Fluoride (F–) binding to humic acid has been measured as a function of pH (5–6.6). The pH dependent binding is attributed to the anion being trapped within the large structure (territorial bound) but is not bound to a particular functional group (site bound). Studying fluoride binding provides insight to cation, anion and neutral species interactions with humic acid.
Authors:J. Varga, S. Kocsubé, Gy. Szigeti, V. Man, B. Tóth, Cs. Vágvölgyi, and T. Bartók
Black mould rot caused by black Aspergilli is an important post-harvest disease of onion worldwide. Usually Aspergillus niger is cited as the causative agent based on morphological criteria. In this study, the mycobiota and fumonisin contamination of mouldy onion bulbs purchased in Hungary were examined. All except one of the examined mouldy samples were found to be contaminated with black Aspergilli, which could be isolated both from the outer dry and the inner fleshy scales of onion bulbs. Species assignment of the isolates was carried out using sequence analysis of part of the calmodulin gene. Sequence data revealed that all 35 black Aspergilli isolated from onions belong to the Aspergillus awamori species. The range of fumonisin isomers present in the onion samples was also examined using reversed-phase high-performance liquid chromatography/electrospray ionization-ion trap mass spectrometry. Two of the examined onion samples were found to be contaminated with fumonisins at a rate of about 0.3 mg kg−1. This is the first report on fumonisin contamination of onion bulbs. The fumonisin isomers observed include fumonisins B2–4, 3-epi-FB4, iso-FB1 (FB6) and an iso-FB2,3 form. The range of fumonisin isomers detected in the onion bulbs indicates that probably A. awamori is responsible both for mould rot and fumonisin contamination of onions in Hungary.
Authors:Anise M. S. Wu, Mark H. C. Lai, Shu Yu, Joseph T. F. Lau, and Man-wai Lei
Background and aims
Internet gaming disorder (IGD) imposes a potential public health threat worldwide. Gaming motives are potentially salient factors of IGD, but research on Chinese gaming motives is scarce. This study empirically evaluated the psychometric properties of the Chinese version of the Motives for Online Gaming Questionnaire (C-MOGQ), the first inventory that measures seven different gaming motives applicable to all type of online games. We also investigated the associations between various gaming motives and IGD symptoms among Chinese gamers.
Three hundred and eighty-three Chinese adult online gamers (Mean age = 23.7 years) voluntarily completed our online, anonymous survey in December 2015.
The confirmatory factor analysis results supported a bi-factor model with a general factor subsuming all C-MOGQ items (General Motivation) and seven uncorrelated domain-specific factors (Escape, Coping, Fantasy, Skill Development, Recreation, Competition, and Social). High internal consistencies of the overall scale and subscales were observed. The criterion-related validity of this Chinese version was also supported by the positive correlations of C-MOGQ scale scores with psychological need satisfaction and time spent gaming. Furthermore, we found that high General Motivation (coupled with high Escape motive and low Skill Development motive) was associated with more IGD symptoms reported by our Chinese participants.
Discussion and conclusions
Our findings demonstrated the utility of C-MOGQ in measuring gaming motives of Chinese online gamers, and we recommend the consideration of both its total score and subscale scores in future studies.
Authors:Joseph T. F. Lau, Danielle L. Walden, Anise M. S. Wu, Kit-man Cheng, Mason C. M. Lau, and Phoenix K. H. Mo
Background and aims
The aim of the study is to investigate (a) whether probable depression status assessed at baseline prospectively predicted new incidence of Internet addiction (IA) at the 12-month follow-up and (b) whether IA status assessed at baseline prospectively predicted new incidence of probable depression at follow-up.
We conducted a 12-month cohort study (n = 8,286) among Hong Kong secondary students, and derived two subsamples. The first subsample (n = 6,954) included students who were non-IA at baseline, using the Chen Internet Addiction Scale (≤63), and another included non-depressed cases at baseline (n = 3,589), using the Center for Epidemiological Studies Depression Scale (<16).
In the first subsample, 11.5% of the non-IA cases developed IA during follow-up, and probable depression status at baseline significantly predicted new incidence of IA [severe depression: adjusted odds ratio (ORa) = 2.50, 95% CI = 2.07, 3.01; moderate: ORa = 1.82, 95% CI = 1.45, 2.28; mild: ORa = 1.65, 95% CI = 1.32, 2.05; reference: non-depressed], after adjusting for sociodemographic factors. In the second subsample, 38.9% of those non-depressed participants developed probable depression during follow-up. Adjusted analysis showed that baseline IA status also significantly predicted new incidence of probable depression (ORa = 1.57, 95% CI = 1.18, 2.09).
Discussion and conclusions
The high incidence of probable depression is a concern that warrants interventions, as depression has lasting harmful effects in adolescents. Baseline probable depression predicted IA at follow-up and vice versa, among those who were free from IA/probable depression at baseline. Healthcare workers, teachers, and parents need to be made aware of this bidirectional finding. Interventions, both IA and depression prevention, should thus take both problems into consideration.