134 research outputs found
A review of historical reconstruction methods of land use/land cover
Understanding long-term human-environment interactions requires historical reconstruction of past land-use and land-cover changes. Most reconstructions have been based primarily on consistently available and relatively standardized information from historical sources. Based on available data sources and a retrospective research, in this paper we review the approaches and methods of the digital reconstruction and analyze their advantages and possible constraints in the following aspects: (1) Historical documents contain qualitative or semi-quantitative information about past land use, which also usually include land-cover data, but preparation of archival documents is very time-consuming. (2) Historical maps and pictures offer visual and spatial quantitative land-cover information. (3) Natural archive has significant advantages as a method for reconstructing past vegetation and has its unique possibilities especially when historical records are missing or lacking, but it has great limits of rebuilding certain land-cover types. (4) Historical reconstruction models have been gradually developed from empirical models to mechanistic ones. The method does not only reconstruct the quantity of land use/cover in historical periods, but it also reproduces the spatial distribution. Yet there are still few historical land-cover datasets with high spatial resolution. (5) Reconstruction method based on multiple-source data and multidisciplinary research could build historical land-cover from multiple perspectives, complement the missing data, verify reconstruction results and thus improve reconstruction accuracy. However, there are challenges that make the method still in the exploratory stage. This method can be a long-term development goal for the historical land-cover reconstruction. Researchers should focus on rebuilding historical land-cover dataset with high spatial resolution by developing new models so that the study results could be effectively applied in simulations of climatic and ecological effects
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Monitoring of the central blood pressure waveform via a conformal ultrasonic device.
Continuous monitoring of the central-blood-pressure waveform from deeply embedded vessels, such as the carotid artery and jugular vein, has clinical value for the prediction of all-cause cardiovascular mortality. However, existing non-invasive approaches, including photoplethysmography and tonometry, only enable access to the superficial peripheral vasculature. Although current ultrasonic technologies allow non-invasive deep-tissue observation, unstable coupling with the tissue surface resulting from the bulkiness and rigidity of conventional ultrasound probes introduces usability constraints. Here, we describe the design and operation of an ultrasonic device that is conformal to the skin and capable of capturing blood-pressure waveforms at deeply embedded arterial and venous sites. The wearable device is ultrathin (240 ÎĽm) and stretchable (with strains up to 60%), and enables the non-invasive, continuous and accurate monitoring of cardiovascular events from multiple body locations, which should facilitate its use in a variety of clinical environments
High flux coherent supercontinuum soft X-ray source driven by a single-stage 10 mJ, kHz, Ti:sapphire laser amplifier
We demonstrate the highest flux tabletop source of coherent soft X-rays to
date, driven by a single-stage 10 mJ Ti:sapphire regenerative amplifier at 1
kHz. We first down-convert the laser to 1.3 um using a parametric amplifier,
before up-converting it to soft X-rays using high harmonic generation in a
high-pressure, phase matched, hollow waveguide geometry. The resulting
optimally phase matched broadband spectrum extends to 200 eV, with a soft X-ray
photon flux of > 10^6 photons/pulse/1% bandwidth at 1 kHz, corresponding to >
10^9 photons/s/1% bandwidth, or approximately a three order-of-magnitude
increase compared with past work. Finally, using this broad bandwidth X-ray
source, we demonstrate X-ray absorption spectroscopy of multiple elements and
transitions in molecules in a single spectrum, with a spectral resolution of
0.25 eV, and with the ability to resolve the near edge fine structure.Comment: 9 pages, 3 figures, under Optics Express peer revie
Carbapenem-resistant Gram-negative bacteria (CR-GNB) in ICUs: resistance genes, therapeutics, and prevention – a comprehensive review
Intensive care units (ICUs) are specialized environments dedicated to the management of critically ill patients, who are particularly susceptible to drug-resistant bacteria. Among these, carbapenem-resistant Gram-negative bacteria (CR-GNB) pose a significant threat endangering the lives of ICU patients. Carbapenemase production is a key resistance mechanism in CR-GNB, with the transfer of resistance genes contributing to the extensive emergence of antimicrobial resistance (AMR). CR-GNB infections are widespread in ICUs, highlighting an urgent need for prevention and control measures to reduce mortality rates associated with CR-GNB transmission or infection. This review provides an overview of key aspects surrounding CR-GNB within ICUs. We examine the mechanisms of bacterial drug resistance, the resistance genes that frequently occur with CR-GNB infections in ICU, and the therapeutic options against carbapenemase genotypes. Additionally, we highlight crucial preventive measures to impede the transmission and spread of CR-GNB within ICUs, along with reviewing the advances made in the field of clinical predictive modeling research, which hold excellent potential for practical application
The impact of gene polymorphism and hepatic insufficiency on voriconazole dose adjustment in invasive fungal infection individuals
Voriconazole (VRZ) is a broad-spectrum antifungal medication widely used to treat invasive fungal infections (IFI). The administration dosage and blood concentration of VRZ are influenced by various factors, posing challenges for standardization and individualization of dose adjustments. On the one hand, VRZ is primarily metabolized by the liver, predominantly mediated by the cytochrome P450 (CYP) 2C19 enzyme. The genetic polymorphism of CYP2C19 significantly impacts the blood concentration of VRZ, particularly the trough concentration (Ctrough), thereby influencing the drug’s efficacy and potentially causing adverse drug reactions (ADRs). Recent research has demonstrated that pharmacogenomics-based VRZ dose adjustments offer more accurate and individualized treatment strategies for individuals with hepatic insufficiency, with the possibility to enhance therapeutic outcomes and reduce ADRs. On the other hand, the security, pharmacokinetics, and dosing of VRZ in individuals with hepatic insufficiency remain unclear, making it challenging to attain optimal Ctrough in individuals with both hepatic insufficiency and IFI, resulting in suboptimal drug efficacy and severe ADRs. Therefore, when using VRZ to treat IFI, drug dosage adjustment based on individuals’ genotypes and hepatic function is necessary. This review summarizes the research progress on the impact of genetic polymorphisms and hepatic insufficiency on VRZ dosage in IFI individuals, compares current international guidelines, elucidates the current application status of VRZ in individuals with hepatic insufficiency, and discusses the influence of CYP2C19, CYP3A4, CYP2C9, and ABCB1 genetic polymorphisms on VRZ dose adjustments and Ctrough at the pharmacogenomic level. Additionally, a comprehensive summary and analysis of existing studies’ recommendations on VRZ dose adjustments based on CYP2C19 genetic polymorphisms and hepatic insufficiency are provided, offering a more comprehensive reference for dose selection and adjustments of VRZ in this patient population
JourneyDB: A Benchmark for Generative Image Understanding
While recent advancements in vision-language models have had a transformative
impact on multi-modal comprehension, the extent to which these models possess
the ability to comprehend generated images remains uncertain. Synthetic images,
in comparison to real data, encompass a higher level of diversity in terms of
both content and style, thereby presenting significant challenges for the
models to fully grasp. In light of this challenge, we introduce a comprehensive
dataset, referred to as JourneyDB, that caters to the domain of generative
images within the context of multi-modal visual understanding. Our meticulously
curated dataset comprises 4 million distinct and high-quality generated images,
each paired with the corresponding text prompts that were employed in their
creation. Furthermore, we additionally introduce an external subset with
results of another 22 text-to-image generative models, which makes JourneyDB a
comprehensive benchmark for evaluating the comprehension of generated images.
On our dataset, we have devised four benchmarks to assess the performance of
generated image comprehension in relation to both content and style
interpretation. These benchmarks encompass prompt inversion, style retrieval,
image captioning, and visual question answering. Lastly, we evaluate the
performance of state-of-the-art multi-modal models when applied to the
JourneyDB dataset, providing a comprehensive analysis of their strengths and
limitations in comprehending generated content. We anticipate that the proposed
dataset and benchmarks will facilitate further research in the field of
generative content understanding. The dataset is publicly available at
https://journeydb.github.io.Comment: Accepted to the Thirty-seventh Conference on Neural Information
Processing Systems (NeurIPS 2023
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