1,374 research outputs found
Depth profiling of PAHs treated with activated carbon using in-situ SPME
Novel and efficient methods to measure the bioavailability of hydrophobic organic contaminants (HOCs) in contaminated sediments will play an important role in the acceptance of alternative sediment remediation strategies. In this project, solid phase microextraction (SPME) fibers, protected in perforated steel tubes, were used as in situ passive samplers to measure the treatment of activated carbon (AC) in polycyclic aromatic hydrocarbon (PAH) contaminated sediment. Contaminated sediment was treated with two modes of AC waterjet amendment. In the first treatment, a single 2-min injection was shot into the center of a test vessel and in the second treatment, multiple 7-sec injections in a grid were placed in sediment. In the single injection no treatment was observed 5 cm away from the injection, while at 2.5 cm greater than 90% removal of PAH pore water concentrations were observed. In the multiple injection experiment greater than 90% PAH pore water reductions were observed throughout the test vessel. Highly contaminated and less contaminated sediments were mixed with 0-5% AC by weight to develop AC treatment curves. Over 99% reduction in PAH bioavailability was observed in the less contaminated sediment at 3% AC while 99% removal was never reached even at 5% AC addition in the highly contaminated sediment. Clear treatment curves were observed for both contaminated sediments, though they were very different. In situ equilibration times were 120,215 and 250 hours for phenanthrene, pyrene and benzo(a)Anthracene respetively [sic]. The results show that in situ SPME is a viable method to observe AC treatment and evaluate reductions in bioavailability --Abstract, Page iv
A mixed-method process evaluation of an East Midlands county summer 2021 holiday activities and food programme highlighting the views of programme co-ordinators, providers, and parents
BACKGROUND: The Holiday Activities and Food (HAF) Programme is a UK Government initiative created to alleviate food insecurity and promote health and well-being among children and their families, who are eligible for Free School Meals (FSM), during the school holidays. This process evaluation investigated factors that facilitated and acted as a barrier to the delivery of the HAF Programme from the perspectives of key stakeholders (Co-ordinators, Providers, and Parents) involved in the HAF Programme across an East Midlands county. METHODS: This evaluation utilized a mixed-methods approach, incorporating focus groups and online surveys to gain rich, multifaceted data. The focus groups were analyzed using a hybrid inductive-deductive thematic analysis and the online surveys were analyzed using mixed-methods approach due to the variation in question type (i.e., quantitative, Likert scale and open response) to align themes to the Government Aims and Standards of the HAF Programme. FINDINGS: The stakeholders highlighted several factors that facilitated and acted as a barrier to the delivery of the HAF Programme. Facilitating factors included existing and maintaining relationships between Co-ordinators, Providers, and facilities/schools/communities as this improved communication and attendance. Additionally, transport provision for those attending the Programme helped overcome barriers to attendance. The primary barrier of the Programme was the late awarding of the Programme contract as this limited the time available to prepare and organize the Programme. This in turn, had several âknock onâ effects that created more barriers and resulted in some of the Government Aims and Standards not being met such as, nutrition education for children and parents. Despite the challenges faced, Co-ordinators and Providers were able to deliver the Programme and positively impact upon the children and their families that attended the Programme. CONCLUSION: Following the facilitators and barriers that were highlighted in this evaluation, several recommendations have been made to enhance the delivery of the HAF Programme and ensure Government Aims and Standards, to improve children and family's health and well-being, are attained
Evaluation Report, Holiday Activities & Food Programme for Northamptonshire Sport, Full Report
According to the Department for Education, there are 1.63 million children eligible for Free School Meals (FSM). Within Northamptonshire there are 184,308 children and young people, aged 0-19 years old, of which 14% are eligible for FSM. As FSM eligibility is a proxy for socioeconomic disadvantage, these statistics highlight that a significant proportion of children in Northamptonshire are from disadvantaged backgrounds. Due to increased costs and reduced income, children and young people from disadvantaged backgrounds are more likely to experience a gap in learning and have âunhealthy holidaysâ during the school holiday period. To bridge this âgapâ, the Holiday Activities and Food (HAF) Programme was created by central Government. This report evaluates the HAF Programme that was delivered in Northamptonshire during the June to August 2021 Summer Holidays. 2,490 children and young people attended the HAF Programme (15.12% of FSM eligible children), from areas across Northamptonshire, with a catchment area of approximately 2,335 km2 and 215 schools
Evaluation Report, Holiday Activities & Food Programme for Northamptonshire Sport, Executive Summary & Key Findings
According to the Department for Education, there are 1.63 million children eligible for Free School Meals (FSM). Within Northamptonshire there are 184,308 children and young people, aged 0-19 years old, of which 14% are eligible for FSM. As FSM eligibility is a proxy for socioeconomic disadvantage, these statistics highlight that a significant proportion of children in Northamptonshire are from disadvantaged backgrounds. Due to increased costs and reduced income, children and young people from disadvantaged backgrounds are more likely to experience a gap in learning and have âunhealthy holidaysâ during the school holiday period. To bridge this âgapâ, the Holiday Activities and Food (HAF) Programme was created by central Government. This report evaluates the HAF Programme that was delivered in Northamptonshire during the June to August 2021 Summer Holidays. 2,490 children and young people attended the HAF Programme (15.12% of FSM eligible children), from areas across Northamptonshire, with a catchment area of approximately 2,335 km2 and 215 schools
Evolution of magnetic fields in galaxies and future observational tests with the Square Kilometre Array
Aims. We investigate the cosmological evolution of large- and small-scale
magnetic fields in galaxies in the light of present models of formation and
evolution of galaxies. Methods. We use the dynamo theory to derive the
timescales of amplification and ordering of magnetic fields in disk and puffy
galaxies. Turbulence in protogalactic halos generated by thermal virialization
can drive an efficient turbulent dynamo. Results from simulations of
hierarchical structure formation cosmology provide a tool to develop an
evolutionary model of regular magnetic fields coupled with galaxy formation and
evolution. Results. The turbulent (small-scale) dynamo was able to amplify a
weak seed magnetic field in halos of protogalaxies to a few muG strength within
a few 10^8 yr. This turbulent field served as a seed to the mean-field
(large-scale) dynamo. Galaxies similar to the Milky Way formed their disks at
z~10 and regular fields of muG strength and a few kpc coherence length were
generated within 2 Gyr (at z~3), but field-ordering on the coherence scale of
the galaxy size required an additional 6 Gyr (at z~0.5). Giant galaxies formed
their disks at z~10, allowing more efficient dynamo generation of strong
regular fields (with kpc coherence length) already at z~4. However, the age of
the Universe is short for fully coherent fields in giant galaxies larger than
15 kpc to have been achieved. Dwarf galaxies should have hosted fully coherent
fields at z~1. After a major merger, the strength of the turbulent field is
enhanced by a factor of a few. Conclusions. This evolutionary scenario can be
tested by measurements of polarized synchrotron emission and Faraday rotation
with the planned SKA. We predict an anticorrelation between galaxy size and
ratio between ordering scale and galaxy size (abridged).Comment: 13 pages, 3 figures, accepted for publication to A&A; new version
which incorporates suggestions of a language edito
Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV
A search for new physics is presented based on an event signature of at least
three jets accompanied by large missing transverse momentum, using a data
sample corresponding to an integrated luminosity of 36 inverse picobarns
collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector
at the LHC. No excess of events is observed above the expected standard model
backgrounds, which are all estimated from the data. Exclusion limits are
presented for the constrained minimal supersymmetric extension of the standard
model. Cross section limits are also presented using simplified models with new
particles decaying to an undetected particle and one or two jets
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Improving Outcomes in Infants of HIV-Infected Women in a Developing Country Setting
Since 1999 GHESKIO, a large voluntary counseling and HIV testing center in Port-au-Prince, Haiti, has had an ongoing collaboration with the Haitian Ministry of Health to reduce the rate of mother to child HIV transmission. There are limited data on the ability to administer complex regimens for reducing mother to child transmission and on risk factors for continued transmission and infant mortality within programmatic settings in developing countries.We analyzed data from 551 infants born to HIV-infected mothers seen at GHESKIO, between 1999 and 2005. HIV-infected mothers and their infants were given "short-course" monotherapy with antiretrovirals for prophylaxis; and, since 2003, highly active antiretroviral therapy (HAART) when clinical or laboratory indications were met. Infected women seen in the pre-treatment era had 27% transmission rates, falling to 10% in this cohort of 551 infants, and to only 1.9% in infants of women on HAART. Mortality rate after HAART introduction (0.12 per year of follow-up [0.08-0.16]) was significantly lower than the period before the availability of such therapy (0.23 [0.16-0.30], P<0.0001). The effects of maternal health, infant feeding, completeness of prophylaxis, and birth weight on mortality and transmission were determined using univariate and multivariate analysis. Infant HIV-1 infection and low birth weight were associated with infant mortality in less than 15 month olds in multivariate analysis.Our findings demonstrate success in prevention of mother-to-child HIV transmission and mortality in a highly resource constrained setting. Elements contributing to programmatic success include provision of HAART in the context of a comprehensive program with pre and postnatal care for both mother and infant
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
Combined search for the quarks of a sequential fourth generation
Results are presented from a search for a fourth generation of quarks
produced singly or in pairs in a data set corresponding to an integrated
luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in
2011. A novel strategy has been developed for a combined search for quarks of
the up and down type in decay channels with at least one isolated muon or
electron. Limits on the mass of the fourth-generation quarks and the relevant
Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a
simple extension of the standard model with a sequential fourth generation of
fermions. The existence of mass-degenerate fourth-generation quarks with masses
below 685 GeV is excluded at 95% confidence level for minimal off-diagonal
mixing between the third- and the fourth-generation quarks. With a mass
difference of 25 GeV between the quark masses, the obtained limit on the masses
of the fourth-generation quarks shifts by about +/- 20 GeV. These results
significantly reduce the allowed parameter space for a fourth generation of
fermions.Comment: Replaced with published version. Added journal reference and DO
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