1. |
- Beal, Jacob, et al.
(author)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
|
|
2. |
-
- 2019
-
Journal article (peer-reviewed)
|
|
3. |
- Maitre, Léa, et al.
(author)
-
State-of-the-art methods for exposure-health studies: Results from the exposome data challenge event
- 2022
-
In: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 168
-
Journal article (peer-reviewed)abstract
- The exposome recognizes that individuals are exposed simultaneously to a multitude of different environmental factors and takes a holistic approach to the discovery of etiological factors for disease. However, challenges arise when trying to quantify the health effects of complex exposure mixtures. Analytical challenges include dealing with high dimensionality, studying the combined effects of these exposures and their interactions, integrating causal pathways, and integrating high-throughput omics layers. To tackle these challenges, the Barcelona Institute for Global Health (ISGlobal) held a data challenge event open to researchers from all over the world and from all expertises. Analysts had a chance to compete and apply state-of-the-art methods on a common partially simulated exposome dataset (based on real case data from the HELIX project) with multiple correlated exposure variables (P > 100 exposure variables) arising from general and personal environments at different time points, biological molecular data (multi-omics: DNA methylation, gene expression, proteins, metabolomics) and multiple clinical phenotypes in 1301 mother–child pairs. Most of the methods presented included feature selection or feature reduction to deal with the high dimensionality of the exposome dataset. Several approaches explicitly searched for combined effects of exposures and/or their interactions using linear index models or response surface methods, including Bayesian methods. Other methods dealt with the multi-omics dataset in mediation analyses using multiple-step approaches. Here we discuss features of the statistical models used and provide the data and codes used, so that analysts have examples of implementation and can learn how to use these methods. Overall, the exposome data challenge presented a unique opportunity for researchers from different disciplines to create and share state-of-the-art analytical methods, setting a new standard for open science in the exposome and environmental health field.
|
|
4. |
- Yan, Xing, et al.
(author)
-
Substantial Underestimation of Fine-Mode Aerosol Loading from Wildfires and Its Radiative Effects in Current Satellite-Based Retrievals over the United States
- 2024
-
In: Environmental Science and Technology. - 1520-5851 .- 0013-936X. ; In Press
-
Journal article (peer-reviewed)abstract
- Wildfires generate abundant smoke primarily composed of fine-mode aerosols. However, accurately measuring the fine-mode aerosol optical depth (fAOD) is highly uncertain in most existing satellite-based aerosol products. Deep learning offers promise for inferring fAOD, but little has been done using multiangle satellite data. We developed an innovative angle-dependent deep-learning model (ADLM) that accounts for angular diversity in dual-angle observations. The model captures aerosol properties observed from dual angles in the contiguous United States and explores the potential of Greenhouse gases Observing Satellite-2’s (GOSAT-2) measurements to retrieve fAOD at a 460 m spatial resolution. The ADLM demonstrates a strong performance through rigorous validation against ground-based data, revealing small biases. By comparison, the official fAOD product from the Moderate Resolution Imaging Spectroradiometer (MODIS), the Visible Infrared Imaging Radiometer Suite (VIIRS), and the Multiangle Imaging Spectroradiometer (MISR) during wildfire events is underestimated by more than 40% over western USA. This leads to significant differences in estimates of aerosol radiative forcing (ARF) from wildfires. The ADLM shows more than 20% stronger ARF than the MODIS, VIIRS, and MISR estimates, highlighting a greater impact of wildfire fAOD on Earth’s energy balance.
|
|
5. |
- Zeng, Jianhua, et al.
(author)
-
Intrinsically stretchable tribotronic mechanoplastic artificial synapse
- 2024
-
In: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 492
-
Journal article (peer-reviewed)abstract
- Stretchable synaptic devices with adaptability to elastic deformation, sensing environmental stimuli, and unique information processing functions are of great significance for the development of the next generation of artificial nervous systems. Here, an intrinsically stretchable tribotronic mechanoplastic artificial synapse (STMAS) is proposed, which is integrated by a triboelectric nanogenerator and an electrolyte-gated transistor with ion-gel as dielectric layer. The STMAS can be modulated by the triboelectric potential induced by mechanical stimulation without the need to apply an external gate voltage, achieving an active mechanical tuning of synaptic plasticity such as excitatory postsynaptic current, paired-pulse facilitation, short-term plasticity, and long-term plasticity. The STMAS exhibits stable synaptic plasticity under 0–50% stretcher strain in parallel and vertical to channel directions, respectively. Furthermore, the International Morse code triggered by mechanical signals has been successfully mimicked. This work has achieved an intrinsically stretchable tribotronic artificial synapse with mechanically tuned synaptic behavior, which will help promote the development of artificial nervous systems and expand the applications of artificial synapses in intelligent robotics, artificial limbs and human–machine interaction.
|
|