scholarly journals Heritability of Schneider's first-rank symptoms

2002 ◽  
Vol 180 (1) ◽  
pp. 35-38 ◽  
Author(s):  
Alastair G. Cardno ◽  
Pak C. Sham ◽  
Anne E. Farmer ◽  
Robin M. Murray ◽  
Peter McGuffin
Keyword(s):  
Model Fitting ◽  
Heritability Estimate ◽  
Best Fitting ◽  
Same Gender ◽  
First Rank Symptoms ◽  
Fitting Model ◽  
Biometric Model

BackgroundSchneider's first-rank symptoms are given particular weight when making a diagnosis of schizophrenia, but the nuclear syndrome, characterised by one or more first-rank symptoms, has been found previously to have no heritability.AimsTo estimate the heritability of the nuclear syndrome.MethodA total of 224 twin pairs (106 monozygotic, 118 same-gender dizygotic) were ascertained from the Maudsley Twin Register in London via probands with any psychosis. Lifetime-ever first-rank symptoms were rated using the OPCRIT checklist. Probandwise concordance rates were calculated for the nuclear syndrome and a heritability estimate was derived from biometric model fitting.ResultsProbandwise concordance rates were 13/49 (26.5%) for monozygotic and 0/45 to 2/46 (0.0–4.3%) for dizygotic pairs. The heritability estimate for the best-fitting model was 71% (95% CI 57–82).ConclusionsThese results indicate that the nuclear syndrome shows substantial heritability, although this is slightly lower than that for schizophrenia as defined by the DSM and ICD systems.

Feeling of Cold Hands and Feet is a Highly Heritable Phenotype

2012 ◽  
Vol 15 (2) ◽  
pp. 166-169 ◽  
Author(s):  
Yoon-Mi Hur ◽  
Jeong-Ho Chae ◽  
Ki Wha Chung ◽  
Jung Jin Kim ◽  
Hoe-Uk Jeong ◽  
...  
Keyword(s):  
Sex Differences ◽  
Measurement Error ◽  
General Population ◽  
Environmental Influences ◽  
Model Fitting ◽  
Environmental Variance ◽  
Best Fitting ◽  
Heritable Phenotype ◽  
Hands And Feet ◽  
Fitting Model

The prevalence of the feeling of cold hands and feet (FCHF) is high in the general population but the etiology of FCHF is largely unknown. The aim of the present study was to explore whether the FCHF is heritable. Eight hundred and ninety-four pairs of twins completed a question about FCHF. Tetrachoric correlations for FCHF were .58, .29, .67, .52, and .04 for monozygotic male, dizygotic male, monozygotic female, and dizygotic female twins, respectively. Model-fitting analyses suggested that in the best fitting model, additive genetic and nonshared environmental variance including measurement error were 64% (95% CI: 55%-72%) and 36% (28%-45%), respectively. Sex differences in genetic and environmental influences were not significant.

A quantitative genetic analysis of schizotypal personality traits

2003 ◽  
Vol 33 (5) ◽  
pp. 803-816 ◽  
Author(s):  
Y. M. LINNEY ◽  
R. M. MURRAY ◽  
E. R. PETERS ◽  
A. M. MacDONALD ◽  
F. RIJSDIJK ◽  
...  
Keyword(s):  
Structural Equation ◽  
Model Fitting ◽  
Twin Studies ◽  
Equation Model ◽  
Common Pathway ◽  
Schizotypal Personality ◽  
Quantitative Genetic ◽  
Best Fitting ◽  
Limited Power ◽  
Fitting Model

Background. Previous twin studies investigating the heritability of schizotypy have often had limited power and have failed to measure the disorganization/social anxiety component.Method. Seven hundred and thirty-three female twin pairs, drawn from the Institute of Psychiatry Volunteer Twin Register, completed the Oxford–Liverpool Inventory of Feelings and Experiences and the Peters et al. Delusions Inventory. Structural equation modelling was carried out on scores for MZ and DZ twin pairs.Results. The best fitting models for all scales comprised additive genetic and unique environmental effects. Heritability was estimated at approximately 50% for most scales, although it was lower at 37% for the PDI scale. Multivariate structural equation model fitting revealed a best-fitting model in which additive genetic and unique environmental influences act through a single common pathway for Cognitive Disorganization, Unusual Experiences and the PDI, and through a separate common pathway for Cognitive Disorganization and Introvertive Anhedonia.Conclusions. The various components of schizotypy are moderately heritable. Multivariate model fitting indicates that at least two latent factor structures are required to account for the covariation between the various components of schizotypy. The positive and negative components of schizotypy are relatively genetically independent, although each in turn may be related to Cognitive Disorganization.

Genetic Susceptibility to Sickness Absence is Similar Among Women and Men: Findings From a Swedish Twin Cohort

2012 ◽  
Vol 15 (5) ◽  
pp. 642-648 ◽  
Author(s):  
Pia Svedberg ◽  
Annina Ropponen ◽  
Kristina Alexanderson ◽  
Paul Lichtenstein ◽  
Jurgita Narusyte
Keyword(s):  
Risk Factors ◽  
Sickness Absence ◽  
Genetic Model ◽  
Model Fitting ◽  
Heritability Estimate ◽  
Population Based ◽  
Population Based Study ◽  
Relative Contribution ◽  
Best Fitting

Previous studies of risk factors for sickness absence (SA) focus primarily on psychosocial and work environmental exposures. The aim of this study was to investigate the relative contribution of genetic influences on SA among women and men. The population-based study sample of Swedish twins (34,547) included 13,743 twin pairs of known zygosity, 3,495 monozygotic, 5,073 same-sexed dizygotic, and 5,175 opposite sexed. The point prevalence of long-term SA (≥15 days) in each zygosity and sex group was calculated. The risk of SA was estimated as an odds ratio (OR) with 95% confidence intervals (CI) where the odds for twins on SA to have a co-twin on SA was compared to the OR for SA in twins whose co-twin were not sickness absent. Intrapair correlations and probandwise concordance rates were calculated and standard biometrical genetic model-fitting methods were used to estimate the heritability of SA. The prevalence of SA was 8.8% (women 10.7%; men 6.5%). Intrapair similarity was higher among monozygotic than dizygotic twin pairs. The best-fitting model showed no sex differences in genetic effects or variance components contributing to SA. The heritability estimate was 36% (95% CI: 35–40%). Results suggest genetic contribution to the variation of SA and that environmental factors have an important role, for women and men. As SA seem to be influenced by genetic factors, future studies of associations between risk factors and SA should consider this potentially confounding effect.

scholarly journals Asteroseismology of the DAV star R808

2020 ◽  
Vol 500 (4) ◽  
pp. 4703-4709
Author(s):  
Y H Chen ◽  
H Shu
Keyword(s):  
Coulomb Potential ◽  
Model Fitting ◽  
Potential Effect ◽  
Data Set ◽  
Trapped Mode ◽  
Star Models ◽  
Diffusion Scheme ◽  
Best Fitting ◽  
Screened Coulomb Potential ◽  
Fitting Model

ABSTRACT The DAV star R808 was observed by 13 different telescopes for more than 170 h in 2009 April on the WET run XCOV26. 25 independent pulsation frequencies were identified by this data set. We assumed 19 m = 0 modes and performed an asteroseismological study on those 19 modes. We evolve grids of DAV star models by wdec adopting the element diffusion scheme with pure and screened Coulomb potential effect. The core compositions are from white dwarf models evolved by mesa, which are thermal nuclear burning results. Our best-fitting model is from the screened Coulomb potential scenario, which has parameters of log(MHe/M*) = −2.4, log(MH/M*) = −5.2, Teff = 11100 K, M* = 0.710 M⊙, logg = 8.194, and σRMS = 2.86 s. The value of σRMS is the smallest among the four existing asteroseismological work. The average period spacing is 46.299 s for l = 1 modes and 25.647 s for l = 2 modes. The other six observed modes can be fitted by $m\, \ne$ 0 components of some modes for our best-fitting model. Fitting the 25 observed modes, we obtain a σRMS value of 2.59 s. Considering the period spacings, we also assume, that at least in one case, we detect an l = 2 trapped mode.

165 Effects of Digestible Lysine Level on Growth Performance and Economics of Grow-finish Pigs

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 58-59
Author(s):  
Larissa L Becker ◽  
Emily E Scholtz ◽  
Joel M DeRouchey ◽  
Mike D Tokach ◽  
Jason C Woodworth ◽  
...  
Keyword(s):  
Phase 1 ◽  
Information Criterion ◽  
Response Curves ◽  
Phase 3 ◽  
Ileal Digestibility ◽  
Distillers Dried Grains ◽  
Feed Cost ◽  
Best Fitting ◽  
Dietary Treatments ◽  
Fitting Model

Abstract A total of 2,124 barrows and gilts (PIC 1050′DNA 600, initially 48.9 kg) were used in a 32-d study to determine the optimal dietary standardized ileal digestibility (SID) Lys level in a commercial setting. Pigs were randomly allotted to 1 of 5 dietary treatments with 24 to 27 pigs/pen and 16 replications/treatment. Similar number of barrows and gilts were placed in each pen. Diets were fed over 3 phases (48.9 to 58.6, 58.6 to 70.9, and 70.9 to 80.8 kg respectively). Dietary treatments were corn-soybean meal-based and contained 10 (phase 1 and 2) or 5% (phase 3) distillers dried grains with solubles. Diets were formulated to 85, 95, 103, 110, or 120% of the current Pig Improvement Company (PIC, Hendersonville, TN) SID Lys gilt recommendations with phase 1 SID Lys levels of 0.90, 1.01, 1.09, 1.17 and 1.27%, phase 2 levels of 0.79, 0.87, 0.94, 1.03, and 1.10%, and phase 3 levels of 0.71, 0.78, 0.85, 0.92, and 0.99%, respectively. Dose response curves were evaluated using linear (LM), quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ) models. For each response variable, the best-fitting model was selected using the Bayesian information criterion. Overall (d 0 to 32), increasing SID Lys increased (linear, P< 0.001) BW, ADG, G:F, Lys intake/d, and Lys intake/kg of gain. Modeling margin over feed cost (MOFC), BLL and QP estimated the requirement at 105.8% and 113.7% respectively. In summary, while growth increased linearly up to 120% of the PIC current feeding level, the optimal MOFC was 106% to 114% depending on the model used.

Genetic and Environmental Influences of Dietary Indices in a UK Female Twin Cohort

2020 ◽  
Vol 23 (6) ◽  
pp. 330-337
Author(s):  
Olatz Mompeo ◽  
Rachel Gibson ◽  
Paraskevi Christofidou ◽  
Tim D. Spector ◽  
Cristina Menni ◽  
...  
Keyword(s):  
Healthy Eating ◽  
Menopausal Status ◽  
Healthy Eating Index ◽  
Healthy Diet ◽  
Nutritional Epidemiology ◽  
Best Fitting ◽  
Heritability Estimates ◽  
Fitting Model ◽  
Dietary Indices ◽  
Health Parameters

AbstractA healthy diet is associated with the improvement or maintenance of health parameters, and several indices have been proposed to assess diet quality comprehensively. Twin studies have found that some specific foods, nutrients and food patterns have a heritable component; however, the heritability of overall dietary intake has not yet been estimated. Here, we compute heritability estimates of the nine most common dietary indices utilized in nutritional epidemiology. We analyzed 2590 female twins from TwinsUK (653 monozygotic [MZ] and 642 dizygotic [DZ] pairs) who completed a 131-item food frequency questionnaire (FFQ). Heritability estimates were computed using structural equation models (SEM) adjusting for body mass index (BMI), smoking status, Index of Multiple Deprivation (IMD), physical activity, menopausal status, energy and alcohol intake. The AE model was the best-fitting model for most of the analyzed dietary scores (seven out of nine), with heritability estimates ranging from 10.1% (95% CI [.02, .18]) for the Dietary Reference Values (DRV) to 42.7% (95% CI [.36, .49]) for the Alternative Healthy Eating Index (A-HEI). The ACE model was the best-fitting model for the Healthy Diet Indicator (HDI) and Healthy Eating Index 2010 (HEI-2010) with heritability estimates of 5.4% (95% CI [−.17, .28]) and 25.4% (95% CI [.05, .46]), respectively. Here, we find that all analyzed dietary indices have a heritable component, suggesting that there is a genetic predisposition regulating what you eat. Future studies should explore genes underlying dietary indices to further understand the genetic disposition toward diet-related health parameters.

Comparing productive vocabulary measures from the CDI and a systematic diary study

1999 ◽  
Vol 26 (1) ◽  
pp. 177-185 ◽  
Author(s):  
BYRON F. ROBINSON ◽  
CAROLYN B. MERVIS
Keyword(s):  
Growth Curves ◽  
Diary Study ◽  
Expressive Vocabulary ◽  
Early Language ◽  
Vocabulary Size ◽  
Early Language Development ◽  
Closed Class ◽  
Communicative Development ◽  
Best Fitting ◽  
Fitting Model

Expressive vocabulary data gathered during a systematic diary study of one male child's early language development are compared to data that would have resulted from longitudinal administration of the MacArthur Communicative Development Inventories spoken vocabulary checklist (CDI). Comparisons are made for (1) the number of words at monthly intervals (9;10.15 to 2;0.15), (2) proportion of words by lexical class (i.e. noun, predicate, closed class, ‘other’), (3) growth curves. The CDI underestimates the number of words in the diary study, with the underestimation increasing as vocabulary size increases. The proportion of diary study words appearing on the CDI differed as a function of lexical class. Finally, despite the differences in vocabulary size, logistic curves proved to be the best fitting model to characterize vocabulary development as measured by both the diary study and the CDI. Implications for the longitudinal use of the CDI are discussed.

scholarly journals Identification-Robust Estimates of the Canadian Natural Rate of Interest

2016 ◽  
Vol 91 (1-2) ◽  
pp. 161-176
Author(s):  
Maral Kichian
Keyword(s):  
Interest Rate ◽  
Robust Methods ◽  
Errors In Variables ◽  
Natural Rate ◽  
Real Rate ◽  
Point Estimates ◽  
Natural Rate Of Interest ◽  
Best Fitting ◽  
Estimate Precision ◽  
Fitting Model

The natural rate of interest is an unobservable entity and its measurement presents some important empirical challenges. In this paper, we use identification-robust methods and central bank real-time staff projections to obtain estimates for the equilibrium real rate from contemporaneous and forward-looking Taylor-type interest rate rules. The methods notably account for the potential presence of endogeneity, under-identification, and errors-in-variables concerns. Our applications are conducted on Canadian data. The results reveal some important identification difficulties associated with some of our models, reinforcing the need to use identification-robust methods to estimate such policy functions. Despite these challenges, we are able to obtain fairly comparable point estimates for the real equilibrium interest rate across our different models, and in the case of the best fitting model, also remarkable estimate precision.

Forward  Modelling of Bouguer Anomalies along a transect of the Southern Apennines and the Tyrrhenian back-arc basin.

2021 ◽  
Author(s):  
Assel Akimbekova ◽  
Paolo Mancinelli ◽  
Massimiliano Rinaldo Barchi ◽  
Cristina Pauselli ◽  
Giorgio Minelli
Keyword(s):  
Gravity Anomalies ◽  
Moho Depth ◽  
Positive Trend ◽  
Tyrrhenian Sea ◽  
Southern Apennines ◽  
Bouguer Anomalies ◽  
Crustal Model ◽  
Density Values ◽  
Best Fitting ◽  
Fitting Model

<p>Abstract</p><p> </p><p>In the present study, starting from original measurement stations, we created the Bouguer anomaly map of Southern Italy with a reduction density of 2670 kg m<sup>-3</sup>. We perform a regional gravity modelling at crustal scale along the trace of the CROP-04 (on-shore) and MB6 (off-shore) deep seismic reflection profiles crossing the Southern Apennines and the Southern Tyrrhenian Sea. Along the 320 km-long modelled profile, we investigate crustal-scale sources for the observed gravity anomalies. </p><p>After a compelling review of the published Moho geometries in the area, that were retrieved from either active or passive seismic methods, we test them in the observed gravity field through forward modeling of the Bouguer gravity anomalies. The comparison between the different Moho interpretations shows that the steepness of the subducting slab, the position of the step between the western (Tyrrhenian) and the eastern (Adriatic) Moho and Moho depth represent the main features influencing the observed Bouguer anomalies at crustal scale.</p><p>Finally, we provide a best-fitting model across both onshore and offshore areas. In the proposed best-fitting model, the wide wavelength and strong regional Bouguer anomalies correlate with the geometry of the Moho discontinuity and deep tectonic structures. On the other hand, the small-amplitude oscillations of the gravity anomalies were attributed to the low-density values of the Pliocene-Quaternary deposits both on- (e.g. the Bradanic trough) and off-shore (e.g. recent deposits in the Tyrrhenian sea bottom). Gravity minima correspond to the crustal doubling underneath the Southern Apennines where the Tyrrhenian Moho (~27 km depth) overlies the deeper Adriatic Moho (~50 km depth). The positive trend of the observed anomaly toward NE is related to the shallowing of the Adriatic Moho to depths of ~28 km in the Adriatic. Similarly, towards SW, the observed anomaly follows a positive trend towards the maxima located in the Central Tyrrhenian Sea. We model this trend as representative of crustal thinning and shallowing to values of ~12 km depth of the Tyrrhenian Moho. We also model a crustal transition from geometries and density values typical of a continental crust in the Adriatic domain towards a more oceanic structure and composition in the Tyrrhenian domain. This crustal model locates the westward flexure of the Adriatic Moho, mimicking the subduction of the Adriatic lithosphere beneath the Peri-Tyrrhenian block and locates step between the western (Tyrrhenian) and the eastern (Adriatic) Moho beneath the Apennines range.</p><p>The resulted gravity forward model provide contributions to the tectonic settings understanding of the area by providing a robust crustal model ranging from the Tyrrhenian Sea to the Apulian foreland.</p><p> Finally, we believe that the proposed model can serve as a starting point for future studies investigating the upper crustal geometries in the area and addressing open questions about its relations with seismicity distribution.</p><p> </p>

Sign in / Sign up

Export Citation Format

Share Document