Exploring Hippocampal Structural Differences in Habitual vs Non-habitual Nappers During Early Childhood

During sleep, memories become less vulnerable to interference, both during overnight sleep and naps. Previous research in adults suggests this effect is partially due to a “transfer” of memories from hippocampus to cortex, but there is little research investigating this process in children. Existing literature suggests habitually napping children need naps more than non-habitually napping children because their hippocampus is less mature. This study examines the relation between habitual versus non-habitual nappers and the hippocampus in early childhood. The participants are part of a larger ongoing study, from which we had 21 participants (Mage= 4.49 years, SD=0.51, 9 female). Of the 21 participants, 8 were nappers (napped 5+ days/week) and 13 were non-nappers (napped <5 days/week). Hippocampal volumes were extracted from T1 weighted MRI scans via FreeSurfer 6.0.0 and refined with a Segmentation Adapter Tool (Morey et al., 2009). Subregions of hippocampal head, body, and tail were identified via standard anatomical landmarks (Watson et al., 1992; Weiss et al., 2005). Preliminary analyses examined possible confounding differences between groups (age, sex, and intercranial volume). There were no differences, thus these measures were not controlled for. Results showed significant differences in hippocampal tail volumes. In the left hemisphere, nappers had larger volumes than non-nappers. Although these are preliminary results, the findings support that variation in hippocampal development may relate to nap status in developing children. Future research will focus on increased sample sizes and investigate other brain regions to determine the specificity of these effects.National Institute of Health (NIH), National Science Foundation (NSF

Relations Between Hippocampal Volume and Story Recall in Early Childhood

Research in adults and children suggest the hippocampus plays an important role in verbal memory (Ezzati et al., 2015; Gold & Trauner, 2014). However, links between verbal memory and the hippocampus in younger children remain relatively under investigated. This relation is important to study during early childhood (i.e., before 6 years) for at least two reasons. First, memory changes rapidly during this time and second, research in children suggests that age- related differences exist between memory and hippocampal subregion volumes (e.g. Riggins et al., 2015; Allard, Canada, & Riggins, March 2019). The current study addresses a gap in the literature by investigating the potential relation between hippocampal subregion volumes and verbal memory in early childhood. A total of 200 children, aged 4-8 years old (mean age=6.21 years, SD=0.11), were enrolled in a larger study on hippocampal memory development. Of these, 177 provided usable behavioral and MRI data. To assess verbal memory performance in these children, the stories subtest of the Children's Memory Scale was administered (Cohen, 1997). In the task, participants heard two stories read aloud by a researcher and were then asked to recall those stories immediately after hearing them, again one hour later, and again one week later. For the current study, analyses focused on the hour-delay performance in order to assess long term memory without the additional prompting that happened before the week-delay performance. Performance on the task was determined by the number of remembered verbatim story units. The maximum number of stories units to be remembered was 57 for both stories heard. Approximately one week following the verbal memory task, a T1-weighted structural MRI scan (0.9 mm3) was obtained. Hippocampal volumes were estimated via Freesurfer v5.1 (Fischl, 2012) and refined using ASAT (Wang et al., 2011). Hippocampal volumes were then divided into subregions (head, body, tail) using standard anatomical landmarks (Weiss, Dewitt, Goff, Ditman, & Heckers, 2005; Watson et al., 1992). Initial analyses examining hippocampal volume and verbal memory performance was non- significant. However, when a median age split was conducted, preliminary findings assessing relations between recall and hippocampal volumes revealed that younger (4- 6.13 years), but not older children (6.14-9 years) showed a significant positive relation between number of story units recalled and volume of the left hippocampal body (r=0.244, n=79, p=0.028). These findings are consistent with previous research that suggests developmental differences exist in brain-behavior relations during early childhood. It also supports the notion that a mature hippocampus is not necessarily larger in size (Riggins et al., 2015). These results reinforce an emerging body of work that propose age-related differences in associations between memory and hippocampal subregion volumes during development. Specifically, these results are consistent with previous findings that showed age-related differences between hippocampal body and performance on a visual spatial memory task and source memory in younger but not older children (Allard, Canada, & Riggins, March 2019; Riggins et al., 2015).Neurocognitive Development Lab and NIH Grant RO1 5205310 (TR)

Le musée, un lieu éducatif

This anthology contains essays on various aspects of museum education, by 35 members of the Special Interest Group on Education and Museums (SIGEM). Originally presented at a conference held in Montreal in 1995, the essays in this book address a wide range of issues related to the educational function of museums. Topics discussed include: educational, scientific and museological research; the value of guided tours and visual arts workshops; the question of evaluation; and relationships between museums and schools. 21 diagrams and 19 charts. 4 texts in English 31 texts in French. Circa 480 bibl. ref

Is nap status related to memory, sleep physiology, and the hippocampus in early childhood?

Research suggests there may be links between developmental changes in sleep (e.g., transition out of a nap), memory, and brain (specifically, hippocampus). The purpose of this investigation was to explore differences in sleep physiology, visuospatial memory, and hippocampal volume based on nap status. Participants were 3 to 5-year-old children (n=51) who were habitual nappers (napping >5 days/week), semi-habitual nappers (3–4 days/week), or non-nappers (<2 days/week). Participants completed a memory task before and after a wake and nap session. Polysomnography (PSG) and hippocampal volumes were also assessed. Findings demonstrated that, regardless of nap status, children performed better on a memory task following a nap. PSG revealed that habitual nappers spent marginally more time in nREM2 sleep and less time in SWS compared to semi-habitual nappers. Finally, non-nappers demonstrated a larger hippocampus than the other groups. These findings support the suggestion that developmental differences in these domains are related during childhood

Relations Between Latent Episodic Memory, Nap Habituality, and the Cortex During Childhood

During childhood, episodic memory demonstrates marked improvements that are supported by the protracted development of the hippocampus and a larger network of cortical regions. To date, most research has focused on associations with the hippocampus in this age group. Few studies have explored the contribution of cortical regions and no studies have explored this longitudinally. Thus, the first aim of this dissertation was to examine the longitudinal co-development of cortical thickness and surface area in memory-related cortical regions with a latent episodic memory variable in 4- to 8-year-old children (N = 177). Findings, uncorrected for multiple comparisons, demonstrated that a thinner cortex in multiple episodic memory network regions (i.e., inferior frontal gyrus, inferior parietal sulcus, lingual gyrus, middle temporal gyrus, precuneus, lateral occipital cortex, superior frontal gyrus, superior parietal lobule, superior temporal gyrus, and temporal pole) at age 4 predicted more rapid improvements in memory performance from age 4 to 6 years. Similarly, greater surface area in the precuneus and less surface area in the medial orbitofrontal gyrus at age 4 also predicted more rapid improvements in memory performance from age 4 to 6 years. Additionally, results revealed that several regions demonstrate parallel co-development with latent episodic memory performance from age 4 to 8 years. Specifically, greater changes in cortical thickness and surface area of the entorhinal cortex were associated with greater changes in memory from age 4 to 6 years. Furthermore, cortical thickness of entorhinal cortex and surface area of anterior cingulate cortex, entorhinal cortex, inferior parietal sulcus, lingual gyrus, and superior temporal gyrus showed co-development with latent episodic memory from age 6 to 8 years. Together, these findings suggest that cortical thickness and surface area of the episodic memory network support improvements in memory performance during childhood. However, these findings did not survive correction for multiple comparisons. Although age-related differences were one focus of this investigation, individual differences were another. Specifically, during childhood children transition away from afternoon napping. This transition has previously been associated with differences in memory consolidation abilities and hippocampal maturation. These associations suggest that habitual nappers require more regular sleep to consolidate memories due to an immature episodic memory network. However, limited work has examined these associations outside the hippocampus. Therefore, the second aim of this dissertation was to examine whether regions that support longitudinal memory development differ as a function of nap habituality (N = 44). Findings revealed significant differences in cortical thickness of right inferior frontal gyrus and surface area of lateral occipital cortex, such that non-nappers demonstrated a thinner cortex and greater surface area in these regions compared to nappers, though these findings did not survive correction for multiple comparisons. Thus, although there is some evidence that memory-related cortical regions may differ based on nap habituality, additional work is needed to support this claim. Together this dissertation provides new data on the co-development of memory with brain structure in the episodic memory network and identifies individual differences that may be associated with these brain structures

Klimaattop Noord 2019

Organisator en presentator op een sessie over klimaatadaptatie samen met de gemeente Groningen, Van Hall Larenstein en een ingenieur van PolyCiviel en Ohpen. Doel van de sessie was het inzicht geven in de ontwerpopgave rondom adaptatie in de publieke ruimte (Gemeente), de technische maatregelen (Polyciviel) en de beleidskundige opgave (VHL/Hanze). Hierbij heeft de Hanze door middel van een rollenspel de kansen en barrières van adaptatie inzichtelijk gemaakt. Het doel van deze sessie was om samen meer inzicht te krijgen in hoe we ons aan het veranderend klimaat kunnen aanpassen

Modelling potential potato yields: Accounting for experimental differences in modern cultivars

Current potential yield simulations of potato crops can be lower than actual yields observed in fields and the potential yield simulations miss important cultivar differences, for instance in terms of cultivar earliness. This causes issues not only for potential yield simulations but also when estimating the limiting effects of water (and nitrogen) and yield gaps in farmers’ fields. To address this issue, we recalibrated potential yield simulations with WOFOST for five commercial Dutch potato cultivars. An experiment conducted during the 2020 season was used for model calibration while the 2019 version of the same experiment was used for evaluation. The focus of the calibration was on phenology, photosynthesis, and biomass allocation. To aid the latter, the WOFOST biomass allocation table functions were replaced with sigmoid functions and biomass reallocation from haulm to tubers was introduced. In total 19 parameters were adjusted and/or introduced. Twelve of these parameters were not cultivar-specific, e.g. the specific leaf area over the plant developmental stage (SLATB), and the maximum leaf CO2 assimilation rate as function of developmental time (AMAXTB). Seven parameters differed between the cultivars, e.g. the thermal time between emergence and tuber initiation (TSUM1), and most of these were correlated to cultivar earliness. For the calibration year, final yields were underestimated by on average 5.4%, while for the evaluation year the final yield was overestimated by 4.4%. In comparison, the final dry matter yields ranged from 16.4 to 18.5 t ha−1 in 2019 and 15.5–17.5 t ha−1 in 2020. The old WOFOST parameters for potato resulted in an underestimation of 23.7% and 28.7% for, respectively, 2019 and 2020. Improving the parameter sets greatly increased accuracy of the simulations and provided insight in which parameters are cultivar specific and related to cultivar-earliness

A complex double deletion in LMNA underlies progressive cardiac conduction disease, atrial arrhythmias, and sudden death

Background-Cardiac conduction disease is a clinically and genetically heterogeneous disorder characterized by defects in electrical impulse generation and conduction and is associated with sudden cardiac death. Methods and Results-We studied a 4-generation family with autosomal dominant progressive cardiac conduction disease, including atrioventricular conduction block and sinus bradycardia, atrial arrhythmias, and sudden death. Genome-wide linkage analysis mapped the disease locus to chromosome 1p22-q21. Multiplex ligation-dependent probe amplification analysis of the LMNA gene, which encodes the nuclear-envelope protein lamin A/C, revealed a novel gene rearrangement involving a 24-bp inversion flanked by a 3.8-kb deletion upstream and a 7.8-kb deletion downstream. The presence of short inverted sequence homologies at the breakpoint junctions suggested a mutational event involving serial replication slippage in trans during DNA replication. Conclusions-We identified for the first time a comple