313 research outputs found
Inability to obtain deferred consent due to early death in emergency research: effect on validity of clinical trial results
PURPOSE: To illustrate the impact on the validity of trial results due to excluding patients from a randomized controlled trial for whom no deferred consent could be obtained after randomization because study procedures had already been finished. METHODS: The unadjusted and adjusted primary outcome measures of a recent randomized controlled multicentre study in the field of intensive care medicine were compared, including (n = 348) or excluding (n = 289) patients with missing deferred consent. RESULTS: Thirty-nine patients (11%) died early, before the patient or his/her proxy could be approached and consent be obtained. In another 20 patients (6%), it was not possible to inform proxies and ask consent within the period of study procedures. A significant treatment effect (p = 0.006) in the adjusted analysis became non-significant (p = 0.35) when the patients with missing deferred consent were excluded. CONCLUSIONS: Exclusion of patients without obtained deferred consent can reduce statistical power, introduce selection bias, make randomization asymmetrical, decrease external validity and thereby jeopardize study results. This may have implications for emergency research in various disciplines
Integrating Information Theory and Adversarial Learning for Cross-modal Retrieval
Accurately matching visual and textual data in cross-modal retrieval has been
widely studied in the multimedia community. To address these challenges posited
by the heterogeneity gap and the semantic gap, we propose integrating Shannon
information theory and adversarial learning. In terms of the heterogeneity gap,
we integrate modality classification and information entropy maximization
adversarially. For this purpose, a modality classifier (as a discriminator) is
built to distinguish the text and image modalities according to their different
statistical properties. This discriminator uses its output probabilities to
compute Shannon information entropy, which measures the uncertainty of the
modality classification it performs. Moreover, feature encoders (as a
generator) project uni-modal features into a commonly shared space and attempt
to fool the discriminator by maximizing its output information entropy. Thus,
maximizing information entropy gradually reduces the distribution discrepancy
of cross-modal features, thereby achieving a domain confusion state where the
discriminator cannot classify two modalities confidently. To reduce the
semantic gap, Kullback-Leibler (KL) divergence and bi-directional triplet loss
are used to associate the intra- and inter-modality similarity between features
in the shared space. Furthermore, a regularization term based on KL-divergence
with temperature scaling is used to calibrate the biased label classifier
caused by the data imbalance issue. Extensive experiments with four deep models
on four benchmarks are conducted to demonstrate the effectiveness of the
proposed approach.Comment: Accepted by Pattern Recognitio
Anticipation of distress after discontinuation of mechanical ventilation in the ICU at the end of life
Background: A considerable number of patients admitted to the intensive care unit (ICU) die following withdrawal of mechanical ventilation. After discontinuation of ventilation without proper preparation, excessive respiratory secretion is common, resulting in a 'death rattle'. Post-extubation stridor can give rise to the relatives' perception that the patient is choking and suffering. Existing protocols lack adequate anticipatory preparation to respond to all distressing symptoms. Methods: We analyzed existing treatment strategies in distressing symptoms after discontinuation of mechanical ventilation. Conclusion: The actual period of discontinuation of mechanical ventilation can be very short, but thoughtful anticipation of distressing symptoms takes time. There is an ethical responsibility to anticipate and treat (iatrogenic) symptoms such as pain, dyspnea-associated respiratory distress, anxiety, delirium, post-extubation stridor, and excessive broncho-pulmonary secretions. This makes withdrawal of mechanical ventilation in ICU patients a thoughtful process, taking palliative actions instead of fast terminal actions. We developed a flowchart covering all possible distressi
Lifelong Person Re-Identification via Adaptive Knowledge Accumulation
Person ReID methods always learn through a stationary domain that is fixed by
the choice of a given dataset. In many contexts (e.g., lifelong learning),
those methods are ineffective because the domain is continually changing in
which case incremental learning over multiple domains is required potentially.
In this work we explore a new and challenging ReID task, namely lifelong person
re-identification (LReID), which enables to learn continuously across multiple
domains and even generalise on new and unseen domains. Following the cognitive
processes in the human brain, we design an Adaptive Knowledge Accumulation
(AKA) framework that is endowed with two crucial abilities: knowledge
representation and knowledge operation. Our method alleviates catastrophic
forgetting on seen domains and demonstrates the ability to generalize to unseen
domains. Correspondingly, we also provide a new and large-scale benchmark for
LReID. Extensive experiments demonstrate our method outperforms other
competitors by a margin of 5.8% mAP in generalising evaluation.Comment: 10 pages, 5 figures, Accepted by CVPR202
Dual Gaussian-based Variational Subspace Disentanglement for Visible-Infrared Person Re-Identification
Visible-infrared person re-identification (VI-ReID) is a challenging and
essential task in night-time intelligent surveillance systems. Except for the
intra-modality variance that RGB-RGB person re-identification mainly overcomes,
VI-ReID suffers from additional inter-modality variance caused by the inherent
heterogeneous gap. To solve the problem, we present a carefully designed dual
Gaussian-based variational auto-encoder (DG-VAE), which disentangles an
identity-discriminable and an identity-ambiguous cross-modality feature
subspace, following a mixture-of-Gaussians (MoG) prior and a standard Gaussian
distribution prior, respectively. Disentangling cross-modality
identity-discriminable features leads to more robust retrieval for VI-ReID. To
achieve efficient optimization like conventional VAE, we theoretically derive
two variational inference terms for the MoG prior under the supervised setting,
which not only restricts the identity-discriminable subspace so that the model
explicitly handles the cross-modality intra-identity variance, but also enables
the MoG distribution to avoid posterior collapse. Furthermore, we propose a
triplet swap reconstruction (TSR) strategy to promote the above disentangling
process. Extensive experiments demonstrate that our method outperforms
state-of-the-art methods on two VI-ReID datasets.Comment: Accepted by ACM MM 2020 poster. 12 pages, 10 appendixe
A Symbiont-Independent Endo-1,4-β-Xylanase from the Plant-Parasitic Nematode Meloidogyne incognita
Substituted xylan polymers constitute a major part of the hemicellulose fraction of plant cell walls, especially in monocotyledons. Endo-1,4-β-xylanases (EC 3.2.1.8) are capable of hydrolyzing substituted xylan polymers into fragments of random size. Many herbivorous animals have evolved inti-
mate relationships with endosymbionts to exploit their enzyme complexes for the degradation of xylan. Here, we report the first finding of a functional endo-1,4-β-xylanase gene from an animal. The gene (Mi-xyl1) was found in the obligate plant-parasitic root-knot nematode Meloidogyne incognita, and encodes a protein that is classified as a member of glycosyl hydrolase family 5. The expression of Mi-xyl1 is localized in the subventral esophageal gland cells of the nematode. Previous studies have shown that M. incognita
has the ability to degrade cellulose and pectic polysaccha - rides in plant cell walls independent of endosymbionts. Including our current data on Mi-xyll, we show that the endogenous enzyme complex in root-knot nematode secretions targets essentially all major cell wall carbohydrates to facili-diffusible fragments cleaved from cell wall polysaccharides may act as elicitors of specific disease resistance responses to invading pathogens and parasites (Boudart et al. 1998)
Psychological outcomes, knowledge and preferences of pregnant women on first-trimester screening for fetal structural abnormalities:A prospective cohort study
INTRODUCTION: The primary aim of this study is to investigate the impact of a 13-week anomaly scan on the experienced levels of maternal anxiety and well-being. Secondly, to explore women's knowledge on the possibilities and limitations of the scan and the preferred timing of screening for structural abnormalities. MATERIAL AND METHODS: In a prospective-cohort study conducted between 2013-2015, pregnant women in the North-Netherlands underwent a 13-week anomaly scan. Four online-questionnaires (Q1, Q2, Q3 and Q4) were completed before and after the 13- and the 20-week anomaly scans. In total, 1512 women consented to participate in the study and 1118 (74%) completed the questionnaires at Q1, 941 (64%) at Q2, 807 (55%) at Q3 and 535 (37%) at Q4. Psychological outcomes were measured by the state-trait inventory-scale (STAI), the patient's positive-negative affect (PANAS) and ad-hoc designed questionnaires. RESULTS: Nine-nine percent of women wished to be informed as early as possible in pregnancy about the absence/presence of structural abnormalities. In 87% of women levels of knowledge on the goals and limitations of the 13-week anomaly scan were moderate-to-high. In women with a normal 13-week scan result, anxiety levels decreased (P < .001) and well-being increased over time (P < .001). In women with false-positive results (n = 26), anxiety levels initially increased (STAI-Q1: 39.8 vs. STAI-Q2: 48.6, P = 0.025), but later decreased around the 20-week anomaly scan (STAI-Q3: 36.4 vs. STAI-Q4: 34.2, P = 0.36). CONCLUSIONS: The 13-week scan did not negatively impact the psychological well-being of pregnant women. The small number of women with screen-positive results temporarily experienced higher anxiety after the scan but, in false-positive cases, anxiety levels normalized again when the abnormality was not confirmed at follow-up scans. Finally, most pregnant women have moderate-to-high levels of knowledge and strongly prefer early screening for fetal structural abnormalities
- …