99 research outputs found
The perceived waning of biologics in severe asthma
BACKGROUND: Biologics are highly effective in severe asthma and used at fixed dosing intervals. However, in clinical practice, dosing intervals are sometimes shortened if patients perceive a decreased biologic effect before the next administration. The occurrence and clinical relevance of this perceived waning of biological effect is unknown.OBJECTIVE: To explore (1) the frequency, severity and conditions, (2) associated symptoms and (3) relationship with clinical characteristics of the patient-perceived waning effect of biologics before the next administration.METHODS: Severe asthma patients receiving biological treatment ≥4 months were included. Based on 17 semi-structured patient interviews, we developed a questionnaire focusing on the waning effect of biologics before the next administration, which was distributed among 129 patients. Clinical characteristics, including asthma control (ACQ) and quality of life (AQLQ) scores, were collected from patient files.RESULTS: 65/101 patients who completed the questionnaire reported a waning of biological effect, graded as severe (median (IQR) 6.5 (5-7.5) on a 0-10 BORG-scale). Waning manifested in a broad spectrum of symptoms. Patients reporting waning had higher ACQ and lower AQLQ scores versus those without (p < 0.05) and higher BORG-scores were associated with higher exacerbation rate (ρ = 0.309, p = 0.013). A third of all patients were in favor of extending or shortening their dosing interval.CONCLUSION: Two-thirds of severe asthma patients report waning of biologic effect at the end of the dosing interval, which is associated with poorer asthma control and quality of life. The diversity in observed waning of effect opens the way for research into more individualized dosing of biologics.</p
A flexible framework for sparse simultaneous component based data integration
<p>Abstract</p> <p>1 Background</p> <p>High throughput data are complex and methods that reveal structure underlying the data are most useful. Principal component analysis, frequently implemented as a singular value decomposition, is a popular technique in this respect. Nowadays often the challenge is to reveal structure in several sources of information (e.g., transcriptomics, proteomics) that are available for the same biological entities under study. Simultaneous component methods are most promising in this respect. However, the interpretation of the principal and simultaneous components is often daunting because contributions of each of the biomolecules (transcripts, proteins) have to be taken into account.</p> <p>2 Results</p> <p>We propose a sparse simultaneous component method that makes many of the parameters redundant by shrinking them to zero. It includes principal component analysis, sparse principal component analysis, and ordinary simultaneous component analysis as special cases. Several penalties can be tuned that account in different ways for the block structure present in the integrated data. This yields known sparse approaches as the lasso, the ridge penalty, the elastic net, the group lasso, sparse group lasso, and elitist lasso. In addition, the algorithmic results can be easily transposed to the context of regression. Metabolomics data obtained with two measurement platforms for the same set of <it>Escherichia coli </it>samples are used to illustrate the proposed methodology and the properties of different penalties with respect to sparseness across and within data blocks.</p> <p>3 Conclusion</p> <p>Sparse simultaneous component analysis is a useful method for data integration: First, simultaneous analyses of multiple blocks offer advantages over sequential and separate analyses and second, interpretation of the results is highly facilitated by their sparseness. The approach offered is flexible and allows to take the block structure in different ways into account. As such, structures can be found that are exclusively tied to one data platform (group lasso approach) as well as structures that involve all data platforms (Elitist lasso approach).</p> <p>4 Availability</p> <p>The additional file contains a MATLAB implementation of the sparse simultaneous component method.</p
Semiclassical Mechanics of the Wigner 6j-Symbol
The semiclassical mechanics of the Wigner 6j-symbol is examined from the
standpoint of WKB theory for multidimensional, integrable systems, to explore
the geometrical issues surrounding the Ponzano-Regge formula. The relations
among the methods of Roberts and others for deriving the Ponzano-Regge formula
are discussed, and a new approach, based on the recoupling of four angular
momenta, is presented. A generalization of the Yutsis-type of spin network is
developed for this purpose. Special attention is devoted to symplectic
reduction, the reduced phase space of the 6j-symbol (the 2-sphere of Kapovich
and Millson), and the reduction of Poisson bracket expressions for
semiclassical amplitudes. General principles for the semiclassical study of
arbitrary spin networks are laid down; some of these were used in our recent
derivation of the asymptotic formula for the Wigner 9j-symbol.Comment: 64 pages, 50 figure
Climate related shifts in the NCP ecosystem, and consequences for future spatial planning
Een uitgebreide meetinspanning op de Noordzee, in combinatie met wiskundige en statistische modellering, laat zien dat de klimaatveranderingen in de vorm van een verandering in de overheersende windrichting, een toename van de windsnelheid, een toename van de zeewatertemperatuur, als wel als een toenemende CO2 concentratie van de atmosfeer, niet alleen leidt tot een verandering van de samenstelling van het zeewater in de vorm van bijvoorbeeld opgelost anorganisch koolstof en zuurgraad, maar ook tot een, zei het beperkte, verlaging van de productiviteit van op en in de zeebodem levende filterende organismen, die op hun beurt het voedsel zijn van bodembewonende vissen
Diagnostic accuracy of a clinical diagnosis of idiopathic pulmonary fibrosis: An international case-cohort study
We conducted an international study of idiopathic pulmonary fibrosis (IPF) diagnosis among a large group of physicians and compared their diagnostic performance to a panel of IPF experts. A total of 1141 respiratory physicians and 34 IPF experts participated. Participants evaluated 60 cases of interstitial lung disease (ILD) without interdisciplinary consultation. Diagnostic agreement was measured using the weighted kappa coefficient (\u3baw). Prognostic discrimination between IPF and other ILDs was used to validate diagnostic accuracy for first-choice diagnoses of IPF and were compared using the Cindex. A total of 404 physicians completed the study. Agreement for IPF diagnosis was higher among expert physicians (\u3baw=0.65, IQR 0.53-0.72, p20 years of experience (C-index=0.72, IQR 0.0-0.73, p=0.229) and non-university hospital physicians with more than 20 years of experience, attending weekly MDT meetings (C-index=0.72, IQR 0.70-0.72, p=0.052), did not differ significantly (p=0.229 and p=0.052 respectively) from the expert panel (C-index=0.74 IQR 0.72-0.75). Experienced respiratory physicians at university-based institutions diagnose IPF with similar prognostic accuracy to IPF experts. Regular MDT meeting attendance improves the prognostic accuracy of experienced non-university practitioners to levels achieved by IPF experts
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Hepcidin-mediated hypoferremia disrupts immune responses to vaccination and infection
Background: How specific nutrients influence adaptive immunity is of
broad interest. Iron deficiency is the most common micronutrient deficiency worldwide and imparts a significant burden of global disease;
however, its effects on immunity remain unclear.
Methods: We used a hepcidin mimetic and several genetic models to
examine the effect of low iron availability on T cells in vitro and on immune responses to vaccines and viral infection in mice. We examined
humoral immunity in human patients with raised hepcidin and low
serum iron caused by mutant TMPRSS6. We tested the effect of iron
supplementation on vaccination-induced humoral immunity in piglets,
a natural model of iron deficiency.
Findings: We show that low serum iron (hypoferremia), caused by
increased hepcidin, severely impairs effector and memory responses
to immunizations. The intensified metabolism of activated lymphocytes
requires the support of enhanced iron acquisition, which is facilitated by
IRP1/2 and TFRC. Accordingly, providing extra iron improved the
response to vaccination in hypoferremic mice and piglets, while
conversely, hypoferremic humans with chronically increased hepcidin
have reduced concentrations of antibodies specific for certain pathogens. Imposing hypoferremia blunted the T cell, B cell, and neutralizing
antibody responses to influenza virus infection in mice, allowing the virus to persist and exacerbating lung inflammation and morbidity.
Conclusions: Hypoferremia, a well-conserved physiological innate
response to infection, can counteract the development of adaptive immunity. This nutrient trade-off is relevant for understanding and
improving immune responses to infections and vaccines in the globally
common contexts of iron deficiency and inflammatory disorders
Addressing climate change with behavioral science: A global intervention tournament in 63 countries
Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions' effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior-several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people's initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors
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