Temporal reproduction and its neuroanatomical correlates in adults with attention deficit hyperactivity disorder and their unaffected first-degree relatives

Background: Little is known about time perception, its putative role as cognitive endophenotype, and its neuroanatomical underpinnings in adults with attention deficit hyperactivity disorder (ADHD). Method: Twenty adults with ADHD, 20 unaffected first-degree relatives and 20 typically developing controls matched for age and gender undertook structural magnetic resonance imaging scans. Voxel-based morphometry with DARTEL was performed to obtain regional grey-matter volumes. Temporal processing was investigated as a putative cognitive endophenotype using a temporal reproduction paradigm. General linear modelling was employed to examine the relationship between temporal reproduction performances and grey-matter volumes. Results: ADHD participants were impaired in temporal reproduction and unaffected first-degree relatives performed in between their ADHD probands and typically developing controls. Increased grey-matter volume in the cerebellum was associated with poorer temporal reproduction performance. Conclusions: Adults with ADHD are impaired in time reproduction. Performances of the unaffected first-degree relatives are in between ADHD relatives and controls, suggesting that time reproduction might be a cognitive endophenotype for adult ADHD. The cerebellum is involved in time reproduction and might play a role in driving time performances

VO2, Liking, and Relative Reinforcing Value of Cooperative and Competitive Exergame Play in Young Children

International Journal of Exercise Science 13(5): 1501-1511, 2020. The purpose of the current study was to examine physiologic response, liking, and relative reinforcing value (RRV) of children playing an exergame with a friend under two goal structures: competitive and cooperative. A sample of twenty participants (8.7 ± 1.3 years old) and a self-selected friend completed three conditions: rest, competitive, and cooperative play. During the competitive condition, participants played Nintendo Wii Tennis® against their friend. During cooperative play, participants and their friend played together against a computer avatar. During each condition, oxygen consumption (VO2, ml∙kg-1∙min-1) and liking (visual analog scale) were recorded. After finishing all conditions, children completed an RRV computer task to assess their motivation to play the competitive versus cooperative goal structures. During this task children performed work (button presses) to participate in additional competitive play, cooperative play, or a combination. The output maximum (Omax), or maximum work for each goal structure, was used as the measure of RRV. It was determined that VO2 was significantly (p ≤ 0.001) greater for cooperative and competitive play than rest. Liking was significantly greater for cooperative play than rest (p ≤ 0.001) and competitive play (p = 0.03). There were no significant differences (p \u3e 0.05) between cooperative and competitive play for VO2 or Omax. In conclusion, while liking was greater for the cooperative condition versus competitive, motivation did not differ between goal structures. Further investigation into methods of making physical activity more reinforcing, in addition to well-liked by children, is necessary to optimize this behavior

Observations and a model of net calcification declines in Palau's largest coral reef lagoon between 1992 and 2015

Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 125(8), (2020): e2020JC016147, doi:10.1029/2020JC016147.Net ecosystem calcification (NEC) rates of Palau's largest lagoon and barrier reef system between 1992 and 2015 are estimated from sparse total alkalinity (TA) and salinity measurements and a tidal exchange model in which surface lagoon water transported offshore on the ebb tide is replaced by saltier (denser) ocean water that sinks to the bottom after entering the lagoon on the flood tide. Observed lagoon salinities are accurately reproduced by the model with no adjustable parameters. To accurately reproduce observed lagoon TA, NEC for the lagoon‐barrier reef system was 70 mmols m−2 day−1 from 1992 to 1998, 35 mmols m−2 day−1 from 1999 to 2012, and 25 mmols m−2 day−1 from 2013 to 2015. This indicates that Palau's largest lagoon and barrier reef system has not recovered, as of 2015, from the 50% decline in NEC in 1998 caused by the loss of coral cover following a severe bleaching event. The cause of the further decline in NEC in 2012–2013 is unclear. Lagoon residence times vary from 8 days during spring tides to 14 days during neap tides and drive substantial spring‐neap variations in lagoon TA (~25% of the mean salinity‐normalized ocean‐lagoon TA difference). Sparse measurements that do not resolve these spring‐neap variations can exhibit apparent long‐term variations in alkalinity that are not due to changes in NEC.This work was partially supported by NSF award 1220529 to A.L.C., S.J.L., and K.E.F.S and NSF award 1737311 to A.L.C. and the Oceanography Department, Texas A&M University K.E.F.S.2021-01-0

Which executive functioning deficits are associated with AD/HD, ODD/CD and comorbid AD/HD+ODD/CD?

Item does not contain fulltextThis study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3)~whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99~children ages 6–12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).17 p

The relationship between core symptoms of ADHD and the Cognitive Reflection Test in a non-clinical sample.

INTRODUCTION: Attention Deficit and Hyperactivity Disorder (ADHD) symptoms are frequently linked to executive function deficits. There is reason to believe that these deficits may give rise to problems with complex reasoning and problem solving. METHODS: Eighty-six men (N = 45) and women (N = 41) completed a self-report measure to assess ADHD symptoms, along with a complex reasoning task; the Cognitive Reflection Test (CRT). IQ was also tested due to its covariance with reasoning ability. RESULTS: Analysis suggested that all three symptoms of ADHD (inattention, hyperactivity, and impulsivity) are negatively related to performance on the CRT, however, only inattention significantly contributed to a model that predicted CRT performance. CONCLUSIONS: Of the three core symptoms of ADHD, inattention is the most important for reasoning ability. Results are discussed with reference to an executive function model of ADHD, with particular emphasis on the role of working memory in inattention

Twist and writhe dynamics of stiff filaments

This letter considers the dynamics of a stiff filament, in particular the coupling of twist and bend via writhe. The time dependence of the writhe of a filament is $W_r^2\sim L t^{1/4}$ for a linear filament and $W_r^2\sim t^{1/2} / L$ for a curved filament. Simulations are used to study the relative importance of crankshaft motion and tube like motion in twist dynamics. Fuller's theorem, and its relation with the Berry phase, is reconsidered for open filamentsComment: 7 Pages with 2 figure

The Physiologic and Behavioral Implications of Playing Active and Sedentary Video Games in a Seated and Standing Position

International Journal of Exercise Science 7(3) : 194-201, 2014. Previous studies have assessed physiologic response while playing video games per manufacturer instructions with participants standing during active video game play and seated during sedentary game play. It is not known whether an assigned seated or standing position affects positional preference and oxygen consumption (VO2) while gaming. The purpose of the study was to assess VO2 and preference of playing active and sedentary video games in a seated and standing position. VO2 was assessed in 25 participants during four, 20-minute conditions; resting, PlayStation 2 Madden NFL Football 2011, Nintendo Wii-Sports Boxing and Nintendo Wii Madden NFL Football 2011. Each condition was divided into two positional conditions (10 minutes seated, 10 minutes standing) and each participant indicated their positional preference after each 20-minute condition. Standing VO2 (4.4 ± 0.2 ml•kg-1•min-1 PS2, 4.6 ± 0.1 ml•kg-1•min-1 Wii Madden, 6.8 ± 0.3 ml•kg-1•min-1Wii Boxing) was significantly (p ≤ 0.001) greater than seated VO2 (4.0 ± 0.1 ml•kg-1•min-1 PS2, 4.2 ± 0.1 ml•kg-1•min-1 Wii Madden, 6.1 ± 0.3 ml•kg-1•min-1Wii Boxing) for each gaming condition. Participants preferred (p ≤ 0.001) to sit for all gaming conditions except Wii Boxing. Playing video games while standing increases VO2 to a greater extent than playing the same games in a seated position. Standing was only preferred for the most physiologically challenging game, Wii Boxing. Gaming position should be considered when assessing the physiologic and behavioral outcomes of playing video games

Theory of spiral wave dynamics in weakly excitable media: asymptotic reduction to a kinematic model and applications

In a weakly excitable medium, characterized by a large threshold stimulus, the free end of an isolated broken plane wave (wave tip) can either rotate (steadily or unsteadily) around a large excitable core, thereby producing a spiral pattern, or retract causing the wave to vanish at boundaries. An asymptotic analysis of spiral motion and retraction is carried out in this weakly excitable large core regime starting from the free-boundary limit of the reaction-diffusion models, valid when the excited region is delimited by a thin interface. The wave description is shown to naturally split between the tip region and a far region that are smoothly matched on an intermediate scale. This separation allows us to rigorously derive an equation of motion for the wave tip, with the large scale motion of the spiral wavefront slaved to the tip. This kinematic description provides both a physical picture and exact predictions for a wide range of wave behavior, including: (i) steady rotation (frequency and core radius), (ii) exact treatment of the meandering instability in the free-boundary limit with the prediction that the frequency of unstable motion is half the primary steady frequency (iii) drift under external actions (external field with application to axisymmetric scroll ring motion in three-dimensions, and spatial or/and time-dependent variation of excitability), and (iv) the dynamics of multi-armed spiral waves with the new prediction that steadily rotating waves with two or more arms are linearly unstable. Numerical simulations of FitzHug-Nagumo kinetics are used to test several aspects of our results. In addition, we discuss the semi-quantitative extension of this theory to finite cores and pinpoint mathematical subtleties related to the thin interface limit of singly diffusive reaction-diffusion models

Bringing Agriculture into the GATT: Designing Acceptable Agricultural Policies

Agricultural and Food Policy, International Relations/Trade,