589 research outputs found
Kumjian-Pask algebras of locally convex higher-rank graphs
The Kumjian-Pask algebra of a higher-rank graph generalises the Leavitt path
algebra of a directed graph. We extend the definition of Kumjian-Pask algebra
to row-finite higher-rank graphs with sources which satisfy a
local-convexity condition. After proving versions of the graded-uniqueness
theorem and the Cuntz-Krieger uniqueness theorem, we study the Kumjian-Pask
algebra of rank-2 Bratteli diagrams by studying certain finite subgraphs which
are locally convex. We show that the desourcification procedure of Farthing and
Webster yields a row-finite higher-rank graph without sources
such that the Kumjian-Pask algebras of and are
Morita equivalent. We then use the Morita equivalence to study the ideal
structure of the Kumjian-Pask algebra of by pulling the appropriate
results across the equivalence.Comment: Minor changes made. This version is to appear in the Journal of
Algebr
AEROBIC DEGRADATION OF NAPHTHALENE, FLUORANTHENE, PYRENE AND CHRYSENE USING INDIGENOUS STRAINS OF BACTERIA ISOLATED FROM A FORMER INDUSTRIAL SITE
Four bacterial strains were isolated from a former industrial site contaminated with organic and inorganic pollutants for
decades. The isolation was done using naphthalene as sole source of carbon and energy during the enrichment. 16S
rRNA gene sequence analyses of the four isolates (OC1, OC2, OC3, and OC4) assigned the strains to the genus,
Enterobacter (OC1) and Pseudomonas (OC2, OC3, and OC4). The degradation and growth behavior of the four isolates
was investigated on naphthalene, fluoranthene, pyrene and chrysene. All the strains utilized naphthalene, fluoranthene,
chrysene but pyrene partially, as sole sources of carbon and energy. The time course studies using relative concentration
> 100ppm, >115ppm, > 89ppm and > 12 ppm for naphthalene, fluoranthene, pyrene and chrysene respectively, resulted
in rapid exponential increases in cell numbers and concomitant disappearance of the test substrates. Naphthalene was
degraded between the range of 25 % and 99%, while chrysene degradation ranged between of 35 and 69%, pyrene 4 -
21% and fluoranthene 7 -19 %. Our results suggest that contaminated, former industrial sites contain a capable microbial
community that may be used for bioremediation of the site
WEATHERING, RADIOGENIC ISOTOPES, AND MARINE RECORDS OF GLACIAL DYNAMICS
Glacial advance and retreat is related to numerous climate system feedbacks; yet, this dynamic glacial activity tends to erase its own terrestrial record. As a result, deep-sea sediments may be the best archives for studying past glacial processes. Interpretations of these archives depend on understanding terrestrial sources to the marine sediments. Systematic spatial variations in dissolved riverine and soil leachate Sr, Nd and Pb isotopes across an ~175 km transect from the Greenland Ice Sheet to the coast present an analog for temporal changes during glacial retreat. Specifically, the offset between dissolved (riverine or soil leachates) and bulk sediment (bedload or leached soil) isotopes is highest in young glacial sediments close to the ice sheet and approaches zero in 10 ky old glacial sediments at the coast. This difference is attributed to a transition from preferential chemical weathering of trace minerals and/or radiation damaged sites in freshly comminuted, ice-proximal sediments to predominant weathering of less radiogenic (Sr and Pb) and more radiogenic (Nd) isotopes from bulk major minerals in more extensively weathered coastal material. These isotopes are transported to the ocean where the residence time of Sr is too long to be an effective tracer of local or regional glacial processes; however, the short residence time of Pb makes it an excellent tracer of local chemical weathering processes and the intermediate residence time of Nd allows application to region studies. Data from IODP Sites 1302/3 (3550 m water depth) in the NW Atlantic illustrate that seawater Pb and Nd isotopes preserved in authigenic FeMn-oxide coatings respond dramatically to retreat of the Laurentide Ice Sheet during the penultimate glacial termination (T2; 135-129 ka) and to rapid variations during Dansgaard-Oeschger cycles. These data suggest deep-sea radiogenic isotopes preserve a more detailed record of the long term history of ice sheet dynamics than terrestrial proxies. The systematic variation in chemical weathering linked to ice sheet retreat and reflected in deep-sea isotope records may also help refine estimates of past and future carbon cycling and fluxes of nutrients and isotopes to the ocean associated with high latitude climate change
Non-destructive evaluation of isotropic plate structures by means of mode filtering in the frequency-wavenumber domain
Non-Destructive Testing (NDT) techniques are prevalent in the aerospace, green energy and automotive industries. These techniques, including ultrasound, despite their use, still have limitations surrounding speed and resolution. This work presents the development of a band-pass mode filtering technique in the frequency wavenumber domain for the purpose of damage detection in isotropic materials. Data was captured in the temporal and spatial domain using a 3D Scanning Laser Doppler Vibrometer (SLDV) with piezoelectric transducers exciting the structure with a variety of steady state signals ranging in frequency from 75 kHz to 400 kHz and a frequency modulated signal from 75 kHz to 400 kHz. A thickness map was created based on the frequency and wavelength of the
A0
Lamb wave mode. The technique was demonstrated on two aluminium specimens with dimensions of 400 mm by 400 mm with a thickness range of 0.5 mm to 8 mm with distinct geometric features. Through using multi-frequency excitation combined with mode based filters an estimation of thickness was achieved with a mean percentage thickness error of 15%. Circular thickness reductions with a diameter of 10 mm were clearly identified at the maximum plate thickness of 8 mm. This technique was shown to perform better than wavenumber filtering by allowing data from multi frequency steady state excitation to be combined into a single resulting thickness map. This improvement was shown to be particularly important at greater thicknesses
A novel small molecule target in human airway smooth muscle for potential treatment of obstructive lung diseases: a staged high-throughput biophysical screening
<p>Abstract</p> <p>Background</p> <p>A newly identified mechanism of smooth muscle relaxation is the interaction between the small heat shock protein 20 (HSP20) and 14-3-3 proteins. Focusing upon this class of interactions, we describe here a novel drug target screening approach for treating airflow obstruction in asthma.</p> <p>Methods</p> <p>Using a high-throughput fluorescence polarization (FP) assay, we screened a library of compounds that could act as small molecule modulators of HSP20 signals. We then applied two quantitative, cell-based biophysical methods to assess the functional efficacy of these molecules and rank-ordered their abilities to relax isolated human airway smooth muscle (ASM). Scaling up to the level of an intact tissue, we confirmed in a concentration-responsive manner the potency of the cell-based hit compounds.</p> <p>Results</p> <p>Among 58,019 compound tested, 268 compounds caused 20% or more reduction of the polarized emission in the FP assay. A small subset of these primary screen hits, belonging to two scaffolds, caused relaxation of isolated ASM cell <it>in vitro </it>and attenuated active force development of intact tissue <it>ex vivo</it>.</p> <p>Conclusions</p> <p>This staged biophysical screening paradigm provides proof-of-principle for high-throughput and cost-effective discovery of new small molecule therapeutic agents for obstructive lung diseases.</p
Theoretical Review of B-physics
Weak decays and mixing of B-hadrons play a special role in our understanding
of the physics of the Standard Model and beyond. The measured amplitudes,
however, result from a complicated interplay of weak and strong interaction
effects. Understanding strong interaction dynamics, which becomes simpler for
heavy quarks, is thus a fundamental part of the game. In this review, several
theoretical aspects of B dynamics which are relevant for current and future
experimental measurements are discussed.Comment: LaTeX, 27 pages, 5 figures. Summary talk given at BEAUTY 96, June
17-21 1996, Rome (Italy), to appear in the Proceeding
The Effect of Intermittent Fasting on Appetite: A Systematic Review and Meta-Analysis
This is the final version. Available on open access from MDPI via the DOI in this recordData Availability Statement:
Data sharing not applicablePreviously, narrative reviews have considered the effects of intermittent fasting on appetite. One suggestion is that intermittent fasting attenuates an increase in appetite that typically accompanies weight loss. Here, we conducted the first systematic review and meta-analysis to quantify the effects of intermittent fasting on appetite, when compared to a continuous energy restriction intervention. Five electronic databases and trial registers were searched in February 2021 and February 2022. Abstracts (N = 2800) were screened and 17 randomized controlled trials (RCTs), consisting of a variety of intermittent fasting regimes, met our inclusion criteria. The total number of participants allocated to interventions was 1111 and all RCTs were judged as having either some concerns or a high risk of bias (Cochrane RoB 2.0 tool). Random effects meta-analyses were conducted on change-from-baseline appetite ratings. There was no clear evidence that intermittent fasting affected hunger (WMD = -3.03; 95% CI [-8.13, 2.08]; p = 0.25; N = 13), fullness (WMD = 3.11; 95% CI [-1.46, 7.69]; p = 0.18; N = 10), desire to eat (WMD = -3.89; 95% CI [-12.62, 4.83]; p = 0.38; N = 6), or prospective food consumption (WMD = -2.82; 95% CI [-3.87, 9.03]; p = 0.43; N = 5), differently to continuous energy restriction interventions. Our results suggest that intermittent fasting does not mitigate an increase in our drive to eat that is often associated with continuous energy restriction.Medical Research Council (MRC)National Institute for Health and Care Research (NIHR
The Metallicity Distribution Functions of SEGUE G and K dwarfs: Constraints for Disk Chemical Evolution and Formation
We present the metallicity distribution function (MDF) for 24,270 G and
16,847 K dwarfs at distances from 0.2 to 2.3 kpc from the Galactic plane, based
on spectroscopy from the Sloan Extension for Galactic Understanding and
Exploration (SEGUE) survey. This stellar sample is significantly larger in both
number and volume than previous spectroscopic analyses, which were limited to
the solar vicinity, making it ideal for comparison with local volume-limited
samples and Galactic models. For the first time, we have corrected the MDF for
the various observational biases introduced by the SEGUE target selection
strategy. The SEGUE sample is particularly notable for K dwarfs, which are too
faint to examine spectroscopically far from the solar neighborhood. The MDF of
both spectral types becomes more metal-poor with increasing |Z|, which reflects
the transition from a sample with small [alpha/Fe] values at small heights to
one with enhanced [alpha/Fe] above 1 kpc. Comparison of our SEGUE distributions
to those of two different Milky Way models reveals that both are more
metal-rich than our observed distributions at all heights above the plane. Our
unbiased observations of G and K dwarfs provide valuable constraints over the
|Z|-height range of the Milky Way disk for chemical and dynamical Galaxy
evolution models, previously only calibrated to the solar neighborhood, with
particular utility for thin- and thick-disk formation models.Comment: 70 pages, 25 figures, 7 tables. Accepted by The Astrophysical Journa
Health Economic Impact of a Multicenter Quality-of-Care Initiative for Reducing Unplanned Healthcare Utilization Among Patients With Inflammatory Bowel Disease
“There's very little that you can do other than refer them to the doctor if you think they've got postnatal depression”: Scoping the potential for perinatal mental health care by community pharmacists: Community pharmacists and perinatal mental health
Background: Twenty percent of women in the UK develop perinatal mental health (PMH) problems, which have widespread effects on maternal and child health. Community pharmacists are ideally placed to identify PMH problems and refer to other trained healthcare professionals. Objective: This study explored community pharmacists’ attitudes, current counselling practices, and barriers to providing mental health advice to perinatal women. Methods: A qualitative focus group study was performed virtually with community pharmacists (n = 11), working in urban settings across London. A topic guide was used to cover current counselling practice, barriers to and confidence in counselling women, and thoughts on potential pharmacist-led perinatal mental health services. The focus groups were recorded, transcribed, and analysed using thematic analysis. Results: Three themes were identified: Doing Mental Health Care; Willing, but Unable; and Introspection and reflection, which were related through a central organising concept of ‘Perinatal mental health care as a new frontier for community pharmacy’. It was found that while community pharmacists provide mental health advice to perinatal women and their partners, they lacked confidence, which was related to a lack of knowledge and inadequate training opportunities. Organisational barriers were identified including a lack of a formal referral pathway to existing mental health services and other trained healthcare professionals. Perceptions of opportunities and recommendations for service improvement and change were also garnered. Conclusion: This study demonstrates community pharmacists have a potential role within community mental healthcare in identification of PMH problems and providing appropriate advice and support. Upskilling community pharmacists in mental health should be considered to increase knowledge and confidence while formal referral pathways to other trained healthcare professionals and existing services should be established and made available to pharmacists
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