1,675 research outputs found

    Testosterone Trajectories and Reference Ranges in a Large Longitudinal Sample of Male Adolescents

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    Pubertal dynamics plays an important role in physical and psychological development of children and adolescents. We aim to provide reference ranges of plasma testosterone in a large longitudinal sample. Furthermore, we describe a measure of testosterone trajectories during adolescence that can be used in future investigations of development.We carried out longitudinal measurements of plasma testosterone in 2,216 samples obtained from 513 males (9 to 17 years of age) from the Avon Longitudinal Study of Parents and Children. We used integration of a model fitted to each participant's testosterone trajectory to calculate a measure of average exposure to testosterone over adolescence. We pooled these data with corresponding values reported in the literature to provide a reference range of testosterone levels in males between the ages of 6 and 19 years.The average values of total testosterone in the ALSPAC sample range from 0.82 nmol/L (Standard Deviation [SD]: 0.09) at 9 years of age to 16.5 (SD: 2.65) nmol/L at 17 years of age; these values are congruent with other reports in the literature. The average exposure to testosterone is associated with different features of testosterone trajectories such as Peak Testosterone Change, Age at Peak Testosterone Change, and Testosterone at 17 years of age as well as the timing of the growth spurt during puberty.The average exposure to testosterone is a useful measure for future investigations using testosterone trajectories to examine pubertal dynamics

    A Longitudinal Investigation of Predictors of the Association Between Age 3 and Age 6 Behavioural Inhibition.

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    Children who exhibit elevated levels of the temperament trait behavioural inhibition (BI) across time may be at greatest risk for anxiety. However, little research has investigated the influence of other temperamental traits, particularly positive emotionality (PE), on the continuity of BI in childhood, nor whether parental overprotection influences associations between early and later child BI. To explore whether PE and overprotection shape associations between early and later BI, this longitudinal study of three-year-olds

    Vertical integration and firm boundaries : the evidence

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    Since Ronald H. Coase's (1937) seminal paper, a rich set of theories has been developed that deal with firm boundaries in vertical or input–output structures. In the last twenty-five years, empirical evidence that can shed light on those theories also has been accumulating. We review the findings of empirical studies that have addressed two main interrelated questions: First, what types of transactions are best brought within the firm and, second, what are the consequences of vertical integration decisions for economic outcomes such as prices, quantities, investment, and profits. Throughout, we highlight areas of potential cross-fertilization and promising areas for future work

    The temporal relationship between local school closure and increased incidence of pediatric diabetic ketoacidosis

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    IMPORTANCE: The incidence of pediatric diabetic ketoacidosis (DKA) increased early in the COVID-19 pandemic, but the relative contribution of behavioral changes and viral-related pathophysiology are unknown. OBJECTIVE: To evaluate the relationship between school closure date and onset of increased DKA to help clarify the etiology of the increased incidence. DESIGN: A multi-center, quality-controlled Pediatric Intensive Care Unit (PICU) database was used to identify the number of admissions to a participating PICU with DKA on each calendar day from 60 days before local school closure to 90 days after, and compared to baseline data from the same periods in 2018-2019. Interrupted time series and multiple linear regression analyses were used to identify admission rates that differed significantly between 2020 and baseline. SETTING: Eighty-one PICUs in the United StatesParticipants: Children ages 29 days to 17 years admitted to a PICU with DKAExposures: Statewide school closureMain outcome/measure: Rate of admission to the PICU for DKA. RESULTS: There were 1936 admissions for children with DKA in 2020 and 1795 admissions/year to those same PICUs in 2018-2019. Demographics and clinical outcomes did not differ before school closure, but pandemic-era patients were less often white and had longer hospital length of stay in the post-school closure period. The difference between 2020 admissions and 2018-2019 admissions was not different than zero before school closure, and significantly higher than zero after school closure, but was significantly increased in 2020 at \u3e30 days after school closure ( CONCLUSIONS/RELEVANCE: An increase in pediatric DKA admissions began one month after school closures. Given that behavioral changes started near school closure dates and viral activity peaked weeks after, this suggests that behavioral factors may not be the primary etiology and it is possible that SARS-CoV-2 infection may have direct effects on pediatric DKA

    Resource: A multi‐species multi‐timepoint transcriptome database and webpage for the pineal gland and retina

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    The website and database https://snengs.nichd.nih.gov provides RNA sequencing data from multi-species analysis of the pineal glands from zebrafish (Danio rerio), chicken (White Leghorn), rat (Rattus novegicus), mouse (Mus musculus), rhesus macaque (Macaca mulatta), and human (Homo sapiens); in most cases, retinal data are also included along with results of the analysis of a mixture of RNA from tissues. Studies cover day and night conditions; in addition, a time series over multiple hours, a developmental time series and pharmacological experiments on rats are included. The data have been uniformly re-processed using the latest methods and assemblies to allow for comparisons between experiments and to reduce processing differences. The website presents search functionality, graphical representations, Excel tables, and track hubs of all data for detailed visualization in the UCSC Genome Browser. As more data are collected from investigators and improved genomes become available in the future, the website will be updated. This database is in the public domain and elements can be reproduced by citing the URL and this report. This effort makes the results of 21st century transcriptome profiling widely available in a user-friendly format that is expected to broadly influence pineal research.Fil: Chang, Eric. National Instituto of Child Health & Human Development; Estados UnidosFil: Fu, Cong. National Instituto of Child Health & Human Development; Estados UnidosFil: Coon, Steven L.. National Instituto of Child Health & Human Development; Estados UnidosFil: Alon, Shahar. No especifĂ­ca;Fil: Bozinoski, Marjan. No especifĂ­ca;Fil: Breymaier, Matthew. National Instituto of Child Health & Human Development; Estados UnidosFil: Bustos, Diego Martin. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Clokie, Samuel J.. National Instituto of Child Health & Human Development; Estados UnidosFil: Gothilf, Yoav. No especifĂ­ca;Fil: Esnault, Caroline. National Instituto of Child Health & Human Development; Estados UnidosFil: Iuvone, P. Michael. Emory University School of Medicine; Estados UnidosFil: Mason, Christopher E.. No especifĂ­ca;Fil: Ochocinska, Margaret J.. National Instituto of Child Health & Human Development; Estados UnidosFil: Tovin, Adi. No especifĂ­ca;Fil: Wang, Charles. Loma Linda University; Estados UnidosFil: Xu, Pinxian. No especifĂ­ca;Fil: Zhu, Jinhang. No especifĂ­ca;Fil: Dale, Ryan. National Instituto of Child Health & Human Development; Estados UnidosFil: Klein, David C.. National Instituto of Child Health & Human Development; Estados Unido

    The Serotonin Transporter Promoter Polymorphism and Childhood Positive and Negative Emotionality

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    Association studies of the serotonin transporter promoter polymorphism (5-HTTLPR) and negative emotionality (NE) are inconclusive. However, emerging evidence suggests that the association between this polymorphism and NE may be influenced by levels of another temperament trait, positive emotionality (PE). Therefore, this study examined whether the association between the 5-HTTLPR and NE was moderated by PE. A community sample of 413 three-year-old children completed a standardized battery of laboratory tasks designed to tap temperamental emotionality. Children were also genotyped for the 5-HTTLPR. No direct association between 5-HTTLPR genotype and NE was found. However, the interaction of child PE and NE predicted 5-HTTLPR genotype. Furthermore, children with a short allele who were also low in PE had significantly greater NE than children without a short allele or children with high PE. Our findings suggest that the short allele of the 5-HTTLPR is associated with NE only in the context of low PE. Inconsistent links between NE and this gene in previous research may stem from the failure to consider other temperament traits that moderate associations. © 2010 American Psychological Association
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