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Run-off-road (ROR) crashes account for a large proportion of fatalities and serious injuries to vehicle occupants, especially in rural areas. While performing crash severity analysis using discrete choice models (DCMs), researchers may be confused by the following questions: first, should an ordered or unordered model structure be used and secondly, which modeling level is more appropriate, basic or advanced? A model selection framework is developed considering the following factors: (1) model structure--ordered or unordered; (2) intrinsic deficiency of each model; (3) computational burdens; (4) complexity of parameter interpretation; and (5) model fitness. Historical ROR crash data were utilized to illustrate how to choose an appropriate DCM based on the proposed framework. Using statistical tests and comparison of evaluation and validation measurements, both the mixed logit model and the partial proportional odds model yield a reasonable performance. All factors that significantly affect the severity level of a single-vehicle ROR crash were identified as well. Key words: roadway safety, severity modeling, run-off-road, DCM. Les accidents causes par une sortie de route (SR) representent une grande proportion des deces et des blessures graves aux occupants de vehicule, particulierement dans les zones rurales. En faisant l'analyse de la gravite d'accident a l'aide des modeles des choix discrets (MCD), les chercheurs peuvent etre deroutes par les questions suivantes: premierement, devrait-on avoir recours a une structure de modele ordonnee ou non ordonnee et deuxiemement quel niveau de modelisation est plus approprie, niveau elementaire ou avance? On developpe un cadre de selection du modele considerant les facteurs suivants: (1) la structure du modele--ordonnee ou non ordonnee; (2) la lacune intrinseque de chaque modele; (3) les fardeaux computationnels; (4) la complexite d'interpretation des parametres; et (5) la justesse du modele. On a utilise les donnees historiques des accidents causes par une SR pour illustrer comment choisir un MCD a l'aide du cadre propose. En utilisant des tests statistiques et la comparaison des mesures d'evaluation et de validation, le modele logit mixte et le modele des cotes partielles proportionnelles produisent tous deux un rendement raisonnable. On a aussi determine tous les facteurs qui influent considerablement sur le niveau de gravite d'un accident cause par une SR a un seul vehicule. [Traduit par la Redaction] Mots-cles: securite routiere, modelisation de la gravite, sortie de route, modele des choix discrets (MCD)., 1. Introduction Run-off-road (ROR) crashes account for a large proportion of fatalities and serious injuries to vehicle occupants. Statistics based on the data compiled from the Fatality Analysis Reporting System [...]

Sediment and tailings samples were collected from sites with a contrasting physicochemical gradient to investigate microbial squalene-hopene cyclase (sqhC) composition and distribution in terrestrial environments. Acidobacteria (66%), Alphaproteobacteria (96%) and Gammaproteobacteria (55%) were found to dominatesqhCcommunities, respectively, at the acidic Dajiuhu Peatland, the alkaline Heshang Cave and strongly acidic tailings of Tongling copper mine in China. Statistical analysis confirmed that pH was the important factor impacting the geographical distribution ofsqhCat phylum level.sqhCgene abundance is comparable at the three sites. However, the total amount of hopanoids in per gram total organic matter content (TOC) is 1.75 times higher in the acidic peatland than that in the alkaline Cave and it is below the detecting limit in tailings of Tongling copper mine, inferring the potential impact of pH in regulating the hopanoid production. [ABSTRACT FROM AUTHOR]

The purpose of this study was to characterize the physiological response of Synechococcus elongatus, a brackish-water cyanobacterium, to salt stress. S. elongatus was grown in artificial sea water medium with different salinities. The response was measured by analysis of extracellular polymeric substances (EPS) and membrane lipids. The EPS yields were positively correlated (r2 = 0.99) with the salinity. The ratio of unsaturated to saturated fatty acids (U/S) increased with salinity in the range of 2.1‰ to 31.5‰ and decreased at 52.5‰. A positive linear correlation (r2 = 0.92) was observed between the average chain length (ACL) of fatty acids and the salinity. These data indicate that S. elongatus adapted to salt stress by the secretion of EPS and by adjusting the membrane fluidity through the changes in ACL or desaturation of fatty acids. These variations in EPS and fatty acids may be used as geochemical biomarkers in sediments to unravel changes in the salinity of ancient evaporative environments. [ABSTRACT FROM AUTHOR]

The article focuses on a study which examined the possible microbial functions in the karst cave ecosystem in Central China. Samples of bacteria were collected from the dripping water above the 4D-M1 stalagmite at the Heshang Cave. Results of the study showed that Pseudomonas, Comamonas, Acinetobacter and Stenotrophomonas were the bacterial genera cultured from the 4D-W dripping water. It also found that some of these bacterial strains can influence the chemical properties of the environment.

The article focuses on a study which examined the bacterial composition of mixed cultures enriched from sediments and water in Tongling Copper Mine in Anhui Province, East China. Results of the study showed saturation in the rarefaction curve of both sediment and water samples. It also found a higher diversity index in the enrichment of the water sample compared to the sediment. It cites Acidithiobacillus as the predominant genus in the two mixture cultures.

Highlights: [•] The δ13C values of n-alkanes (δ13Calk) in Dajiuhu peatland were investigated. [•] They displayed site-dependent relationships with water level. [•] Most sites showed a positive correlation between δ13Calk and water level. [•] Influence of methanotrophs on δ13Calk was not apparent in non-submerged Sphagnum. [ABSTRACT FROM AUTHOR]

Two new phthalide derivatives, namely bialowalides A (1) and B (8), and one new isochromanone analogue biourgalide C (11), together with 8 known phthalides (2-7, 9, and 10) as well as two known isochromanones (12 and 13) were discovered from the EtOAc extract of the deep-sea-derived fungus Penicillium bialowiezense A3. The structures were resolved on the basis of extensive spectroscopic analyses (NMR and HRESIMS data), in association with the modified Mosher's method and ECD data for the determination of the absolute configurations. All isolated secondary metabolites (1-13) were tested their antiviral activities against the SARS-CoV-2 trVLP pseudovirus at a concentration of 25 μM. As a result, compounds 1, 5, 11, and 12 exhibited the inhibitory effects against the luminescence at 46.2 %, 39.6 %, 45.5 %, and 48.8 %, respectively., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)