1,018 research outputs found
Advances in photostop
This thesis is an expansion on previous work using the photostop technique for
the production of near-zero velocity atoms and molecules. The goal is to produce
stopped SH molecules and trap them in a permanent magnetic trap and the aim of
this project was to construct a new experimental apparatus to accomplish this.
During initial tests of the apparatus, the Rayleigh scattering cross-section of N2 was
measured to provide a reference point for future experiments. The uncertainty and
systematic errors in the measurements was such that denitive quantitative results
of this were not be obtained at this stage.
The emerging technique of cavity-enhanced laser-induced
uorescence (CELIF) was
used to perform absolute number density measurements of a molecular beam of
SO2. CELIF was then applied to measuring the photostop of SD/SH. This showed
that CELIF would not have the required sensitivity to measure the trapped SD/SH
molecules due to issues of stray light from the lasers. As a result of this we elected
to use resonance-enhanced multi-photon ionisation (REMPI) as an alternative.
We devised and constructed a novel ion extraction system for use in performing
REMPI, which was based on a time-of-
ight mass spectroscopy system, but utilising
the magnets themselves as electrodes, as well as some ion lensing components.
This was initially tested using Xe, showing a strong signal and good mass resolution.
Using this, the photostop of SH and S was measured showing that the detection apparatus
is able to distinguish signal over a range of 9 orders of magnitude. However,
despite this sensitivity, the trapping of these stopped molecules could not initially
be demonstrated as the signal from these stopped molecules was obscured by signal
from the inadvertent dissociation of the background parent molecules by the probe
laser. More recent measurements in the group have directly addressed this issue
with background subtraction and the results have now demonstrated the trapping
of SH.
Signicant headway has been made in the demonstration of the trapping of SH
produced by photostop. From the results produced using REMPI the detection limit
has improved signicantly over the prior experiments and very recent measurements
have successfully demonstrated the trapping of SH
An Unusual Treatment for Chronic Myelomonocytic Leukemia
A 76-year-old female with a past medical history of an extraosseous chondrasrcoma status-post-resection thirty years prior, hypertension, hyperlipidemia, and hypothyroidsimm presented to her primary care physicial with fatigue, two weeks of dyspnea on exertion, lightheadedness, and nausea
Why a basic income alone will not be a panacea to social insecurity
At the start of this year, Finland began a trial of a 'universal basic income' system, under which 2,000 individuals who were receiving welfare were selected to receive a guaranteed monthly income of 560 euros over the next two years. But can basic income systems really address problems of social insecurity? Neil Warner, Frederick Harry Pitts, and Lorena Lombardozzi explain why a successful implementation of a basic income will require a wider and more radical intervention in the economy
Activity of OP0595-β-lactam combination against Gram-negative bacteria with extended-spectrum, AmpC and carbapenem-hydrolysing β-lactama
Background: OP0595 is a diazabicyclooctane that (i) acts as a PBP2-ctive antibacterial, (ii) inhibits Class A and C β-lactamases and (iii), like mecillinam, gives β-lactamase-independent potentiation of β-lactams targeting other PBPs. We tested its behaviour against β-lactam-resistant Enterobacteriaceae and non-fermenters. Methods: Organisms were UK clinical isolates; MICs were determined by CLSI agar dilution for OP0595 alone or combined at 1–4 mg/L with aztreonam, biapenem, cefepime or piperacillin. Results: MICs of OP0595 for Escherichia coli, Enterobacter, Citrobacter and Klebsiella spp. were mostly 1–4 mg/L but values >4 mg/L were seen for minorities of isolates irrespective of other resistances, and for 50%–60% of those with ertapenem resistance involving porin loss plus ESBL or AmpC activity. OP0595 MICs for Serratia, Proteeae and non-fermenters mostly were >4 mg/L. When its MIC was ≤4 mg/L, OP0595's antibacterial activity dominated combination activity. For ‘OP0595-resistant’ (MIC >4 mg/L) isolates with Class A or C β-lactamases OP0595 achieved strong potentiation of substrate β-lactams, contingent on β-lactamase inhibition. β-Lactamase-independent potentiation was evident with aztreonam, cefepime and piperacillin—less so for biapenem—for many OP0595-resistant Enterobacteriaceae with Class B carbapenemases, which are not inhibited by OP0595. OP0595 acted solely as a β-lactamase inhibitor for non-fermenters. Conclusions: OP0595 inhibited Enterobacteriaceae, not non-fermenters; its combinations had broad activity versus Enterobacteriaceae, largely contingent on OP0595's antibacterial activity but also on inhibition of Class A and C β-lactamases and on the β-lactam-enhancer effect, which allowed activity against many OP0595-resistant metallo-β-lactamase-producing Enterobacteriaceae. For non-fermenters OP0595 acted only as a β-lactamase inhibitor
Widening perspectives on social impact bonds
Social Impact Bonds (SIBs) are a novel financing mechanism for public services delivery. This special issue about SIBs in the UK argues that they necessitate closer examination to understand the implications for all stakeholders. This introductory paper critically explores and challenges dominant practitioner narratives of SIBs as “win-win” solutions for governments and service providers. While SIBs may foster innovation it is unclear if they deliver better value given the complexity of public services. SIBs are a strategically ambiguous policy tool and policymakers should be cautious about SIBs due to contractual complexity and issues with ethics, governance, accountability and transparency
Development of a coupled wave-flow-vegetation interaction model
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Computers & Geosciences 100 (2017): 76–86, doi:10.1016/j.cageo.2016.12.010.Emergent and submerged vegetation can significantly affect coastal hydrodynamics. However, most deterministic numerical models do not take into account their influence on currents, waves, and turbulence. In this paper, we describe the implementation of a wave-flow-vegetation module into a Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modeling system that includes a flow model (ROMS) and a wave model (SWAN), and illustrate various interacting processes using an idealized shallow basin application. The flow model has been modified to include plant posture-dependent three-dimensional drag, in-canopy wave-induced streaming, and production of turbulent kinetic energy and enstrophy to parameterize vertical mixing. The coupling framework has been updated to exchange vegetation-related variables between the flow model and the wave model to account for wave energy dissipation due to vegetation. This study i) demonstrates the validity of the plant posture-dependent drag parameterization against field measurements, ii) shows that the model is capable of reproducing the mean and turbulent flow field in the presence of vegetation as compared to various laboratory experiments, iii) provides insight into the flow-vegetation interaction through an analysis of the terms in the momentum balance, iv) describes the influence of a submerged vegetation patch on tidal currents and waves separately and combined, and v) proposes future directions for research and development.This study was part of the Estuarine Physical Response to Storms project (GS2-2D), supported by the Department of Interior Hurricane Sandy Recovery program
In vitro activity of cefepime/zidebactam (WCK 5222) against Gram-negative bacteria
Background: Diazabicyclooctanes (DBOs) inhibit class A, class C and some class D β-lactamases. A few also bind PBP2, conferring direct antibacterial activity and a β-lactamase-independent ‘enhancer' effect, potentiating β-lactams targeting PBP3. We tested a novel DBO, zidebactam, combined with cefepime. Methods: CLSI agar dilution MICs were determined with cefepime/zidebactam in a chequerboard format. Bactericidal activity was also measured. Results: Zidebactam MICs were ≤2 mg/L (mostly 0.12–0.5 mg/L) for most Escherichia coli, Klebsiella, Citrobacter and Enterobacter spp., but were >32 mg/L for Proteeae, most Serratia and a few E. coli, Klebsiella and Enterobacter/Citrobacter. The antibacterial activity of zidebactam dominated chequerboard studies for Enterobacteriaceae, but potentiation of cefepime was apparent for zidebactam-resistant isolates with class A and C enzymes, illustrating β-lactamase inhibition. Overall, cefepime/zidebactam inhibited almost all Enterobacteriaceae with AmpC, ESBL, K1, KPC and OXA-48-like β-lactamases at 1 + 1 mg/L and also 29 of 35 isolates with metallo-carbapenemases, including several resistant to zidebactam alone. Zidebactam MICs for 36 of 50 Pseudomonas aeruginosa were 4–16 mg/L, and the majority of AmpC, metallo-β-lactamase-producing and cystic fibrosis isolates were susceptible to cefepime/zidebactam at 8 + 8 mg/L. Zidebactam MICs for Acinetobacter baumannii and Stenotrophomonas maltophilia were >32 mg/L; potentiation of cefepime was frequent for S. maltophilia, but minimal for A. baumannii. Kill curve results largely supported MICs. Conclusion: Zidebactam represents a second triple-action DBO following RG6080, with lower MICs for Enterobacteriaceae and P. aeruginosa. Clinical evaluation of cefepime/zidebactam must critically evaluate the reliance that can be placed on this direct antibacterial activity and on the enhancer effect as well as β-lactamase inhibition
Potential of high-dose cefepime/tazobactam against multi-resistant Gram-negative pathogens
Background: Early β-lactamase inhibitors were combined with established penicillins, but different combinations may be more appropriate to counter current β-lactamase threats, with development facilitated by the US Generating Antibiotic Incentives Now (GAIN) Act. Cefepime/tazobactam is especially attractive, combining an AmpC-stable cephalosporin with a clinically established inhibitor, active against ESBLs and suitable for high-dose administration. Methods: Organisms (n = 563) were clinical isolates submitted to the UK national reference laboratory. MICs were determined by CLSI agar dilution with tazobactam at 4 mg/L and, for a subset, at 8 mg/L. Results: Cefepime/tazobactam 8 + 4 mg/L achieved coverage of 96%–100% of Enterobacteriaceae with penicillinases, AmpC, ESBL, K1 or OXA-48 β-lactamases. Even at 1 + 4 mg/L, the combination inhibited >94% of isolates with penicillinases, AmpC enzymes or ESBLs. Most Enterobacteriaceae with KPC and NDM carbapenemase were resistant at current cefepime breakpoints but 80% of those with VIM types were susceptible at 8 + 4 mg/L. Tazobactam did little to potentiate cefepime against non-fermenter groups, though gains were seen against AmpC-producing Acinetobacter spp. and Stenotrophomonas maltophilia. Increasing the tazobactam concentration to 8 mg/L gave further small increases in activity against Enterobacteriaceae groups. Conclusions: High-dose cefepime/tazobactam, justifying an 8 + 4 or 8 + 8 mg/L breakpoint, can achieve a carbapenem-like spectrum, with some additional coverage of OXA-48 (and maybe VIM) Enterobacteriaceae. Clinical evaluation is warranted
Comparison of Pitching from Flat Ground vs. 10-Inch Mound Regarding Elbow Varus Torque and Arm Speed
Purpose: The purpose of this study was to examine the effect of throwing surface and distance on varus elbow torque and arm speed. Methods: 11 male collegiate baseball pitchers (age = 20.73 ± 1.56 years, height = 175.26 ± 9.03 cm, mass = 70.31 ± 9.03 kg) participated in this study. Varus elbow torque and distance were measured using a 3D motion sensor housed in a spandex sleeve at the medial joint line of the elbow. Participants were instructed to complete their normal warmup routine as if they were about to pitch in a bullpen session or a game. Participants were then fitted with the sleeve and 3D motion sensor and then instructed to throw 5 maximum effort fastballs at both 60 feet 6 inches and 50 feet 6 inches from a 10-inch mound and 5 maximum effort fastballs at both 60 feet 6 inches and 50 feet 6 inches from flat ground. A two-way ANOVA with repeated measures was used to analyze the differences in elbow varus torque and arm speed when pitching from 60 feet 6 inches and 50 feet 6 inches from a 10-inch mound and from flat ground. Tests of significance were carried out at an alpha level p \u3c 0.05. Results: Significant differences in elbow varus torque were found when throwing from a 10-inch mound compared to flat ground (10-inch mound = 46.99 ± 2.36, Flat ground = 42.67 ± 3.14). No significant differences in elbow varus torque were found when throwing from 60 feet 6 inches compared to 50 feet 6 inches regardless of surface (60 feet 6 inches = 45.38 ± 2.96, 50 feet 6 inches = 44.28 ± 2.59). No significant differences in arm speed were found regardless of surface or distance. Conclusions: Throwing from a 10-inch mound appears to place more torque on the elbow than throwing from flat ground. Clinicians should be mindful of this fact when progressing patients through throwing programs
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Association between English Proficiency and Kidney Disease Knowledge and Communication Quality among Patients with ESKD
KEY POINTS: In one hospital-based safety-net dialysis unit, only one half of patients with ESKD knew their cause of kidney failure, which did not differ by English proficiency status. Patients with limited English proficiency (versus English-proficient patients) reported poorer communication with the dialysis care team (less listening, fewer clear explanations, less time spent). We highlight the need for tailored, patient-centered communication between limited English-proficient patients and dialysis care team members. BACKGROUND: ESKD is a chronic health condition for which communication between health care teams and patients is important to guide patient self-management activities. Yet, little is known about the quality of communication among patients with ESKD and their care team members. We examined the influence of patient's limited English proficiency (LEP) status on communication experiences at one dialysis center. METHODS: A survey was administered to adults receiving ESKD care at a dialysis unit within a public health care delivery system between July 2022 and February 2023, to ascertain kidney disease knowledge and perceptions of communication quality with the dialysis care team. Multivariable logistic and ordinal logistic regression models adjusted for age and sex were used to determine associations between LEP status and CKD knowledge. RESULTS: Among 93 eligible patients, 88.2% (n=82) completed the survey. Approximately 37.8% (n=31) had LEP, mean age was 58.8 years, 68.3% were men, mean dialysis vintage was 3.9 years, and 25% had a positive depression screen (LEP 30%; English-proficient 22%). A higher proportion of English-proficient patients screened positive for limited health literacy compared to those with LEP (74.5% versus 38.7%, P = 0.002). Overall, knowledge of assigned cause of ESKD (53.4%) and CKD/transplant knowledge (57.3%) was suboptimal. After adjustment, LEP status was not significantly associated with knowing the correct cause of kidney failure (odds ratio, 0.49; 95% confidence interval, 0.19 to 1.27) but was significantly associated with having a higher score on a CKD/transplant knowledge scale (odds ratio, 3.99; 95% confidence interval, 1.66 to 9.58). Patients with LEP reported poorer communication quality with dialysis providers and staff (less listening, fewer clear explanations, less time spent with patients) compared with English-proficient patients, although differences were not statistically significant. CONCLUSIONS: Overall communication between patients with ESKD and members of the dialysis care team was suboptimal, regardless of English proficiency. Interventions to enhance communication for ESKD patients are needed
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