1,241 research outputs found
A new connection between the opening angle and the large-scale morphology of extragalactic radio sources
In the case of an initially conical jet, we study the relation between jet
collimation by the external pressure and large-scale morphology. We first
consider the important length-scales in the problem, and then carry out
axisymmetric hydrodynamic simulations that include, for certain parameters, all
these length-scales. We find three important scales related to the collimation
region: (i) where the sideways ram-pressure equals the external pressure, (ii)
where the jet density equals the ambient density, and (iii) where the forward
ram-pressure falls below the ambient pressure. These scales are set by the
external Mach-number and opening angle of the jet. We demonstrate that the
relative magnitudes of these scales determine the collimation, Mach-number,
density and morphology of the large scale jet. Based on analysis of the shock
structure, we reproduce successfully the morphology of Fanaroff-Riley (FR)
class I and II radio sources. Within the framework of the model, an FR I radio
source must have a large intrinsic opening angle. Entrainment of ambient gas
might also be important. We also show that all FR I sources with radio lobes or
similar features must have had an earlier FR II phase.Comment: 14 pages, 10 figures, accepted by MNRAS, same as previous versio
Health Care Opinion Leaders' Views on Vulnerable Populations in the U.S. Health System
Presents survey responses from healthcare experts about the equity of the health system; healthcare reform's potential effects on safety-net institutions, access, and financial protection; and strategies for improving quality of care
Approaches to overcome flow cytometry limitations in the analysis of cells from veterinary relevant species
BACKGROUND: Flow cytometry is a powerful tool for the multiparameter analysis of leukocyte subsets on the single cell level. Recent advances have greatly increased the number of fluorochrome-labeled antibodies in flow cytometry. In particular, an increase in available fluorochromes with distinct excitation and emission spectra combined with novel multicolor flow cytometers with several lasers have enhanced the generation of multidimensional expression data for leukocytes and other cell types. However, these advances have mainly benefited the analysis of human or mouse cell samples given the lack of reagents for most animal species. The flow cytometric analysis of important veterinary, agricultural, wildlife, and other animal species is still hampered by several technical limitations, even though animal species other than the mouse can serve as more accurate models of specific human physiology and diseases.
RESULTS: Here we present time-tested approaches that our laboratory regularly uses in the multiparameter flow cytometric analysis of ovine leukocytes. The discussed approaches will be applicable to the analysis of cells from most animal species and include direct modification of antibodies by covalent conjugation or Fc-directed labeling (Zenonโข technology), labeled secondary antibodies and other second step reagents, labeled receptor ligands, and antibodies with species cross-reactivity.
CONCLUSIONS: Using refined technical approaches, the number of parameters analyzed by flow cytometry per cell sample can be greatly increased, enabling multidimensional analysis of rare samples and giving critical insight into veterinary and other less commonly analyzed species. By maximizing information from each cell sample, multicolor flow cytometry can reduce the required number of animals used in a study
Interpretation of Blood Gas and Acid-Base Data
Before discussing clinical cases we would like to present a brief recent history of developments in the area of acid-base and blood gas analysis so some appreciation of the efforts of those who have worked to simplify measurement techniques and clarify clinical evaluation procedures may be justly given. We would also like to illustrate with the aid of two clinical cases the importance of proper interpretation of acid-base and blood gas data
Recent advances in the use of opioids for cancer pain
Opioids are the mainstay of treatment for moderate to severe cancer pain. In recent years there have been many advances in the use of opioids for cancer pain. Availability and consumption of opioids have increased and opioids other than morphine (including methadone, fentanyl, oxycodone) have become more widely used. Inter-individual variation in response to opioids has been identified as a significant challenge in the management of cancer pain. Many studies have been published demonstrating the benefits of opioid switching as a clinical maneuver to improve tolerability. Constipation has been recognized as a significant burden in cancer patients on opioids. Peripherally restricted opioid antagonists have been developed for the prevention and management of opioid induced constipation. The phenomenon of breakthrough pain has been characterized and novel modes of opioid administration (transmucosal, intranasal, sublingual) have been explored to facilitate improved management of breakthrough cancer pain. Advances have also been made in the realm of molecular biology. Pharmacogenetic studies have explored associations between clinical response to opioids and genetic variation at a DNA level. To date these studies have been small but future research may facilitate prospective prediction of response to individual drugs
Measurements of the Cosmological Evolution of Magnetic Fields with the Square Kilometre Array
We investigate the potential of the Square Kilometre Array (SKA) for
measuring the magnetic fields in clusters of galaxies via Faraday rotation of
background polarised sources. [...] We find that about 10 per cent of the sky
is covered by a significant extragalactic Faraday screen. Most of it has
rotation measures between 10 and 100 rad/m/m. We argue that the cluster centres
should have up to about 5000 rad/m/m. We show that the proposed mid frequency
aperture array of the SKA as well as the lowest band of the SKA dish array are
well suited to make measurements for most of these rotation measure values,
typically requiring a signal-to-noise of ten. We calculate the spacing of
sources forming a grid for the purpose of measuring foreground rotation
measures: it reaches a spacing of 36 arcsec for a 100 hour SKA observation per
field. We also calculate the statistics for background RM measurements in
clusters of galaxies. We find that a first phase of the SKA would allow us to
take stacking experiments out to high redshifts (>1), and provide improved
magnetic field structure measurements for individual nearby clusters. The full
SKA aperture array would be able to make very detailed magnetic field structure
measurements of clusters with more than 100 background sources per cluster up
to a redshift of 0.5 and more than 1000 background sources per cluster for
nearby clusters, and could for reasonable assumptions about future measurements
of electron densities in high redshift clusters constrain the power law index
for the magnetic field evolution to better than dm=0.4, if the magnetic field
in clusters should follow B ~ (1+z)^m.Comment: 12 pages, 10 figures, 3 tables, accepted by MNRAS, minor correction
to eq (5
Quasars from the 7C Survey - I:sample selection and radio maps
We describe the selection of candidate radio-loud quasars obtained by
cross-matching radio source positions from the low-frequency (151 MHz) 7C
survey with optical positions from five pairs of EO POSS-I plates scanned with
the Cambridge Automatic Plate-measuring Machine (APM). The sky region studied
is centred at RA 10 h 28 m, Dec +41 and covers 0.057 sr. We present VLA
observations of the quasar candidates, and tabulate various properties derived
from the radio maps. We discuss the selection criteria of the resulting `7CQ'
sample of radio-loud quasars. The 70 confirmed quasars, and some fraction of
the 36 unconfirmed candidates, constitute a filtered sample with the following
selection criteria: 151-MHz flux density S151 > 100 mJy; POSS-I E-plate
magnitude E approx R < 20; and POSS-I colour (O - E) < 1.8; the effective area
of the survey drops significantly below S151 approx 200 mJy. We argue that the
colour criterion excludes few if any quasars, but note, on the basis of recent
work by Willott et al. (1998b), that the E magnitude limit probably excludes
more than 50 per cent of the radio-loud quasars.Comment: Latex, 30 pages. Accepted by MNRA
A Population-Based Surveillance Study of Shared Genotypes of Escherichia coli Isolates from Retail Meat and Suspected Cases of Urinary Tract Infections.
There is increasing evidence that retail food may serve as a source of Escherichia coli that causes community-acquired urinary tract infections, but the impact of this source in a community is not known. We conducted a prospective, population-based study in one community to examine the frequency of recovery of uropathogenic E. coli genotypes from retail meat samples. We analyzed E. coli isolates from consecutively collected urine samples of patients suspected to have urinary tract infections (UTIs) at a university-affiliated health service and retail meat samples from the same geographic region. We genotyped all E. coli isolates by multilocus sequence typing (MLST) and tested them for antimicrobial susceptibility. From 2016 to 2017, we cultured 233 E. coli isolates from 230 (21%) of 1,087 urine samples and 177 E. coli isolates from 120 (28%) of 427 retail meat samples. Urine samples contained 61 sequence types (STs), and meat samples had 95 STs; 12 STs (ST10, ST38, ST69, ST80, ST88, ST101, ST117, ST131, ST569, ST906, ST1844, and ST2562) were common to both. Thirty-five (81%) of 43 meat isolates among the 12 STs were from poultry. Among 94 isolates in the 12 STs, 26 (60%) of 43 retail meat isolates and 15 (29%) of 51 human isolates were pan-susceptible (P < 0.005). We found that 21% of E. coli isolates from suspected cases of UTIs belonged to STs found in poultry. Poultry may serve as a possible reservoir of uropathogenic E. coli (UPEC). Additional studies are needed to demonstrate transmission pathways of these UPEC genotypes and their food sources.IMPORTANCE Community-acquired urinary tract infection caused by Escherichia coli is one of the most common infectious diseases in the United States, affecting approximately seven million women and costing approximately 11.6 billion dollars annually. In addition, antibiotic resistance among E. coli bacteria causing urinary tract infection continues to increase, which greatly complicates treatment. Identifying sources of uropathogenic E. coli and implementing prevention measures are essential. However, the reservoirs of uropathogenic E. coli have not been well defined. This study demonstrated that poultry sold in retail stores may serve as one possible source of uropathogenic E. coli This finding adds to a growing body of evidence that suggests that urinary tract infection may be a food-borne disease. More research in this area can lead to the development of preventive strategies to control this common and costly infectious disease
Digital Advance Care Planning with Severe Mental Illness:A retrospective observational cohort analysis of the use of an electronic palliative care coordination system
Abstract Background People living with severe mental illness (SMI) face significant health inequalities, including in palliative care. Advance Care Planning (ACP) is widely recommended by palliative care experts and could reduce inequalities. However, implementing ACP with this group is challenging. Electronic Palliative Care Coordination Systems such as Coordinate my Care (CMC) have been introduced to support documentation and sharing of ACP records with relevant healthcare providers. This study explores the use of CMC amongst those with SMI and aims to describe how those with a primary diagnosis of SMI who have used CMC for ACP, and makes recommendations for future research and policy. Method A retrospective observational cohort analysis was completed of CMC records created 01/01/2010โ31/09/2021 where the service user had a primary diagnosis of SMI, with no exclusions based on comorbidities. Descriptive statistics were used to report on characteristics including: age, diagnosis, individual prognosis and resuscitation status. Thematic analysis was used to report on the content of patientsโ statements of preference. Results 1826 records were identified. Of this sample most (60.1%) had capacity to make treatment decisions, 47.8% were aged under 70, 86.7% were given a prognosis of โyearsโ and most (63.1%) remained for full cardio-pulmonary resuscitation in the event of cardio-pulmonary arrest. Records with completed statements of preferences (20.3%) contained information about preferences for physical and mental health treatment care as well as information about patient presentation and capacity, although most were brief and lacked expression of patient voice. Discussion Compared to usual CMC users, the cohort of interest are relatively able, younger people using CMC to make long-term plans for active physical and mental health treatment. ADM is a service user-driven process, and so it was expected that authentic patient voice would be expressed within statements of preference, however this was mostly not achieved. Conclusions This digital tool is being used by people with SMI but to plan for more than palliative care. This cohort and supporting professionals have used CMC to plan for longer term physical and mental healthcare. Future research and policy should focus on development of tailored digital tools for people with SMI to plan for palliative, physical and mental healthcare and support expression of patient voice
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