251
|
Husted JA, Ahmed R, Chow EW, Brzustowicz LM, Bassett AS. Early environmental exposures influence schizophrenia expression even in the presence of strong genetic predisposition. Schizophr Res 2012; 137:166-8. [PMID: 22381191 PMCID: PMC3436901 DOI: 10.1016/j.schres.2012.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 02/07/2012] [Accepted: 02/08/2012] [Indexed: 11/27/2022]
Abstract
There are few studies of environmental factors in familial forms of schizophrenia. We investigated whether childhood adversity or environmental factors were associated with schizophrenia in a familial sample where schizophrenia is associated with the NOSA1P gene. We found that a cumulative adversity index including childhood illness, family instability and cannabis use was significantly associated with narrow schizophrenia, independent of NOSA1P risk genotype, previously measured childhood trauma, covariates and familial clustering (adjusted odds ratio (95% confidence interval)=1.55 (1.01, 2.38)). The results provide further support that early environmental exposures influence schizophrenia expression even in the presence of strong genetic predisposition.
Collapse
|
252
|
Ahmed R, Hannigan I, MacDougall H, Halmagyi M. Imbalance and Oscillopsia Due to Gentamicin Vestibulotoxicity (Unilateral and Bilateral) in 127 Patients (S48.004). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.s48.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
253
|
Ahmed R, León-Velarde C, Odumeru J. Evaluation of novel agars for the enumeration of Campylobacter spp. in poultry retail samples. J Microbiol Methods 2012; 88:304-10. [DOI: 10.1016/j.mimet.2011.12.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Accepted: 12/18/2011] [Indexed: 11/29/2022]
|
254
|
Ahmed R, Denton M, Clifton I, Peckham D. P169 Characteristics and survival of patients without cystic fibrosis (CF), isolating mucoid P aeruginosa (mPA) in sputum samples. Thorax 2011. [DOI: 10.1136/thoraxjnl-2011-201054c.169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
255
|
Elton-Marshall T, Leatherdale ST, Manske SR, Wong K, Ahmed R, Burkhalter R. Research methods of the Youth Smoking Survey (YSS). CHRONIC DISEASES AND INJURIES IN CANADA 2011; 32:47-54. [PMID: 22153176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This paper describes the survey development, design and data collection protocol for the 2008/2009 Youth Smoking Survey (YSS) and the changes to the YSS survey and protocols across the 5 survey cycles (1994, 2002, 2004/2005, 2006/2007, 2008/2009). Canada's Youth Smoking Survey is a nationally representative school-based survey of students (grades 6 to 12 in 2008/2009) from randomly sampled public and private schools in the ten provinces. The main objective of the YSS is to provide benchmark data on national smoking prevalence rates for youth. Key features of the 2008/2009 YSS include consistent measures across survey cycles, a survey team of researchers and non-governmental organizations, a link to school and student level measures, provision of tailored feedback reports to schools and publicly available datasets.
Collapse
|
256
|
Shehzad F, Zafar Yab M, Ahmed R. Minimal neighbor designs in circular blocks of unequal sizes. J Stat Plan Inference 2011. [DOI: 10.1016/j.jspi.2011.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
257
|
Shehzad F, Zafar Yab M, Ahmed R. Some series of proper generalized neighbor designs. J Stat Plan Inference 2011. [DOI: 10.1016/j.jspi.2011.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
258
|
Vu M, Leatherdale ST, Ahmed R. Examining correlates of different cigarette access behaviours among Canadian youth: data from the Canadian Youth Smoking Survey (2006). Addict Behav 2011; 36:1313-6. [PMID: 21821363 DOI: 10.1016/j.addbeh.2011.07.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 03/02/2011] [Accepted: 07/14/2011] [Indexed: 10/18/2022]
Abstract
Understanding factors associated with youth cigarette access behaviours can provide insight into the development of more effective means of preventing youth from accessing cigarettes. This cross-sectional study used self-reported data collected from 41,886 students in grades 9 to 12 who participated in the 2006-07 Youth Smoking Survey to examine the student- and school-level characteristics that differentiate youth smokers who usually access cigarettes from a social source versus buying their own from retailers. Multi-level regression analyses revealed significant between-school variability in the odds of a smoking student reporting that they usually buy their own cigarettes. Important student-level characteristics associated with how youth usually access their cigarettes included binge drinking and being asked for age or photo identification when purchasing cigarettes from a retailer. Future studies should further explore the school- and student-level characteristics associated with youth cigarette access behaviour.
Collapse
|
259
|
Ahmed R, Faisal N, Paradowska A, Fitzpatrick M, Khor K. Neutron diffraction residual strain measurements in nanostructured hydroxyapatite coatings for orthopaedic implants. J Mech Behav Biomed Mater 2011; 4:2043-54. [DOI: 10.1016/j.jmbbm.2011.07.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 05/19/2011] [Accepted: 07/06/2011] [Indexed: 11/29/2022]
|
260
|
Sheybani A, Ahmed R, Anderson K, Pennington E, Buatti J. High Dose Fractionated Stereotactic Photon Radiation Therapy: An Equivalent Treatment for Skull Based Chordomas Compared to Protons? Int J Radiat Oncol Biol Phys 2011. [DOI: 10.1016/j.ijrobp.2011.06.1796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
261
|
Schwabegger G, Ullah M, Irimia-Vladu M, Baumgartner M, Kanbur Y, Ahmed R, Stadler P, Bauer S, Sariciftci N, Sitter H. High mobility, low voltage operating C(60) based n-type organic field effect transistors. SYNTHETIC METALS 2011; 161-66:2058-2062. [PMID: 22049252 PMCID: PMC3197884 DOI: 10.1016/j.synthmet.2011.06.042] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 03/11/2011] [Accepted: 06/23/2011] [Indexed: 05/29/2023]
Abstract
We report on C(60) based organic field effect transistors (OFETs) that are well optimized for low voltage operation. By replacing commonly used dielectric layers by thin parylene films or by utilizing different organic materials like divinyltetramethyldisiloxane-bis(benzocyclo-butene) (BCB), low density polyethylene (PE) or adenine in combination with aluminum oxide (AlOx) to form a bilayer gate dielectric, it was possible to significantly increase the capacitance per unit area (up to two orders of magnitude). The assembly of metal-oxide and organic passivation layer combines the properties of the high dielectric constant of the metal oxide and the good organic-organic interface between semiconductor and insulator provided by a thin capping layer on top of the AlOx film. This results in OFETs that operate with voltages lower than 500 mV, while exhibiting field effect mobilities exceeding 3 cm(2) V(-1) s(-1).
Collapse
|
262
|
|
263
|
Leatherdale ST, Ahmed R. Screen-based sedentary behaviours among a nationally representative sample of youth: are Canadian kids couch potatoes? CHRONIC DISEASES AND INJURIES IN CANADA 2011; 31:141-146. [PMID: 21978636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
PURPOSE To determine the percentage of Canadian youth meeting screen-time guidelines and to identify characteristics associated with different screen-time behaviours. METHODS Using nationally representative data collected from the 2008/2009 Youth Smoking Survey (YSS), we analyzed three screen-time behaviours, cigarette smoking, weekly spending money, self esteem, region and grade by sex, and conducted four logistic regression models to examine factors associated with more than 2 hours a day of sedentary screen time. RESULTS Of 51 922 Canadian youth in grades 6 to 12, 50.9% spent more than 2 hours per day in screen-based behaviours. The average daily screen time was 7.8 (± 2.3) hours. Males and current smokers were more likely to report over 2 hours per day watching TV and videos or playing video games, whereas students in higher grades and those with weekly spending money were more likely to report playing or surfing on a computer. Youth with higher self-esteem were less likely to report spending over 2 hours per day in each of the three screen-time behaviours examined. CONCLUSION Developing a better understanding of the factors associated with more hours of screen time is required to develop and target interventions that reduce screen-time behaviours.
Collapse
|
264
|
Leatherdale ST, Ahmed R. Screen-based sedentary behaviours among a nationally representative sample of youth: are Canadian kids couch potatoes? ACTA ACUST UNITED AC 2011. [DOI: 10.24095/hpcdp.31.4.01] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Purpose
To determine the percentage of Canadian youth meeting screen-time guidelines and to identify characteristics associated with different screen-time behaviours.
Methods
Using nationally representative data collected from the 2008/2009 Youth Smoking Survey (YSS), we analyzed three screen-time behaviours, cigarette smoking, weekly spending money, self esteem, region and grade by sex, and conducted four logistic regression models to examine factors associated with more than 2 hours a day of sedentary screen time.
Results
Of 51 922 Canadian youth in grades 6 to 12, 50.9% spent more than 2 hours per day in screen-based behaviours. The average daily screen time was 7.8 (± 2.3) hours. Males and current smokers were more likely to report over 2 hours per day watching TV and videos or playing video games, whereas students in higher grades and those with weekly spending money were more likely to report playing or surfing on a computer. Youth with higher self-esteem were less likely to report spending over 2 hours per day in each of the three screen-time behaviours examined.
Conclusion
Developing a better understanding of the factors associated with more hours of screen time is required to develop and target interventions that reduce screen-time behaviours.
Collapse
|
265
|
Kennedy RD, Leatherdale ST, Burkhalter R, Ahmed R. Prevalence of smokeless tobacco use among Canadian youth between 2004 and 2008: findings from the Youth Smoking Survey. CANADIAN JOURNAL OF PUBLIC HEALTH = REVUE CANADIENNE DE SANTE PUBLIQUE 2011; 102:358-63. [PMID: 22032102 PMCID: PMC6973813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 04/25/2011] [Indexed: 03/29/2024]
Abstract
OBJECTIVES The current study team sought to understand smokeless tobacco (SLT) usage trends among youth, using nationally representative data collected as part of the Canadian Youth Smoking Survey (YSS) between 2004 and 2008. METHODS Descriptive analyses of SLT ever use among respondents in grades 6 to 9 were examined according to year of data collection (2008, n = 31,249; 2006, n = 34,050; and 2004, n = 23,362). Using the 2008 data from respondents in grades 6 to 12 (n = 51,922), logistic regression models were used to examine characteristics associated with SLT ever use and current use. RESULTS Between 2004 and 2008, the prevalence of youth in grades 6 to 9 reporting they have ever tried SLT significantly decreased by 30.8%. In 2008, male students were more likely than females to have tried SLT (OR 4.87, 95% CI 4.34-5.45) or to currently use SLT (OR 4.96, 95% CI 4.12-5.96). There are regional differences in prevalence of SLT use across Canada, with the highest rates in western provinces and the lowest in Quebec. Current smokers were also more likely to use SLT (OR 11.86, 95% CI 10.22-13.76) compared to non-smokers. Older students are more likely to report ever use or current use of SLT. CONCLUSION The findings from this study demonstrate that in Canada, adolescent SLT use is primarily an issue with males and there are significant regional differences. Ongoing monitoring of SLT is encouraged considering the tobacco industry's recent investments and product development and increased use in countries like the United States.
Collapse
|
266
|
Leatherdale ST, Ahmed R, Vu M. Factors associated with different cigarette access behaviours among underage smoking youth who usually smoke contraband (native) cigarettes. Canadian Journal of Public Health 2011. [PMID: 21608380 DOI: 10.1007/bf03404156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Given that little is known about how youth access contraband cigarettes, the current study seeks to examine factors associated with how underage smoking youth report usually accessing contraband cigarettes. METHODS This study used nationally representative data collected from 41,886 students (grades 9 to 12) as part of the 2006-07 Canadian Youth Smoking Survey (YSS). Using data from current smokers who report that their usual brand of cigarettes is contraband, three logistic regression models were used to examine factors associated with buying cigarettes from a store, getting cigarettes from a family member, or getting cigarettes from friends or strangers. RESULTS In 2006, 7.9% (n = 1 3,300) of Canadian youth who were current smokers reported that their usual brand of cigarettes was contraband. Among these youth, the majority reported that they usually get their cigarettes from a friend or stranger (54.8%), whereas 26.4% report usually getting them from a family member and 18.8% usually buying their own from a store. Boys were more likely to buy contraband cigarettes from a store, whereas youth with a parent who smokes contraband cigarettes were substantially more likely to get contraband cigarettes from a family member and youth with friends who smoke contraband cigarettes were substantially more likely to get contraband cigarettes from a friend or stranger. CONCLUSION Ongoing surveillance of contraband cigarette use among youth and how youth access contraband cigarettes is required for guiding future tobacco control policy and programming activities.
Collapse
|
267
|
Mosavel M, Ahmed R, Simon C. Perceptions of gender-based violence among South African youth: implications for health promotion interventions. Health Promot Int 2011; 27:323-30. [PMID: 21733916 DOI: 10.1093/heapro/dar041] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Gender-based violence is a widespread problem in South Africa. Past structural inequities have created a climate conducive to violence against women. As an initial step toward developing a health promotion program, we conducted exploratory formative research to examine the barriers that affect the health and well-being of youth. Fourteen focus groups (nine with girls and five with boys) were conducted with 112 adolescents in a racially mixed community on the outskirts of Cape Town, South Africa. We utilized grounded theory and thematic analysis to examine the data. The impact of poverty, ubiquitous gendered violence, transactional sex and unsafe recreational spaces emerged as the major themes. The experiences of youth were consumed by issues of safety rather than the pursuit of other developmentally appropriate markers. Our findings suggest that health promotion programs should create safe spaces for youth and opportunities to critically question the assumptions and manifestations of a patriarchal society. Furthermore, the findings indicate that there is a strong need for multi-sectorial interventions directed at many levels to prevent gender-based violence.
Collapse
|
268
|
Chan WC, Leatherdale ST, Burkhalter R, Ahmed R. Bidi and hookah use among Canadian youth: an examination of data from the 2006 Canadian Youth Smoking Survey. J Adolesc Health 2011; 49:102-4. [PMID: 21700168 DOI: 10.1016/j.jadohealth.2010.11.250] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 11/16/2010] [Accepted: 11/17/2010] [Indexed: 11/17/2022]
Abstract
PURPOSE To examine the prevalence and associated factors of bidi and hookah use among Canadian youth. METHODS Data from 41,886 grade 7 to 12 youth were used to examine factors associated with bidi and hookah use. RESULTS Youth who are current or former cigarette smokers, have tried marijuana or alcohol, were more likely to use bidi or hookah. CONCLUSIONS Results suggest bidi and hookah use may be an emerging issue in tobacco control among youth. Findings also support an integrated approach where future prevention efforts should address multiple risk behaviors.
Collapse
|
269
|
Hayat J, Ahmed R, Alizai S, Awan MU. Giant ganglioneuroma of the posterior mediastinum. Interact Cardiovasc Thorac Surg 2011; 13:344-5. [DOI: 10.1510/icvts.2011.267393] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
270
|
Ahmed R, Williams K, Whitaker P, Jamil H, Etherington C, Denton M, Conway S, Peckham D. 144 Sputum and bronchoalveolar lavage in diagnosing ‘atypical’ infections. J Cyst Fibros 2011. [DOI: 10.1016/s1569-1993(11)60160-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
271
|
Ahmed R, Muckett P, Cook S. 73 Heritability of coronary flow reserve. BRITISH HEART JOURNAL 2011. [DOI: 10.1136/heartjnl-2011-300198.73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
272
|
Ismail F, Khan N, Van de Werke I, Ahmed R. A severe case of astrogliosis and encephalomalacia in a neonate with a massive vein of Galen malformation (VGM). SA J Radiol 2011. [DOI: 10.4102/sajr.v15i2.324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Vein of Galen malformations (VGMs) are rare anomalies of intracranial circulation that constitute 1% of all intracranial vascular malformations. We describe a case of severe encephalomalacia associated with a VGM, which has not been previously described.
Collapse
|
273
|
Mosavel M, Ahmed R, Daniels D, Simon C. Community researchers conducting health disparities research: Ethical and other insights from fieldwork journaling. Soc Sci Med 2011; 73:145-52. [PMID: 21680071 DOI: 10.1016/j.socscimed.2011.04.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 03/31/2011] [Accepted: 04/27/2011] [Indexed: 11/18/2022]
Abstract
Lay persons who are trained to conduct research in their own communities form an essential part of many research projects. However, the effects of conducting research in their own communities have not been adequately explored. This paper examines the experiences, perceptions, and challenges faced by a group of community researchers during their involvement in a research project that examined if, and how, the relationships between mothers and their adolescent daughters could be harnessed to develop a daughter-initiated cervical cancer intervention. Seven community researchers interviewed 157 mother-daughter pairs in Cape Town, South Africa. We examine the use of journaling as a tool to document the experiences of community researchers, and we consider how journaling may help the community-based researcher grapple with the research process, and, more broadly, what such journal content illustrates with respect to the nature and challenges of community-engaged health research. An analysis of the content of the journals provides a strong indication of how personal and intimate the research process can be for community researchers by virtue of the background that they bring into the process as well as the additional weight of the research process itself. The complexities of navigating dual and somewhat oppositional roles - the role of impartial scientist or researcher and the role of invested community person - has been both underestimated and insufficiently researched.
Collapse
|
274
|
Barbour SY, Morrow GR, Ahmed R, Ballinari G, Thorn MD, Cox D, Schwartzberg LS. Analysis of phase III clinical studies for palonosetron, ondansetron, dolasetron, and granisetron in the prevention of chemotherapy-induced nausea and vomiting (CINV). J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.9091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
275
|
Komorowski AW, Morrow GR, Ahmed R, Cox D, Hesketh PJ. A multicenter, single-arm evaluation of palonosetron for the prevention of chemotherapy-induced nausea and vomiting (CINV) in patients who have experienced CINV during the previous cycle of low emetogenic chemotherapy (LEC). J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.e19587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|