scholarly journals Introduction. Contending with the Hourglass: Time, Reproduction, and the Problematization of Ageing

2021 ◽  
Vol 42 (1) ◽  
pp. 1-9
Author(s):  
Anindita Majumdar
Keyword(s):  

.

2021 ◽  
Vol 24 ◽  
pp. S114
Author(s):  
S. Emerson ◽  
K. Johnston ◽  
A. Howarth ◽  
J. Schneider ◽  
M. Friesen ◽  
...  

1997 ◽  
Vol 3 (4) ◽  
pp. 359-369 ◽  
Author(s):  
RUSSELL A. BARKLEY ◽  
SETH KOPLOWITZ ◽  
TAMARA ANDERSON ◽  
MARY B. McMURRAY

A recent theory of ADHD predicts a deficiency in sense of time in the disorder. Two studies were conducted to test this prediction, and to evaluate the effects of interval duration, distraction, and stimulant medication on the reproductions of temporal durations in children with ADHD. Study I: 12 ADHD children and 26 controls (ages 6–14 years) were tested using a time reproduction task in which subjects had to reproduce intervals of 12, 24, 36, 48, and 60 s. Four trials at each duration were presented with a distraction occurring on half of these trials. Control subjects were significantly more accurate than ADHD children at most durations and were unaffected by the distraction. ADHD children, in contrast, were significantly less accurate when distracted. Both groups became less accurate with increasing durations to be reproduced. Study II: Tested three doses of methylphenidate (MPH) and placebo on the time reproductions of the 12 ADHD children. ADHD children became less accurate with increasing durations and distraction was found to reduce accuracy at 36 s or less. No effects of MPH were evident. The results of these preliminary studies seem to support the prediction that sense of time is impaired in children with ADHD. The capacity to accurately reproduce time intervals in ADHD children does not seem to improve with administration of stimulant medication. (JINS, 1997, 3, 359–369.)


BMJ Open ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. e050346
Author(s):  
Daniel J Laydon ◽  
Swapnil Mishra ◽  
Wes R Hinsley ◽  
Pantelis Samartsidis ◽  
Seth Flaxman ◽  
...  

ObjectiveTo measure the effects of the tier system on the COVID-19 pandemic in the UK between the first and second national lockdowns, before the emergence of the B.1.1.7 variant of concern.DesignThis is a modelling study combining estimates of real-time reproduction number Rt (derived from UK case, death and serological survey data) with publicly available data on regional non-pharmaceutical interventions. We fit a Bayesian hierarchical model with latent factors using these quantities to account for broader national trends in addition to subnational effects from tiers.SettingThe UK at lower tier local authority (LTLA) level. 310 LTLAs were included in the analysis.Primary and secondary outcome measuresReduction in real-time reproduction number Rt.ResultsNationally, transmission increased between July and late September, regional differences notwithstanding. Immediately prior to the introduction of the tier system, Rt averaged 1.3 (0.9–1.6) across LTLAs, but declined to an average of 1.1 (0.86–1.42) 2 weeks later. Decline in transmission was not solely attributable to tiers. Tier 1 had negligible effects. Tiers 2 and 3, respectively, reduced transmission by 6% (5%–7%) and 23% (21%–25%). 288 LTLAs (93%) would have begun to suppress their epidemics if every LTLA had gone into tier 3 by the second national lockdown, whereas only 90 (29%) did so in reality.ConclusionsThe relatively small effect sizes found in this analysis demonstrate that interventions at least as stringent as tier 3 are required to suppress transmission, especially considering more transmissible variants, at least until effective vaccination is widespread or much greater population immunity has amassed.


2005 ◽  
Vol 62 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Nathalie Chèvre ◽  
Alessandra R. Brazzale ◽  
Kristin Becker-van Slooten ◽  
Renata Behra ◽  
Joseph Tarradellas ◽  
...  

2007 ◽  
Vol 55 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Danuza Nogueira Moysés ◽  
Andréa de Oliveira R. Junqueira ◽  
Helena Passeri Lavrado ◽  
Sérgio Henrique Gonçalves da Silva

This paper introduces a method for temporal studies of steep rocky intertidal communities. It combines the use of digital image technology with field methodology, so that a wide area of the community can be sampled in a short time. Two current nondestructive percent cover estimation methods (visual estimation and point intersection) were compared in terms of cost, operational advantages and data quality, with a proposed method for a sucessional study . The proposed method used sequential photos to sample multiple fixed vertical transects over time. Reproduction of the mid-intertidal transect over time was possible by overlaying temporal transects in an image editing program. This method was similar to the point intersection quadrat method used to estimate percent cover. Benefits included reduced time on field work, economic advantages and other advantages of using digital photography, such as recording. Temporal photography of transects provided measurements of recruitment, mortality and population growth, and made it possible to manufacture an animation of sucessional stages. We suggest that this is the best method for providing information and understanding on the process of succession and for monitoring benthic invertebrate intertidal communities on steep rocky shores.


1995 ◽  
Vol 6 (1) ◽  
pp. 1-25 ◽  
Author(s):  
Jun Ohya ◽  
Yasuichi Kitamura ◽  
Fumio Kishino ◽  
Nobuyoshi Terashima ◽  
Haruo Takemura ◽  
...  

2016 ◽  
Vol 46 (12) ◽  
pp. 2561-2569 ◽  
Author(s):  
V. A. Pironti ◽  
M.-C. Lai ◽  
S. Morein-Zamir ◽  
U. Müller ◽  
E. T. Bullmore ◽  
...  

BackgroundLittle is known about time perception, its putative role as cognitive endophenotype, and its neuroanatomical underpinnings in adults with attention deficit hyperactivity disorder (ADHD).MethodTwenty 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.ResultsADHD 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.ConclusionsAdults 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.


2020 ◽  
Vol 32 (9) ◽  
pp. 1624-1636
Author(s):  
Tadeusz W. Kononowicz ◽  
Tilmann Sander ◽  
Hedderik Van Rijn ◽  
Virginie van Wassenhove

Precise timing is crucial for many behaviors ranging from conversational speech to athletic performance. The precision of motor timing has been suggested to result from the strength of phase–amplitude coupling (PAC) between the phase of alpha oscillations (α, 8–12 Hz) and the power of beta activity (β, 14–30 Hz), herein referred to as α–β PAC. The amplitude of β oscillations has been proposed to code for temporally relevant information and the locking of β power to the phase of α oscillations to maintain timing precision. Motor timing precision has at least two sources of variability: variability of timekeeping mechanism and variability of motor control. It is ambiguous to which of these two factors α–β PAC should be ascribed: α–β PAC could index precision of stopwatch-like internal timekeeping mechanisms, or α–β PAC could index motor control precision. To disentangle these two hypotheses, we tested how oscillatory coupling at different stages of a time reproduction task related to temporal precision. Human participants encoded and subsequently reproduced a time interval while magnetoencephalography was recorded. The data show a robust α–β PAC during both the encoding and reproduction of a temporal interval, a pattern that cannot be predicted by motor control accounts. Specifically, we found that timing precision resulted from the trade-off between the strength of α–β PAC during the encoding and during the reproduction of intervals. These results support the hypothesis that α–β PAC codes for the precision of temporal representations in the human brain.


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