781 research outputs found
The Bobath Clinical Reasoning Framework: A systems science approach to the complexity of neurodevelopmental conditions, including cerebral palsy
The current recommended developmental Bobath practice within the Bobath Clinical Reasoning Framework (BCRF) can be conceptualized using the lens of systems science, thereby providing a holistic perspective on the interrelatedness and interconnectedness of the variables associated with childhood-onset disability. The BCRF is defined as an in-depth clinical reasoning framework that can be applied to help understand the relationships between the domains of the International Classification of Functioning, Disability and Health, how those domains can be influenced, and how they impact each other. The BCRF is a transdisciplinary observational system and practical reasoning approach that results in an intervention plan. This provides a holistic understanding of the complexity of situations associated with disorders such as cerebral palsy (CP) and the basis for the lifelong management and habilitation of people living with neurological disorders. The clinical reasoning used by the BCRF draws on the important contextual factors of the individual and their social environment, primarily the family unit. It is rooted in an understanding of the interrelationships between typical and atypical development, pathophysiology (sensorimotor, cognitive, behavioural), and neuroscience, and the impact of these body structure and function constructs on activity and participation. The systems science model integral to the BCRF is a useful way forward in understanding and responding to the complexity of CP, the overarching goal being to optimize the lived experience of any individual in any context
Role of WDHD1 in Human Papillomavirus-Mediated Oncogenesis Identified by Transcriptional profiling of E7-expressing cells
Supernova 2007bi as a pair-instability explosion
Stars with initial masses 10 M_{solar} < M_{initial} < 100 M_{solar} fuse
progressively heavier elements in their centres, up to inert iron. The core
then gravitationally collapses to a neutron star or a black hole, leading to an
explosion -- an iron-core-collapse supernova (SN). In contrast, extremely
massive stars (M_{initial} > 140 M_{solar}), if such exist, have oxygen cores
which exceed M_{core} = 50 M_{solar}. There, high temperatures are reached at
relatively low densities. Conversion of energetic, pressure-supporting photons
into electron-positron pairs occurs prior to oxygen ignition, and leads to a
violent contraction that triggers a catastrophic nuclear explosion. Tremendous
energies (>~ 10^{52} erg) are released, completely unbinding the star in a
pair-instability SN (PISN), with no compact remnant. Transitional objects with
100 M_{solar} < M_{initial} < 140 M_{solar}, which end up as iron-core-collapse
supernovae following violent mass ejections, perhaps due to short instances of
the pair instability, may have been identified. However, genuine PISNe, perhaps
common in the early Universe, have not been observed to date. Here, we present
our discovery of SN 2007bi, a luminous, slowly evolving supernova located
within a dwarf galaxy (~1% the size of the Milky Way). We measure the exploding
core mass to be likely ~100 M_{solar}, in which case theory unambiguously
predicts a PISN outcome. We show that >3 M_{solar} of radioactive 56Ni were
synthesized, and that our observations are well fit by PISN models. A PISN
explosion in the local Universe indicates that nearby dwarf galaxies probably
host extremely massive stars, above the apparent Galactic limit, perhaps
resulting from star formation processes similar to those that created the first
stars in the Universe.Comment: Accepted version of the paper appearing in Nature, 462, 624 (2009),
including all supplementary informatio
Left ventricular non-compaction: clinical features and cardiovascular magnetic resonance imaging
Background: It is apparent that despite lack of family history, patients with the morphological characteristics of left ventricular non-compaction develop arrhythmias, thrombo-embolism and left ventricular dysfunction. METHODS: Forty two patients, aged 48.7 +/- 2.3 yrs (mean +/- SEM) underwent cardiovascular magnetic resonance (CMR) for the quantification of left ventricular volumes and extent of non-compacted (NC) myocardium. The latter was quantified using planimetry on the two-chamber long axis LV view (NC area). The patients included those referred specifically for CMR to investigate suspected cardiomyopathy, and as such is represents a selected group of patients. RESULTS: At presentation, 50% had dyspnoea, 19% chest pain, 14% palpitations and 5% stroke. Pulmonary embolism had occurred in 7% and brachial artery embolism in 2%. The ECG was abnormal in 81% and atrial fibrillation occurred in 29%. Transthoracic echocardiograms showed features of NC in only 10%. On CMR, patients who presented with dyspnoea had greater left ventricular volumes (both p < 0.0001) and a lower left ventricular ejection fraction (LVEF) (p < 0.0001) than age-matched, healthy controls. In patients without dyspnoea (n = 21), NC area correlated positively with end-diastolic volume (r = 0.52, p = 0.0184) and end-systolic volume (r = 0.56, p = 0.0095), and negatively with EF (r = -0.72, p = 0.0001). CONCLUSION: Left ventricular non-compaction is associated with dysrrhythmias, thromboembolic events, chest pain and LV dysfunction. The inverse correlation between NC area and EF suggests that NC contributes to left ventricular dysfunction
A Relativistic Type Ibc Supernova Without a Detected Gamma-ray Burst
Long duration gamma-ray bursts (GRBs) mark the explosive death of some
massive stars and are a rare sub-class of Type Ibc supernovae (SNe Ibc). They
are distinguished by the production of an energetic and collimated relativistic
outflow powered by a central engine (an accreting black hole or neutron star).
Observationally, this outflow is manifested in the pulse of gamma-rays and a
long-lived radio afterglow. To date, central engine-driven SNe have been
discovered exclusively through their gamma-ray emission, yet it is expected
that a larger population goes undetected due to limited satellite sensitivity
or beaming of the collimated emission away from our line-of-sight. In this
framework, the recovery of undetected GRBs may be possible through radio
searches for SNe Ibc with relativistic outflows. Here we report the discovery
of luminous radio emission from the seemingly ordinary Type Ibc SN 2009bb,
which requires a substantial relativistic outflow powered by a central engine.
The lack of a coincident GRB makes SN 2009bb the first engine-driven SN
discovered without a detected gamma-ray signal. A comparison with our extensive
radio survey of SNe Ibc reveals that the fraction harboring central engines is
low, ~1 percent, measured independently from, but consistent with, the inferred
rate of nearby GRBs. Our study demonstrates that upcoming optical and radio
surveys will soon rival gamma-ray satellites in pinpointing the nearest
engine-driven SNe. A similar result for a different supernova is reported
independently.Comment: To appear in Nature on Jan 28 2010. Embargoed for discussion in the
press until 13:00 US Eastern Time on Jan 27 (Accepted version, 27 pages,
Manuscript and Suppl. Info.
Spatial heterogeneity and peptide availability determine CTL killing efficiency in vivo
The rate at which a cytotoxic T lymphocyte (CTL) can survey for infected cells is a key ingredient of models of vertebrate immune responses to intracellular pathogens. Estimates have been obtained using in vivo cytotoxicity assays in which peptide-pulsed splenocytes are killed by CTL in the spleens of immunised mice. However the spleen is a heterogeneous environment and splenocytes comprise multiple cell types. Are some cell types intrinsically more susceptible to lysis than others? Quantitatively, what impacts are made by the spatial distribution of targets and effectors, and the level of peptide-MHC on the target cell surface? To address these questions we revisited the splenocyte killing assay, using CTL specific for an epitope of influenza virus. We found that at the cell population level T cell targets were killed more rapidly than B cells. Using modeling, quantitative imaging and in vitro killing assays we conclude that this difference in vivo likely reflects different migratory patterns of targets within the spleen and a heterogeneous distribution of CTL, with no detectable difference in the intrinsic susceptibilities of the two populations to lysis. Modeling of the stages involved in the detection and killing of peptide-pulsed targets in vitro revealed that peptide dose influenced the ability of CTL to form conjugates with targets but had no detectable effect on the probability that conjugation resulted in lysis, and that T cell targets took longer to lyse than B cells. We also infer that incomplete killing in vivo of cells pulsed with low doses of peptide may be due to a combination of heterogeneity in peptide uptake and the dissociation, but not internalisation, of peptide-MHC complexes. Our analyses demonstrate how population-averaged parameters in models of immune responses can be dissected to account for both spatial and cellular heterogeneity
An optical supernova associated with the X-ray flash XRF 060218
Long-duration gamma-ray bursts (GRBs) are associated with type Ic supernovae
that are more luminous than average and that eject material at very high
velocities. Less-luminous supernovae were not hitherto known to be associated
with GRBs, and therefore GRB-supernovae were thought to be rare events. Whether
X-ray flashes - analogues of GRBs, but with lower luminosities and fewer
gamma-rays - can also be associated with supernovae, and whether they are
intrinsically 'weak' events or typical GRBs viewed off the axis of the burst,
is unclear. Here we report the optical discovery and follow-up observations of
the type Ic supernova SN 2006aj associated with X-ray flash XRF 060218.
Supernova 2006aj is intrinsically less luminous than the GRB-supernovae, but
more luminous than many supernovae not accompanied by a GRB. The ejecta
velocities derived from our spectra are intermediate between these two groups,
which is consistent with the weakness of both the GRB output and the supernova
radio flux. Our data, combined with radio and X-ray observations, suggest that
XRF 060218 is an intrinsically weak and soft event, rather than a classical GRB
observed off-axis. This extends the GRB-supernova connection to X-ray flashes
and fainter supernovae, implying a common origin. Events such as XRF 060218 are
probably more numerous than GRB-supernovae.Comment: Final published versio
Interacting Supernovae: Types IIn and Ibn
Supernovae (SNe) that show evidence of strong shock interaction between their
ejecta and pre-existing, slower circumstellar material (CSM) constitute an
interesting, diverse, and still poorly understood category of explosive
transients. The chief reason that they are extremely interesting is because
they tell us that in a subset of stellar deaths, the progenitor star may become
wildly unstable in the years, decades, or centuries before explosion. This is
something that has not been included in standard stellar evolution models, but
may significantly change the end product and yield of that evolution, and
complicates our attempts to map SNe to their progenitors. Another reason they
are interesting is because CSM interaction is an efficient engine for making
bright transients, allowing super-luminous transients to arise from normal SN
explosion energies, and allowing transients of normal SN luminosities to arise
from sub-energetic explosions or low radioactivity yield. CSM interaction
shrouds the fast ejecta in bright shock emission, obscuring our normal view of
the underlying explosion, and the radiation hydrodynamics of the interaction is
challenging to model. The CSM interaction may also be highly non-spherical,
perhaps linked to binary interaction in the progenitor system. In some cases,
these complications make it difficult to definitively tell the difference
between a core-collapse or thermonuclear explosion, or to discern between a
non-terminal eruption, failed SN, or weak SN. Efforts to uncover the physical
parameters of individual events and connections to possible progenitor stars
make this a rapidly evolving topic that continues to challenge paradigms of
stellar evolution.Comment: Final draft of a chapter in the "SN Handbook". Accepted. 25 pages, 3
fig
Percutaneous Exposure Incidents of the Health Care Personnel in a Newly Founded Tertiary Hospital: A Prospective Study
BACKGROUND: Percutaneous exposure incidents (PEIs) and blood splashes on the skin of health care workers are a major concern, since they expose susceptible employees to the risk of infectious diseases. We undertook this study in order to estimate the overall incidence of such injuries in a newly founded tertiary hospital, and to evaluate possible changes in their incidence over time. METHODOLOGY/PRINCIPAL FINDINGS: We prospectively studied the PEIs and blood splashes on the skin of employees in a newly founded (October 2000) tertiary hospital in Athens, Greece, while a vaccination program against hepatitis B virus, as well as educational activities for avoidance of injuries, were taking place. The study period ranged from October 1, 2002 to February 28, 2005. Serologic studies for hepatitis B (HBV) and C virus (HCV) as well as human immunodeficiency virus (HIV) were performed in all injured employees and the source patients, when known. High-titer immunoglobulin (250 IU anti-HBs intramuscularly) and HBV vaccination were given to non-vaccinated or previously vaccinated but serologically non-responders after exposure. Statistical analysis of the data was performed using Mc Nemar's and Fisher's tests. 60 needlestick, 11 sharp injuries, and two splashes leading to exposure of the skin or mucosa to blood were reported during the study period in 71 nurses and two members of the cleaning staff. The overall incidence (percutaneous injuries and splashes) per 100 full-time employment-years (100 FTEYs) for high-risk personnel (nursing, medical, and cleaning staff) was 3.48, whereas the incidence of percutaneous injuries (needlestick and sharp injuries) alone per 100 FTEYs was 3.38. A higher incidence of injuries was noted during the first than in the second half of the study period (4.67 versus 2.29 per 100 FTEYs, p = 0.005). No source patient was found positive for HCV or HIV. The use of high-titer immunoglobulin after adjustment for the incidence of injuries was higher in the first than in the second half of the study period, although the difference was not statistically significant [9/49 (18.37%) vs 1/24 (4.17%), p = 0.15]. CONCLUSIONS/SIGNIFICANCE: Our data show that nurses are the healthcare worker group that reports most of PEIs. Doctors did not report such injuries during the study period in our setting. However, the possibility of even relatively frequent PEIs in doctors cannot be excluded. This is due to underreporting of such events that has been previously described for physicians and surgeons. A decrease of the incidence of PEIs occurred during the operation of this newly founded hospital
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