Objective: To examine the role of intent and other theory of planned behavior (TPB) constructs in predicting college students' willingness to text while driving (TWD).
Methods: This was a cross-sectional study. 243 male and female college students enrolled in the 2013–2014 academic year in the College of Health, Human Services & Nursing completed a survey on TWD. Inclusion criteria: All races and ethnicities, ≥18 years of age, cell phone owner, and licensed driver.
Results: Over 70% of the sample (n = 243) reported talking on a cell phone and sending and receiving text messages “at least a few times” while driving within the past week. However, only 27% reported being stopped by police. Of these, 22% reported being fined. Within the past 30 days, 26% reported reading or sending TWD and having to slam on the brakes to avoid hitting another car or pedestrian(s) as a result. In all, 47% of the variance in intention to send TWD was accounted for by the full TPB model. Intention, in turn, predicted willingness to TWD. Intention also mediated the relationship between perceived behavioral control and willingness to TWD.
Conclusion: Attitude was found to be the strongest predictor of intention. In addition, intention was found to mediate the relationship of willingness to TWD on perceived behavioral control. These findings highlight potential factors that could be targeted in behavioral change interventions seeking to prevent TWD. 相似文献
A total of 54 soil and 54 potato samples have been collected from Weining County to evaluate the accumulation of cadmium in potatoes. The concentrations of the total Cd and the available Cd in the soil samples have been detected. The total concentrations of Cd were from 0.41 to 10.0 mg/kg with an average value of 2.60 mg/kg in soil. The concentrations of available Cd in the soil were 0.07 to 3.47 mg/kg with an average value of 0.59 mg/kg. The concentration of the available Cd showed a good linear positive correlation with the total Cd content in the soil. For the 54 potato samples, the Cd concentrations were from 0.023 to 0.18 mg/kg with an average value 0.083 mg/kg (fresh weight).The bioconcentration factor (BCF) values of Cd in potatoes, based on dry weight, were from 0.02 to 0.96 with an average value 0.24. The uptake of cadmium by plants is dependent on various soil and environmental factors. A regression model to predict the concentration of cadmium in Weining potatoes based on soil properties and elevation was developed. The results showed the elevation and the soil pH played an important role and had a negative influence on the uptake of Cd by potato in Weining County. The mean intake of Cd by adults through consumption of potato from Weining would be 5.9 μg/day, and it is well below the provisionally tolerable daily intake for Cd (70 μg/day). 相似文献
Residues of dinotefuran and its metabolites, 1-methyl-3-(tetrahydro-3-furylmethyl)urea (UF) and 1-methyl-3-(tetrahydro-3-furylmethyl)guanidine (DN), in apple were investigated using a “QuEChERS” (quick, easy, cheap, effective, rugged, safe) pretreatment and liquid chromatography–tandem mass spectrometry. Limits of detection (LODs) and quantification (LOQs) of dinotefuran, UF, and DN in apples were 0.011–0.960 and 0.037–3.200 μg/kg, respectively. The average recoveries of dinotefuran, UF, and DN in apple ranged from 70.0 to 83.6% with relative standard deviations less than 13%. A formulation of 20% water-dispersible dinotefuran granules was sprayed at 1–1.5-fold the recommended dose 3–4 times on apple trees. Total terminal residues of dinotefuran in apple were less than 2 mg/kg, which is the maximum residue limit (MRL) set by Japan. When following the recommended application guidelines, dinotefuran is unlikely to present significant health concerns to the Chinese population because the risk quotient (RQ) is less than 100%. This work could provide guidance for the safe use of dinotefuran and serve as a reference for the establishment of a maximum residue limit of dinotefuran in apple in China. 相似文献
全球气候变化下陆地生态系统的适应性是当前科学研究关注的主题之一,了解生态系统如何响应及影响全球气候变化有利于人类对未来生存环境的预测和适应。生态系统中不同来源水分对植物生长相对贡献决的大小一定程度上决定了生态系统对气候变化的响应方式、程度和响应结果,因此跟踪和分析植物利用水分的来源是制定全球气候变化对策的一个重要研究内容。本文介绍了稳定氢氧同位素技术研究历史及其在定量区分植物利用水分的来源研究中的应用原理与具体方法。由于土壤水分在被植物根系吸收及随后沿导管向上传输的过程中,与外界环境不发生水分交换,因此不存在同位素的分馏过程,所以植物茎木质部水分同位素组成能反映出植物利用的来源水分同位素信息。通过比较植物茎木质部水分与植物利用的不同来源水分同位素值,利用二项或三项分隔线性混合模型(two-orthree-compartment linear mixing model),可以估算出植物对不同来源水分的相对使用量。而由于植物叶片水分同位素组成受到周围环境的温度、湿度、降雨和土壤水分的异质性等许多因素的影响,通过比较分析植物茎木质部水分和叶片水分同位素组成的差异可以得到植物周围环境的气候信息。植物利用水分的来源存在显著的季节性差异,并且,不同生活型植物在利用水分来源上存在明显不同。植物根系的分布及根深是决定植物利用水分来源的一个重要的因素,表层和深层根系的相对分布及其活性影响着植物吸收水分的范围。当然,利用线型分隔混合模型定量区分植物利用水分的不同来源,还有许多值得改进的地方,而且,尽管稳定同位素技术在植物科学中的应用正迅速发展起来,但利用稳定氢氧同位素来分析环境因素对植物影响的研究还只是刚刚展开,还有许多方面值得去进一步探索。 相似文献