The completion theorem in K-theory for proper actions of a discrete group

We prove a version of the Atiyah-Segal completion theorem for proper actions of an infinite discrete group G. More precisely, for any finite proper G-CW-complex X, KH(EG� X) is the completion of KH (X) with respect to a certain ideal. We also show, for such G and X, that K (X) can be defined as the Grothendieck group of the monoid of G-vector bundles over X

Malocclusion and craniofacial characteristics in Saudi adolescents with sickle cell disease

Background: Sickle cell disease can result in dentofacial abnormalities. However, in Saudi Arabia, there are limited data with respect to orthodontic manifestations in patients with sickle cell disease. Objective: To determine the malocclusion and craniofacial characteristics in sickle cell disease adolescents and compare them with that of controls from the Eastern Province of Saudi Arabia. Methods: This comparative cross-sectional study included 112 Saudi patients with sickle cell disease, aged 12–18 years, and 124 age-matched Saudi controls from three major hospitals in Al Khobar and Dammam, Saudi Arabia. The Dental Aesthetic Index was used to assess malocclusion and orthodontic treatment needs. Digital lateral cephalometric radiographs were recorded for each patient and control, and its analysis included linear and angular measurements. Results: The prevalence of malocclusion was 87.5% in sickle cell disease patients and 54% in controls (P = 0.0001). The percentage of sickle cell disease patients with severe malocclusion that required orthodontic treatment was higher than that of controls (37.5% vs. 26.6%). In the sickle cell disease cohort, incisal segment crowding (72.4%), overjet (67.3%) and maxillary misalignment in the anterior segment (56%) were the most prevalent types of malocclusions and were significantly higher than that of controls (P < 0.05). About 38% and 67% of the sickle cell disease patients had openbite and posterior crossbite, respectively, compared with 19.3% (P = 0.001) and 37.1% (P = 0.0001) of controls, respectively. Cephalometric analysis showed that SNA (86.7°) and ANB (9.9°) angles were significantly higher in sickle cell disease patients than in controls (81.5° and 2°, respectively). In addition, lower central incisor-to-Frankfort horizontal plane (55°) and interincisal angles (121.5°) were significantly lower in sickle cell disease patients than in controls. Conclusion: Adolescents with sickle cell disease had a higher prevalence of malocclusion and greater orthodontic treatment needs than controls. Similarly, they had greater incisal crowding, overjet, openbite and posterior crossbite and demonstrated higher SNA, ANB and lower interincisal angles than controls. The findings of this study suggest that adolescents with sickle cell disease should be provided frequent dental examinations and early orthodontic treatment to improve their oral health, and thus quality of life

Validity and reliability of the Arabic sedentary behavior questionnaire among university students aged between 18–30 years old

Abstract Purpose The study aimed to test the validity and reliability of the Arabic version of the sedentary behavior questionnaire (SBQ). Methods A total of 624 university students (273 males; 351 females, mean age = 20.8 years) were recruited from Taibah University, Madinah, Saudi Arabia. For criterion and constructive validity (n = 352), the Arabic SBQ was compared with total sitting time from the International Physical Activity Questionnaire-short form (IPAQ-SF) and the International Physical Activity Questionnaire-long form (IPAQ-LF). For concurrent validity, the English and Arabic SBQ versions were given concurrently to bilingual university students (n = 122) once. For test–retest reliability, the Arabic SBQ was given twice to participants (n = 150) at a one-week interval. Results Sitting time of IPAQ-SF (7th question: sitting time on weekdays) and IPAQ-LF (21st question: sitting time on weekdays and 22nd question: sitting time on weekends) correlated significantly with total sitting time/week of the Arabic SBQ (r = 0.29, p = 0.003; r = 0.14, p = 0.02, respectively). Motorized transportation measured with the IPAQ-LF correlated significantly with time spent driving in a car, bus, or train from the Arabic SBQ on weekdays and weekends (r = 0.53, p < 0.001; r = 0.44 p < 0.001, respectively). The total sitting time of the Arabic SBQ was inversely correlated with BMI (r = -0.18, p = 0.001). The correlations between the Arabic and the English SBQ versions ranged from 0.25–0.96; p < 0.001 on weekdays and 0.50–0.90; p < 0.001 on weekends. Moderate to good reliability was also found between test and retest for all SBQ items and total score during weekdays (0.72 to 0.8), and weekends (0.64 to 0.87), with exception of the 7th item "play musical instrument", ICC = 0.46). Mean difference of test–retest of the Arabic SBQ was not significantly different from zero for the total sitting time of the Arabic SBQ (t = -0.715, P = 0.476). Conclusion The Arabic SBQ had satisfactory levels of reliability, with total sitting time of the Arabic SBQ correlating significantly with sitting times derived from IPAQ-SF, IPAQ-LF, and the English SBQ versions. Hence, the Arabic SBQ can be used as a tool to measure sedentary behavior among adult Arabs aged between 18 to 30 years old in future epidemiologic and clinical practice

The prevalence of sedentary behavior among university students in Saudi Arabia

Abstract Background A considerable body of research has demonstrated that reducing sitting time benefits health. Therefore, the current study aimed to explore the prevalence of sedentary behavior (SB) and its patterns. Methods A total of 6975 university students (49.1% female) were chosen randomly to participate in a face-to-face interview. The original English version of the sedentary behavior questionnaire (SBQ) was previously translated into Arabic. Then, the validated Arabic version of the SBQ was used to assess SB. The Arabic SBQ included 9 types of SB (watching television, playing computer/video games, sitting while listening to music, sitting and talking on the phone, doing paperwork or office work, sitting and reading, playing a musical instrument, doing arts and crafts, and sitting and driving/riding in a car, bus or train) on weekdays and weekends. Results SBQ indicated that the total time of SB was considerably high (478.75 ± 256.60 and 535.86 ± 316.53 (min/day) during weekdays and weekends, respectively). On average, participants spent the most time during the day doing office/paperwork (item number 4) during weekdays (112.47 ± 111.11 min/day) and weekends (122.05 ± 113.49 min/day), followed by sitting time in transportation (item number 9) during weekdays (78.95 ± 83.25 min/day) and weekends (92.84 ± 100.19 min/day). The average total sitting time of the SBQ was 495.09 ± 247.38 (min/day) and 58.4% of the participants reported a high amount of sitting time (≥ 7 hours/day). Independent t-test showed significant differences (P ≤ 0.05) between males and females in all types of SB except with doing office/paperwork (item number 4). The results also showed that male students have a longer daily sitting time (521.73 ± 236.53 min/day) than females (467.38 ± 255.28 min/day). Finally, 64.1% of the males reported a high amount of sitting time (≥ 7 hours/day) compared to females (52.3%). Conclusion In conclusion, the total mean length of SB in minutes per day for male and female university students was considerably high. About 58% of the population appeared to spend ≥7 h/day sedentary. Male university students are likelier to sit longer than female students. Our findings also indicated that SB and physical activity interventions are needed to raise awareness of the importance of adopting an active lifestyle and reducing sitting time

Proceedings of the 4th World Conference on Research Integrity

CITATION: O’Brien, S. P., et al. 2016. Proceedings of the 4th World Conference on Research Integrity. Research Integrity and Peer Review, 1:9, doi:10.1186/s41073-016-0012-9.The original publication is available at https://researchintegrityjournal.biomedcentral.comThese Proceedings contain the abstracts of the presentations given at the 4th World Conference in concurrent sessions, partner symposia, and poster sessions. Also included are summaries of the discussions in three focus tracks, which allowed delegates to consider and work on questions about the roles of funders, institutions, and countries in improving research systems and strengthening research integrity. Videos of the plenary presentations are available at the conference website (www.wcri2015.org).https://researchintegrityjournal.biomedcentral.com/articles/10.1186/s41073-016-0012-