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Plasma sparks from an electrical discharge machining (EDM) process were observed using fiber optics positioned in the dielectric oil. Measurement techniques were developed to observe the spark in the extremely noisy environment. Optical data were used along with current pulse wave forms from the EDM machine to study the temporal characteristics of the spark in both the pulse time and the pause time. During the pause time, extinction of the sparks was longer than previously thought—perhaps due to the remaining infrared radiation after the collapse of the spark. Further, an optical pattern was identified that indicated in advance when an arc was being formed instead of a spark. Spectral data of the plasma spark was obtained by using a scanning grating spectrometer in conjunction with crosscorrelation to maximize the signal-to-noise ratio. Average spark temperatures from the spectral data were found to be significantly higher than those previously predicted from energy balances. The results showed a shift in the optical spectra to longer wavelengths during the spark, showing that the spark temperature decreased with time. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The first dedicated PETICT centre in Norway was established at the Norwegian Radiumhospital in Oslo in 2005. Knowing that the introductions of PET-isotopes in nuclear medicine give increased occupational radiation dose to the technicians, a study was carried out in order to map the doses to staff members during different working operations and to see if any dose reducing measures were needed. The results of the study are in good agreement with other studies, and a technician dose of 20-25 nSv per injected MBq of 18F seems to be representative for such centres. For an average injected activity of 350 MBq per patient, the dose limit is reached after handling around 3000 patients annually. For an annual number of less than 500 patients at the centre and rotation of the staff, an annual individual dose for the technicians would realistically be less than 2-3 mSv. Even a major increase in the number of patients will not result in individual doses near the ICRP dose limit. [ABSTRACT FROM AUTHOR]

Purpose: Evidence on whether the immigrant health paradox (i.e., immigrants having better health than natives of nonmigrant background) extends to children and youth is mixed and often based on self-reported survey data. In this study, we use population-wide administrative microdata from Norwegian demographic and health registries to investigate health inequalities between adolescents with foreign-born and native-born parents, paying specific attention to variation across immigrant generations, origin countries, and types of diagnoses., Methods: In this registry-based study, we estimate differences in the likelihood of somatic and mental disorders using logistic regression and population-wide health records for adolescents aged 16-20 years (N = 616,835)., Results: Child immigrants and native-born children of immigrants have fewer consultations for somatic and psychiatric diagnoses in adolescence compared to natives, while native-born children with mixed parental background have health outcomes more similar to natives. The differences are most pronounced for mental disorders. Differences across immigrant generations persist when stratifying by country of origin and when looking at specific diagnoses., Discussion: The findings support the existence of an immigrant health advantage, which we find across various psychiatric and somatic diagnoses and for most immigrant generations. A key task for future research is to explore specific mechanisms underlying these patterns and to address potential inequities in the quality of health care provided to immigrant-background youth., (Copyright © 2024 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Child mortality has declined rapidly over the last century in many high-income countries. However, little is known about the socio-economic differences in this decline and whether these vary across causes of death., Methods: We used register data that included all Norwegian births between 1968 and 2010 (2.1 million), and we analysed how all-cause and cause-specific child (0-4 years) and adolescent (5-20 years) mortality rates vary with relative parental income the year before the birth., Results: Child and adolescent all-cause mortality decreased with increasing parental relative income within all birth cohorts. Among children aged 0-4 years, the socio-economic gradient in all-cause mortality and in mortality due to external causes, sudden infant deaths and perinatal factors declined over the period, while there was no systematic decline in mortality from congenital malformations. Among children aged 5-20 years, the gradient did not weaken similarly, although there were indications of declines in the socio-economic gradient related to all-cause deaths and deaths because of suicides and other external causes. While the absolute differences in mortality declined over time, the relative differences remained stable., Conclusions: Although children of low-income parents still have elevated mortality, there has been a large reduction in child mortality in all socio-economic groups across 50 years for all causes combined and most of the groups of specific causes of death., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

We examined the impact of child disability on Grade Points Average (GPA) using all children aged 15-16 years who completed their lower secondary education and registered with a GPA score in the period from 2016 to 2020 in Norway (n = 247 120). We use registry data that contain information on the child's main diagnosis, such as physical-, neurological- and neurodevelopmental conditions, and the severity of the condition, additional to the child's family characteristics. First, we examined whether the impact of the child's disability on the GPA scores varied by diagnosis and the severity of the child's condition. Second, we examined whether higher parental socioeconomic status (SES) buffers against the negative impact of child disability on GPA scores. Using longitudinal register data with the school fixed-effect model, the results showed that children with neurological and neurodevelopmental disabilities obtained lower GPA scores than their typically developing peers without chronic conditions, however children with asthma and diabetes had comparable GPA scores. These associations were most evident for neurodevelopmental conditions, such as ADHD and autism but also notable for neurological conditions such as epilepsy. In general, a severe condition impacts GPA scores more negatively than a less severe condition. Moreover, our analysis revealed that children of highly educated parents obtained higher GPA scores than children who had parents with short education. This applied to both disabled and typically developing peers, except children with autism and epilepsy, among whom buffering due to the parent's education did not seem to apply., Competing Interests: The authors declare that they have no competing interests., (© 2023 The Author(s).)

The COVID-19 pandemic and its associated restrictions may have affected children and adolescent's mental health adversely. We cast light on this question using primary and specialist consultations data for the entire population of children of age 6-19 years in Norway (N = 908 272). Our outcomes are the monthly likelihood of having a consultation or hospitalization related to mental health problems and common mental health diagnoses. We compared a pandemic (2019-2021) to a pre-pandemic (2017-2019) cohort using event study and difference-in-difference designs that separate the shock of the pandemic from linear period trends and seasonal variation. We found temporary reductions in all mental health consultations during lockdown in spring 2020. In fall 2020 and winter 2021, consultation volumes in primary care increased, stabilizing at a higher level in 2021. Consultations in specialist care increased from spring 2021. Our findings could suggest a worsening of mental health among adolescents., (© 2022. The Author(s).)

Background: Children with low-income parents have a higher risk of mental disorders, although it is unclear whether other parental characteristics or genetic confounding explain these associations and whether it is true for all mental disorders., Methods: In this registry-based study of all children in Norway (n = 1 354 393) aged 5-17 years from 2008 to 2016, we examined whether parental income was associated with childhood diagnoses of mental disorders identified through national registries from primary healthcare, hospitalizations and specialist outpatient services., Results: There were substantial differences in mental disorders by parental income, except for eating disorders in girls. In the bottom 1% of parental income, 16.9% [95% confidence interval (CI): 15.6, 18.3] of boys had a mental disorder compared with 4.1% (95% CI: 3.3, 4.8) in the top 1%. Among girls, there were 14.2% (95% CI: 12.9, 15.5) in the lowest, compared with 3.2% (95% CI: 2.5, 3.9) in the highest parental-income percentile. Differences were mainly attributable to attention-deficit hyperactivity disorder in boys and anxiety and depression in girls. There were more mental disorders in children whose parents had mental disorders or low education, or lived in separate households. Still, parental income remained associated with children's mental disorders after accounting for parents' mental disorders and other factors, and associations were also present among adopted children., Conclusions: Mental disorders were 3- to 4-fold more prevalent in children with parents in the lowest compared with the highest income percentiles. Parents' own mental disorders, other socio-demographic factors and genetic confounding did not fully explain these associations., (© The Author(s) 2021. Published by Oxford University Press on behalf of the International Epidemiological Association.)

Aims: In order to prevent a major outbreak of COVID-19 disease in Norway, a series of lockdown measures was announced on 12 March 2020. The aim of the present paper was to describe the impact of this lockdown on the treatment of injuries., Methods: We collected hospital data on injury diagnoses from a national emergency preparedness register established during the pandemic. We identified the number of injured patients per day in the period 1 January-30 June 2020, and analysed the change in patient volumes over two three-week periods before and during the lockdown by sex, age, level of care, level of urgency, type of contact and type of injury., Results: Compared to pre-lockdown levels, there was an overall reduction of 43% in injured patients during the first three weeks of lockdown. The decrease in patient contacts did not differ by sex, but was most pronounced among young people. Substantial reductions were observed for both acute and elective treatment and across all levels of care and types of contact, with the exception of indirect patient contacts. The change in patient contacts varied considerably by injury type, with the largest reduction observed for dislocations/sprains/strains. The decrease was much lower for burns/corrosions and poisoning., Conclusions: A substantial reduction in the treatment of injuries was observed during lockdown in Norway. Possible explanations for this finding include an overall decrease in injury risk, a redistribution of hospital resources and a higher threshold for seeking medical attention as a result of the pandemic.

Competing Interests: Competing interests: None declared.

Background: Disparities in health by adult income are well documented, but we know less about the childhood origins of health inequalities, and it remains unclear how the shape of the gradient varies across health conditions. This study examined the association between parental income in childhood and several measures of morbidity in adulthood., Methods: We used administrative data on seven complete Norwegian birth cohorts born in 1967-1973 (N = 429,886) to estimate the association between parental income from birth to age 18, obtained from tax records available from 1967, linked with administrative registries on health. Health measures, observed between ages 39 and 43, were taken from registry data on consultations at primary health care services based on diagnostic codes from the International Classification of Primary Care (ICPC-2) and hospitalizations and outpatient specialist consultations registered in the National Patient Registry (ICD-10)., Results: Low parental income during childhood was associated with a higher risk of being diagnosed with several chronic and pain-related disorders, as well as hospitalization, but not overall primary health care use. Absolute differences were largest for disorders related to musculoskeletal pain, injuries, and depression (7-9 percentage point difference). There were also differences for chronic disorders such as hypertension (8%, CI 7.9-8.5 versus 4%, CI 4.1-4.7) and diabetes (3.2%, CI 3.0-3.4 versus 1.4%, CI 1.2-1.6). There was no difference in consultations related to respiratory disorders (20.9%, CI 20.4-21.5 versus 19.7%, CI 19.2-20.3). Childhood characteristics (parental education, low birth weight, and parental marital status) and own adult characteristics (education and income) explained a large share of the association., Conclusions: Children growing up at the bottom of the parental income distribution, compared to children in the top of the income distribution, had a two- to threefold increase in somatic and psychological disorders measured in adulthood. This shows that health inequalities by socioeconomic family background persist in a Scandinavian welfare-state context with universal access to health care.

While a large literature documents how mental health problems in adolescence have long-term consequences for adult socioeconomic outcomes, less is known about the relation with family-formation behavior. In this paper, we use data from a population based Norwegian health survey (the Young-HUNT study) linked to administrative registry data (N = 8,113) to examine the long-term consequences of symptoms of internalizing and externalizing problems, the two most common forms of mental health problems, on family-formation outcomes: the likelihood of a first birth, the union status of a first birth, and entering first marriage. For men, externalizing problems are associated with earlier parenthood, especially becoming a father without having a coresidential relationship with the child's mother. Internalizing problems, on the other hand, are associated with lower first-birth rates and the association grows progressively stronger with age. We also find that the associations are more pronounced among men with low childhood socioeconomic status. In contrast, women's family-formation appears for the most part unrelated to their mental health., (Copyright © 2020. Published by Elsevier Ltd.)

A mobile phone camera with an innovative electrically tunable liquid crystal lens (TLCL) concept is demonstrated. We first report the comparative theoretical and experimental analyses of the performance of a traditional "modal control" TLCL versus a TLCL using a floating (unpowered) transparent electrode (FTE). It is shown that the appropriate choice of voltage and frequency values of the driving electric signal may improve significantly (almost twice) the optical quality of the lens using the FTE. Exceptionally low spherical aberrations of the lens (< λ/10 for up to 10 diopters of optical power) and high modulation transfer functions of a mobile phone camera (using those lenses for autofocus function) are demonstrated in a very simple operation mode (frequency tuning of the lens' optical power at a fixed driving voltage). The capacity of the camera to perform high quality long distance photography and near distance bar code recognition within a short autofocus convergence time are demonstrated.

Background: Previous studies have shown that adolescent mental health problems are associated with lower employment probabilities and risk of unemployment. The evidence on how earnings are affected is much weaker, and few have addressed whether any association reflects unobserved characteristics and whether the consequences of mental health problems vary across the earnings distribution., Methods: A population-based Norwegian health survey linked to administrative registry data (N=7885) was used to estimate how adolescents' mental health problems (separate indicators of internalising, conduct, and attention problems and total sum scores) affect earnings (≥30 years) in young adulthood. We used linear regression with fixed-effects models comparing either students within schools or siblings within families. Unconditional quantile regressions were used to explore differentials across the earnings distribution., Results: Mental health problems in adolescence reduce average earnings in adulthood, and associations are robust to control for observed family background and school fixed effects. For some, but not all mental health problems, associations are also robust in sibling fixed-effects models, where all stable family factors are controlled. Further, we found much larger earnings loss below the 25th centile., Conclusions: Adolescent mental health problems reduce adult earnings, especially among individuals in the lower tail of the earnings distribution. Preventing mental health problems in adolescence may increase future earnings., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

In different autoimmune diseases, tissue damage is mediated by the Fc portion of autoantibodies. These include autoimmunity to type VII collagen, a major hemidesmosomal skin constituent, where autoantibodies activate both complement and leukocytes, leading to separation within the dermal-epidermal junction. Fc-dependent effector functions differ among IgG subclasses. To elucidate the still controversial role of IgG subclasses in the pathogenesis of autoimmunity to type VII collagen, we generated a unique set of V gene-matched recombinant chimeric anti-type VII collagen autoantibodies of the four human IgG subclasses. Binding specificities and avidities of all four autoantibodies were comparable. Using ex vivo models, our results demonstrate that a monoclonal autoantibody is sufficient to activate complement and to induce dermal-epidermal separation. However, only IgG1 and IgG3, but not IgG2 and IgG4 against type VII collagen, were pathogenic in our ex vivo model systems. To our knowledge, this is the first time that a full-length recombinant disease-related human autoantibody has been investigated. Our results demonstrate the usefulness of recombinant antibody technology to dissect the contribution of F(ab')(2) and Fc portions of autoantibodies to their biological effects. These findings may eventually contribute to novel diagnostic tools for monitoring disease and to the development of more specific therapies in autoantibody-mediated diseases, i.e. the generation of subclass-specific adsorbers, used for extracorporal immunoapheresis, or the shifting of the autoimmune response to production of non-pathogenic autoantibodies.

As the proportion of physicians who enter residency training in family practice steadily increases, so does the need to evaluate the impact of their training and postgraduate education on the quality of care in their practices. We audited the practices of 120 randomly selected family physicians in Ontario, who were separated into four groups: nonmembers of the College of Family Physicians of Canada (CFPC), members of the CFPC with no certification in family medicine, certificated members without residency training in family medicine and certificated members with residency training in family medicine. The practices were assessed according to predetermined criteria for charting, procedures in periodic health examination, quality of medical care and use of indicator drugs. Generally the scores were significantly higher for CFPC members with residency training in family medicine than for those in the other groups, nonmembers having the lowest scores. Patient questionnaires indicated no difference in satisfaction with specific aspects of care between the four groups. Self-selection into residency training and CFPC membership may account for some of the results; nevertheless, the findings support the contention that residency training in family medicine should be mandatory for family physicians.

Obtaining the voluntary participation of family physicians in quality of care research is a major problem in family practice research. An innovative approach was therefore required to recruit 120 randomly selected family physicians in southern Ontario in a quality of care study by the College of Family Physicians of Canada. A network of physician recruiters oriented to the study was organized for each district. This recruitment method resulted in an 84.5% participation rate. The relationship of these physician recruiters to the candidate and the method of approach were important factors in the enrolment process: the highest participation rate (95%) was obtained when the recruiters were friends of the candidate and when a personal meeting was arranged (91%). Recruiters were given an information package to help them in the recruitment process and rated the most useful items as follows: a policy statement about confidentiality, a description of the study and reprints of a published feasibility study. These results illustrate that cooperation in research in family physicians' offices can become a reality.