4 research outputs found
Cotton (Gossypium hirsutum l.) plant water status as a function of soil water supply and evaporative demand in a semiarid environment
No full textThe Southern High Plains of Texas (SHPT) representing a major cotton iGossypium hirsutum L.) growing area of the United States and the world is characterized as a semiarid environment with inadequate rainfall to meet the high evaporative demand. Soil water content and evaporative demand interact with the plant to determine tissue water status. Leaf water potential (øL), the primary indicator of plant water status, is commonly used in crop simulation models to determine growth rates and yield potential. Functional relationships between cotton øL and soil water supply and evaporative demand have not been well-defined for cotton grown in the SHPT area. A field experiment was conducted for two years to determine the relationship between *FL of cotton plants as a function of Ts, plant size and atmospheric factors affecting evaporative demand. Three irrigation levels (0%, 50% , and 100%) of replacement of water used as evapotranspiration (ETa) were used to provide a range of soil water supplies in two soil types (Amarillo loamy sand and Pullman clay loam), øL, soil water supply as indicated by soil matric potential Q^s), air temperature, relative humidity, incident and absorbed solar radiation, and plant growth were monitored throughout the growing season. Correlation and stepwise multiple regression were used to investigate and develop relationships between øL and øs and the evaporative demand. The variables highly correlated with øL were øs, and daily (24 hrs) average air temperatures (Tavg) as the most effective parameters of the evaporative demand. The relative contribution of each parameter on the variation explained for øL was shown not to be sensitive of plant growth stage as indicated by LAI ranges, but was sensitive to existing soil water supply. The overall effect of soil water supply was more dominant than the evaporative demand across the entire period of data measurement and within all LAI ranges. Crop growth rate (CGR), mainstem elongation rate (MER) and leaf area growth rate (LAGR) declined sharply when øL declined from its non-limiting conditions of -1.2 MPa to -1.6 MPa. From -1.6 MPa to -2.5 MPa øL growth rates continued to decline but at a slower rate. Essentially zero growth of all parameters was observed when øL dropped below -2.7 MPa. Results also indicated no differential sensitivity of reproductive versus vegetative growth rates to declining øL. In general, for cotton grown in the SHPT area, plant water status should be maintained above -1.6 MPa for maximum growth
Prediction of rear-end conflict frequency using multiple-location traffic parameters
No full textTraffic conflicts are heavily correlated with traffic collisions and may provide insightful information on the failure mechanism and factors that contribute more towards a collision. Although proactive traffic management systems have been supported heavily in the research community, and autonomous vehicles (AVs) are soon to become a reality, analyses are concentrated on very specific environments using aggregated data. This study aims at investigating –for the first time- rear-end conflict frequency in an urban network level using vehicle-to-vehicle interactions and at correlating frequency with the corresponding network traffic state. The Time-To-Collision (TTC) and Deceleration Rate to Avoid Crash (DRAC) metrics are utilized to estimate conflict frequency on the current network situation, as well as on scenarios including AV characteristics. Three critical conflict points are defined, according to TTC and DRAC thresholds. After extracting conflicts, data are fitted into Zero-inflated and also traditional Negative Binomial models, as well as quasi-Poisson models, while controlling for endogeneity, in order to investigate contributory factors of conflict frequency. Results demonstrate that conflict counts are significantly higher in congested traffic and that high variations in speed increase conflicts. Nevertheless, a comparison with simulated AV traffic and the use of more surrogate safety indicators could provide more insight into the relationship between traffic state and traffic conflicts in the near future.Safety and Security Scienc
Author Correction: Metabolic pathway and cell adaptation mechanisms revealed through genomic, proteomic and transcription analysis of a Sphingomonas haloaromaticamans strain degrading ortho-phenylphenol
No full textA correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.</jats:p
European first-year university students accept evolution but lack substantial knowledge about it: a standardized European cross-country assessment
No full text22 Pags.- 4 Figs.- 6 Tabls. © The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which
permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the
original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.Background
Investigations of evolution knowledge and acceptance and their relation are central to evolution education research. Ambiguous results in this field of study demonstrate a variety of measuring issues, for instance differently theorized constructs, or a lack of standardized methods, especially for cross-country comparisons. In particular, meaningful comparisons across European countries, with their varying cultural backgrounds and education systems, are rare, often include only few countries, and lack standardization. To address these deficits, we conducted a standardized European survey, on 9200 first-year university students in 26 European countries utilizing a validated, comprehensive questionnaire, the “Evolution Education Questionnaire”, to assess evolution acceptance and knowledge, as well as influencing factors on evolution acceptance.
Results
We found that, despite European countries’ different cultural backgrounds and education systems, European first-year university students generally accept evolution. At the same time, they lack substantial knowledge about it, even if they are enrolled in a biology-related study program. Additionally, we developed a multilevel-model that determines religious faith as the main influencing factor in accepting evolution. According to our model, knowledge about evolution and interest in biological topics also increase acceptance of evolution, but to a much lesser extent than religious faith. The effect of age and sex, as well as the country’s affiliation, students’ denomination, and whether or not a student is enrolled in a biology-related university program, is negligible.
Conclusions
Our findings indicate that, despite all their differences, most of the European education systems for upper secondary education lead to acceptance of evolution at least in university students. It appears that, at least in this sample, the differences in knowledge between countries reflect neither the extent to which school curricula cover evolutionary biology nor the percentage of biology-related students in the country samples. Future studies should investigate the role of different European school curricula, identify particularly problematic or underrepresented evolutionary concepts in biology education, and analyze the role of religious faith when teaching evolution.Open Access funding enabled and organized by Projekt DEAL. Networking
activities for the purpose of this project, as well as a professional proofread,
were funded by COST (European Cooperation in Science and Technology;
www.cost.eu) via COST Action 17127.Peer reviewe
