We explored the frequency and indices of smartphone addiction in a group of King Saud University students and investigated whether there were differences in smartphone addiction based on gender, ...social status, educational level, monthly income and hours of daily use. We developed a questionnaire probing smartphone addiction consisting of five dimensions: 1) overuse of smartphone, 2) the psychological-social dimension, 3) the health dimension, 4) preoccupation with smartphones, and 5) the technological dimension. After being validated, the questionnaire was administered to 416 students, both male and female, at King Saud University. Results revealed that addiction percentage among participants was 48%. The order of smartphone addiction indices were as follows: overuse of smartphone, the technological dimension, the psychological-social dimension, preoccupation with smartphones, and the health dimension. Significant gender differences were found in the degree of addiction on the whole questionnaire and all of its dimensions with the exception of the technological dimension in favor of males. Significant differences by social status were found in favor of the unmarried. Bachelor degree students were found to have the highest degree of addiction. Significant differences by hours of daily use were also detected in favor of participants using the smartphone for more than 4 h a day. As to the monthly income dimension, significant differences were found on the health dimension in favor of participants with lower monthly income.
•The addiction percentage among participants was 48%.•There are Significant gender and social status differences were found in the degree of addiction.•There are significant differences due to monthly income were found in the degree of addiction.•Bachelor degree students were found to have the highest degree of addiction.•There are significant differences due to hours of daily use were found in degree of addiction.
This review summarizes the influences of pyrolysis conditions and feedstock types on biochar properties and how biochar properties in turn affect soil properties. Mechanistic evidence of biochar's ...potential for enhancing crop productivity, carbon sequestration, and nutrient use efficiency are also discussed. The review identifies the knowledge gaps, limitations, and future research directions for large‐scale use of biochar. Both pyrolytic parameters and feedstock types are considered to be the main factors controlling biochar properties such as nutrient content, recalcitrance, and pH. Biochar produced at low temperatures may improve nutrient availability and crop yield in acidic and alkaline soils, whereas high‐temperature biochar may enhance long‐term soil carbon sequestration. Biochar can also improve the efficiency of inorganic and organic fertilizers by enhancing microbial functions and reducing nutrient loss, thereby making nutrients more available to plants. Integration of biochar and chemical or organic fertilizers generally provides for better nutrient management and crop yield in most types of soils. Although biochar can improve degraded soils, it is not a panacea; as such, soil‐ and crop‐specific biochar are needed in order to ensure optimum crop yield and agricultural sustainability.
Classroom context and climate are inherently classroom-level (L2) constructs, but applied researchers sometimes-inappropriately-represent them by student-level (L1) responses in single-level models ...rather than more appropriate multilevel models. Here we focus on important conceptual issues (distinctions between climate and contextual variables; use of classroom L2 rather than student-level L1 measures) and more appropriate multilevel models. To illustrate these issues, we consider the effects of two L2 classroom climate variables and one L2 classroom contextual variable on two L1 student-level outcomes for 2261 students in 128 classes. Through this example, we illustrate how to apply evolving doubly latent multilevel models to (a) evaluate the factor structure of L1 and L2 constructs based on multiple indicators of classroom climate and context measures, (b) control measurement error at L1 and L2, (c) control sampling error in the aggregation of L1 responses to form L2 constructs (the average of student-level responses to form classroom-level constructs), and (d) provide guidelines for appropriate analysis of classroom climate as an L2 construct.
Supplementary materials are available for this article. Go to the publisher's online edition of Educational Psychologist for the following free supplemental resources: Substantive basis of the present investigation and more detailed description of the methodology.
The Passion Scale, based on the dualistic model of passion, measures 2 distinct types of passion: Harmonious and obsessive passions are predictive of adaptive and less adaptive outcomes, ...respectively. In a substantive-methodological synergy, we evaluate the construct validity (factor structure, reliability, convergent and discriminant validity) of Passion Scale responses (N = 3,571). The exploratory structural equation model fit to the data was substantially better than the confirmatory factor analysis solution, and resulted in better differentiated (less correlated) factors. Results from a 13-model taxonomy of measurement invariance supported complete invariance (factor loadings, factor correlations, item uniquenesses, item intercepts, and latent means) over language (French vs. English; the instrument was originally devised in French, then translated into English) and gender. Strong measurement partial invariance over 5 passion activity groups (leisure, sport, social, work, education) indicates that the same set of items is appropriate for assessing passion across a wide variety of activities-a previously untested, implicit assumption that greatly enhances practical utility. Support was found for the convergent and discriminant validity of the harmonious and obsessive passion scales, based on a set of validity correlates: life satisfaction, rumination, conflict, time investment, activity liking and valuation, and perceiving the activity as a passion.
We investigated the removal of aqueous glyphosate using woody (dendro) biochar obtained as a waste by product from bioenergy industry. Equilibrium isotherms and kinetics data were obtained by ...adsorption experiments. Glyphosate adsorption was strongly pH dependent occurring maximum in the pH range of 5–6. The protonated amino moiety of the glyphosate molecule at this pH may interact with π electron rich biochar surface via π–π electron donor–acceptor interactions. Isotherm data were best fitted to the Freundlich and Temkin models indicating multilayer sorption of glyphosate. The maximum adsorption capacity of dendro biochar for glyphosate was determined by the isotherm modeling to be as 44 mg/g. Adsorption seemed to be quite fast, reaching the equilibrium <1 h. Pseudo-second order model was found to be the most effective in describing kinetics whereas the rate limiting step possibly be chemical adsorption involving valence forces through sharing or exchanging electrons between the adsorbent and sorbate. The FTIR spectral analysis indicated the involvement of functional groups such as phenolic, amine, carboxylic and phosphate in adsorption. Hence, a heterogeneous chemisorption process between adsorbate molecules and functional groups on biochar surface can be suggested as the mechanisms involved in glyphosate removal.
•A waste byproduct of a bioenergy industry was used for glyphosate remediation.•Maximum glyphosate removal at pH 5–6 due to electron donor–acceptor interactions.•Rate limiting step may be chemisorption through sharing or exchange of electrons.•Phenolic, amine, and carboxylic functional groups were involved in adsorption.
Biochar (BC) was produced from date palm tree leaves and its composites were prepared with nano zerovalent iron (nZVI-BC) and hen eggshell powder (EP-BC). The produced BC and its composites were ...characterized by SEM, XRD, BET, and FTIR for surface structural, mineralogical, and chemical groups and tested for their efficiency for nitrate removal from aqueous solutions in the presence and absence of chloride ions. The incidence of graphene and nano zerovalent iron (Fe
0
) in the nZVI-BC composite was confirmed by XRD. The nZVI-BC composite possessed highest surface area (220.92 m
2
g
−1
), carbon (80.55%), nitrogen (3.78%), and hydrogen (11.09%) contents compared to other materials. Nitrate sorption data was fitted well to the Langmuir (
R
2
= 0.93–0.98) and Freundlich (
R
2
= 0.90–0.99) isotherms. The sorption kinetics was adequately explained by the pseudo-second-order, power function, and Elovich models. The nZVI-BC composite showed highest Langmuir predicted sorption capacity (148.10 mg g
−1
) followed by EP-BC composite (72.77 mg g
−1
). In addition to the high surface area, the higher nitrate removal capacity of nZVI-BC composite could be attributed to the combination of two processes, i.e., chemisorption (outer-sphere complexation) and reduction of nitrate to ammonia or nitrogen by Fe
0
. The appearance of Fe-O stretching and N-H bonds in post-sorption FTIR spectra of nZVI-BC composite suggested the occurrence of redox reaction and formation of Fe compound with N, such as ferric nitrate (Fe(NO
3
)
3
·9H
2
O). Coexistence of chloride ions negatively influenced the nitrate sorption. The decrease in nitrate sorption with increasing chloride ion concentration was observed, which could be due to the competition of free active sites on the sorbents between nitrate and chloride ions. The nZVI-BC composite exhibited higher nitrate removal efficiency compared to other materials even in the presence of highest concentration (100 mg L
−1
) of coexisting chloride ion.
•Academic self-concepts are formed by dimensional, social and temporal comparisons.•In contrasting school subjects, better achievement can lead to lower self-concepts.•School grades drive academic ...self-concepts more than test scores.•Dimensional comparison theory helps teacher provide more effective feedback.
In a comprehensive study (15,356 Dutch 9th grade students from 651 classes in 95 schools) we empirically tested the dimensional comparison theory (DCT) propositions formulated by Möller & Marsh (2013) as an extension of I/E theory, exploring methodological, theoretical, and substantive insights. According to DCT, academic self-concepts (ASC) are formed in relation to dimensional comparisons in different school subjects, as well as to social and temporal comparisons. In support of DCT predictions, paths from achievement to ASC in matching domains were substantially positive, but paths to non-matching domains (e.g., math achievement to verbal self-concept) were significantly negative. Extending DCT, we show that the more dissimilar the subjects, the more negative the cross paths (far comparisons), whereas cross paths relating more similar subjects (near comparisons) are much less negative and sometimes positive. Extending previous self-concept research and its integration with DCT, we found that positive paths for matching domains and negative paths for non-matching domains were larger for class marks based on classroom performance than for standardized test scores. Controlling for direct measures of social comparison (meVclass ratings of how each student compares to classmates) substantially reduced positive paths from achievement to ASC in matching domains, but also reduced the size of the negative paths from non-matching domains. Supplemental analyses suggest that dimensional comparison processes in both subjective rankings and actual class marks are consistent with those found in ASCs.
Clinical activities at dental premises after the COVID-19 lockdown period or post-COVID-19 are likely to be a challenge for all practicing dentists. To assess the impact of the COVID-19 pandemic on ...dentists and change in dental practice following lockdown, a total of 1150 participants were approached through online survey forms registered on www.surveys.google. A link containing details of the questionnaire and a consent form was sent to dentists through emails and social media forums. The questionnaire included 3 domains comprising of seventeen questions. The first section focused on demographics. The second section inquired about the change in dental practice, that is, clinical hours, use of PPE, type of treatment, and patient flow. The third section investigated the impact of COVID-19 on dentistry. Means, standard deviation, and percentages were calculated using descriptive statistics. Chi-square was used to find an association between different variables. The response rate was 87%. Demographic factors revealed participants aged from 20.45 to 40.55 years. The data showed around 89.6% (896) of dentists have altered their clinical working hours post lockdown and, approximately, 59.7% (597) of dentists provided only emergency treatments. 88.1% (881) of the dentists wore PPE during dental procedures. Overall, a huge negative impact of the COVID-19 pandemic was observed among practicing dentists in terms of the dental supply chain, cost, and availability of dental equipment, treatment cost, and bill payments.COVID-19 pandemic compromised dental care. Though dentists were taking precautionary measures and have changed their practice according to the guidelines provided by the ADA and World Health Organization, they were still experiencing monetary loss due to decrease patient influx post lockdown.
To assess the association between far vision impairment (objective and subjective) and perceived stress among older adults from six low- and middle-income countries (LMICs, i.e., China, Ghana, India, ...Mexico, Russia, and South Africa).
Data from the WHO Study on global AGEing and adult health were analyzed. Objective visual acuity was measured using the tumbling E LogMAR chart and was used as a four-category variable (no, mild, moderate, and severe visual impairment). Subjective visual impairment referred to difficulty in seeing and recognizing an object or a person across the road. Using two questions from the Perceived Stress Scale, a perceived stress variable was computed, and ranged from 0 (lowest stress) to 100 (highest stress). Multivariable linear regression with perceived stress as the outcome was conducted.
Data on 14,585 adults aged ≥65 years mean (SD) age 72.6 (11.5) years; 55.0% females were analyzed. Only severe objective visual impairment (versus no visual impairment) was significantly associated with higher levels of stress (b = 6.91; 95% CI = 0.94-12.89). In terms of subjective visual impairment, compared with no visual impairment, mild (b = 2.67; 95% CI = 0.56-4.78), moderate (b = 8.18; 95% CI = 5.84-10.52), and severe (b = 11.86; 95% CI = 9.11-14.61) visual impairment were associated with significantly higher levels of perceived stress.
This large study showed that far vision impairment was associated with increased perceived stress levels among older adults in LMICs. Increased availability of eye care services may reduce stress among those with visual impairment in LMICs, while more research is needed to better characterize the directionality of the far vision impairment-perceived stress relationship.
Workaholism (WH) is related with high mental trouble and physical objections, low employment and family fulfillment, and low occupation execution; however, work commitment is related with job and ...life satisfaction. This study aimed to assess the impact of WH and work engagement (WE) on medical university employee job stress and satisfaction.
This descriptive analytical study was conducted on workers employed in medical universities using validated questionnaires for data collection. The sample size was 330, from which 305 responded with completed questionnaire. The employees were the direct workers of different accessible medical universities in Karachi, Pakistan. The employee enrolment and distribution of the questionnaire was performed using non-probability convenient sampling. The Brief Job Questionnaire (BJQ), Dutch Work Addiction Scale (DUWAS) and Utrecht Work Engagement Scale (UWES) were used to assess the impact of job stress on job satisfaction and WE. The data was analyzed by applying descriptive statistics, Spearman correlation and regression analysis. A
-value of ≤ 0.05 was taken as significant.
The study consisted of 117 (38.4%) male and 188 (61.6%) female participants; the mean age of participating employee was 28.50 ± 6.192. The mean score for WE was 3.78 ± 0.467, that of WH was 3.42 ± 0.559, for JS was 4.29 ± 0.400, whereas JSF was 3.10 ± 0.591. A positive correlation was observed between job stress, WH and WE. WH had a strong correlation with job stress and weak correlation with job satisfaction and performance. A significant difference was observed between WE and WH among males and females.
The study presented with a significant effect of job satisfaction with WH and WE with job stress. Hence, indicating the importance of social skills and WE with fellow employees to increase the work productivity and performance. However, in case of over work and WH, an increase of job stress is inevitable.
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