2,871 research outputs found
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Understanding individuals’ decisions about vaccination: a comparison between Expected Utility and Regret Theory models
Haemophilus influenzae-like bacilli in the human vagina
The factor which initiated the present investigation was the routine use of the blood agar
medium developed by Professor W.M. Levinthal and
used in this Unit for many years. The details of
its production are given in the Appendix, but the
important features in so far as HILB are concerned
are:(1) the use of human blood, which is much superior
to horse, ox, sheep or rabbit blood, (2) the addition of horse pancreatic digest made with the minimum possible amount of heating, (3) the use of 2%
Evans peptone (with no Lab Lemco) which has also
received the minimum amount of heating (4) the use of
{the minimum amount of agar for adequate solidity
(0.8-0.9% New Zealand, according to batch), (5) the
use of thick plates (25 ml. in a 4" Petri dish) with
the minimum amount of drying and (6) the addition of
it small amount of penicillinase to destroy traces of
penicillin which the donor may have been given
before the blood was collected.Our finding concerning the superiority of
Transfusion Service citrated blood over the blood
of other species, contrasts with the use of sheep
271
blood by Lutz et al, (1956) and by Gardner and
Dukes (1955) in their studies on similar organisms
in France and the U.S.A. respectively. Gardner
and Dukes went so far as to state that citrated
human blood was unsuitable for solid medium. It
may be that their organism, which they call Haemophilus va inalis is different from HILB, or the
medium may differ in other respects, e.g., pH,
ordinary laboratory media being near the upper
limit for growth of HILB of around pH 7.5, and
relatively small increases therefore jeopardising
the growth- promoting quality of the medium. It
seems likely at this stage of our experience of the
organism, that some unexplained failures of growth
may have been due to undetected variations in pH,
although some cases were adequately explained by
the demonstration of traces of penicillin in the
medium.Clinically, the outstanding feature of this
organism is, in our experience, its apparent ability
to cause puerperal pyrexia. Attempts to arrange
for inoculation of volunteers failed, owing to the
natural reluctance of clinicians in charge to put
at risk patients in the puerperium, so that the
evidence for its human pathogenicity is limited to
the marked association with pyrexia revealed by
comparison with control cases, 71% being the
incidence in cases of puerperal pyrexia of 99° F.
272
or over, as compared with 31 ¡, in a control group
collected at the same time. The high incidence of
positive cultures throughout the series, even in
control groups, naturally throws some doubt on the
pathogenicity of the organism and it is clear that
it does not rank with,for example, Strep. pyogenes
as a pathogen of the female genital tract. However,
one may draw a comparison here with H. influenzae,
which is a commonly occurring organism capable of
both commensal and pathogenic properties.The effects of puerperal HILB infection are
not confined entirely to mild degrees of pyrexia,
as is seen in Table 3, where, out of 12 cases with
a temperature of 100 °F. or more, 11 (92%) yielded
HILB, of which 9 were in almost pure + ++ growth.
None of these cases showed evidence of any other
possible cause of pyrexia apart from HILB. This
power to produce quite severe reactions in a
minority of cases has been confirmed by experience
since gained, and the unwillingness of the clinicians in charge of the patients to subject them to
inoculation with HILB, indicates that they have a considerable respect for its pathogenic powers.
In one case, a temperature of 103°F. has been
recorded, without any other cause found than the
isolation of HILB in +++ growth
Modelling alternative strategies for delivering hepatitis B vaccine in prisons : the impact on the vaccination coverage of the injecting drug user population
Since 2001 hepatitis B vaccination has been offered to prisoners on reception into prisons in
England and Wales. However, short campaigns of vaccinating the entire population of individual
prisons have achieved high vaccination coverage for limited periods, suggesting that short
campaigns may be a preferable way of vaccinating prisoners. A model is used that describes the
flow of prisoners through prisons stratified by injecting status to compare a range of vaccination
scenarios that describe vaccination on prison reception or via regular short campaigns. Model
results suggest that vaccinating on prison reception can capture a greater proportion of the
injecting drug user (IDU) population than the comparable campaign scenarios (63% vs. 55 . 6%
respectively). Vaccination on prison reception is also more efficient at capturing IDUs for
vaccination than vaccination via a campaign, although vaccination via campaigns may have a
role with some infections for overall control
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The economics of health
This report presents results from the Economics of Health project funded by the East Midlands Development Agency. The work was undertaken between November 2007 and February 2008. The main aim of the project was to examine the relationship between mental and physical health and employability, labour market participation and economic performance, with specific attention given to the direction of causal relationships
Metallicity Evolution in the Early Universe
Observations of the damped Lya systems provide direct measurements on the
chemical enrichment history of neutral gas in the early universe. In this
Letter, we present new measurements for four damped Lya systems at high
redshift. Combining these data with [Fe/H] values culled from the literature,
we investigate the metallicity evolution of the universe from z~1.5-4.5.
Contrary to our expectations and the predictions of essentially every chemical
evolution model, the N(HI)-weighted mean [Fe/H] metallicity exhibits minimal
evolution over this epoch. For the individual systems, we report tentative
evidence for an evolution in the unweighted [Fe/H] mean and the scatter in
[Fe/H] with the higher redshift systems showing lower scatter and lower typical
[Fe/H] values. We also note that no damped Lya system has [Fe/H] < -2.7 dex.
Finally, we discuss the potential impact of small number statistics and dust on
our conclusions and consider the implications of these results on chemical
evolution in the early universe.Comment: 6 pages, 2 encapsulated figures, Latex2e, uses emulateapj.sty and
onecolfloat.sty. Accepted for publication in ApJ Letters: Feb 28, 200
Modelling the hepatitis B vaccination programme in prisons
A vaccination programme offering hepatitis B (HBV) vaccine at reception into prison has been introduced into selected prisons in England and Wales. Over the coming years it is anticipated this vaccination programme will be extended. A model has been developed to assess the potential impact of the programme on the vaccination coverage of prisoners, ex-prisoners, and injecting drug users (IDUs). Under a range of coverage scenarios, the model predicts the change over time in the vaccination status of new entrants to prison, current prisoners and IDUs in the community. The model predicts that at baseline in 2012 57% of the IDU population will be vaccinated with up to 72% being vaccinated depending on the vaccination scenario implemented. These results are sensitive to the size of the IDU population in England and Wales and the average time served by an IDU during each prison visit. IDUs that do not receive HBV vaccine in the community are at increased risk from HBV infection. The HBV vaccination programme in prisons is an effective way of vaccinating this hard-to-reach population although vaccination coverage on prison reception must be increased to achieve this
The Diverse Infrared Properties of a Complete Sample of Star-Forming Dwarf Galaxies
We present mid-infrared Spitzer Space Telescope observations of a complete
sample of star-forming dwarf galaxies selected from the KPNO International
Spectroscopic Survey. The galaxies span a wide range in mid-infrared
properties. Contrary to expectations, some of the galaxies emit strongly at 8
micron indicating the presence of hot dust and/or PAHs. The ratio of this
mid-infrared dust emission to the stellar emission is compared with the
galaxies' luminosity, star-formation rate, metallicity, and optical reddening.
We find that the strength of the 8.0 micron dust emission to the stellar
emission ratio is more strongly correlated with the star-formation rate than it
is with the metallicity or the optical reddening in these systems. Nonetheless,
there is a correlation between the 8.0 micron luminosity and metallicity. The
slope of this luminosity-metallicity correlation is shallower than
corresponding ones in the B-band and 3.6 micron. The precise nature of the 8.0
micron emission seen in these galaxies (i.e., PAH versus hot dust or some
combination of the two) will require future study, including deep mid-IR
spectroscopy.Comment: 14 pages, accepted Ap
Antibody responses to nasopharyngeal carriage of Streptococcus pneumoniae in adults: A longitudinal household study
Background. Natural immunity to Streptococcus pneumoniae is thought to be induced by exposure to S. pneumoniae or cross-reactive antigens. No longitudinal studies of carriage of and immune responses to S. pneumoniae have been conducted using sophisticated immunological laboratory techniques.Methods. We enrolled 121 families with young children into this study. Nasopharyngeal (NP) swabs were collected monthly for 10 months from all family members and were cultured in a standard fashion. Cultured S. pneumoniae isolates were serotyped. At the beginning (month 0) and end (month 10) of the study, venous blood was collected from family members 118 years old. Serotype-specific antipolysaccharide immunoglobulin G (IgG) and functional antibody and antibodies to pneumolysin, pneumococcal surface protein A (PspA), and pneumococcal surface antigen A (PsaA) were measured in paired serum samples.Results. Levels of anticapsular IgG increased significantly after carriage of serotypes 9V, 14, 18C, 19F, and 23F by an individual or family member. For serotype 14, a higher level of anticapsular IgG at the beginning of the study was associated with reduced odds of carriage (P = .0006). There was a small (similar to 20%) but significant increase in titers of antibodies to PsaA and pneumolysin but no change in titers of antibody to PspA.Conclusions. Adults respond to NP carriage by mounting anticapsular and weak antiprotein antibody responses, and naturally induced anticapsular IgG can prevent carriage
Homogeneous AlGaN/GaN superlattices grown on free-standing (1(1)over-bar00) GaN substrates by plasma-assisted molecular beam epitaxy
Two-dimensional and homogeneous growth of m-plane AlGaN by plasma-assisted molecular beam epitaxy has been realized on free-standing (1 (1) over bar 00) GaN substrates by implementing high metal-to-nitrogen (III/N) flux ratio. AlN island nucleation, often reported for m-plane AlGaN under nitrogen-rich growth conditions, is suppressed at high III/N flux ratio, highlighting the important role of growth kinetics for adatom incorporation. The homogeneity and microstructure of m-plane AlGaN/GaN superlattices are assessed via a combination of scanning transmission electron microscopy and high resolution transmission electron microscopy (TEM). The predominant defects identified in dark field TEM characterization are short basal plane stacking faults (SFs) bounded by either Frank-Shockley or Frank partial dislocations. In particular, the linear density of SFs is approximately 5 x 10(-5) cm(-1), and the length of SFs is less than 15 nm. (C) 2013 AIP Publishing LLC
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