38 research outputs found
De Morgan's law and the theory of fields
We show that the classifying topos for the theory of fields does not satisfy
De Morgan's law, and we identify its largest dense De Morgan subtopos as the
classifying topos for the theory of fields of nonzero characteristic which are
algebraic over their prime fields
Words into action : bridging the gap between theory and practice when supporting young people in care
The authors elucidate Johnstone's ABC Formulation Framework and 6D model for understanding and intervening with young people who display distressed behaviour. This approach equips care professionals with a theoretically informed method of identifying unmet needs that drive harmful behaviours. By simplifying complex psychological theories, the approach empowers practitioners to apply best practices effectively. The authors describe the implementation of this framework in the secure care context at Rossie Young People’s Trust, providing a clear account of its transformative impact on both staff and young people
Characterizing the Near-infrared Spectra of Flares from TRAPPIST-1 During JWST Transit Spectroscopy Observations
We present the first analysis of JWST near-infrared spectroscopy of stellar
flares from TRAPPIST-1 during transits of rocky exoplanets. Four flares were
observed from 0.6--2.8 m with NIRISS and 0.6--3.5 m with NIRSpec
during transits of TRAPPIST-1b, f, and g. We discover P and Br
line emission and characterize flare continuum at wavelengths from 1--3.5
m for the first time. Observed lines include H,
P-P, Br, He I 0.7062m, two Ca II
infrared triplet (IRT) lines, and the He I IRT. We observe a reversed Paschen
decrement from P-P alongside changes in the light curve shapes
of these lines. The continuum of all four flares is well-described by blackbody
emission with an effective temperature below 5300 K, lower than temperatures
typically observed at optical wavelengths. The 0.6--1 m spectra were
convolved with the TESS response, enabling us to measure the flare rate of
TRAPPIST-1 in the TESS bandpass. We find flares of 10 erg large enough
to impact transit spectra occur at a rate of 3.6 flare
d, 10 higher than previous predictions from K2. We measure
the amount of flare contamination at 2 m for the TRAPPIST-1b and f
transits to be 500450 and 2100400 ppm, respectively. We find up to
80% of flare contamination can be removed, with mitigation most effective from
1.0--2.4 m. These results suggest transits affected by flares may still be
useful for atmospheric characterization efforts.Comment: 29 pages, 17 figures, 3 tables, accepted to The Astrophysical Journa
ATOCA: an algorithm to treat order contamination. Application to the NIRISS SOSS mode
After a successful launch, the James Webb Space Telescope is preparing to
undertake one of its principal missions, the characterization of the
atmospheres of exoplanets. The Single Object Slitless Spectroscopy (SOSS) mode
of the Near Infrared Imager and Slitless Spectrograph (NIRISS) is the only
observing mode that has been specifically designed for this objective. It
features a wide simultaneous spectral range (0.6--2.8\,\micron) through two
spectral diffraction orders. However, due to mechanical constraints, these two
orders overlap slightly over a short range, potentially introducing a
``contamination'' signal in the extracted spectrum. We show that for a typical
box extraction, this contaminating signal amounts to 1\% or less over the
1.6--2.8\,\micron\ range (order 1), and up to 1\% over the 0.85--0.95\,\micron\
range (order 2). For observations of exoplanet atmospheres (transits, eclipses
or phase curves) where only temporal variations in flux matter, the
contamination signal typically biases the results by order of 1\% of the
planetary atmosphere spectral features strength. To address this problem, we
developed the Algorithm to Treat Order ContAmination (ATOCA). By constructing a
linear model of each pixel on the detector, treating the underlying incident
spectrum as a free variable, ATOCA is able to perform a simultaneous extraction
of both orders. We show that, given appropriate estimates of the spatial trace
profiles, the throughputs, the wavelength solutions, as well as the spectral
resolution kernels for each order, it is possible to obtain an extracted
spectrum accurate to within 10\,ppm over the full spectral range.Comment: Submitted to PASP. 22 pages, 12 figure
Having a word with yourself:neural correlates of self-criticism and self-reassurance
Self-criticism is strongly correlated with a range of psychopathologies, such as depression, eating disorders and anxiety. In contrast, self-reassurance is inversely associated with such psychopathologies. Despite the importance of self-judgements and evaluations, little is known about the neurophysiology of these internal processes. The current study therefore used a novel fMRI task to investigate the neuronal correlates of self-criticism and self-reassurance. Participants were presented statements describing two types of scenario, with the instruction to either imagine being self-critical or self-reassuring in that situation. One scenario type focused on a personal setback, mistake or failure, which would elicit negative emotions, whilst the second was of a matched neutral event. Self-criticism was associated with activity in lateral prefrontal cortex (PFC) regions and dorsal anterior cingulate (dAC), therefore linking self-critical thinking to error processing and resolution, and also behavioural inhibition. Self-reassurance was associated with left temporal pole and insula activation, suggesting that efforts to be self-reassuring engage similar regions to expressing compassion and empathy towards others. Additionally, we found a dorsal/ventral PFC divide between an individual's tendency to be self-critical or self-reassuring. Using multiple regression analyses, dorsolateral PFC activity was positively correlated with high levels of self-criticism (assessed via self-report measure), suggesting greater error processing and behavioural inhibition in such individuals. Ventrolateral PFC activity was positively correlated with high self-reassurance. Our findings may have implications for the neural basis of a range of mood disorders that are characterised by a preoccupation with personal mistakes and failures, and a self-critical response to such events
Immunoprotectivity of HLA-A2 CTL Peptides Derived from Respiratory Syncytial Virus Fusion Protein in HLA-A2 Transgenic Mouse
Identification of HLA-restricted CD8+ T cell epitopes is important to study RSV-induced immunity and illness. We algorithmically analyzed the sequence of the fusion protein (F) of respiratory syncytial virus (RSV) and generated synthetic peptides that can potentially bind to HLA-A*0201. Four out of the twenty-five 9-mer peptides tested: peptides 3 (F33–41), 13 (F214–222), 14 (F273–281), and 23 (F559–567), were found to bind to HLA-A*0201 with moderate to high affinity and were capable of inducing IFN-γ and IL-2 secretion in lymphocytes from HLA-A*0201 transgenic (HLA-Tg) mice pre-immunized with RSV or recombinant adenovirus expressing RSV F. HLA-Tg mice were immunized with these four peptides and were found to induce both Th1 and CD8+ T cell responses in in vitro secondary recall. Effector responses induced by these peptides were observed to confer differential protection against live RSV challenge. These peptides also caused better recovery of body weight loss induced by RSV. A significant reduction of lung viral load was observed in mice immunized with peptide 23, which appeared to enhance the levels of inflammatory chemokines (CCL17, CCL22, and IL-18) but did not increase eosinophil infiltration in the lungs. Whereas, significant reduction of infiltrated eosinophils induced by RSV infection was found in mice pre-immunized with peptide 13. Our results suggest that HLA-A2-restricted epitopes of RSV F protein could be useful for the development of epitope-based RSV vaccine
Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial
Background: Tranexamic acid reduces surgical bleeding and reduces death due to bleeding in patients with trauma.
Meta-analyses of small trials show that tranexamic acid might decrease deaths from gastrointestinal bleeding. We
aimed to assess the effects of tranexamic acid in patients with gastrointestinal bleeding.
Methods: We did an international, multicentre, randomised, placebo-controlled trial in 164 hospitals in 15 countries.
Patients were enrolled if the responsible clinician was uncertain whether to use tranexamic acid, were aged above the
minimum age considered an adult in their country (either aged 16 years and older or aged 18 years and older), and
had significant (defined as at risk of bleeding to death) upper or lower gastrointestinal bleeding. Patients were
randomly assigned by selection of a numbered treatment pack from a box containing eight packs that were identical
apart from the pack number. Patients received either a loading dose of 1 g tranexamic acid, which was added to
100 mL infusion bag of 0·9% sodium chloride and infused by slow intravenous injection over 10 min, followed by a
maintenance dose of 3 g tranexamic acid added to 1 L of any isotonic intravenous solution and infused at 125 mg/h
for 24 h, or placebo (sodium chloride 0·9%). Patients, caregivers, and those assessing outcomes were masked to
allocation. The primary outcome was death due to bleeding within 5 days of randomisation; analysis excluded patients
who received neither dose of the allocated treatment and those for whom outcome data on death were unavailable.
This trial was registered with Current Controlled Trials, ISRCTN11225767, and ClinicalTrials.gov, NCT01658124.
Findings: Between July 4, 2013, and June 21, 2019, we randomly allocated 12 009 patients to receive tranexamic acid
(5994, 49·9%) or matching placebo (6015, 50·1%), of whom 11 952 (99·5%) received the first dose of the allocated
treatment. Death due to bleeding within 5 days of randomisation occurred in 222 (4%) of 5956 patients in the
tranexamic acid group and in 226 (4%) of 5981 patients in the placebo group (risk ratio [RR] 0·99, 95% CI 0·82–1·18).
Arterial thromboembolic events (myocardial infarction or stroke) were similar in the tranexamic acid group and
placebo group (42 [0·7%] of 5952 vs 46 [0·8%] of 5977; 0·92; 0·60 to 1·39). Venous thromboembolic events (deep vein
thrombosis or pulmonary embolism) were higher in tranexamic acid group than in the placebo group (48 [0·8%] of
5952 vs 26 [0·4%] of 5977; RR 1·85; 95% CI 1·15 to 2·98).
Interpretation: We found that tranexamic acid did not reduce death from gastrointestinal bleeding. On the basis of our
results, tranexamic acid should not be used for the treatment of gastrointestinal bleeding outside the context of a
randomised trial