1,011 research outputs found
Field Evaluation of Four Low-cost PM Sensors and Design, Development and Field Evaluation of A Wearable PM Exposure Monitoring System
To mitigate the significant biases/errors in research studying the
associations between PM and health, which are introduced by the
coarse/inadequate assessments of PM exposure from conventional PM monitoring
paradigm, a personalized monitoring system consisting of a low-cost wearable PM
device is proposed. However, due to the absence of a unifying evaluation
protocol for low-cost PM sensors, the evaluation results/performance
specifications from existing studies/datasheets are of limited reference values
when attempting to determine the best candidate for the proposed system. In
this regard, the authors appeal to the research community to develop a
standardized evaluation protocol for low-cost PM sensors/devices, and a
unifying attempt is established in this manuscript by adopting the definitive
terminology from international documents and the evaluation metrics regarded as
best practices. Collocated on the rooftop of the HKUST Supersite, four
empirically selected PM sensors were compared against each other and calibrated
against two reference monitors. They were then evaluated against the reference
following the protocol. The PlanTower PMS-A003 sensor was selected for the
wearable device as it outperformed the others in terms of affordability,
portability, detection capability, data quality, as well as humidity and
condensation insusceptibility. An automated approach was proposed to identify
and remove the condensation associated abnormal measurements. The proposed
device has better affordability and portability as well as similar usability
and data accessibility compared to those existing devices recognized. The first
10 devices were also evaluated and calibrated at the Supersite. Additional 120
units were manufactured and delivered to the subjects to acquire their daily
PM2.5 exposures for investigating the association with subclinical
atherosclerosis
Accelerating Wireless Federated Learning via Nesterov's Momentum and Distributed Principle Component Analysis
A wireless federated learning system is investigated by allowing a server and
workers to exchange uncoded information via orthogonal wireless channels. Since
the workers frequently upload local gradients to the server via
bandwidth-limited channels, the uplink transmission from the workers to the
server becomes a communication bottleneck. Therefore, a one-shot distributed
principle component analysis (PCA) is leveraged to reduce the dimension of
uploaded gradients such that the communication bottleneck is relieved. A
PCA-based wireless federated learning (PCA-WFL) algorithm and its accelerated
version (i.e., PCA-AWFL) are proposed based on the low-dimensional gradients
and the Nesterov's momentum. For the non-convex loss functions, a finite-time
analysis is performed to quantify the impacts of system hyper-parameters on the
convergence of the PCA-WFL and PCA-AWFL algorithms. The PCA-AWFL algorithm is
theoretically certified to converge faster than the PCA-WFL algorithm. Besides,
the convergence rates of PCA-WFL and PCA-AWFL algorithms quantitatively reveal
the linear speedup with respect to the number of workers over the vanilla
gradient descent algorithm. Numerical results are used to demonstrate the
improved convergence rates of the proposed PCA-WFL and PCA-AWFL algorithms over
the benchmarks
Towards Personalized Healthcare in Cardiac Population: The Development of a Wearable ECG Monitoring System, an ECG Lossy Compression Schema, and a ResNet-Based AF Detector
Cardiovascular diseases (CVDs) are the number one cause of death worldwide.
While there is growing evidence that the atrial fibrillation (AF) has strong
associations with various CVDs, this heart arrhythmia is usually diagnosed
using electrocardiography (ECG) which is a risk-free, non-intrusive, and
cost-efficient tool. Continuously and remotely monitoring the subjects' ECG
information unlocks the potentials of prompt pre-diagnosis and timely
pre-treatment of AF before the development of any life-threatening
conditions/diseases. Ultimately, the CVDs associated mortality could be
reduced. In this manuscript, the design and implementation of a personalized
healthcare system embodying a wearable ECG device, a mobile application, and a
back-end server are presented. This system continuously monitors the users' ECG
information to provide personalized health warnings/feedbacks. The users are
able to communicate with their paired health advisors through this system for
remote diagnoses, interventions, etc. The implemented wearable ECG devices have
been evaluated and showed excellent intra-consistency (CVRMS=5.5%), acceptable
inter-consistency (CVRMS=12.1%), and negligible RR-interval errors (ARE<1.4%).
To boost the battery life of the wearable devices, a lossy compression schema
utilizing the quasi-periodic feature of ECG signals to achieve compression was
proposed. Compared to the recognized schemata, it outperformed the others in
terms of compression efficiency and distortion, and achieved at least 2x of CR
at a certain PRD or RMSE for ECG signals from the MIT-BIH database. To enable
automated AF diagnosis/screening in the proposed system, a ResNet-based AF
detector was developed. For the ECG records from the 2017 PhysioNet CinC
challenge, this AF detector obtained an average testing F1=85.10% and a best
testing F1=87.31%, outperforming the state-of-the-art
rad21 Is Involved in Corneal Stroma Development by Regulating Neural Crest Migration
Previously, we identified RAD21(R450C) from a peripheral sclerocornea pedigree. Injection of this rad21 variant mRNA into Xenopus laevis embryos disrupted the organization of corneal stroma fibrils. To understand the mechanisms of RAD21-mediated corneal stroma defects, gene expression and chromosome conformation analysis were performed using cells from family members affected by peripheral sclerocornea. Both gene expression and chromosome conformation of cell adhesion genes were affected in cells carrying the heterozygous rad21 variant. Since cell migration is essential in early embryonic development and sclerocornea is a congenital disease, we studied neural crest migration during cornea development in X. laevis embryos. In X. laevis embryos injected with rad21 mutant mRNA, neural crest migration was disrupted, and the number of neural crest-derived periocular mesenchymes decreased significantly in the corneal stroma region. Our data indicate that the RAD21(R450C) variant contributes to peripheral sclerocornea by modifying chromosome conformation and gene expression, therefore disturbing neural crest cell migration, which suggests RAD21 plays a key role in corneal stroma development
Where to draw the line? Using movement data to inform protected area design and conserve mobile species
Protected areas (PAs) are a cornerstone of modern conservation. For PAs that are established to conserve mobile species, it is important to cover all the key areas regularly used by these species. However, zonation and boundaries of PAs have often been established with limited knowledge of animal movements, leaving the effectiveness of some PAs doubtful. We used radio tracking data to evaluate the extent to which two coastal PAs in mainland China encompassed the full range of habitats used by migratory shorebirds during non-breeding seasons. The core zone (highest restriction on human activities) of the Yalu Jiang Estuary National Nature Reserve (Liaoning) incorporated only 22 ± 6% (n = 34) of the diurnal home range (95% kernel density) of the endangered great knots Calidris tenuirostris. In contrast, the core zone of Chongming Dongtan (Shanghai) incorporated 73 ± 24% (n = 25) of the home range of dunlins Calidris alpina. During high tide, great knots in Yalu Jiang mostly occurred in the experimental zone (least restriction on human activities) or sometimes outside the PA boundary altogether, where the birds could face substantial threats. By investigating satellite tracking records, consulting published literature, interviewing local experts and mapping habitat composition in different coastal PAs in China, we found that wet artificial supratidal habitats were frequently used by migratory shorebirds but the coverage of these habitats in coastal PAs was low. These PA boundaries and/or zonations should be revised to conserve mobile species more effectively. With the increasing number of tracking studies, analysing the spatial relationships between PAs and the movement ranges of mobile species can increasingly inform the development of a representative, comprehensive PA network
Sodium-Glucose Cotransporter 2 Inhibitors and the Risk of Pneumonia and Septic Shock
CONTEXT: Individuals with type 2 diabetes mellitus (DM) have an increased risk of pneumonia and septic shock. Traditional glucose-lowering drugs have recently been found to be associated with a higher risk of infections. It remains unclear whether sodium-glucose cotransporter 2 inhibitors (SGLT2is), which have pleiotropic/anti-inflammatory effects, may reduce the risk of pneumonia and septic shock in DM. METHODS: MEDLINE, Embase, and ClinicalTrials.gov were searched from inception up to May 19, 2022, for randomized, placebo-controlled trials of SGLT2i that included patients with DM and reported outcomes of interest (pneumonia and/or septic shock). Study selection, data extraction, and quality assessment (using the Cochrane Risk of Bias Assessment Tool) were conducted by independent authors. A fixed-effects model was used to pool the relative risk (RRs) and 95% CI across trials. RESULTS: Out of 4568 citations, 26 trials with a total of 59 264 patients (1.9% developed pneumonia and 0.2% developed septic shock) were included. Compared with placebo, SGLT2is significantly reduced the risk of pneumonia (pooled RR 0.87, 95% CI 0.78-0.98) and septic shock (pooled RR 0.65, 95% CI 0.44-0.95). There was no significant heterogeneity of effect size among trials. Subgroup analyses according to the type of SGLT2i used, baseline comorbidities, glycemic control, duration of DM, and trial follow-up showed consistent results without evidence of significant treatment-by-subgroup heterogeneity (all P(heterogeneity) > .10). CONCLUSION: Among DM patients, SGLT2is reduced the risk of pneumonia and septic shock compared with placebo. Our findings should be viewed as hypothesis generating, with concepts requiring validation in future studies
Effect of carbon source on production, characterization and bioactivity of exopolysaccharide produced by Phellinus vaninii Ljup
Psychometric Properties of the Chinese Version of the Perceived Stress Scale in Policewomen
BACKGROUND: The 10-item Perceived Stress Scale (PSS-10) is one of most widely used instruments to measure a global level of perceived stress in a range of clinical and research settings. This study was conducted to examine the psychometric properties of the Simplified Chinese version of the PSS-10 in policewomen. METHODOLOGY: A total of 240 policewomen were recruited in this study. The Simplified Chinese versions of the PSS-10, the Beck Depression Inventory Revised (BDI-II), and the Beck Anxiety Inventory (BAI) were administered to all participants, and 36 of the participants were re-tested two weeks after the initial testing. PRINCIPAL FINDINGS: The overall Cronbach's alpha was 0.86, and the test-retest reliability coefficient was 0.68. Exploratory Factor Analysis (EFA) yielded 2 factors with eigenvalues of 4.76 and 1.48, accounting for 62.41% of variance. Factor 1 consisted of 6 items representing "negative feelings"; whereas Factor 2 consisted of 4 items representing "positive feelings". The item loadings ranged from 0.72 to 0.83. The Confirmatory factor analysis (CFA) indicated a very good fit of this two-factor model to this sample. The PSS-10 significantly correlated with both BDI-II and BAI, indicating an acceptable concurrent validity. CONCLUSIONS: The Simplified Chinese version of the PSS-10 demonstrated adequate psychometric properties for evaluating stress levels. The results support its use among the Chinese population
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