup/preprints.htm
A Gaussian Theory of Superfluid--Bose-Glass Phase Transition
We show that gaussian quantum fluctuations, even if infinitesimal, are
sufficient to destroy the superfluidity of a disordered boson system in 1D and
2D. The critical disorder is thus finite no matter how small the repulsion is
between particles. Within the gaussian approximation, we study the nature of
the elementary excitations, including their density of states and mobility edge
transition. We give the gaussian exponent at criticality in 1D and show
that its ratio to of the pure system is universal.Comment: Revtex 3.0, 11 pages (4 figures will be sent through airmail upon
request
The Reaction Process A+A->O in Sinai Disorder
The single-species reaction-diffusion process is examined in the
presence of an uncorrelated, quenched random velocity field. Utilising a
field-theoretic approach, we find that in two dimensions and below the density
decay is altered from the case of purely diffusing reactants. In two-dimensions
the density amplitude is reduced in the presence of weak disorder, yielding the
interesting result that Sinai disorder can cause reactions to occur at an {\it
increased} rate. This is in contrast to the case of long-range correlated
disorder, where it was shown that the reaction becomes sub-diffusion limited.
However, when written in terms of the microscopic diffusion constant it is seen
that increasing the disorder has the effect of reducing the rate of the
reaction. Below two dimensions, the effect of Sinai disorder is much more
severe and the reaction is shown to become sub-diffusion limited. Although
there is no universal amplitude for the time-dependence of the density, it is
universal when expressed in terms of the disorder-averaged diffusion length.
The appropriate amplitude is calculated to one-loop order.Comment: 12 pages, 2 figure
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