946 research outputs found
The calibration of WET-sensor for volumetric water content and pore water electrical conductivity in different horticultural substrates
Outbreak report of investigation and control of an outbreak of Panton-Valentine Leukocidin-positive methicillin-sensitive Staphylococcus aureus (PVL-MSSA) infection in neonates and mothers
Background In January 2011, there was an outbreak of Panton-Valentine Leukocidin-positive methicillin-sensitive Staphylococcus aureus (PVL-MSSA) infection in a neonatal unit (NNU). We describe the investigation and control of an outbreak of PVL-MSSA infection in neonates. Setting: Neonatal unit in West London. Methods We performed descriptive and analytical (case-control study) epidemiological investigations. Microbiological investigations including screening of MSSA isolates by PCR for the presence of the luk-PV, mecA and mecC genes and comparison of isolate with Pulsed field gel electrophoresis (PFGE). Control measures were also introduced. Results Sixteen babies were infected/colonised with the outbreak strain. Of these, one baby developed blood stream infection, 12 developed skin pustules and four babies were colonised. Four mothers developed breast abscesses. Eighty-seven babies in the unit were screened and 16 were found to have same PVL-MSSA strain (spa type t005, belonging to MLST clonal complex 22). Multivariate analysis showed gestational age was significantly lower in cases compared to controls (mean gestational age: 31.7 weeks v 35.6 weeks; P = 0.006). Length of stay was significantly greater for cases, with a median of 25 days, compared to only 6 days for controls (P = 0.01). Most (88%) cases were born through caesarean section, compared to less than half of controls. (P = 0.002). No healthcare worker carriers and environmental source was identified. The outbreak was controlled by stopping new admissions to unit and reinforcing infection control precautions. The outbreak lasted for seven weeks. No further cases were reported in the following year. Conclusions Infection control teams have to be vigilant for rising prevalence of particular S. aureus clones in their local community as they may cause outbreaks in vulnerable populations in healthcare settings such as NNUs
DEMENTIA CARE ON MEDICAL AND MEDICINE FOR THE ELDERLY WARDS
Dementia is associated with increased health care resource utilisation and greater co-morbidity burden. Due to the
psychophysiological and social demands of dementia, specific approaches to care, communication, environment and clinical
treatment are needed. Timely diagnosis can greatly improve quality of life. Dementia is often not coded in hospitals as it is not
considered the primary reason for admission. These missed opportunities have potential to serve as important checkpoints for proper
diagnostic assessment. Upon discharge, adjustments can be made to manage these patients better.
In April 2012, the dementia CQUIN was introduced with goals for early diagnosis of dementia at point of hospital admission.
This study aims to investigate if the raised profile of dementia care has been generalised across the whole system, the impact on
management and whether there is a difference in dementia care between geriatric and medical wards.
There was excellent performance across the board for review of medication, prescription of anti-psychotics, ordering of routine
bloods and neurological examinations. . Increased awareness is needed for dementia-specific blood tests, namely: thyroid function
test, B12 and folate. Geriatric wards performed consistently better than medical wards for all aspects of clinical care examined. For
medical wards, incorporating multi-disciplinary care would be useful in managing these patients more holistically
Empirical constraints on the origin of fast radio bursts: volumetric rates and host galaxy demographics as a test of millisecond magnetar connection
The localization of the repeating FRB 121102 to a low-metallicity dwarf
galaxy at , and its association with a quiescent radio source,
suggests the possibility that FRBs originate from magnetars, formed by the
unusual supernovae in such galaxies. We investigate this via a comparison of
magnetar birth rates, the FRB volumetric rate, and host galaxy demographics. We
calculate average volumetric rates of possible millisecond magnetar production
channels such as superluminous supernovae (SLSNe), long and short gamma-ray
bursts (GRBs), and general magnetar production via core-collapse supernovae.
For each channel we also explore the expected host galaxy demographics using
their known properties. We determine for the first time the number density of
FRB emitters (the product of their volumetric birthrate and lifetime), Gpc, assuming that FRBs are predominantly emitted
from repetitive sources similar to FRB 121102 and adopting a beaming factor of
0.1. By comparing rates we find that production via rare channels (SLSNe, GRBs)
implies a typical FRB lifetime of 30-300 yr, in good agreement with
other lines of argument. The total energy emitted over this time is consistent
with the available energy stored in the magnetic field. On the other hand, any
relation to magnetars produced via normal core-collapse supernovae leads to a
very short lifetime of 0.5yr, in conflict with both theory and
observation. We demonstrate that due to the diverse host galaxy distributions
of the different progenitor channels, many possible sources of FRB birth can be
ruled out with host galaxy identifications. Conversely, targeted
searches of galaxies that have previously hosted decades-old SLSNe and GRBs may
be a fruitful strategy for discovering new FRBs and related quiescent radio
sources, and determining the nature of their progenitors
Explosion of a massive, He-rich star at z=0.16
We present spectroscopic and photometric data of the peculiar SN 2001gh,
discovered by the 'Southern inTermediate Redshift ESO Supernova Search'
(STRESS) at a redshift z=0.16. SN 2001gh has relatively high luminosity at
maximum (M_B = -18.55 mag), while the light curve shows a broad peak. An
early-time spectrum shows an almost featureless, blue continuum with a few weak
and shallow P-Cygni lines that we attribute to HeI. HeI lines remain the only
spectral features visible in a subsequent spectrum, obtained one month later. A
remarkable property of SN 2001gh is the lack of significant spectral evolution
over the temporal window of nearly one month separating the two spectra. In
order to explain the properties of SN 2001gh, three powering mechanism are
explored, including radioactive decays of a moderately large amount of 56Ni,
magnetar spin-down, and interaction of SN ejecta with circumstellar medium. We
favour the latter scenario, with a SN Ib wrapped in a dense, circumstellar
shell. The fact that no models provide an excellent fit with observations,
confirms the troublesome interpretation of the nature of SN 2001gh. A rate
estimate for SN 2001gh-like event is also provided, confirming the intrinsic
rarity of these objects.Comment: 11 pages, 8 figures, 3 tables. Accepted by MNRA
Spitzer Space Telescope Infrared Observations of the Binary Neutron Star Merger GW170817
We present Spitzer Space Telescope 3.6 and 4.5 micron observations of the
binary neutron star merger GW170817 at 43, 74, and 264 days post-merger. Using
the final observation as a template, we uncover a source at the position of
GW170817 at 4.5 micron with a brightness of 22.9+/-0.3 AB mag at 43 days and
23.8+/-0.3 AB mag at 74 days (the uncertainty is dominated by systematics from
the image subtraction); no obvious source is detected at 3.6 micron to a
3-sigma limit of >23.3 AB mag in both epochs. The measured brightness is dimmer
by a factor of about 2-3 times compared to our previously published kilonova
model, which is based on UV, optical, and near-IR data at <30 days. However,
the observed fading rate and color (m_{3.6}-m_{4.5}> 0 AB mag) are consistent
with our model. We suggest that the discrepancy is likely due to a transition
to the nebular phase, or a reduced thermalization efficiency at such late time.
Using the Spitzer data as a guide, we briefly discuss the prospects of
observing future binary neutron star mergers with Spitzer (in LIGO/Virgo
Observing Run 3) and the James Webb Space Telescope (in LIGO/Virgo Observing
Run 4 and beyond).Comment: 6 pages, 2 figures, submitted to ApJ
Cell migration in response to the amino-terminal fragment of urokinase requires epidermal growth factor receptor activation through an ADAM-mediated mechanism
BackgroundCell migration is an integral component of intimal hyperplasia development and proteases are pivotal in the process. Understanding the role of urokinase signaling within the cells of vasculature remains poorly defined. The study examines the role of amino-terminal fragment (ATF) of urokinase on a pivotal cross-talk receptor, epidermal growth factor receptor (EGFR). EGFR is transactivated by both G-protein-coupled receptors and receptor tyrosine kinases and is key to many of their responses. We hypothesize that A Disintegrin and Metalloproteinase Domains (ADAM) allows the transactivation of EGFR by ATF.ObjectiveTo determine the role of ADAM in EGFR transactivation by ATF in human vascular smooth muscle cells (VSMC) during cell migration.MethodsHuman coronary VSMC were cultured in vitro. Assays of EGFR phosphorylation were examined in response to ATF (10 nM) in the presence and absence of the matrix metalloprotease (MMP) inhibitor GM6001, the ADAM inhibitors TAPI-0 and TAPI-1, heparin binding epidermal growth factor (HB-EGF) inhibitor, CRM197, HB-EGF inhibitory antibodies, epidermal growth factor (EGF) inhibitory antibodies, and the EGFR inhibitor AG1478. The small interference ribonucleic acid (siRNA) against EGFR and ADAM-9, ADAM-10, ADAM-12, and adenoviral delivered Gbg inhibitor, βARKCT were also used.ResultsATF produced concentration-dependent VSMC migration (by wound assay and Boyden chamber), which was inhibited by increasing concentrations of AG1478. ATF was shown to induce time-dependent EGFR phosphorylation, which peaked at fourfold greater than control. Pre-incubation with the Gβγ inhibitor βARKCT inhibited EGFR activation by ATF. This migratory and EGFR response was inhibited by AG1478 in a concentration-dependent manner. Incubation with siRNA against EGFR blocked the ATF-mediated migratory and EGFR responses. EGFR phosphorylation by ATF was blocked by inhibition of MMP activity and the ligand HB-EGF. The presence of the ADAM inhibitors, TAPI-0 and TAPI-1 significantly decreased EGFR activation. EGFR phosphorylation by EGF was not interrupted by inhibition of MMP, ADAMs, or HB-EGF. Direct blockade of the EGFR prevented activation by both ATF and EGF. Incubation with siRNA to ADAM-9 and -10 significantly reduced HB-EGF release from VSMC and EGFR activation in response to ATF. The siRNA against ADAM-12 had no effect.ConclusionATF can induce transactivation of EGFR by an ADAM-mediated, HB-EGF-dependent process. Targeting a pivotal cross-talk receptor such as EGFR is an attractive molecular target to inhibit cell migration.Clinical RelevanceCell migration is an integral component of intimal hyperplasia development and proteases are pivotal in the process. Understanding the role of urokinase signaling within the cells of vasculature remains poorly defined. The study examines the role of ATF of urokinase on a pivotal cross-talk receptor, EGFR. EGFR is transactivated by both G-protein-coupled receptors and receptor tyrosine kinases and is key to many of their responses. ATF can induce transactivation of EGFR by an ADAM-mediated, HB-EGF-dependent process. Targeting a pivotal cross-talk receptor such as EGFR, which can be transactivated by both G-protein-coupled receptors and receptor tyrosine kinases is an attractive molecular target
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