15 results
E-cigarettes: no smoke without fire?
- N. Daniels, C. Cosma, A. Llewellyn, D. Banks, H. Morris, J. Copeland, E. Djarlijeva
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- British Actuarial Journal / Volume 25 / 2020
- Published online by Cambridge University Press:
- 01 June 2020, e12
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Smoking was one of the biggest preventable killers of the 20th century, and it continues to cause the death of millions across the globe. The rapid growth of the e-cigarette market in the last 10 years and the claims that it is a safer form of smoking, and can help with smoking cessation, have led to questions being raised on their possible impact to society, the health of the population and the insurance industry. Recent media attention around the possible health implications of e-cigarette use has also ensured that this topic remains in the public eye. The e-cigarette working party was initiated by the Institute and Faculty of Actuaries’ Health and Care Research Sub-Committee in July 2016, with the primary objective of understanding the impact of e-cigarettes on life and health insurance. In this paper, we have looked at all areas of e-cigarette usage and how it relates to insurance in the UK market. In particular, we have covered the potential risks and benefits of switching to e-cigarettes, the results of studies that have been published, the potential impact on underwriting and claims processes and the potential impact on pricing (based on what modelling is possible with the data available). Research in this area is still in its infancy and data are not yet mature, which makes predicting the long-term impact of e-cigarette smoking extremely challenging, for example, there are no studies that directly measure the mortality or morbidity impact of long-term e-cigarette use and so we have had to consider studies that consider more immediate health impacts or look more simply at the constituents of the output of an e-cigarette and compare them to that of a cigarette. The data issue is further compounded by the findings of studies and the advice of national health authorities often being conflicting. For example, while National Health Service England has publicly stated that it supports the growth of e-cigarette usage as an aid to reduce traditional smoking behaviour, the US Food and Drug Administration has been much more vocal in highlighting the perceived dangers of this new form of smoking. Users’ behaviour also adds complexity, as dual use (using both e-cigarettes and cigarettes) is seen in a high percentage of users and relapse rates back to cigarette smoking are currently unknown. Having talked to a number of experts in the field, we have discovered that there is certainly not a common view on risk. We have heard from experts who have significant concerns but also to experts who do believe that e-cigarettes are far safer than tobacco. We have purposefully considered conflicting evidence and have consulted with various parties so we can present differing points of view, thereby ensuring a balanced, unbiased and fair picture of our findings is presented. The evidence we have reviewed does suggest that e-cigarettes are a safer alternative to traditional smoking, but not as safe as non-smoking. There are no large, peer-reviewed, long-term studies yet available to understand the true impact of a switch to e-cigarette use, so currently we are unable to say where on the risk spectrum between cigarette smoking and life-time non-smoking it lies. We do not yet understand if the benefits seen in the studies completed so far will reduce the risk in the long term or whether other health risks will come to light following more prolonged use and study. This, coupled with concerns with the high proportion of dual use of cigarettes and e-cigarettes, relapse rates and the recent growth in medical problems linked with e-cigarette use, means that we need to wait for experience to emerge fully before firm conclusions can be drawn. Although we have presented a view, it is vitally important that our industry continues to monitor developments in this area and fully considers what next steps and future actions may be required to ensure our position reflects the potential benefits and risks that e-cigarette use may bring. We feel that the time is right for a body such as the IFoA to analyse the feasibility of collecting the necessary data through the Continuous Mortality Investigation that would allow us to better analyse the experience that is emerging.
The CODATwins Project: The Current Status and Recent Findings of COllaborative Project of Development of Anthropometrical Measures in Twins
- K. Silventoinen, A. Jelenkovic, Y. Yokoyama, R. Sund, M. Sugawara, M. Tanaka, S. Matsumoto, L. H. Bogl, D. L. Freitas, J. A. Maia, J. v. B. Hjelmborg, S. Aaltonen, M. Piirtola, A. Latvala, L. Calais-Ferreira, V. C. Oliveira, P. H. Ferreira, F. Ji, F. Ning, Z. Pang, J. R. Ordoñana, J. F. Sánchez-Romera, L. Colodro-Conde, S. A. Burt, K. L. Klump, N. G. Martin, S. E. Medland, G. W. Montgomery, C. Kandler, T. A. McAdams, T. C. Eley, A. M. Gregory, K. J. Saudino, L. Dubois, M. Boivin, M. Brendgen, G. Dionne, F. Vitaro, A. D. Tarnoki, D. L. Tarnoki, C. M. A. Haworth, R. Plomin, S. Y. Öncel, F. Aliev, E. Medda, L. Nisticò, V. Toccaceli, J. M. Craig, R. Saffery, S. H. Siribaddana, M. Hotopf, A. Sumathipala, F. Rijsdijk, H.-U. Jeong, T. Spector, M. Mangino, G. Lachance, M. Gatz, D. A. Butler, W. Gao, C. Yu, L. Li, G. Bayasgalan, D. Narandalai, K. P. Harden, E. M. Tucker-Drob, K. Christensen, A. Skytthe, K. O. Kyvik, C. A. Derom, R. F. Vlietinck, R. J. F. Loos, W. Cozen, A. E. Hwang, T. M. Mack, M. He, X. Ding, J. L. Silberg, H. H. Maes, T. L. Cutler, J. L. Hopper, P. K. E. Magnusson, N. L. Pedersen, A. K. Dahl Aslan, L. A. Baker, C. Tuvblad, M. Bjerregaard-Andersen, H. Beck-Nielsen, M. Sodemann, V. Ullemar, C. Almqvist, Q. Tan, D. Zhang, G. E. Swan, R. Krasnow, K. L. Jang, A. Knafo-Noam, D. Mankuta, L. Abramson, P. Lichtenstein, R. F. Krueger, M. McGue, S. Pahlen, P. Tynelius, F. Rasmussen, G. E. Duncan, D. Buchwald, R. P. Corley, B. M. Huibregtse, T. L. Nelson, K. E. Whitfield, C. E. Franz, W. S. Kremen, M. J. Lyons, S. Ooki, I. Brandt, T. S. Nilsen, J. R. Harris, J. Sung, H. A. Park, J. Lee, S. J. Lee, G. Willemsen, M. Bartels, C. E. M. van Beijsterveldt, C. H. Llewellyn, A. Fisher, E. Rebato, A. Busjahn, R. Tomizawa, F. Inui, M. Watanabe, C. Honda, N. Sakai, Y.-M. Hur, T. I. A. Sørensen, D. I. Boomsma, J. Kaprio
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- Twin Research and Human Genetics / Volume 22 / Issue 6 / December 2019
- Published online by Cambridge University Press:
- 31 July 2019, pp. 800-808
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The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural–geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.
Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts
- Karri Silventoinen, Aline Jelenkovic, Antti Latvala, Reijo Sund, Yoshie Yokoyama, Vilhelmina Ullemar, Catarina Almqvist, Catherine A. Derom, Robert F. Vlietinck, Ruth J. F. Loos, Christian Kandler, Chika Honda, Fujio Inui, Yoshinori Iwatani, Mikio Watanabe, Esther Rebato, Maria A. Stazi, Corrado Fagnani, Sonia Brescianini, Yoon-Mi Hur, Hoe-Uk Jeong, Tessa L. Cutler, John L. Hopper, Andreas Busjahn, Kimberly J. Saudino, Fuling Ji, Feng Ning, Zengchang Pang, Richard J. Rose, Markku Koskenvuo, Kauko Heikkilä, Wendy Cozen, Amie E. Hwang, Thomas M. Mack, Sisira H. Siribaddana, Matthew Hotopf, Athula Sumathipala, Fruhling Rijsdijk, Joohon Sung, Jina Kim, Jooyeon Lee, Sooji Lee, Tracy L. Nelson, Keith E. Whitfield, Qihua Tan, Dongfeng Zhang, Clare H. Llewellyn, Abigail Fisher, S. Alexandra Burt, Kelly L. Klump, Ariel Knafo-Noam, David Mankuta, Lior Abramson, Sarah E. Medland, Nicholas G. Martin, Grant W. Montgomery, Patrik K. E. Magnusson, Nancy L. Pedersen, Anna K. Dahl Aslan, Robin P. Corley, Brooke M. Huibregtse, Sevgi Y. Öncel, Fazil Aliev, Robert F. Krueger, Matt McGue, Shandell Pahlen, Gonneke Willemsen, Meike Bartels, Catharina E. M. van Beijsterveldt, Judy L. Silberg, Lindon J. Eaves, Hermine H. Maes, Jennifer R. Harris, Ingunn Brandt, Thomas S. Nilsen, Finn Rasmussen, Per Tynelius, Laura A. Baker, Catherine Tuvblad, Juan R. Ordoñana, Juan F. Sánchez-Romera, Lucia Colodro-Conde, Margaret Gatz, David A. Butler, Paul Lichtenstein, Jack H. Goldberg, K. Paige Harden, Elliot M. Tucker-Drob, Glen E. Duncan, Dedra Buchwald, Adam D. Tarnoki, David L. Tarnoki, Carol E. Franz, William S. Kremen, Michael J. Lyons, José A. Maia, Duarte L. Freitas, Eric Turkheimer, Thorkild I. A. Sørensen, Dorret I. Boomsma, Jaakko Kaprio
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- Twin Research and Human Genetics / Volume 20 / Issue 5 / October 2017
- Published online by Cambridge University Press:
- 04 October 2017, pp. 395-405
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Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
Somatic, positive and negative domains of the Center for Epidemiological Studies Depression (CES-D) scale: a meta-analysis of genome-wide association studies
- A. Demirkan, J. Lahti, N. Direk, A. Viktorin, K. L. Lunetta, A. Terracciano, M. A. Nalls, T. Tanaka, K. Hek, M. Fornage, J. Wellmann, M. C. Cornelis, H. M. Ollila, L. Yu, J. A. Smith, L. C. Pilling, A. Isaacs, A. Palotie, W. V. Zhuang, A. Zonderman, J. D. Faul, A. Sutin, O. Meirelles, A. Mulas, A. Hofman, A. Uitterlinden, F. Rivadeneira, M. Perola, W. Zhao, V. Salomaa, K. Yaffe, A. I. Luik, NABEC, UKBEC, Y. Liu, J. Ding, P. Lichtenstein, M. Landén, E. Widen, D. R. Weir, D. J. Llewellyn, A. Murray, S. L. R. Kardia, J. G. Eriksson, K. Koenen, P. K. E. Magnusson, L. Ferrucci, T. H. Mosley, F. Cucca, B. A. Oostra, D. A. Bennett, T. Paunio, K. Berger, T. B. Harris, N. L. Pedersen, J. M. Murabito, H. Tiemeier, C. M. van Duijn, K. Räikkönen
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- Psychological Medicine / Volume 46 / Issue 8 / June 2016
- Published online by Cambridge University Press:
- 21 March 2016, pp. 1613-1623
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Background
Major depressive disorder (MDD) is moderately heritable, however genome-wide association studies (GWAS) for MDD, as well as for related continuous outcomes, have not shown consistent results. Attempts to elucidate the genetic basis of MDD may be hindered by heterogeneity in diagnosis. The Center for Epidemiological Studies Depression (CES-D) scale provides a widely used tool for measuring depressive symptoms clustered in four different domains which can be combined together into a total score but also can be analysed as separate symptom domains.
MethodWe performed a meta-analysis of GWAS of the CES-D symptom clusters. We recruited 12 cohorts with the 20- or 10-item CES-D scale (32 528 persons).
ResultsOne single nucleotide polymorphism (SNP), rs713224, located near the brain-expressed melatonin receptor (MTNR1A) gene, was associated with the somatic complaints domain of depression symptoms, with borderline genome-wide significance (pdiscovery = 3.82 × 10−8). The SNP was analysed in an additional five cohorts comprising the replication sample (6813 persons). However, the association was not consistent among the replication sample (pdiscovery+replication = 1.10 × 10−6) with evidence of heterogeneity.
ConclusionsDespite the effort to harmonize the phenotypes across cohorts and participants, our study is still underpowered to detect consistent association for depression, even by means of symptom classification. On the contrary, the SNP-based heritability and co-heritability estimation results suggest that a very minor part of the variation could be captured by GWAS, explaining the reason of sparse findings.
Twin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age: A Pooled Study of 26 Twin Cohorts Participating in the CODATwins Project
- Yoshie Yokoyama, Aline Jelenkovic, Reijo Sund, Joohon Sung, John L. Hopper, Syuichi Ooki, Kauko Heikkilä, Sari Aaltonen, Adam D. Tarnoki, David L. Tarnoki, Gonneke Willemsen, Meike Bartels, Toos C. E. M. van Beijsterveldt, Kimberly J. Saudino, Tessa L. Cutler, Tracy L. Nelson, Keith E. Whitfield, Jane Wardle, Clare H. Llewellyn, Abigail Fisher, Mingguang He, Xiaohu Ding, Morten Bjerregaard-Andersen, Henning Beck-Nielsen, Morten Sodemann, Yun-Mi Song, Sarah Yang, Kayoung Lee, Hoe-Uk Jeong, Ariel Knafo-Noam, David Mankuta, Lior Abramson, S. Alexandra Burt, Kelly L. Klump, Juan R. Ordoñana, Juan F. Sánchez-Romera, Lucia Colodro-Conde, Jennifer R. Harris, Ingunn Brandt, Thomas Sevenius Nilsen, Jeffrey M. Craig, Richard Saffery, Fuling Ji, Feng Ning, Zengchang Pang, Lise Dubois, Michel Boivin, Mara Brendgen, Ginette Dionne, Frank Vitaro, Nicholas G. Martin, Sarah E. Medland, Grant W. Montgomery, Patrik K. E. Magnusson, Nancy L. Pedersen, Anna K. Dahl Aslan, Per Tynelius, Claire M. A. Haworth, Robert Plomin, Esther Rebato, Richard J. Rose, Jack H. Goldberg, Finn Rasmussen, Yoon-Mi Hur, Thorkild I. A. Sørensen, Dorret I. Boomsma, Jaakko Kaprio, Karri Silventoinen
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- Twin Research and Human Genetics / Volume 19 / Issue 2 / April 2016
- Published online by Cambridge University Press:
- 09 March 2016, pp. 112-124
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We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.
Modelling gravity currents without an energy closure
- N. A. Konopliv, Stefan G. Llewellyn Smith, J. N. McElwaine, E. Meiburg
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- Journal of Fluid Mechanics / Volume 789 / 25 February 2016
- Published online by Cambridge University Press:
- 26 January 2016, pp. 806-829
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We extend the vorticity-based modelling approach of Borden & Meiburg (Phys. Fluids, vol. 25 (10), 2013, 101301) to non-Boussinesq gravity currents and derive an analytical expression for the Froude number without the need for an energy closure or any assumptions about the pressure. The Froude-number expression we obtain reduces to the correct form in the Boussinesq limit and agrees closely with simulation data. Via detailed comparisons with simulation results, we furthermore assess the validity of three key assumptions underlying both our as well as earlier models: (i) steady-state flow in the moving reference frame; (ii) inviscid flow; and (iii) horizontal flow sufficiently far in front of and behind the current. The current approach does not require an assumption of zero velocity in the current.
Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age: A Study of the CODATwins Project
- Aline Jelenkovic, Yoshie Yokoyama, Reijo Sund, Chika Honda, Leonie H Bogl, Sari Aaltonen, Fuling Ji, Feng Ning, Zengchang Pang, Juan R. Ordoñana, Juan F. Sánchez-Romera, Lucia Colodro-Conde, S. Alexandra Burt, Kelly L. Klump, Sarah E. Medland, Grant W. Montgomery, Christian Kandler, Tom A. McAdams, Thalia C. Eley, Alice M. Gregory, Kimberly J. Saudino, Lise Dubois, Michel Boivin, Adam D. Tarnoki, David L. Tarnoki, Claire M. A. Haworth, Robert Plomin, Sevgi Y. Öncel, Fazil Aliev, Maria A. Stazi, Corrado Fagnani, Cristina D’Ippolito, Jeffrey M. Craig, Richard Saffery, Sisira H. Siribaddana, Matthew Hotopf, Athula Sumathipala, Fruhling Rijsdijk, Timothy Spector, Massimo Mangino, Genevieve Lachance, Margaret Gatz, David A. Butler, Gombojav Bayasgalan, Danshiitsoodol Narandalai, Duarte L Freitas, José Antonio Maia, K. Paige Harden, Elliot M. Tucker-Drob, Bia Kim, Youngsook Chong, Changhee Hong, Hyun Jung Shin, Kaare Christensen, Axel Skytthe, Kirsten O. Kyvik, Catherine A. Derom, Robert F. Vlietinck, Ruth J. F. Loos, Wendy Cozen, Amie E. Hwang, Thomas M. Mack, Mingguang He, Xiaohu Ding, Billy Chang, Judy L. Silberg, Lindon J. Eaves, Hermine H. Maes, Tessa L. Cutler, John L. Hopper, Kelly Aujard, Patrik K. E. Magnusson, Nancy L. Pedersen, Anna K. Dahl Aslan, Yun-Mi Song, Sarah Yang, Kayoung Lee, Laura A. Baker, Catherine Tuvblad, Morten Bjerregaard-Andersen, Henning Beck-Nielsen, Morten Sodemann, Kauko Heikkilä, Qihua Tan, Dongfeng Zhang, Gary E. Swan, Ruth Krasnow, Kerry L. Jang, Ariel Knafo-Noam, David Mankuta, Lior Abramson, Paul Lichtenstein, Robert F. Krueger, Matt McGue, Shandell Pahlen, Per Tynelius, Glen E. Duncan, Dedra Buchwald, Robin P. Corley, Brooke M. Huibregtse, Tracy L. Nelson, Keith E. Whitfield, Carol E. Franz, William S. Kremen, Michael J. Lyons, Syuichi Ooki, Ingunn Brandt, Thomas Sevenius Nilsen, Fujio Inui, Mikio Watanabe, Meike Bartels, Toos C. E. M. van Beijsterveldt, Jane Wardle, Clare H. Llewellyn, Abigail Fisher, Esther Rebato, Nicholas G. Martin, Yoshinori Iwatani, Kazuo Hayakawa, Joohon Sung, Jennifer R. Harris, Gonneke Willemsen, Andreas Busjahn, Jack H. Goldberg, Finn Rasmussen, Yoon-Mi Hur, Dorret I. Boomsma, Thorkild I. A. Sørensen, Jaakko Kaprio, Karri Silventoinen
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- Twin Research and Human Genetics / Volume 18 / Issue 5 / October 2015
- Published online by Cambridge University Press:
- 04 September 2015, pp. 557-570
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A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits
- Karri Silventoinen, Aline Jelenkovic, Reijo Sund, Chika Honda, Sari Aaltonen, Yoshie Yokoyama, Adam D. Tarnoki, David L. Tarnoki, Feng Ning, Fuling Ji, Zengchang Pang, Juan R. Ordoñana, Juan F. Sánchez-Romera, Lucia Colodro-Conde, S. Alexandra Burt, Kelly L. Klump, Sarah E. Medland, Grant W. Montgomery, Christian Kandler, Tom A. McAdams, Thalia C. Eley, Alice M. Gregory, Kimberly J. Saudino, Lise Dubois, Michel Boivin, Claire M. A. Haworth, Robert Plomin, Sevgi Y. Öncel, Fazil Aliev, Maria A. Stazi, Corrado Fagnani, Cristina D’Ippolito, Jeffrey M. Craig, Richard Saffery, Sisira H. Siribaddana, Matthew Hotopf, Athula Sumathipala, Timothy Spector, Massimo Mangino, Genevieve Lachance, Margaret Gatz, David A. Butler, Gombojav Bayasgalan, Danshiitsoodol Narandalai, Duarte L. Freitas, José Antonio Maia, K. Paige Harden, Elliot M. Tucker-Drob, Kaare Christensen, Axel Skytthe, Kirsten O. Kyvik, Changhee Hong, Youngsook Chong, Catherine A. Derom, Robert F. Vlietinck, Ruth J. F. Loos, Wendy Cozen, Amie E. Hwang, Thomas M. Mack, Mingguang He, Xiaohu Ding, Billy Chang, Judy L. Silberg, Lindon J. Eaves, Hermine H. Maes, Tessa L. Cutler, John L. Hopper, Kelly Aujard, Patrik K. E. Magnusson, Nancy L. Pedersen, Anna K. Dahl Aslan, Yun-Mi Song, Sarah Yang, Kayoung Lee, Laura A. Baker, Catherine Tuvblad, Morten Bjerregaard-Andersen, Henning Beck-Nielsen, Morten Sodemann, Kauko Heikkilä, Qihua Tan, Dongfeng Zhang, Gary E. Swan, Ruth Krasnow, Kerry L. Jang, Ariel Knafo-Noam, David Mankuta, Lior Abramson, Paul Lichtenstein, Robert F. Krueger, Matt McGue, Shandell Pahlen, Per Tynelius, Glen E. Duncan, Dedra Buchwald, Robin P. Corley, Brooke M. Huibregtse, Tracy L. Nelson, Keith E. Whitfield, Carol E. Franz, William S. Kremen, Michael J. Lyons, Syuichi Ooki, Ingunn Brandt, Thomas Sevenius Nilsen, Fujio Inui, Mikio Watanabe, Meike Bartels, Toos C. E. M. van Beijsterveldt, Jane Wardle, Clare H. Llewellyn, Abigail Fisher, Esther Rebato, Nicholas G. Martin, Yoshinori Iwatani, Kazuo Hayakawa, Finn Rasmussen, Joohon Sung, Jennifer R. Harris, Gonneke Willemsen, Andreas Busjahn, Jack H. Goldberg, Dorret I. Boomsma, Yoon-Mi Hur, Thorkild I. A. Sørensen, Jaakko Kaprio
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- Twin Research and Human Genetics / Volume 18 / Issue 4 / August 2015
- Published online by Cambridge University Press:
- 27 May 2015, pp. 348-360
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For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
Income and the midlife peak in common mental disorder prevalence
- I. A. Lang, D. J. Llewellyn, R. E. Hubbard, K. M. Langa, D. Melzer
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- Psychological Medicine / Volume 41 / Issue 7 / July 2011
- Published online by Cambridge University Press:
- 10 December 2010, pp. 1365-1372
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Background
The prevalence of psychological distress and common mental disorders has been shown to peak in midlife but analyses have ignored the association of poor material circumstances with prevalence. This study aimed to test the hypothesis that the midlife prevalence peak occurs only in lower-income households.
MethodPooled data were used from the annual Health Survey for England, a nationally representative cross-sectional study, on community-dwelling individuals aged ⩾16 years from years 1997 to 2006 (n=100 457). 12-item General Health Questionnaire scores, reported mental illness diagnoses and receipt of relevant medication were assessed in relation to household income and age. Analyses were separated by gender and adjusted for age, ethnicity, smoking, social class, education and co-morbidities.
ResultsPrevalence of psychological distress, diagnoses and treatments rose with age until early middle age and declined subsequently. In analyses conducted separately by income categories, this pattern was marked in low-income groups but absent in high-income groups. Income-related inequalities in the prevalence of psychological distress were greatest in midlife; for example, in men aged 45–54 years the odds ratio of receiving psychiatric medication in the lowest income group compared with the highest was 7.50 [95% confidence interval (CI) 4.24–13.27] and in women aged 45–54 years the odds ratio of reporting mental illness was 10.25 (95% CI 6.16–17.05).
ConclusionsAn increased prevalence of psychological distress, common mental disorder diagnoses and treatment in midlife is not a universal phenomenon but is found only in those in low-income households. This implies the phenomenon is not inevitable but is potentially manageable or preventable.
“A Victory for Secular India”? Hindu Nationalism in the 2004 Election
- J. E. Llewellyn
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- Journal:
- Politics and Religion / Volume 4 / Issue 1 / April 2011
- Published online by Cambridge University Press:
- 02 November 2010, pp. 49-70
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At least since the last decade of the 20th century, there has been strong scholarly interest in a perceived global wave of religious nationalism. Critical to that movement was the most important recent development in Indian politics, the rise of the Hindu right. Commentators lamented a fundamental change in the Indian body politic, the demise of India's celebrated secularism. However, others predicted that the Hindu nationalists would be forced to move to the center to gain votes, jettisoning much of their peculiar ideology in the process. The 2004 national parliamentary election was a crucial test of these contending interpretations. Would the Bharatiya Janata Party rely on its established arsenal of communally controversial issues? Would it emphasize themes designed to appeal to a broader audience? Analyzing reports published in national newspapers and news magazines, I will reach the surprising conclusion that the answer to both of these questions is yes.
Learning and memory in monozygotic twins discordant for schizophrenia
- Terry E. Goldberg, E. Fuller Torrey, James M. Gold, J. Daniel Ragland, Llewellyn B. Bigelow, Daniel R. Weinberger
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- Journal:
- Psychological Medicine / Volume 23 / Issue 1 / February 1993
- Published online by Cambridge University Press:
- 09 July 2009, pp. 71-85
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Learning and memory were assessed in 24 monozygotic (MZ) pairs of individuals discordant for schizophrenia or delusional disorder and seven normal pairs of MZ twins. On declarative memory tasks, the affected group displayed a pattern that might best be characterized as dysmnesic in that they performed significantly worse than the discordant unaffected group on story recall, paired associated learning, and visual recall of designs, but they learned over time, had relatively preserved recognition memory, and did not show profoundly accelerated rates of forgetting. Effortful, volitional retrieval from the lexicon, measured by verbal fluency, was also compromised in the affected group. On the other hand, procedural learning of the motor skill in a pursuit rotor task was relatively intact in the affected group. Comparisons of the normal group and unaffected group indicated that the latter group had very mild impairments in some aspects of episodic memory, namely, immediate and delayed recall of stories and delayed recall of designs. It is highly unlikely that the impairments observed in the affected group can be attributed to differences in genome, family environment, socioeconomic circumstance, or educational opportunity, as all of these were controlled by the twin paradigm. Rather, the impairments appear to be related to the intercession of disease. The neuropsychological profile is consistent with frontal lobe and medial temporal lobe dysfunction, as noted in this sample as well as other samples of schizophrenic singletons. Significant correlations between many measures of memory and global level of social and vocational functioning within the discordant group were also found. Thus difficulties in rapidly acquiring new information and propitiously retrieving old information may burden patients with schizophrenia in many of the transactions of everyday life.
A linkage study of schizophrenia with DNA markers from the long arm of chromosome 11
- M. Gill, P. McGuffin, E. Parfitt, R. Mant, P. Asherson, D. Collier, H. Vallada, J. Powell, S. Shaikh, C. Taylor, M. Sargeant, A. Clements, S. Nanko, N. Takazawa, D. Llewellyn, J. Williams, S. Whatley, R. Murray, M. Owen
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- Journal:
- Psychological Medicine / Volume 23 / Issue 1 / February 1993
- Published online by Cambridge University Press:
- 09 July 2009, pp. 27-44
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We report the results of a collaborative linkage study using 12 polymorphic markers (9 loci) from the long arm of chromosome 11, and 24 families multiply affected with schizophrenia and other closely related disorders. This region is of interest because several families have been reported in which balanced translocations involving 11q apparently co-segregate with psychotic illness. In addition, the dopamine D2 receptor, porphobilinogen deaminase, and tyrosinase genes map within the region studied and may be aetiologically involved in schizophrenia. We have primarily analysed genotypic data by the LOD score method using a range of single gene models. In order to minimize error due to mis-specification of genetic parameters we have analysed data from markers at candidate gene loci by the non-parametric extended sib-pair method in addition to the LOD score method. Our results suggest that most of the region can be excluded from containing a gene of major effect in the aetiology of this disease.
Host-Specificity and Speciation in Diclidophoran (Monogenean) Gill Parasites of Trisopteran (Gadoid) Fishes at Plymouth
- J. Llewellyn, Sheila Macdonald, J. E. Green
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- Journal:
- Journal of the Marine Biological Association of the United Kingdom / Volume 60 / Issue 1 / February 1980
- Published online by Cambridge University Press:
- 11 May 2009, pp. 73-79
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The Marine Biological Association (1957) lists the poor cod Trisopterus minutus minutus (L.) (=Gadus minutus) as being parasitized by two monogenean gill parasites Diclidophora luscae and D. denticulata but at various times over the past 25 years we have, between us, examined the gills of upwards of 1000 specimens of T. m. minutus without ever having found a monogenean parasite. We concluded that the 1957 records were probably due to a misidentification of the hosts. However, in January 1979 one of us (J. E. G.) found several specimens of a monogenean very closely resembling D. luscae (Beneden & Hesse) on the gills of poor cod. D. luscae is normally found at Plymouth (Llewellyn, 1956) on only the pouting Trisopterus luscus (L.), a fish which from time to time is caught in the same trawl as T. m. minutus, e.g. in a total of 46 standard hauls between July 1976 and June 1978 (information supplied by Mr A. D. Mattacola), on 11 occasions (23%)T. luscus and T. m. minutus were caught together. On eight of these 11 occasions the lesser abundant of the two fish species constituted 10% or more of the combined total, and on three occasions the lesser abundant fish made up at least 40% of the combined total. Thus there is evidence that T. m. minutus and T. luscus from time to time occupy the same or neighbouring habitats (a standard haul may be over a distance of up to 8 km) and so presumably there has been opportunity for parasitic invasion from one species to the other to take place. That this has not in fact happened we have regarded as an example of the very strict species-specificity to their hosts manifested by most monogeneans and especially by diclidophorans on gadoids (Llewellyn & Tully, 1969). It was decided therefore to investigate how the sudden appearance in 1979 of a monogenean parasite on a previously uninfected population of poor cod may have come about.
A check-list of monogenean (platyhelminth) parasites of Plymouth hosts
- J. Llewellyn, J. E. Green, G. C. Kearn
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- Journal:
- Journal of the Marine Biological Association of the United Kingdom / Volume 64 / Issue 4 / November 1984
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- 11 May 2009, pp. 881-887
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The Plymouth Marine Fauna (Marine Biological Association, 1957) list of monogenean parasites of fishes has been increased from 39 to 58 species and in addition 2 species have been recorded from a cephalopod host. The increase in listed species represents an increased ‘parasitological effort’ rather than an influx of new species into Plymouth waters.
The occurrence at Plymouth of Dictyocotyle coeliaca Nybelin, 1941 (Trematoda: Monogenea)
- J. Llewellyn, J. E. Green
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- Journal:
- Journal of the Marine Biological Association of the United Kingdom / Volume 36 / Issue 1 / February 1957
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- 11 May 2009, pp. 77-79
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In a sample of over 1000 rays belonging to four species of Raia examined at Plymouth between May 1955 and August 1956, the ‘very rare’ monogenetic trematode Dictyocotyle coeliaca Nybelin, 1941 (total of four previous records) was found in the coelom of thirty-five out of 135 specimens of Raia naevus but absent from 478 R. clavata, 420 R. montagui and 34 R. brachyura.