2,777 research outputs found
Data-Driven ECG Denoising Techniques for Characterising Bipolar Lead Sets along the Left Arm in Wearable Long-Term Heart Rhythm Monitoring
Abnormal heart rhythms (arrhythmias) are a major cause of cardiovascular disease and death in Europe. Sudden cardiac death accounts for 50% of cardiac mortality in developed countries; ventricular tachycardia or ventricular fibrillation is the most common underlying arrhythmia. In the ambulatory population, atrial fibrillation is the most common arrhythmia and is associated with an increased risk of stroke and heart failure, particularly in an aging population. Early detection of arrhythmias allows appropriate intervention, reducing disability and death. However, in the early stages of disease arrhythmias may be transient, lasting only a few seconds, and are thus difficult to detect. This work addresses the problem of extracting the far-field heart electrogram signal from noise components, as recorded in bipolar leads along the left arm, using a data driven ECG (electrocardiogram) denoising algorithm based on ensemble empirical mode decomposition (EEMD) methods to enable continuous non-invasive monitoring of heart rhythm for long periods of time using a wrist or arm wearable device with advanced biopotential sensors. Performance assessment against a control denoising method of signal averaging (SA) was implemented in a pilot study with 34 clinical cases. EEMD was found to be a reliable, low latency, data-driven denoising technique with respect to the control SA method, achieving signal-to-noise ratio (SNR) enhancement to a standard closer to the SA control method, particularly on the upper arm-ECG bipolar leads. Furthermore, the SNR performance of the EEMD was improved when assisted with an FFT (fast Fourier transform ) thresholding algorithm (EEMD-fft)
Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in acute lung injury to reduce pulmonary dysfunction (HARP-2) trial : study protocol for a randomized controlled trial
Acute lung injury (ALI) is a common devastating clinical syndrome characterized by life-threatening respiratory failure requiring mechanical ventilation and multiple organ failure. There are in vitro, animal studies and pre-clinical data suggesting that statins may be beneficial in ALI. The Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in Acute lung injury to Reduce Pulmonary dysfunction (HARP-2) trial is a multicenter, prospective, randomized, allocation concealed, double-blind, placebo-controlled clinical trial which aims to test the hypothesis that treatment with simvastatin will improve clinical outcomes in patients with ALI
Robotic milking technologies and renegotiating situated ethical relationships on UK dairy farms
Robotic or automatic milking systems (AMS) are novel technologies that take over the labor of dairy farming and reduce the need for human-animal interactions. Because robotic milking involves the replacement of 'conventional' twice-a-day milking managed by people with a system that supposedly allows cows the freedom to be milked automatically whenever they choose, some claim robotic milking has health and welfare benefits for cows, increases productivity, and has lifestyle advantages for dairy farmers. This paper examines how established ethical relations on dairy farms are unsettled by the intervention of a radically different technology such as AMS. The renegotiation of ethical relationships is thus an important dimension of how the actors involved are re-assembled around a new technology. The paper draws on in-depth research on UK dairy farms comparing those using conventional milking technologies with those using AMS. We explore the situated ethical relations that are negotiated in practice, focusing on the contingent and complex nature of human-animal-technology interactions. We show that ethical relations are situated and emergent, and that as the identities, roles, and subjectivities of humans and animals are unsettled through the intervention of a new technology, the ethical relations also shift. © 2013 Springer Science+Business Media Dordrecht
Loss of cilia causes embryonic lung hypoplasia, liver fibrosis and cholestasis in the talpid3 ciliopathy mutant
Sonic hedgehog plays an essential role in maintaining hepatoblasts in a proliferative non-differentiating state during embryogenesis. Transduction of the Hedgehog signaling pathway is dependent on the presence of functional primary cilia and hepatoblasts, therefore, must require primary cilia for normal function. In congenital syndromes in which cilia are absent or non-functional (ciliopathies) hepatorenal fibrocystic disease is common and primarily characterized by ductal plate malformations which underlie the formation of liver cysts, as well as less commonly, by hepatic fibrosis, although a role for abnormal Hedgehog signal transduction has not been implicated in these phenotypes. We have examined liver, lung and rib development in the talpid(3) chicken mutant, a ciliopathy model in which abnormal Hedgehog signaling is well characterized. We find that the talpid(3) phenotype closely models that of human short-rib polydactyly syndromes which are caused by the loss of cilia, and exhibit hypoplastic lungs and liver failure. Through an analysis of liver and lung development in the talpid(3) chicken, we propose that cilia in the liver are essential for the transduction of Hedgehog signaling during hepatic development. The talpid(3) chicken represents a useful resource in furthering our understanding of the pathology of ciliopathies beyond the treatment of thoracic insufficiency as well as generating insights into the role Hedgehog signaling in hepatic development
Identification of HIV-1 Epitopes that Induce the Synthesis of a R5 HIV-1 Suppression Factor by Human CD4+ T Cells Isolated from HIV-1 Immunized Hu-PBL SCID Mice
We have previously reported that immunization of the severe combined
immunodeficiency (SCID) mice reconstituted with human peripheral blood
mononuclear cells (PBMC) (hu-PBL-SCID mice) with inactivated human
immunodeficiency virus type-1 (HIV-1)-pulsed-autologous dendritic cells (HIV-DC)
elicits HIV-1-reactive CD4+ T cells that produce an as yet to be defined novel
soluble factor in vitro with anti-viral properties
against CCR5 tropic (R5) HIV-1
infection. These findings led us to perform studies designed to identify the lineage
of the cell that synthesizes such a factor in vitro and define the epitopes of HIV-1
protein that have specificity for the induction of such anti-viral factor. Results of
our
studies show that this property is a function of CD4+ but not
CD8+ T cells. Human
CD4+ T cells were thus recovered from the HIV-DC-immunized
hu-PBL-SCID mice
and were re-stimulated in vitro by co-culture for 2 days with
autologous adherent
PBMC as antigen presenting cells, APC previously pulsed with inactivated HIV in
IL-2-containing medium to expand HIV-1-reactive CD4+
T cells. Aliquots of these
re-stimulated CD4+ T cells were then co-cultured with
similar APC's that were
previously pulsed with 10 μg/ml of a panel of HIV peptides for
an additional 2 days,
and their culture supernatants were examined for the production of both the R5
HIV-1 suppression factor and IFN-Υ. The data presented herein
show that the HIV-1
primed CD4+ T cells produced the R5 suppression factor in
response to a wide
variety of HIV-1 gag, env, pol, nef or vif peptides, depending on the donor of
the CD4+ T cells. Simultaneous production of human interferon
(IFN)-Υ was
observed in some cases. These results indicate that human
CD4+ T cells in
PBMC of HIV-1 naive donors have a wide variety of HIV-1 epitope-specific
CD4+ T
cell precursors that are capable of producing the R5 HIV-1
suppression factor upon DC-based vaccination with whole inactivated HIV-1
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