4,010 research outputs found
Economic burden of antibiotic resistance: how much do we really know?
AbstractThe declining effectiveness of antibiotics imposes potentially large health and economic burdens on societies. Quantifying the economic outcomes of antibiotic resistance effectively can help policy-makers and healthcare professionals to set priorities, but determining the actual effect of antibiotic resistance on clinical outcomes is a necessary first step. In this article, we review and discuss the contributions and limitations of studies that estimate the disease burden attributable to antibiotic resistance and studies that estimate the economic burden of resistance. We also consider other factors that are important in a comprehensive approach to evaluating the economic burden of antibiotic resistance
Perceptions and discourses relating to genetic testing : interviews with people with Down syndrome
Background:
The perceptions of individuals with Down syndrome are conspicuously absent in discussions about the use of prenatal testing.
Method:
Eight individuals with Down syndrome were interviewed about their views and experience of the topic of prenatal testing.
Results:
Interpretative Phenomenological Analysis revealed two major themes with sub themes: 1) A devalued condition and a valued life and 2) A question of ‘want?’ Foucauldian Discourse Analysis highlighted two main discursive practices: 1) Social deviance and 2) Tragedy and catastrophe of the birth of a baby with Down syndrome.
Conclusions:
The findings suggest that individuals with intellectual disabilities can make a valuable contribution to discussions surrounding the use of prenatal testing. Implications for clinical practice include the use of information about Down syndrome given to prospective parents, and the possible psychological impact of prenatal testing practices on individuals with Down syndrome
Photonic qubits, qutrits and ququads accurately prepared and delivered on demand
Reliable encoding of information in quantum systems is crucial to all
approaches to quantum information processing or communication. This applies in
particular to photons used in linear optics quantum computing (LOQC), which is
scalable provided a deterministic single-photon emission and preparation is
available. Here, we show that narrowband photons deterministically emitted from
an atom-cavity system fulfill these requirements. Within their 500 ns coherence
time, we demonstrate a subdivision into d time bins of various amplitudes and
phases, which we use for encoding arbitrary qu-d-its. The latter is done
deterministically with a fidelity >95% for qubits, verified using a newly
developed time-resolved quantum-homodyne method.Comment: 5 pages, 4 figure
Patients presenting to an acute general hospital with acute mental health needs. A retrospective observational cohort study
Objectives To examine the numbers and patterns of patients presenting to an urban acute general hospital with acute mental health presentations and to further investigate any variation related to the COVID-19 pandemic. Design Retrospective observational cohort study. Setting An urban acute general hospital in London, UK, comprising of five sites and two emergency departments. The hospital provides tertiary level general acute care but is not an acute mental health services provider. There is an inpatient liaison psychiatry service. Participants 358 131 patients attended the emergency departments of our acute general hospital during the study period. Of these, 14 871 patients attended with an acute mental health presentation. A further 14 947 patients attending with a physical illness were also noted to have a concurrent recorded mental health diagnosis. Results Large numbers of patients present to our acute general hospital with mental health illness even though the organisation does not provide mental health services other than inpatient liaison psychiatry. There was some variation in the numbers and patterns of presentations related to the COVID-19 pandemic. Patient numbers reduced to a mean of 9.13 (SD 3.38) patients presenting per day during the first ‘lockdown’ compared with 10.75 (SD 1.96) patients per day in an earlier matched time period (t=3.80, p<0.01). Acute mental health presentations following the third lockdown increased to a mean of 13.84 a day. Conclusions Large numbers of patients present to our acute general hospital with mental health illness. This suggests a need for appropriate resource, staffing and training to address the needs of these patients in a non-mental health provider organisation and subsequent appropriate transfer for timely treatment. The COVID-19 pandemic and the resulting lockdowns have resulted in variation in the numbers and patterns of patients presenting with acute mental health illness but these presentations are not new. Considerable work is still needed to provide integrated care which addresses the physical and mental healthcare needs of patients presenting to acute and general hospitals
Cold atom gravimetry with a Bose-Einstein Condensate
We present a cold atom gravimeter operating with a sample of Bose-condensed
Rubidium-87 atoms. Using a Mach-Zehnder configuration with the two arms
separated by a two-photon Bragg transition, we observe interference fringes
with a visibility of 83% at T=3 ms. We exploit large momentum transfer (LMT)
beam splitting to increase the enclosed space-time area of the interferometer
using higher-order Bragg transitions and Bloch oscillations. We also compare
fringes from condensed and thermal sources, and observe a reduced visibility of
58% for the thermal source. We suspect the loss in visibility is caused partly
by wavefront aberrations, to which the thermal source is more susceptible due
to its larger transverse momentum spread. Finally, we discuss briefly the
potential advantages of using a coherent atomic source for LMT, and present a
simple mean-field model to demonstrate that with currently available
experimental parameters, interaction-induced dephasing will not limit the
sensitivity of inertial measurements using freely-falling, coherent atomic
sources.Comment: 6 pages, 4 figures. Final version, published PR
Influence of anodizing process on fatigue life of a machined aluminium alloy
In order to investigate the coupled effects of machining and anodizing processes on fatigue life of alloy 7010-T7451, a series of rotating bending fatigue tests were conducted at 60Hz. In the as machined condition, test results showed that fatigue life is surface roughness dependent and that fatigue life decreases with an increase in surface roughness and this effect is found to be more pronounced in high cycle fatigue where major portion of fatigue life is consumed in nucleating the cracks. Effects of pretreatments, like degreasing and pickling employed prior to anodizing, on fatigue life of the given alloy were also studied. Results demonstrated that degreasing showed no change in fatigue life while pickling had negative impact on fatigue life of specimens. The small decrease in fatigue life of anodized specimens as compare to pickled specimens is attributed to brittle and microcracking of the coating. Scanning electron microscopic (SEM) examination revealed multi-site crack initiation for the pickled and anodized specimens. SEM examination showed that pickling solution attacked the grain boundaries and intermetallic inclusions present on the surface resulting in pits formation. These pits are of primary concern with respect to accelerated fatigue crack nucleation and subsequent anodized coating formation
On the USAF ‘risk of failure’ approach and its applicability to composite repairs to metal airframes
The USAF report on the risk analysis of aging aircraft fleets notes that the operational life of individual airframes is seldom equal to the design life of the fleet and that the life of an aircraft fleet t ends to be determined more by its inherent operational capability and maintenance costs rather than by the number of flight hours specified at the design stage. As such this paper focuses on whether the USAF approach to risk assessment can be used for airf rames repaired with a composite patch/doubler. To this end the present paper describes a test program designed to study the effect of adhesively -bonded composite repairs to fatigue cracks that, prior to repair, have grown from small naturally -occurring mat erials discontinuities. This study reveals that crack growth in composite repairs conforms to the exponential growth equation used in the USAF approach to assessing the risk of failure. Furthermore, the exponent, ω, in the exponential growth law can be de termined from the crack growth history associated with the unrepaired specimens and the simple reduction in the stress due to the application of the composite patch/doubler, using the ‘cubic rule’ that was previously used to assess crack growth in the RAAF F/A -18 (Hornet) fleet
Trajectories of Exposure to Neighborhood Deprivation and the Odds of Experiencing Intimate Partner Violence Among Women: Are There Sensitive Periods for Exposure?
Neighborhood disadvantage is commonly hypothesized to be positively associated with intimate partner violence (IPV) against women. However, longitudinal investigation of this association has been limited, with no studies on whether the timing of exposure matters. We used data from 2,115 women in the UK-based Avon Longitudinal Study of Parents and Children. Exposure to neighborhood-level deprivation was measured at 10-time points from baseline (gestation) until age 18. Family-level socioeconomic characteristics were measured at baseline. At age 21, participants self-reported whether they had experienced any IPV since age 18. We used a three-step bias-adjusted longitudinal latent class analysis to investigate how different patterns of neighborhood deprivation exposure were associated with the odds of experiencing IPV. A total of 32% of women experienced any IPV between ages 18 and 21. Women who consistently lived in deprived neighborhoods (chronic high deprivation) or spent their early childhoods in more deprived neighborhoods and later moved to less deprived neighborhoods (decreasing deprivation) had higher odds of experiencing IPV compared to those who consistently lived in non-deprived neighborhoods. The odds of experiencing IPV did not consistently differ between women who lived in non-deprived neighborhoods during early childhood and later moved to deprived neighborhoods (increasing deprivation) and those stably in non-deprived neighborhoods. Living in more deprived neighborhoods during early childhood, regardless of later exposure, was associated with higher odds of experiencing later IPV. This is congruent with prior research demonstrating the persistent effects of early neighborhood disadvantage on health and well-being. Replication, and underlying mechanisms, should be assessed across contexts
Optically trapped atom interferometry using the clock transition of large Rb-87 Bose-Einstein condensates
We present a Ramsey-type atom interferometer operating with an optically
trapped sample of 10^6 Bose-condensed Rb-87 atoms. The optical trap allows us
to couple the |F =1, mF =0>\rightarrow |F =2, mF =0> clock states using a
single photon 6.8GHz microwave transition, while state selective readout is
achieved with absorption imaging. Interference fringes with contrast
approaching 100% are observed for short evolution times. We analyse the process
of absorption imaging and show that it is possible to observe atom number
variance directly, with a signal-to-noise ratio ten times better than the
atomic projection noise limit on 10^6 condensate atoms. We discuss the
technical and fundamental noise sources that limit our current system, and
outline the improvements that can be made. Our results indicate that, with
further experimental refinements, it will be possible to produce and measure
the output of a sub-shot-noise limited, large atom number BEC-based
interferometer.
In an addendum to the original paper, we attribute our inability to observe
quantum projection noise to the stability of our microwave oscillator and
background magnetic field. Numerical simulations of the Gross-Pitaevskii
equations for our system show that dephasing due to spatial dynamics driven by
interparticle interactions account for much of the observed decay in fringe
visibility at long interrogation times. The simulations show good agreement
with the experimental data when additional technical decoherence is accounted
for, and suggest that the clock states are indeed immiscible. With smaller
samples of 5 \times 10^4 atoms, we observe a coherence time of {\tau} =
(1.0+0.5-0.3) s.Comment: 22 pages, 6 figures Addendum: 11 pages, 6 figure
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