6,840 research outputs found
Idiopathic Fascicular Ventricular Tachycardia
Idiopathic fascicular ventricular tachycardia is an important cardiac arrhythmia with specific electrocardiographic features and therapeutic options. It is characterized by relatively narrow QRS complex and right bundle branch block pattern. The QRS axis depends on which fascicle is involved in the re-entry. Left axis deviation is noted with left posterior fascicular tachycardia and right axis deviation with left anterior fascicular tachycardia. A left septal fascicular tachycardia with normal axis has also been described. Fascicular tachycardia is usually seen in individuals without structural heart disease. Response to verapamil is an important feature of fascicular tachycardia. Rare instances of termination with intravenous adenosine have also been noted. A presystolic or diastolic potential preceding the QRS, presumed to originate from the Purkinje fibers can be recorded during sinus rhythm and ventricular tachycardia in many patients with fascicular tachycardia. This potential (P potential) has been used as a guide to catheter ablation. Prompt recognition of fascicular tachycardia especially in the emergency department is very important. It is one of the eminently ablatable ventricular tachycardias. Primary ablation has been reported to have a higher success, lesser procedure time and fluoroscopy time
An empirical investigation of intuitions about uptake
Since Austinâs introduction of the locutionary-illocutionary-perlocutionary distinction, it has been a matter of debate within speech act theory whether illocutionary acts like promising, warning, refusing and telling require audience âuptakeâ in order to be performed. Philosophers on different sides of this debate have tried to support their positions by appealing to hypothetical scenarios, designed to elicit intuitive judgements about the role of uptake. However, philosophersâ intuitions appeared to remain deadlocked, while laypeopleâs intuitions have not yet been probed. To begin rectifying that, we ran two experiments probing lay intuitions about the implications of uptake failure. Overall, we found that participantsâ responses were skewed towards agreement that speech acts were performed, despite the lack of uptake. There were, however, significant differences across the four different speech act types we investigated (with the highest levels of agreement found for refusing, followed by warning, then telling, and finally promising). We also obtained evidence of complex effects relating to the (high or low) stakes involved in the scenarios. While this study only represents an initial exploration of intuitions about uptake, our results form a basis for further research into their nature and significance, across a range of speech acts, scenarios, and experimental designs
A complete sample of quasars from the 7C redshift survey
We present details of a new sample of radio-loud quasars drawn from 0.013 sr
of the 7C Redshift Survey. This sample is small (21 quasars) but complete in
that every object with an unresolved nucleus and/or broad emission lines with
S(151MHz) > 0.5 Jy has been discovered. The dependence of the quasar fraction
with redshift and radio luminosity is investigated, providing new evidence
supporting the unification of radio-loud quasars and powerful radio galaxies.
This 7C sample is compared with optically-selected quasars, in order to
determine whether there are systematic biases in the different selection
techniques. There are no lightly reddened (Av approx. 1) quasars in our sample
amongst the 14 with z < 2. The discovery of a reddened quasar at z = 2.034 and
its implications are discussed. A tight correlation between radio luminosity
and optical/near infrared continuum luminosity for a subset of the sample is
also found.Comment: 6 pages Latex, To appear in the "Cosmology with the New Radio
Surveys" Conference - Tenerife 13-15 January 199
Global health learning outcomes for pharmacy students in the UK
Context : The pharmacy world is a highly globalised environment. Pharmacy graduates must therefore be adequately prepared. The question for educators is, how best to prepare our students. We propose that integrating global health learning outcomes within the core curriculum would ensure that all students â irrespective of their personal interest and intended work sector - are engaged with global issues. / Description: Internal discussions were held with representatives from all disciplines within University College London (UCL) School of Pharmacy and existing curriculum documents were reviewed. A draft set of learning outcomes was proposed and then revised following consultation with representatives from the United Kingdom (UK) pharmacy profession and others with an interest in global health. / Evaluation: Analysis of the consultation data led to the derivation of a revised set of global health learning outcomes for pharmacy. / Future plan: Embedding and assessing global health learning outcomes within the UCL School of Pharmacyâs undergraduate curriculum is now our focus
Decadal changes of the Western Arabian sea ecosystem
Historical data from oceanographic expeditions and remotely sensed data on outgoing longwave radiation, temperature, wind speed and ocean color in the western Arabian Sea (1950â2010) were used to investigate decadal trends in the physical and biochemical properties of the upper 300 m. 72 % of the 29,043 vertical profiles retrieved originated from USA and UK expeditions. Increasing outgoing longwave radiation, surface air temperatures and sea surface temperature were identified on decadal timescales. These were well correlated with decreasing wind speeds associated with a reduced Siberian High atmospheric anomaly. Shoaling of the oxycline and nitracline was observed as well as acidification of the upper 300 m. These physical and chemical changes were accompanied by declining chlorophyll-a concentrations, vertical macrofaunal habitat compression, declining sardine landings and an increase of fish kill incidents along the Omani coast
Garden varieties: how attractive are recommended garden plants to butterflies?
One way the public can engage in insect conservation is through wildlife gardening, including the growing of insect-friendly flowers as sources of nectar. However, plant varieties differ in the types of insects they attract. To determine which garden plants attracted which butterflies, we counted butterflies nectaring on 11 varieties of summer-flowering garden plants in a rural garden in East Sussex, UK. These plants were all from a list of 100 varieties considered attractive to British butterflies, and included the five varieties specifically listed by the UK charity Butterfly Conservation as best for summer nectar. A total of 2659 flower visits from 14 butterfly and one moth species were observed. We performed a principal components analysis which showed contrasting patterns between the species attracted to Origanum vulgare and Buddleia davidii. The âbutterfly bushâ Buddleia attracted many nymphalines, such as the peacock, Inachis io, but very few satyrines such as the gatekeeper, Pyronia tithonus, which mostly visited Origanum. Eupatorium cannibinum had the highest Simpsonâs Diversity score of 0.75, while Buddleia and Origanum were lower, scoring 0.66 and 0.50 respectively. No one plant was good at attracting all observed butterfly species, as each attracted only a subset of the butterfly community. We conclude that to create a butterfly-friendly garden, a variety of plant species are required as nectar sources for butterflies. Furthermore, garden plant recommendations can probably benefit from being more precise as to the species of butterfly they attract
Pharmacokinetic and pharmacodynamic modelling after subcutaneous, intravenous and buccal administration of a high-concentration formulation of buprenorphine in conscious cats
The aim of this study was to describe the joint pharmacokinetic-pharmacodynamic model and evaluate thermal antinociception of a high-concentration formulation of buprenorphine (Simbadolâą) in cats
Erratum: Towards graded-index magnonics: Steering spin waves in magnonic networks [Phys. Rev. B 92, 020408(R) (2015)]
This is the final version of the article. Available from the American Physical Societ via the DOI in this record.This is the erratum to 'Towards graded-index magnonics: Steering spin waves in magnonic networks'. Physical Review B 92, 020408(R), 20 July 2015. DOI: https://doi.org/10.1103/PhysRevB.92.020408The article for which this is the erratum is in ORE: http://hdl.handle.net/10871/26167-The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 247556 (NoWaPhen), from the Engineering and Physical Sciences Research Council of the United Kingdom under Projects No. EP/L019876/1 and No. EP/L020696/1, from Russian Science Foundation (Project No. 14-19-00760), and the Scholarship of the President of Russian Federation (SP-313.2015.5)
Resonance as the Mechanism of Daytime Periodic Breathing in Patients with Heart Failure
Rationale: In patients with chronic heart failure, daytime oscillatory breathing at rest is associated with a high risk of mortality. Experimental evidence, including exaggerated ventilatory responses to CO2 and prolonged circulation time, implicates the ventilatory control system and suggests feedback instability (loop gainâ>â1) is responsible. However, daytime oscillatory patterns often appear remarkably irregular versus classic instability (Cheyne-Stokes respiration), suggesting our mechanistic understanding is limited.
Objectives: We propose that daytime ventilatory oscillations generally result from a chemoreflex resonance, in which spontaneous biological variations in ventilatory drive repeatedly induce temporary and irregular ringing effects. Importantly, the ease with which spontaneous biological variations induce irregular oscillations (resonance âstrengthâ) rises profoundly as loop gain rises toward 1. We tested this hypothesis through a comparison of mathematical predictions against actual measurements in patients with heart failure and healthy control subjects.
Methods: In 25 patients with chronic heart failure and 25 control subjects, we examined spontaneous oscillations in ventilation and separately quantified loop gain using dynamic inspired CO2 stimulation.
Measurements and Main Results: Resonance was detected in 24 of 25 patients with heart failure and 18 of 25 control subjects. With increased loop gainâconsequent to increased chemosensitivity and delayâthe strength of spontaneous oscillations increased precipitously as predicted (râ=â0.88), yielding larger (râ=â0.78) and more regular (interpeak interval SD, râ=ââ0.68) oscillations (Pâ<â0.001 for all, both groups combined).
Conclusions: Our study elucidates the mechanism underlying daytime ventilatory oscillations in heart failure and provides a means to measure and interpret these oscillations to reveal the underlying chemoreflex hypersensitivity and reduced stability that foretells mortality in this population
Broken rotational symmetry in the pseudogap phase of a high-Tc superconductor
The nature of the pseudogap phase is a central problem in the quest to
understand high-Tc cuprate superconductors. A fundamental question is what
symmetries are broken when that phase sets in below a temperature T*. There is
evidence from both polarized neutron diffraction and polar Kerr effect
measurements that time- reversal symmetry is broken, but at temperatures that
differ significantly. Broken rotational symmetry was detected by both
resistivity and inelastic neutron scattering at low doping and by scanning
tunnelling spectroscopy at low temperature, but with no clear connection to T*.
Here we report the observation of a large in-plane anisotropy of the Nernst
effect in YBa2Cu3Oy that sets in precisely at T*, throughout the doping phase
diagram. We show that the CuO chains of the orthorhombic lattice are not
responsible for this anisotropy, which is therefore an intrinsic property of
the CuO2 planes. We conclude that the pseudogap phase is an electronic state
which strongly breaks four-fold rotational symmetry. This narrows the range of
possible states considerably, pointing to stripe or nematic orders.Comment: Published version. Journal reference and DOI adde
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