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16 results

  • Disentangling nature from nurture in examining the interplay between parent–child relationships, ADHD, and early academic attainment
  • R. Sellers, G. T. Harold, A. F. Smith, J. M. Neiderhiser, D. Reiss, D. Shaw, M. N. Natsuaki, A. Thapar, L. D. Leve
  • Journal: Psychological Medicine / Volume 51 / Issue 4 / March 2021
  • Published online by Cambridge University Press: 16 December 2019, pp. 645-652
  • Print publication: March 2021
  • View abstract
    Background

    Attention deficit hyperactivity disorder (ADHD) is highly heritable and is associated with lower educational attainment. ADHD is linked to family adversity, including hostile parenting. Questions remain regarding the role of genetic and environmental factors underlying processes through which ADHD symptoms develop and influence academic attainment.

    Method

    This study employed a parent-offspring adoption design (N = 345) to examine the interplay between genetic susceptibility to child attention problems (birth mother ADHD symptoms) and adoptive parent (mother and father) hostility on child lower academic outcomes, via child ADHD symptoms. Questionnaires assessed birth mother ADHD symptoms, adoptive parent (mother and father) hostility to child, early child impulsivity/activation, and child ADHD symptoms. The Woodcock–Johnson test was used to examine child reading and math aptitude.

    Results

    Building on a previous study (Harold et al., 2013, Journal of Child Psychology and Psychiatry, 54(10), 1038–1046), heritable influences were found: birth mother ADHD symptoms predicted child impulsivity/activation. In turn, child impulsivity/activation (4.5 years) evoked maternal and paternal hostility, which was associated with children's ADHD continuity (6 years). Both maternal and paternal hostility (4.5 years) contributed to impairments in math but not reading (7 years), via impacts on ADHD symptoms (6 years).

    Conclusion

    Findings highlight the importance of early child behavior dysregulation evoking parent hostility in both mothers and fathers, with maternal and paternal hostility contributing to the continuation of ADHD symptoms and lower levels of later math ability. Early interventions may be important for the promotion of child math skills in those with ADHD symptoms, especially where children have high levels of early behavior dysregulation.

  • Why Early Season Weed Control Is Important in Maize
  • Eric R. Page, Diego Cerrudo, Philip Westra, Mark Loux, Kenneth Smith, Chuck Foresman, Harold Wright, Clarence J. Swanton
  • Journal: Weed Science / Volume 60 / Issue 3 / September 2012
  • Published online by Cambridge University Press: 20 January 2017, pp. 423-430
  • View abstract

    Control of early-emerging weeds is essential to protect the yield potential of maize. An understanding of the physiological changes that occur as a result of weed interference is required to address variability in yield loss across sites and years. Field trials were conducted at the University of Guelph (UG), the Ohio State University (OSU), and Colorado State University (CSU) during 2009 and 2010. There were six treatments (season-long weedy and weed-free, and weed control at the 1st-, 3rd-, 5th-, and 10th-leaf-tip stages of maize development) and 20 individual plants per plot were harvested at maturity. We hypothesized that, as weed control was delayed, weed interference in the early stages of maize development would increase plant-to-plant variability in plant dry-matter accumulation, which would result in a reduction of grain yield at maturity. The onset of the critical period for weed control (CPWC) occurred on average between the third and fifth leaf tip stages of development (i.e., V1 to V3, respectively). Rate of yield loss following the onset of the CPWC ranged from 0.05 MG ha−1 d−1 at UG 2009 to 0.22 MG ha−1 d−1 at CSU 2010 (i.e., 0.5 and 1.6% d−1, respectively). On average, reductions in kernel number per plant accounted for approximately 65% of the decline in grain yield as weed control was delayed. Biomass partitioning to the grain was stable through early weed removal treatments, increased and peaked at the 10th-leaf-tip time of control, and decreased in the season-long weedy treatment. Plant-to-plant variability in dry matter at maturity and incidence of bareness increased as weed control was delayed. As weed control was delayed, the contribution of plant-to-plant variability at maturity to the overall yield loss was small, relative to the decline of mean plant dry matter.

  • Chapter 13 - Physician as patient
  • Edited by Antonio Culebras
  • Book: Sleep, Stroke and Cardiovascular Disease
  • Published online: 05 January 2013
  • Print publication: 06 December 2012, pp 151-154
  • View abstract

    Summary

    The mechanism by which patent foramen ovale (PFOs) are associated with ischemic stroke is believed to be paradoxical embolism. It has been observed that people with migraine with aura have a larger than expected concomitant prevalence of PFO compared to people without migraine. Transient global amnesia is considered to have a similar pathophysiology to migraine, and an association with PFO has also been observed. The mechanisms by which obstructive sleep apnea (OSA) increases the risk of ischemic stroke are multiple and all contribute to the ischemic event. As the risk seems associated with the multiple physiological abnormalities that accompany OSA and facilitated by a PFO, stroke prevention could potentially be achieved by improving OSA and reducing the right-to-left shunt treatment, antithrombotic therapy, PFO closure. Antithrombotic therapy should be given as well, in light of the greater overall cardiovascular risk.
Sleep Medicine
  • Sleep Medicine
  • Edited by Harold R. Smith, Cynthia L. Comella, Birgit Högl
  • Published online: 08 August 2009
  • Print publication: 10 April 2008
  • View description
    Sleep disorders exact a high toll on society in terms of diminished quality of life, reduced productivity and cost to medical services. This book guides the reader through the basic science of sleep and how to evaluate individuals suffering from sleep irregularities. Complex features of sleep disorders are then discussed, including parasomnias, sleep apnea, night terrors and restless legs syndrome. The book also looks at how these sleep abnormalities can affect individuals with other psychiatric disorders such as epilepsy, depression and anxiety disorders. Covering disorders from insomnia to narcolepsy, and specialty areas from pediatric to geriatric, this wide ranging and accessible guide allows non-sleep specialists to approach and understand important information that is clinically relevant in everyday practice. Illustrated with summary tables, figures and treatment algorithms, this book will be a useful guide for neurologists, psychiatrists, psychologists, pulmonologists and internists as well as health care professionals in training.
  • Introduction: the basic neurology of sleep
  • from SECTION 1 - NORMAL SLEEP
  • Edited by Harold R. Smith, University of California, Irvine, Cynthia L. Comella, Birgit Högl
  • Book: Sleep Medicine
  • Published online: 08 August 2009
  • Print publication: 10 April 2008, pp 1-8
  • View extract

    Summary

    Overview

    Sleep is not an inactive state.

    Dating back to early modern classifications of sleep based on electrophysiological measurements, the inherent activities of various neural substrates in sleep have been readily recognized.

    Normal sleep has been classified as having two characteristic divisions: non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. These sleep states are defined by neurophysiological parameters of electroencephalogram (EEG), electrooculogram (EOG), and surface electromyogram (EMG), as detailed by Dr. Billiard in the following chapter. These characteristics clearly distinguish the NREM and REM sleep states from the wakefulness state.

    Behaviorally, sleep is a reversible state characterized by perceptual disengagement and apparent unresponsiveness to the environment with closed eyes, reduced movements, and recumbency. Early behaviorally based studies revealed that even in those with unequivocal electrophysiologic correlates of being asleep, arousal to one's own name and responsiveness to other auditory stimuli persist.

    Additionally, the understanding that continues to evolve of the neurophysiology and neurochemistry of normal sleep suggests that many of the neurologic substrates involved are by no means passive, but rather very active in sleep. An example is the increase in cerebral blood flow that occurs in normal sleep. Both animal and human studies have shown that cerebral blood flow in NREM sleep may increase up to 25% greater than in wakefulness, and up to 80% greater in REM sleep. These changes in cerebral blood flow, at least in part, correlate with concomitant increased brain oxygen metabolism in sleep.

  • SECTION 3 - SLEEP IN SPECIALTY AREAS
  • Edited by Harold R. Smith, University of California, Irvine, Cynthia L. Comella, Birgit Högl
  • Book: Sleep Medicine
  • Published online: 08 August 2009
  • Print publication: 10 April 2008, pp -
  • View abstract

    Summary

    This chapter describes a selection of neurological diseases, those which are most strongly associated with sleep disorders. Certain neurological disorders include Parkinson's disease (PD), stroke, neuromuscular diseases, headache, multiple sclerosis, and epilepsy. Sleep breathing disorders are common in PD. About half of all individuals with PD show obstructive sleep-disordered breathing. Snoring, which almost invariably accompanies obstructive sleep apnea (OSA), is reported to be a risk factor for stroke. The quality of life in those with amyotrophic lateral sclerosis correlates with both daytime respiratory muscle function and polysomnographic indices of nocturnal sleep-related respiratory disturbances. Improved sleep architecture and daytime arterial blood gases, and increased ventilatory response to carbon dioxide, result from nocturnal ventilation in neuromuscular disease. In a study of 14 children with neuromuscular disease, symptoms of daytime sleepiness and headache improved after initiation of non-invasive ventilation. Epileptic seizures during REM sleep are an extremely rare phenomenon.
  • SECTION 2 - SLEEP DISORDERS
  • Edited by Harold R. Smith, University of California, Irvine, Cynthia L. Comella, Birgit Högl
  • Book: Sleep Medicine
  • Published online: 08 August 2009
  • Print publication: 10 April 2008, pp -
  • View abstract

    Summary

    Parasomnias involve automatic behavior, i.e., seemingly goal-directed, complex purposeful behaviors enacted without the conscious awareness and volition of the individual, who cannot exercise conscious deliberate control over his or her behaviors and sleep-related experiences. It could be subdivided by taking into account the motoric versus autonomic/ sensory activation. This chapter deals with the most common disorders, covering the appropriate diagnostic and therapeutic strategies. Disorders of arousal include sleepwalking or somnambulism, sleep terrors, and confusional arousals. The pathophysiology of REM sleep behavior disorder (RBD) lies in a dysfunction of the brainstem structures modulating REM sleep. Enuresis consists of recurrent involuntary urination during sleep. It includes primary forms, where bladder control has never been achieved, and secondary variants occurring after a period of bladder control. Catathrenia, also known as nocturnal groaning or expiratory vocalization during sleep, consists of the emission of an unusual expiratory noise occurring in bursts without associated motor phenomena.