| 1. |
- Colins, Olivier F., 1978-, et al.
(författare)
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Psychopathic Traits in Early Childhood : Further Validation of the Child Problematic Traits Inventory
- 2017
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Ingår i: Assessment. - Thousand Oaks, USA : Sage Publications. - 1073-1911 .- 1552-3489. ; 24:5, s. 602-614
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to further test the reliability and validity of a newly developed instrument designed to assess psychopathic personality traits in children, the Child Problematic Traits Inventory (CPTI). Data from the Preschool Twin Study in Sweden were used, a national general population study of 5-year-old twins (n = 1,188, 50.3% girls). Both preschool teachers and parents were used as informants. Confirmatory factor analysis replicated the intended three-factorial structure of the 28 items of the CPTI. Overall, our findings demonstrated good internal consistency and convergent validity, with all the teacher-rated CPTI scores being associated with teacher and parent ratings of externalizing psychopathology, aggressive behavior, fearlessness, and prosocial peer involvement. In conclusion, the CPTI hold promise as a teacher-rated tool for assessing psychopathic traits in childhood, though more research is needed to see if these findings can be generalized to other countries, settings, and older children.
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| 2. |
- Drislane, Laura E., et al.
(författare)
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A triarchic model analysis of the youth psychopathic traits inventory
- 2015
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Ingår i: Journal of Personality Disorders. - : Guilford Publications. - 0885-579X .- 1943-2763. ; 29:1, s. 15-41
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Tidskriftsartikel (refereegranskat)abstract
- The Triarchic model of psychopathy characterizes this complex condition in terms of distinct phenotypic constructs of boldness, meanness, and disinhibition. The current study evaluated the coverage of these constructs provided by a well-established inventory for assessing psychopathy in adolescents, the Youth Psychopathic Traits Inventory (YPI). A consensus rating approach was used to identify YPI items relevant to each Triarchic model construct, and convergent and discriminant validity of the resulting YPI-Triarchic scales were examined in relation to criterion measures consisting of scores on other psychopathy measures and relevant personality trait variables (N = 618, M age = 18.8). The YPI-Triarchic scales showed good internal consistency and exhibited properties largely consistent with predictions based on the Triarchic model, aside from somewhat greater than expected covariance between boldness and other facet scales. Findings are discussed in terms of their implications for interpreting scores on the YPI and for investigating distinctive components of psychopathy in youth.
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| 3. |
- Thunman, Henrik, 1970, et al.
(författare)
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Advanced biofuel production via gasification – lessons learned from 200 man-years of research activity with Chalmers’ research gasifier and the GoBiGas demonstration plant.
- 2018
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Ingår i: Energy Science and Engineering. - : Wiley. - 2050-0505. ; 6:1, s. 6-34
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the main experiences gained and conclusions drawn from the demonstration of a first-of-its-kind wood-based biomethane production plant (20-MW capacity, 150 dry tonnes of biomass/day) and 10 years of operation of the 2–4-MW (10–20 dry tonnes of biomass/day) research gasifier at Chalmers University of Technology in Sweden. Based on the experience gained, an elaborated outline for commercialization of the technology for a wide spectrum of applications and end products is defined. The main findings are related to the use of biomass ash constituents as a catalyst for the process and the application of coated heat exchangers, such that regular fluidized bed boilers can be retrofitted to become biomass gasifiers. Among the recirculation of the ash streams within the process, presence of the alkali salt in the system is identified as highly important for control of the tar species. Combined with new insights on fuel feeding and reactor design, these two major findings form the basis for a comprehensive process layout that can support a gradual transformation of existing boilers in district heating networks and in pulp, paper and saw mills, and it facilitates the exploitation of existing oil refineries and petrochemical plants for large-scale production of renewable fuels, chemicals, and materials from biomass and wastes. The potential for electrification of those process layouts are also discussed. The commercialization route represents an example of how biomass conversion develops and integrates with existing industrial and energy infrastructures to form highly effective systems that deliver a wide range of end products. Illustrating the potential, the existing fluidized bed boilers in Sweden alone represent a jet fuel production capacity that corresponds to 10% of current global consumption.
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| 4. |
- Brikell, Isabell, et al.
(författare)
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Relative Immaturity in Childhood and Attention-Deficit/Hyperactivity Disorder Symptoms From Childhood to Early Adulthood : Exploring Genetic and Environmental Overlap Across Development
- 2016
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - : Elsevier. - 0890-8567 .- 1527-5418. ; 55:10, s. 886-895
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Attention-deficit/hyperactivity disorder (ADHD) has been linked to immaturity relative to peers in childhood, yet it is unclear how such immaturity is associated with ADHD across development. This longitudinal twin study examined the genetic and environmental contributions to the association between parents' perception of their child's immaturity relative to peers (RI) in childhood and ADHD symptoms across development.Method: 1,302 twin pairs from the Swedish Twin Study of Child and Adolescent Development were followed prospectively from childhood to early adulthood. Parent ratings of RI were collected at 8 to 9 years and parent and self-ratings of ADHD symptoms were collected at 8 to 9, 13 to 14, 16 to 17, and 19 to 20 years using the Child Behavior Checklist Attention Problems scale. In addition, ADHD symptoms corresponding to DSM criteria were used for sensitivity analysis. Analyses were conducted using longitudinal structural equation modeling with multiple raters.Results: RI-related etiologic factors, predominantly influenced by genes, explained 10-14% of the variance in ADHD symptoms from 8 to 9 up to 16 to 17 years. The influence of these RI-related factors on ADHD symptoms attenuated to 4% by 19 to 20 years of age. The remaining variance in ADHD symptoms was primarily explained by genetic factors independent of RI, which remained relatively stable across development, explaining 19% to 30% of the variance in ADHD symptoms from 13 to 14 up to 19 to 20 years.Conclusion: The results show that RI is significantly associated with ADHD symptoms, particularly during childhood and adolescence, and that the association is primarily explained by a shared genetic liability. Nevertheless, the magnitude of associations across development was modest, highlighting that RI is merely one aspect contributing to the complex etiology of ADHD symptoms.
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| 5. |
- Haglund, Axel, et al.
(författare)
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Suicide Immediately After Discharge From Psychiatric Inpatient Care : A Cohort Study of Nearly 2.9 Million Discharges
- 2019
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Ingår i: Journal of Clinical Psychiatry. - : Physicians Postgraduate Press. - 0160-6689 .- 1555-2101. ; 80:2
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The risk of suicide is elevated after discharge from a psychiatric hospital. This study aimed to investigate how recent suicidal behavior affects the risk of suicide in patients with different psychiatric diagnoses immediately after discharge.METHODS: Registers with national coverage were linked to create a study cohort including all individuals discharged from psychiatric hospitals in Sweden from 1973 through 2009. Hazard ratios for discharge diagnoses were calculated. The risk of suicide within 30 days after discharge in each diagnostic category when suicidal behavior had been registered within 30 days before admission was estimated.RESULTS: A total of 3,695 suicides occurred after 2,883,088 discharges. If recent suicidal behavior was registered, the risk of completed suicide increased prominently in all diagnostic categories, but particularly for schizophrenia (hazard ratio [HR] = 8.9; 95% CI, 6.4-12.4) and other nonorganic psychosis (HR = 6.8; 95% CI, 5.1-9.0). Patients suffering from depression had the highest overall risk of suicide postdischarge (HR = 3.0; 95% CI, 2.7-3.3). This finding applied especially to male patients with depression (HR = 4.5; 95% CI, 4.0-5.0) or with reaction to crisis (HR = 3.6; 95% CI 3.0-4.4).CONCLUSIONS: A distinct elevation of the risk of suicide was seen in all diagnostic groups if a recent self-harm event had occurred, particularly among patients with psychotic disorders. Overall, the immediate risk of suicide after discharge was high regardless of recent suicidal behavior. The findings in this study have relevance for clinical decisions about immediate after-care and treatment in connection with discharge from psychiatric inpatient care.
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| 6. |
- Holmberg, K., et al.
(författare)
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Impact of asthma medication and familial factors on the association between childhood asthma and attention-deficit/hyperactivity disorder: a combined twin- and register-based study
- 2015
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Ingår i: Clinical and Experimental Allergy. - Stockholm : Wiley. - 0954-7894 .- 1365-2222. ; 45:5, s. 964-973
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAsthma and attention-deficit/hyperactivity disorder (ADHD) are prevalent in childhood and may cause functional impairment and stress in families. Previous research supports an association between asthma and ADHD in children, but several aspects of this relationship are unclear. ObjectiveOur aim was to study whether the association between asthma and ADHD is restricted to either the inattentive or the hyperactive/impulsive symptoms of ADHD, to explore the impact of asthma severity and asthma medication and the contribution of shared genetic and environmental risk factors on the asthma-ADHD relationship. MethodsData on asthma, ADHD, zygosity and possible confounders were collected from parental questionnaires at 9 or 12years on 20072 twins through the Swedish Twin Register, linked to the Swedish Medical Birth Register, the National Patient Register and the Prescribed Drug Register. The association between asthma and ADHD, the impact of asthma severity and medication, was assessed by generalized estimating equations. Cross-twin-cross-trait correlations (CTCT) were estimated to explore the relative importance of genes and environment for the association. ResultsAsthmatic children had a higher risk of also having ADHD [odds ratio (OR) 1.53, 95% confidence interval (CI): 1.16-2.02]. The association was not restricted to either of the two dimensions of ADHD. The magnitude of the association increased with asthma severity (OR 2.84, 95% CI: 1.86-4.35) for 4 asthma attacks in the last 12months and was not affected by asthma treatment. The CTCTs possibly indicate that the genetic component in overlap of the disorders is weak. Conclusions and Clinical RelevanceChildhood asthma, especially severe asthma, is associated with ADHD. Asthma medication seems not to increase the risk of ADHD. Clinicians should be aware of the potential of ADHD in asthma. Optimal asthma care needs to be integrated with effective evaluation and treatment of ADHD in children with co-existing disorders.
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| 7. |
- 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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| 8. |
- 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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| 9. |
- 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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| 10. |
- 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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