32,870 research outputs found
Poverty and inequality in Britain: 2006
This Commentary provides an update on trends in poverty and inequality in Great Britain, based on the latest official government statistics. It uses the same approach to measuring incomes and poverty in Great Britain as the government employs in its Households Below Average Income (HBAI) publication
Characteristics of an anechoic chamber for fan noise testing
Acoustical and mechanical design features of NASA Lewis Research Center's engine fan noise facility are described. Acoustic evaluation of the chamber, which is lined with an array of stepped wedges, is described. Results from the evaluation in terms of cut-off frequency and non-anechoic areas near the walls are detailed. Fan models are electrically driven to 20,600 RPM in either the inlet mode or exhaust mode to facilitate study of both fore and aft fan noise. Inlet noise characteristics of the first fan tested are discussed and compared to full-scale levels. Turbulence properties of the inlet flow and acoustic results are compared with and without a turbulence reducing screen over the fan inlet
Ethnic parity in labour market outcomes for benefit claimants
A significant gap exists in the UK between the employment rate for Ethnic Minorities and that for
Whites. From a policy perspective, it is important to know whether this gap is due to differences in
the characteristics of White and Ethnic Minority groups (which reduce the employability of Ethnic
Minority groups relative to Whites) or whether it results from some form of discriminatory behaviour
in the labour market. In this paper, we use administrative data to estimate ethnic differences in
employment and benefit receipt amongst individuals who began claiming a Jobcentre Plus benefit
in 2003. In contrast to much of the previous UK literature, we use a number of different quantitative
techniques to estimate this gap, and show that in a lot of cases the estimates obtained are very
sensitive to the techniques used. We argue that for the questions we are interested in and the data
we have, propensity score matching methods are the most robust approach to estimating ethnic
parity. We compare this preferred approach with estimates derived using alternative approaches
commonly used in the literature (generally regression-based techniques) to determine the extent to
which more straightforward methods are able to replicate those produced by matching. In many
cases, it turns out not to be possible to calculate satisfactory quantitative estimates even with
matching techniques: the characteristics of Whites and Ethnic Minorities are simply too different
before the Jobcentre Plus intervention to reliably estimate the parameters of interest. Moreover, for
a number of the groups, results seem to be very sensitive to the methodology used. This calls into
question previous results based on simple regression techniques, which are likely to hide the fact
that observationally different ethnic groups are de facto being compared on the basis of parametric
extrapolations. Two groups for which it was possible to calculate reasonably reliable results are
incapacity benefit (IB) and income support (IS). For these groups we find that large and significant
raw penalties almost always disappear once we appropriately control for pre-inflow background
and labour market characteristics. There is also a good degree of consistency across
methodologies
Sub-femtosecond electron bunches created by direct laser acceleration in a laser wakefield accelerator with ionization injection
In this work, we will show through three-dimensional particle-in-cell
simulations that direct laser acceleration in laser a wakefield accelerator can
generate sub-femtosecond electron bunches. Two simulations were done with two
laser pulse durations, such that the shortest laser pulse occupies only a
fraction of the first bubble, whereas the longer pulse fills the entire first
bubble. In the latter case, as the trapped electrons moved forward and
interacted with the high intensity region of the laser pulse, micro-bunching
occurred naturally, producing 0.5 fs electron bunches. This is not observed in
the short pulse simulation.Comment: AAC 201
The constrained modified KP hierarchy and the generalized Miura transformations
In this letter, we consider the second Hamiltonian structure of the
constrained modified KP hierarchy. After mapping the Lax operator to a pure
differential operator the second structure becomes the sum of the second and
the third Gelfand-Dickey brackets defined by this differential operator. We
simplify this Hamiltonian structure by factorizing the Lax operator into linear
terms.Comment: 8 pages, latex, no figure
Feeding interventions for growth and development in infants with cleft lip, cleft palate or cleft lip and palate.
BACKGROUND: Cleft lip and cleft palate are common birth defects, affecting about one baby of every 700 born. Feeding these babies is an immediate concern and there is evidence of delay in growth of children with a cleft as compared to those without clefting. In an effort to combat reduced weight for height, a variety of advice and devices are recommended to aid feeding of babies with clefts. OBJECTIVES: This review aims to assess the effects of these feeding interventions in babies with cleft lip and/or palate on growth, development and parental satisfaction. SEARCH STRATEGY: The following electronic databases were searched: the Cochrane Oral Health Group Trials Register (to 27 October 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 4), MEDLINE via OVID (1950 to 27 October 2010), EMBASE via OVID (1980 to 27 October 2010), PsycINFO via OVID (1950 to 27 October 2010) and CINAHL via EBSCO (1980 to 27 October 2010). Attempts were made to identify both unpublished and ongoing studies. There was no restriction with regard to language of publication. SELECTION CRITERIA: Studies were included if they were randomised controlled trials (RCTs) of feeding interventions for babies born with cleft lip, cleft palate or cleft lip and palate up to the age of 6 months (from term). DATA COLLECTION AND ANALYSIS: Studies were assessed for relevance independently and in duplicate. All studies meeting the inclusion criteria were data extracted and assessed for validity independently by each member of the review team. Authors were contacted for clarification or missing information whenever possible. MAIN RESULTS: Five RCTs with a total of 292 babies, were included in the review. Comparisons made within the RCTs were squeezable versus rigid feeding bottles (two studies), breastfeeding versus spoon-feeding (one study) and maxillary plate versus no plate (two studies). No statistically significant differences were shown for any of the primary outcomes when comparing bottle types, although squeezable bottles were less likely to require modification. No difference was shown for infants fitted with a maxillary plate compared to no plate. However, there was some evidence of an effect on weight at 6 weeks post-surgery in favour of breastfeeding when compared to spoon-feeding (mean difference 0.47; 95% confidence interval 0.20 to 0.74). AUTHORS' CONCLUSIONS: Squeezable bottles appear easier to use than rigid feeding bottles for babies born with clefts of the lip and/or palate, however, there is no evidence of a difference in growth outcomes between the bottle types. There is weak evidence that breastfeeding is better than spoon-feeding following surgery for cleft. There was no evidence to suggest that maxillary plates assist growth in babies with clefts of the palate. No evidence was found to assess the use of any types of maternal advice and/or support for these babies
National evaluation of the neighbourhood nurseries: impact report
This study assessed the impact of NNI on parental employment, use of formal childcare, and take-up of benefits and tax credits, particularly for disadvantaged groups such as lone parents, low income families and ethnic minority groups
Effectiveness of an inlet flow turbulence control device to simulate flight noise fan in an anechoic chamber
A hemispherical inlet flow control device was tested on a 50.8 cm. (20-inch) diameter fan stage in the NASA-Lewis anechoic chamber. The control device used honeycomb and wire mesh to reduce turbulence intensities entering the fan. Far field acoustic power level results show about a 5 db reduction in blade passing tone and about 10 dB reduction in multiple pure tone sound power at 90% design fan speed with the inlet device in place. Hot film cross probes were inserted in the inlet to obtain data for two components of the turbulence at 65 and 90% design fan speed. Without the flow control device, the axial intensities were below 1.0%, while the circumferential intensities were almost twice this value. The inflow control device significantly reduced the circumferential turbulence intensities and also reduced the axial length scale
XMM-Newton reveals ~100 new LMXBs in M31 from variability studies
We have conducted a survey of X-ray sources in XMM-Newton observations of
M31, examining their power density spectra (PDS) and spectral energy
distributions (SEDs). Our automated source detection yielded 535 good X-ray
sources; to date, we have studied 225 of them. In particular, we examined the
PDS because low mass X-ray binaries (LMXBs) exhibit two distinctive types of
PDS. At low accretion rates, the PDS is characterised by a broken power law,
with the spectral index changing from ~0 to ~1 at some frequency in the range
\~0.01--1 Hz; we refer to such PDS as Type A. At higher accretion rates, the
PDS is described by a simple power law; we call these PDS Type B. Of the 225
sources studied to date, 75 exhibit Type A variability, and are almost
certainly LMXBs, while 6 show Type B but not Type A, and are likely LMXBs. Of
these 81 candidate LMXBs, 71 are newly identified in this survey; furthermore,
they are mostly found near the centre of M31. Furthermore, most of the X-ray
population in the disc are associated with the spiral arms, making them likely
high mass X-ray binaries (HMXBs). In general these HMXBs do not exhibit Type A
variability, while many central X-ray sources (LMXBs) in the same luminosity
range do. Hence the PDS may distinguish between LMXBs and HMXBs in this
luminosity range.Comment: 4 pages, 2 figures. To appear in proceedings of IAUS230: "Populations
of High Energy Sources in Galaxies", 14-19 August 2005, Dublin, Eds E.J.A.
Meurs and G. Fabbian
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