| 31. |
- Larsson, Jan-Olov, et al.
(författare)
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Genetic and environmental contributions to stability and change of ADHD symptoms between 8 and 13 years of age : a longitudinal twin study
- 2004
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - Philadelphia, USA : Lippincott Williams & Wilkins. - 0890-8567 .- 1527-5418. ; 43:10, s. 1267-1275
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To study the genetic and environmental contributions to stability and change of attention-deficit/hyperactivity disorder (ADHD) symptoms between 8 and 9 and 13 and 14 years of age.Method: The sample included 1,480 twin pairs born in Sweden between May 1985 and December 1986. At wave 1 in 1994, when twins were 8-9 years old, 1,106 (75%) of the parents responded to a mailed questionnaire, and at wave 2 when the twins were 13-14 years old, 1,063 (73%) responded. A checklist with 14 items based on the 14 DSM-III-R symptoms for ADHD was completed. Structural equation modeling was used to analyze the data.Results: A relatively high stability of ADHD symptoms over this 5-year period was found. This continuity was mainly due to the same genetic effects operating at both points in time. Change in symptoms between childhood and early adolescence was to a large extent due to new genetic effects in early adolescence but also due to new nonshared environmental effects that became important during adolescence.Conclusions: The genetic stability highlights the importance of the continuing search for genes and endophenotypes of ADHD.
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| 32. |
- Lichtenstein, P., et al.
(författare)
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Associations between conduct problems in childhood and adverse outcomes in emerging adulthood: a longitudinal Swedish nationwide twin cohort
- 2020
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Ingår i: Journal of Child Psychology and Psychiatry and Allied Disciplines. - : Wiley. - 0021-9630 .- 1469-7610. ; 61:7, s. 798-806
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Tidskriftsartikel (refereegranskat)abstract
- Background We examined whether childhood conduct problems predicted a wide range of adverse outcomes in emerging adulthood and whether the association with internalizing problems remained after adjusting for general comorbidity and externalizing problems. Methods Participants were 18,649 twins from the Child and Adolescent Twin Study in Sweden. At age 9/12, parents rated their children on eight conduct problems. Adverse outcomes were retrieved from national registers in emerging adulthood (median follow‐up time = 9.2 years), including diagnoses of six psychiatric disorders, prescriptions of antidepressants, suicide attempts, criminality, high school ineligibility, and social welfare recipiency. We estimated risk for the separate outcomes and examined if conduct problems predicted an internalizing factor above and beyond a general comorbidity and an externalizing factor. We used twin analyses to estimate genetic and environmental contributions to these associations. Results On the average, each additional conduct symptom in childhood was associated with a 32% increased risk of the adverse outcomes in emerging adulthood (mean hazard ratio = 1.32; range = 1.16, 1.56). A latent childhood conduct problems factor predicted the internalizing factor in emerging adulthood (βboys = .24, standard error, SE = 0.03; βgirls = .17, SE = 0.03), above and beyond its association with the externalizing (βboys = 0.21, SE = 0.04; βgirls = 0.17, SE = 0.05) and general factors (βboys = 0.45, SE = 0.03; βgirls = 0.34, SE = 0.04). These associations were differentially influenced by genetic and environmental factors. Conclusions It is important to monitor boys and girls with conduct problems not only for future externalizing problems, but also for future internalizing problems. Prevention of specific outcomes, however, might require interventions at different levels.
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| 33. |
- Lundström, Sebastian, et al.
(författare)
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Autism spectrum disorders and autistic like traits: similar etiology in the extreme end and the normal variation.
- 2012
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Ingår i: Archives of General Psychiatry. - Chicago, USA : American Medical Association (AMA). - 0003-990X .- 1538-3636. ; 69:1, s. 46-52
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Autism spectrum disorders (ASDs) have been suggested to represent the extreme end of a normal distribution of autisticlike traits (ALTs). However, the evidence of this notion is inconclusive. OBJECTIVE: To study whether there are similar genetic and/or environmental etiologies behind ASDs and ALTs. DESIGN: A nationwide twin study. PARTICIPANTS: Consenting parents of all Swedish twins aged 9 and 12 years, born between July 1, 1992, and December 31, 2001 (n = 19 208), were interviewed by telephone to screen for child psychiatric conditions, including ASDs. MAIN OUTCOME MEASURES: Two validated cutoffs for ASDs, 2 cutoffs encompassing the normal variation, and 1 continuous measure of ALTs were used with DeFries-Fulker extreme-end analyses and standard twin study methods. RESULTS: We discerned a strong correlation between the 4 cutoffs and the full variation of ALTs. The correlation was primarily affected by genes. We also found that the heritability for the 4 cutoffs was similar. CONCLUSION: We demonstrate an etiological similarity between ASDs and ALTs in the normal variation and, with results from previous studies, our data suggest that ASDs and ALTs are etiologically linked.
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| 34. |
- Maggiolo, Dario, 1985, et al.
(författare)
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Self‐Cleaning Surfaces for Heat Recovery During Industrial Hydrocarbon‐Rich Gas Cooling: An Experimental and Numerical Study
- 2019
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Ingår i: AICHE Journal. - : Wiley. - 1547-5905 .- 0001-1541. ; 65:1, s. 317-325
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Tidskriftsartikel (refereegranskat)abstract
- The cooling of hydrocarbon-rich gases in industrial processes often leads to severe fouling, which impedes heat recovery, restricts operative conditions and increases maintenance costs. In the present work, we investigate whether self-cleaning surfaces represent a possible solution to overcome this technological bottleneck. Hydrophilic and hydrophobic treatments of compact heat exchanger plates are experimentally and numerically investigated during cooling of syngas produced from biomass gasification. The experimental evidences related to the operation of heat exchanger plates are assessed first, and a deeper insight into the relevant phenomena is thereafter obtained by performing numerical simulations. Our analysis identifies the hydrophobic treatment as the most promising solution and unveils the induced self-cleaning mechanism: the formation of small-sized and movable condensed droplets that enhance the collection and removal of gas impurities. These findings open up new routes towards the development of cheaper, more efficient and sustainable gas cooling systems.
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| 35. |
- Maggiolo, Dario, 1985, et al.
(författare)
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Two-phase flow patterns and condensation on wetted surfaces for innovative self-cleaning heat exchangers: experiments and numerics
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Fouling is a common and pervasive problem in industrial processes that involve the cooling of hydrocarbon-rich gas mixtures and and it is considered responsible for 1%÷2.5% of the global anthropogenic emissions of CO2. One of the major drawbacks related to fouling is that it impedes heat recovery and thereby it considerably limits the efficiency of many industrial processes. We experimentally and numerically have investigated whether self-cleaning surfaces of heat exchangers represent a possible solution to overcome this technological bottleneck. Hydrophilically and hydrophobically treated corrugated plates of heat exchangers have been experimentally tested in a 2 MW th research-gasifier and their capabilities to resist fouling have been evaluated. Results revealed that hydrophobically treated surfaces exhibit good anti-fouling and self-cleaning properties. By means of numerical Lattice-Boltzmann-based simulations we then unveiled the self-cleaning phenomenon induced by the wetted surfaces: with a similar mechanism to lotus-leaves, small and motile condensed water droplets are able to collect and remove impurities present in the gas and prevent surfaces fouling. Condensation, two-phase flows patterns formation and droplets coalescence all contribute to promote or weaken the self-cleaning effects. Therefore, numerical simulations have been finally used to identify the main mass and heat transport mechanisms that affect self-cleaning and the optimal operative conditions of the heat exchangers.
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| 36. |
- Mataix-Cols, David, et al.
(författare)
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Familial risks of Tourette syndrome and chronic tic disorders : a population-based cohort study
- 2015
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Ingår i: JAMA Psychiatry. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 2168-622X .- 2168-6238.
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Tidskriftsartikel (refereegranskat)abstract
- Importance: Chronic Tic Disorders (CTD), including Tourette Syndrome (TS), are assumed to be strongly familial and heritable. While gene-searching efforts are well underway, precise estimates of familial risk and heritability are lacking. Previous controlled family studies were small and typically conducted within specialist clinics, resulting in potential ascertainment biases. They were also underpowered to disentangle genetic from environmental factors contributing to the observed familiality. Twin studies have been either very small or based on parent-reported tics in population-based (non-clinical) twin samples. Objective: To provide unbiased estimates of familial risk and heritability of TS/CTD at the population level. Design and Setting: Population cohort, multigenerational, family study. Participants: Using a validated algorithm, we identified 4,826 individuals diagnosed with TS/CTD (76% male) in the Swedish National Patient Register between 1969-2009. Main outcome measure: Risks (Odds Ratios; OR) for TS/CTD in all biological relatives of probands, compared to relatives of unaffected individuals (matched on a 1:10 ratio) from the general population. Structural equation modeling was used to estimate the heritability of TS/CTD. Results: The risk for TS/CTD amongst relatives of TS/CTD probands increased proportionally to the degree of genetic relatedness. The risks for first-degree relatives (OR= 18.69, 95% CI 14.53-24.05) were significantly higher than for second-degree relatives (OR= 4.58, 95% CI 3.22-6.52) and third-degree relatives (OR= 3.07, 95% CI 2.08-4.51). First-degree relatives at similar genetic distances (e.g. parents, siblings, offspring) had similar risks for TS/CTD, despite different degrees of shared environment. The risks for full siblings (50% genetic similarity; OR=17.68, 95% CI 12.90-24.23) were significantly higher than that for maternal-half siblings (25% genetic similarity; OR= 4.41, 95% CI 2.24-8.67), despite similar environmental exposures. The heritability of TS/CTD was estimated to be 0.77 (95% CI 0.70-0.85). There were no differences in familial risk or heritability between male and female patients. Conclusions and relevance: TS/CTD clusters in families primarily due to genetic factors and appears to be amongst the most heritable neuropsychiatric conditions.
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| 37. |
- Mendoza, Patricia, et al.
(författare)
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DamID transcriptional profiling identifies the Snail/Scratch transcription factor Kahuli as an Alk target in the Drosophila visceral mesoderm
- 2021
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Ingår i: Development. - : The Company of Biologists. - 0950-1991 .- 1477-9129. ; 148:23
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Tidskriftsartikel (refereegranskat)abstract
- Development of the Drosophila visceral muscle depends on Anaplastic Lymphoma Kinase (Alk) receptor tyrosine kinase (RTK) signaling, which specifies founder cells (FCs) in the circular visceral mesoderm (VM). Although Alk activation by its ligand Jelly Belly (Jeb) is well characterized, few target molecules have been identified. Here, we used targeted DamID (TaDa) to identify Alk targets in embryos overexpressing Jeb versus embryos with abrogated Alk activity, revealing differentially expressed genes, including the Snail/Scratch family transcription factor Kahuli (Kah). We confirmed Kah mRNA and protein expression in the VM, and identified midgut constriction defects in Kah mutants similar to those of pointed (pnt). ChIP and RNA-Seq data analysis defined a Kah target-binding site similar to that of Snail, and identified a set of common target genes putatively regulated by Kah and Pnt during midgut constriction. Taken together, we report a rich dataset of Alk-responsive loci in the embryonic VM and functionally characterize the role of Kah in the regulation of embryonic midgut morphogenesis.
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| 38. |
- Pettersson, Erik, et al.
(författare)
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Birth weight as an independent predictor of ADHD symptoms : a within-twin pair analysis
- 2015
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Ingår i: Journal of Child Psychology and Psychiatry. - Hoboken, USA : Wiley-Blackwell. - 0021-9630 .- 1469-7610. ; 56:4, s. 453-459
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Tidskriftsartikel (refereegranskat)abstract
- Background Studies have found an association between low birth weight and ADHD, but the nature of this relation is unclear. First, it is uncertain whether birth weight is associated with both of the ADHD dimensions, inattentiveness and hyperactivity-impulsivity. Second, it remains uncertain whether the association between birth weight and ADHD symptom severity is confounded by familial factors.Method: Parents of all Swedish 9- and 12-year-old twins born between 1992 and 2000 were interviewed for DSM-IV inattentive and hyperactive-impulsive ADHD symptoms by the Autism - Tics, AD/HD and other Comorbidities (A-TAC) inventory (N = 21,775 twins). Birth weight was collected prospectively through the Medical Birth Registry. We used a within-twin pair design to control for genetic and shared environmental factors.Results: Reduced birth weight was significantly associated with a mean increase in total ADHD (β = -.42; 95% CI: -.53, -.30), inattentive (β = -.26; 95% CI: -.33, -.19), and hyperactive-impulsive (β = -.16; 95% CI: -.22, -.10) symptom severity. These results imply that a change of one kilogram of birth weight corresponded to parents rating their child nearly one unit higher (going from "no" to "yes, to some extent" on a given symptom) on the total ADHD scale. These associations remained within pairs of MZ and DZ twins, and were also present when restricting the analyses to full term births.Conclusions: There is an independent association between low birth weight and all forms of ADHD symptoms, even after controlling for all environmental and genetic confounds shared within twin pairs. These results indicate that fetal growth restriction (as reflected in birth weight differences within twin pairs) and/or the environmental factors which influence it is in the casual pathway leading to ADHD.
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| 39. |
- Quinn, Patrick D., et al.
(författare)
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Childhood attention-deficit/hyperactivity disorder symptoms and the development of adolescent alcohol problems : A prospective, population-based study of Swedish twins
- 2016
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Ingår i: American Journal of Medical Genetics Part B. - Hoboken, USA : John Wiley & Sons. - 1552-4841 .- 1552-485X. ; 171:7, s. 958-970
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Tidskriftsartikel (refereegranskat)abstract
- Children with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of problematic alcohol and other substance use in adolescence. This study used data from an ongoing, prospective, population-based twin study of Swedish children and adolescents to evaluate the extent to which the association between ADHD symptoms and alcohol problems reflects a unique source of genetic or environmental risk related to ADHD versus a broader predisposition to youth externalizing behavior. We used all available data from same-sex monozygotic (MZ) and dizygotic (DZ) twins on ADHD symptoms in childhood (age 9/12; N = 15,549) and alcohol problems in late adolescence (age 18; N = 2,564). Consistent with prior longitudinal studies, the phenotypic association between hyperactive/impulsive ADHD symptoms and alcohol problems was small in magnitude, whereas the association for inattentive symptoms was even weaker. Additive genetic influences explained 99.8% of the association between hyperactive/impulsive symptoms and alcohol problems. Furthermore, we found that the genetic risk specifically associated with hyperactive/impulsive symptoms was attenuated when estimated in the context of externalizing behavior liability during childhood, of which ADHD symptoms were specific expressions. In sensitivity analyses exploring hyperactivity in mid-adolescence, we found a similar pattern of genetic associations. These results are consistent with previous findings of genetically driven overlap in the etiology of ADHD and problematic alcohol use. At least some of this co-occurrence may result from a general predisposition to externalizing behaviors in youth. © 2015 Wiley Periodicals, Inc.
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| 40. |
- Rejnö, Gustaf, et al.
(författare)
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Adverse Pregnancy Outcomes in Asthmatic Women : A Population-Based Family Design Study
- 2018
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier. - 2213-2198 .- 2213-2201. ; 6:3, s. 916-922.e6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Asthma is associated with several adverse pregnancy and perinatal outcomes. Familial factors may confound these associations.OBJECTIVE: To examine the role of measured and unmeasured confounding by conducting a study that compared differentially exposed cousins and siblings from the same families.METHODS: We retrieved data on adverse pregnancy outcomes, prescribed drugs, and physician-diagnosed asthma from nationwide registers for all women in Sweden with singleton births between 2001 and 2013. Logistic and linear regression estimated the association between maternal asthma and several outcomes in the whole population and within differently exposed pregnant relatives.RESULTS: In total, 1,075,153 eligible pregnancies were included and 10.1% of the study population had asthma. We identified 475,200 cousin and 341,205 sister pregnancies. Women with asthma had increased risks for preeclampsia (adjusted odds ratio [aOR], 1.17; 95% CI, 1.13-1.21), emergency cesarean section (aOR, 1.24; 95% CI, 1.22-1.27), and having a child small for gestational age (aOR, 1.18; 95% CI, 1.12-1.23). In the conditional regression analyses, after adjustment for familial factors, the associations remained: preeclampsia in cousins (aOR, 1.16; 95% CI, 1.07-1.25) and siblings (aOR, 1.23; 95% CI, 1.08-1.38), emergency cesarean section in cousins (aOR, 1.28) and siblings (aOR, 1.21), and small for gestational age in cousins (aOR, 1.17) and siblings (aOR, 1.13).CONCLUSIONS: Factors shared by siblings and cousins do not seem to explain the observed association between maternal asthma and adverse pregnancy outcomes. This implies that targeting the asthma disease will continue to be important in reducing risks for adverse outcomes in pregnancy.
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