2,801 research outputs found
Differentiating patterns of violence in the family
The feasibility and prevalence of Reciprocal, Hierarchical and Paternal patterns of family aggression hypothesised by Dixon and Browne (2003) were explored within a sample of maltreating families. The psychological reports of 67 families referred to services for alleged child maltreatment that evidenced concurrent physical intimate partner violence and child maltreatment were investigated. Of these, 29 (43.3%) cases were characterised by hierarchical; 28 (41.8%) Reciprocal and 10 (14.9%) Paternal patterns. Significant differences in the form of child maltreatment perpetrated by mothers and fathers and parent dyads living in different patterns were found. In Hierarchical sub-patterns, fathers were significantly more likely to have been convicted for a violent and/or sexual offence than mothers and were significantly less likely to be biologically related to the child. The findings demonstrate the existence of the different patterns in a sample of families involved in the Child Care Protection process in England and Wales, supporting the utility of a holistic approach to understanding aggression in the family
Impact of Simulated 1/f Noise for HI Intensity Mapping Experiments
Cosmology has entered an era where the experimental limitations are not due
to instrumental sensitivity but instead due to inherent systematic
uncertainties in the instrumentation and data analysis methods. The field of HI
intensity mapping (IM) is still maturing, however early attempts are already
systematics limited. One such systematic limitation is 1/f noise, which largely
originates within the instrumentation and manifests as multiplicative gain
fluctuations. To date there has been little discussion about the possible
impact of 1/f noise on upcoming single-dish HI IM experiments such as BINGO,
FAST or SKA. Presented in this work are Monte-Carlo end-to-end simulations of a
30 day HI IM survey using the SKA-MID array covering a bandwidth of 950 and
1410 MHz. These simulations extend 1/f noise models to include not just
temporal fluctuations but also correlated gain fluctuations across the receiver
bandpass. The power spectral density of the spectral gain fluctuations are
modelled as a power-law, and characterised by a parameter . It is found
that the degree of 1/f noise frequency correlation will be critical to the
success of HI IM experiments. Small values of ( < 0.25) or high
correlation is preferred as this is more easily removed using current component
separation techniques. The spectral index of temporal fluctuations ()
is also found to have a large impact on signal-to-noise. Telescope slew speed
has a smaller impact, and a scan speed of 1 deg s should be sufficient
for a HI IM survey with the SKA.Comment: 22 pages, 15 figures, 2 table
The Postoperative Morbidity Survey was validated and used to describe morbidity after major surgery.
OBJECTIVES: To describe the reliability and validity of the Postoperative Morbidity Survey (POMS). To describe the level and pattern of short-term postoperative morbidity after major elective surgery using the POMS. STUDY DESIGN AND SETTING: This was a prospective cohort study of 439 adults undergoing major elective surgery in a UK teaching hospital. The POMS, an 18-item survey that address nine domains of postoperative morbidity, was recorded on postoperative days 3, 5, 8, and 15. RESULTS: Inter-rater reliability was perfect for 11/18 items (Kappa=1.0), with Kappa=0.94 for 6/18 items. A priori hypotheses that the POMS would discriminate between patients with known measures of morbidity risk, and predict length of stay were generally supported through observation of data trends, and there was statistically significant evidence of construct validity for all but the wound and neurological domains. POMS-defined morbidity was present in 325 of 433 patients (75.1%) remaining in hospital on postoperative day 3 after surgery, 231 of 407 patients (56.8%) on day 5, 138 of 299 patients (46.2%) on day 8, and 70 of 111 patients (63.1%) on day 15. Gastrointestinal (47.4%), infectious (46.5%), pain-related (40.3%), pulmonary (39.4%), and renal problems (33.3%) were the most common forms of morbidity. CONCLUSION: The POMS is a reliable and valid survey of short-term postoperative morbidity in major elective surgery. Many patients remain in hospital without any morbidity as recorded by the POMS
Microplastic moves pollutants and additives to worms, reducing functions linked to health and biodiversity.
PublishedJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.Inadequate products, waste management, and policy are struggling to prevent plastic waste from infiltrating ecosystems [1, 2]. Disintegration into smaller pieces means that the abundance of micrometer-sized plastic (microplastic) in habitats has increased [3] and outnumbers larger debris [2, 4]. When ingested by animals, plastic provides a feasible pathway to transfer attached pollutants and additive chemicals into their tissues [5-15]. Despite positive correlations between concentrations of ingested plastic and pollutants in tissues of animals, few, if any, controlled experiments have examined whether ingested plastic transfers pollutants and additives to animals. We exposed lugworms (Arenicola marina) to sand with 5% microplastic that was presorbed with pollutants (nonylphenol and phenanthrene) and additive chemicals (Triclosan and PBDE-47). Microplastic transferred pollutants and additive chemicals into gut tissues of lugworms, causing some biological effects, although clean sand transferred larger concentrations of pollutants into their tissues. Uptake of nonylphenol from PVC or sand reduced the ability of coelomocytes to remove pathogenic bacteria by >60%. Uptake of Triclosan from PVC diminished the ability of worms to engineer sediments and caused mortality, each by >55%, while PVC alone made worms >30% more susceptible to oxidative stress. As global microplastic contamination accelerates, our findings indicate that large concentrations of microplastic and additives can harm ecophysiological functions performed by organisms.Work was funded by Leverhulme Trust (grant F/00/568/C) to R.C.T., T.S.G., and S.J.R. During preparation of manuscript, M.A.B. was supported as a Postdoctoral Fellow at NCEAS, a center funded by the NSF (grant number EF-0553768), UCSB, with support from Ocean Conservancy
Simulations for single-dish intensity mapping experiments
HI intensity mapping is an emerging tool to probe dark energy. Observations
of the redshifted HI signal will be contaminated by instrumental noise,
atmospheric and Galactic foregrounds. The latter is expected to be four orders
of magnitude brighter than the HI emission we wish to detect. We present a
simulation of single-dish observations including an instrumental noise model
with 1/f and white noise, and sky emission with a diffuse Galactic foreground
and HI emission. We consider two foreground cleaning methods: spectral
parametric fitting and principal component analysis. For a smooth frequency
spectrum of the foreground and instrumental effects, we find that the
parametric fitting method provides residuals that are still contaminated by
foreground and 1/f noise, but the principal component analysis can remove this
contamination down to the thermal noise level. This method is robust for a
range of different models of foreground and noise, and so constitutes a
promising way to recover the HI signal from the data. However, it induces a
leakage of the cosmological signal into the subtracted foreground of around 5%.
The efficiency of the component separation methods depends heavily on the
smoothness of the frequency spectrum of the foreground and the 1/f noise. We
find that as, long as the spectral variations over the band are slow compared
to the channel width, the foreground cleaning method still works.Comment: 14 pages, 12 figures. Submitted to MNRA
HI intensity mapping with FAST
We discuss the detectability of large-scale HI intensity fluctuations using
the FAST telescope. We present forecasts for the accuracy of measuring the
Baryonic Acoustic Oscillations and constraining the properties of dark energy.
The FAST -beam L-band receivers (-- GHz) can provide
constraints on the matter power spectrum and dark energy equation of state
parameters () that are comparable to the BINGO and CHIME
experiments. For one year of integration time we find that the optimal survey
area is . However, observing with larger frequency coverage
at higher redshift (-- GHz) improves the projected errorbars on the
HI power spectrum by more than confidence level. The combined
constraints from FAST, CHIME, BINGO and Planck CMB observations can provide
reliable, stringent constraints on the dark energy equation of state.Comment: 7 pages, 3 figures, submitted to "Frontiers in Radio Astronomy and
FAST Early Sciences Symposium 2015" conference proceedin
The validity and reliability of the exposure index as a metric for estimating the radiation dose to the patient
Introduction
With the introduction of digital radiography, the feedback between image quality and over-exposure has been partly lost which in some cases has led to a steady increase in dose. Over the years the introduction of exposure index (EI) has been used to resolve this phenomenon referred to as ‘dose creep’. Even though EI is often vendor specific it is always a related of the radiation exposure to the detector. Due to the nature of this relationship EI can also be used as a patient dose indicator, however this is not widely investigated in literature.
Methods
A total of 420 dose-area-product (DAP) and EI measurements were taken whilst varying kVp, mAs and body habitus on two different anthropomorphic phantoms (pelvis and chest). Using linear regression, the correlation between EI and DAP were examined. Additionally, two separate region of interest (ROI) placements/per phantom where examined in order to research any effect on EI.
Results
When dividing the data into subsets, a strong correlation between EI and DAP was shown with all R-squared values > 0.987. Comparison between the ROI placements showed a significant difference between EIs for both placements.
Conclusion
This research shows a clear relationship between EI and radiation dose which is dependent on a wide variety of factors such as ROI placement, body habitus. In addition, pathology and manufacturer specific EI’s are likely to be of influence as well.
Implications for practice
The combination of DAP and EI might be used as a patient dose indicator. However, the influencing factors as mentioned in the conclusion should be considered and examined before implementation
Experimental Realization of a Four-Photon Seven-Qubit Graph State for One-Way Quantum Computation
We propose and demonstrate the scaling up of photonic graph state through
path qubit fusion. Two path qubits from separate two-photon four-qubit states
are fused to generate a two-dimensional seven-qubit graph state composed of
polarization and path qubits. Genuine seven-qubit entanglement is verified by
evaluating the witness operator. Six qubits from the graph state are used to
execute the general two-qubit Deutsch-Jozsa algorithm with a success
probability greater than 90%.Comment: 4 pages. Supplementary Material is included in the zip fil
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