8,752 research outputs found
Fractionation of human immune γ-globulin
Equine and bovine serum proteins have recently been fractionated by means of a physical method utilizing an electrophoretic adaptation of the principles of the Clusius column (l-4), first described and tested by Kirkwood (5) and Nielsen (6). The method of electrophoresis-convection has now been applied to the fractionation of human γ-globulin. The γ-globulin was prepared by ethanol fractionation (7) from the plasma of individuals hyperimmunized to Hemophilus pertussis organisms. The resulting fractions of γ-globulin have been characterized electrophoretically, and the protective antibody activity and agglutinin titer have been measured
Reconsidering the One Leptoquark solution: flavor anomalies and neutrino mass
We reconsider a model introducing a scalar leptoquark to explain recent deviations from the standard model in
semileptonic decays. The leptoquark can accommodate the persistent tension
in the decays as long as its mass is
lower than approximately , and we show that a sizeable Yukawa
coupling to the right-chiral tau lepton is necessary for an acceptable
explanation. Agreement with the measured rates is mildly compromised for parameter choices addressing the
tensions in , where the model can significantly reduce the
discrepancies in angular observables, branching ratios and the
lepton-flavor-universality observables and . The leptoquark can
also reconcile the predicted and measured value of the anomalous magnetic
moment of the muon and appears naturally in models of radiative neutrino mass
derived from lepton-number violating effective operators. As a representative
example, we incorporate the particle into an existing two-loop neutrino mass
scenario derived from a dimension-nine operator. In this specific model, the
structure of the neutrino mass matrix provides enough freedom to explain the
small masses of the neutrinos in the region of parameter space dictated by
agreement with the anomalies in , but
not the transition. This is achieved without excessive fine-tuning in
the parameters important for neutrino mass.Comment: 43 pages, 17 figures, 3 tables; corrected fit contours in fig. 1
Compilation of a materials cost database for a web-based composites cost estimator
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.Includes bibliographical references (p. 44-45).The production of composite materials continues to be an expensive process. The WEB-Based Cost Estimation Model enables one to approximate the cost of manufacturing composites, so as to assist the user in making sound economic decisions. An extensive, up-to-date materials database is an essential part of such a cost estimator. This paper presents a list of materials to be added to the existing database and also derives a materials selection chart for six manufacturing processes.by John R. Boyer.S.B
A Quaker Experiment in Town Planning: George Cadbury and the Construction of Bournville Model Village
In 1893, George Cadbury initiated the construction of Bournville Model Village, Birmingham (UK). This was the first model settlement to provide low-density housing not restricted to facto1y employees. This paper examines the relationship between Cadbury\u27s Quaker faith, the growth of his business and the development of a model community. The focus is on exploring the ways in which Cadbury departed from traditional Quaker practices, with respect to visual artistic display and religious intervention in social relations. The article, first, reviews the contribution of Quakerism to the building of George Cadbury\u27s business empire. Second, it examines the relationship between Cadbury\u27s religiously infom1ed brand of benign capitalism and the choice of a particular architectural aesthetic for Bournville. Third, the article shows how evangelical Quaker faith and practice were important in shaping the social development of the Bournville community
Prospective, multicenter study of P4HB (Phasix) mesh for hernia repair in cohort at risk for complications: 3-Year follow-up
Background: This study represents a prospective, multicenter, open-label study to assess the safety, performance, and outcomes of poly-4-hydroxybutyrate (P4HB, Phasix) mesh for primary ventral, primary incisional, or multiply-recurrent hernia in subjects at risk for complications. This study reports 3-year clinical outcomes.
Materials and methods: P4HB mesh was implanted in 121 patients via retrorectus or onlay technique. Physical exam and/or quality of life surveys were completed at 1, 3, 6,12, 18, 24, and 36 months, with 5-year (60-month) follow-up ongoing.
Results: A total of n = 121 patients were implanted with P4HB mesh (n = 75 (62%) female) with a mean age of 54.7 +/- 12.0 years and mean BMI of 32.2 +/- 4.5 kg/m(2) (+/-standard deviation). Comorbidities included: obesity (78.5%), active smokers (23.1%), COPD (28.1%), diabetes mellitus (33.1%), immunosuppression (8.3%), coronary artery disease (21.5%), chronic corticosteroid use (5.0%), hypo-albuminemia (2.5%), advanced age (5.0%), and renal insufficiency (0.8%). Hernias were repaired via retrorectus (n = 45, 37.2% with myofascial release (MR) or n = 43, 35.5% without MR), onlay (n = 8, 6.6% with MR or n = 24, 19.8% without MR), or not reported (n = 1, 0.8%). 82 patients (67.8%) completed 36-month follow-up. 17 patients (17.9% +/- 0.4%) experienced hernia recurrence at 3 years, with n = 9 in the retrorectus group and n = 8 in the onlay group. SSI (n = 11) occurred in 9.3% +/- 0.03% of patients.
Conclusions: Long-term outcomes following ventral hernia repair with P4HB mesh demonstrate low recurrence rates at 3-year (36-month) postoperative time frame with no patients developing late mesh complications or requiring mesh removal. 5-year (60-month) follow-up is ongoing
X-ray Line Diagnostics of Hot Accretion Flows around Black Holes
We compute X-ray emission lines from thermal plasma in hot accretion flows.
We show that line profiles are strong probes of the gas dynamics, and we
present line-ratio diagnostics which are sensitive to the distribution of mass
with temperature in the flow. We show how these can be used to constrain the
run of density with radius, and the size of the hot region. We also present
diagnostics which are primarily sensitive to the importance of recombination
versus collisional ionization, and which could help discriminate ADAFs from
photoionization-dominated accretion disk coronae. We apply our results to the
Galactic center source Sagittarius A* and to the nucleus of M87. We find that
the brightest predicted lines are within the detection capability of current
-ray instruments.Comment: 16 pages, 1 table, 9 figures, accepted to Ap
A Detailed Analysis of a Cygnus Loop Shock-Cloud Interaction
The XA region of the Cygnus Loop is a complex zone of radiative and
nonradiative shocks interacting with interstellar clouds. We combine five far
ultraviolet spectral observations from the Hopkins Ultraviolet Telescope (HUT),
a grid of 24 IUE spectra and a high-resolution longslit Halpha spectrum to
study the spatial emission line variations across the region. These spectral
data are placed in context using ground-based, optical emission line images of
the region and a far-UV image obtained by the Ultraviolet Imaging Telescope
(UIT). The presence of high-ionization ions (OVI, NV, CIV) indicates a shock
velocity near 170 km/s while other diagnostics indicate v_shock=140 km/s. It is
likely that a large range of shock velocities may exist at a spatial scale
smaller than we are able to resolve. By comparing CIV 1550, CIII 977 and CIII]
1909, we explore resonance scattering across the region. We find that a
significant column depth is present at all positions, including those not near
bright optical/UV filaments. Analysis of the OVI doublet ratio suggests an
average optical depth of about unity in that ion while flux measurements of
[SiVIII] 1443 suggest a hot component in the region at just below 10^6K. Given
the brightness of the OVI emission and the age of the interaction, we rule out
the mixing layer interpretation of the UV emission. Furthermore, we formulate a
picture of the XA region as the encounter of the blast wave with a finger of
dense gas protruding inward from the pre-SN cavity.Comment: 21 pages, 9 figures, accepted by the Astronomical Journal, July 2001
Full resolution figures available at http://fuse.pha.jhu.edu/~danforth/xa
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