Swede midge (Diptera: Cecidomyiidae) diapause initiation under stable conditions: not a family affair

2019 ◽  
Vol 151 (04) ◽  
pp. 465-474
Author(s):  
Lauren E. Des Marteaux ◽  
Rebecca H. Hallett
Keyword(s):  
Developmental Trajectories ◽  
Mendelian Inheritance ◽  
Developmental Trajectory ◽  
Day Length ◽  
Invasive Pest ◽  
Bet Hedging ◽  
Developmental Variation ◽  
Stable Conditions ◽  
Swede Midge ◽  
Diapause Incidence

AbstractLarvae of the swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), rely on environmental cues to initiate the diapause programme. This facultative diapause strategy, which provides opportunities for both bet hedging and multivoltinism, likely contributed to the successful colonisation and spread of this invasive pest in North America. Population diapause incidence is variable even under relatively stable conditions (especially at the critical day length), yet the mechanisms influencing the developmental trajectory of individuals under such conditions are unknown. Here we approach the non-environmental (i.e., heritable) controls of this variation by comparing diapause frequencies within and among full-sibling swede midge families reared in one of two stable environments. Under warm, long-day conditions > 99% of swede midges pupated directly, while 86% of swede midges entered diapause under cool, short-day conditions. In the latter condition, most families exhibited mixed developmental trajectories (ranging from 36% to 96% diapause). This developmental variation among siblings indicates that the diapause induction threshold does not follow simple Mendelian inheritance with complete dominance for a particular allele, but may follow incomplete dominance or a more complex heredity. Alternatively, within-family diapause variation may result from maternal bet hedging or factors such as maternal age or larval nutrition.

From a molar to a molecular approach to the developmental trajectory of syntax comprehension by persons with intellectual disability

2020 ◽  
Author(s):  
Bruno Facon
Keyword(s):  
Developmental Trajectories ◽  
Developmental Trajectory ◽  
Typically Developing ◽  
Cognitive Level ◽  
Cross Sectional ◽  
Test Items ◽  
Complex Sentences ◽  
Regression Curves ◽  
Cognitive Measure ◽  
Syntactic Skills

The aim was to investigate whether a progressive dissociation between the cognitive level and syntax comprehension occurs during the development of persons with intellectual disabilities (ID). Two cross-sectional developmental trajectory analyses were successively conducted. Study 1 comprised 615 typically developing participants and 615 participants with ID. Their total scores on a syntax comprehension test were regressed on a nonverbal cognitive measure and the slopes of the two groups’ regression lines were compared. In Study 2, logistic regression curves of the two groups for each of the 92 test items were compared. Results showed only negligible between-groups differences of developmental trajectories, whatever the level of analysis. The idea of a progressive dissociation between cognitive level and receptive syntactic skills of people with ID is not confirmed. However, a syntax test evaluating more complex sentences than those used in this study might show such a dissociation.

scholarly journals Cognitive and School Functioning in Children and Adolescents with Chronic Pain: A Critical Review

2010 ◽  
Vol 15 (4) ◽  
pp. 238-244 ◽  
Author(s):  
Bruce D Dick ◽  
Rebecca Pillai Riddell
Keyword(s):  
Chronic Pain ◽  
Cognitive Function ◽  
Children And Adolescents ◽  
School Attendance ◽  
Developmental Trajectories ◽  
Critical Factor ◽  
Developmental Trajectory ◽  
Future Research ◽  
Research Directions ◽  
Future Research Directions

Cognitive function is a critical factor related to a child’s overall developmental trajectory. There is increasing evidence that chronic pain disrupts cognitive function in adults. Little is known about the nature or impact of cognitive disruption in children and adolescents with chronic pain. The present review examines the current literature related to cognitive function in children and adolescents with chronic pain, implications of these findings and future research directions. Nine studies on this topic were found, with a relatively recent increase in publications related to school attendance and subjective studies of school performance. The studies that were found on this topic suggested that chronic pain affects cognitive function in children but the scope of these effects on children’s function and developmental trajectories is not yet clear. While methodological issues surely make it difficult to study cognitive function in children with chronic pain, the potential gains from such research warrant a pursuit of such work. Much remains to be studied on this important topic.

scholarly journals Multidimensional brain-age prediction reveals altered brain developmental trajectory in psychiatric disorders

2020 ◽  
Author(s):  
Xin Niu ◽  
Alexei Taylor ◽  
Russell T. Shinohara ◽  
John Kounios ◽  
Fengqing Zhang
Keyword(s):  
Psychiatric Disorders ◽  
Robust Regression ◽  
Developmental Trajectories ◽  
Brain Structures ◽  
Brain Regions ◽  
Developmental Trajectory ◽  
Imaging Features ◽  
Neuroimaging Data ◽  
Brain Age ◽  
Age Prediction

AbstractBrain regions change in different ways and at different rates. This staggered developmental unfolding is determined by genetics and postnatal experience and is implicated in the progression of psychiatric and neurological disorders. Neuroimaging-based brain-age prediction has emerged as an important new approach for studying brain development. However, the unidimensional brain-age estimates provided by previous methods do not capture the divergent developmental trajectories of various brain structures. Here we propose and illustrate an analytic pipeline to compute an index of multidimensional brain-age that provides regional age predictions. First, using a database of 556 subjects that includes psychiatric and neurological patients as well as healthy controls we conducted robust regression to characterize the developmental trajectory of each MRI-based brain-imaging feature. We then utilized cluster analysis to identify subgroups of imaging features with a similar developmental trajectory. For each identified cluster, we obtained a brain-age prediction by applying machine-learning models with imaging features belonging to each cluster. Brain-age predictions from multiple clusters form a multidimensional brain-age index (MBAI). The MBAI is more sensitive to alterations in brain structures and captured distinct regional change patterns. In particular, the MBAI provided a more flexible analysis of brain age across brain regions that revealed changes in specific structures in psychiatric disorders that would otherwise have been combined in a unidimensional brain age prediction. More generally, brain-age prediction using a subset of homogeneous features circumvents the curse of dimensionality in neuroimaging data.

scholarly journals Germ-layer commitment and axis formation in sea anemone embryonic cell aggregates

2018 ◽  
Vol 115 (8) ◽  
pp. 1813-1818 ◽  
Author(s):  
Anastasia Kirillova ◽  
Grigory Genikhovich ◽  
Ekaterina Pukhlyakova ◽  
Adrien Demilly ◽  
Yulia Kraus ◽  
...  
Keyword(s):  
Normal Development ◽  
Developmental Trajectories ◽  
Embryonic Cell ◽  
Sea Anemone ◽  
Developmental Trajectory ◽  
Nematostella Vectensis ◽  
Axis Formation ◽  
Cell Aggregates ◽  
Embryonic Cells ◽  
Developmental Context

Robust morphogenetic events are pivotal for animal embryogenesis. However, comparison of the modes of development of different members of a phylum suggests that the spectrum of developmental trajectories accessible for a species might be far broader than can be concluded from the observation of normal development. Here, by using a combination of microsurgery and transgenic reporter gene expression, we show that, facing a new developmental context, the aggregates of dissociated embryonic cells of the sea anemone Nematostella vectensis take an alternative developmental trajectory. The self-organizing aggregates rely on Wnt signals produced by the cells of the original blastopore lip organizer to form body axes but employ morphogenetic events typical for normal development of distantly related cnidarians to re-establish the germ layers. The reaggregated cells show enormous plasticity including the capacity of the ectodermal cells to convert into endoderm. Our results suggest that new developmental trajectories may evolve relatively easily when highly plastic embryonic cells face new constraints.

The Cascading Effects of Gross Motor Development and the Impact of Intervention in Early Childhood

2021 ◽  
pp. 1-15
Author(s):  
Ali S. Brian
Keyword(s):  
Early Childhood ◽  
Physical Education ◽  
School Readiness ◽  
Motor Development ◽  
Developmental Trajectories ◽  
Developmental Trajectory ◽  
Gross Motor ◽  
Cascading Effects ◽  
Secular Decline ◽  
Developmental Domains

Today's preschoolers are facing a secular decline with their motor development. Intervention, via physical education in preschool, can be effective to remediate gross motor delays. Teachers need ongoing support in order to intervene. If teachers intervene, children may be placed onto a positive developmental trajectory towards lifespan health. Children's gains in gross motor can transcend into other domains of development. Thus, the author urges early childhood policymakers to strongly consider hiring a licensed physical educator to implement daily physical education to preschoolers to maximize positive developmental trajectories of health. If these policy changes do not occur, children may continue on their secular decline with deleterious consequences across multiple developmental domains and school readiness.

scholarly journals 3279 First in Man

2019 ◽  
Vol 3 (s1) ◽  
pp. 45-45
Author(s):  
Laura Adang ◽  
Francesco Gavazzi ◽  
Valentina De Giorgis ◽  
Micaela De Simone ◽  
Elisa Fazzi ◽  
...  
Keyword(s):  
Skill Acquisition ◽  
Classification System ◽  
Developmental Trajectories ◽  
Spastic Paraparesis ◽  
Altered Mental Status ◽  
Developmental Trajectory ◽  
Global Developmental Delay ◽  
P Value ◽  
Kaplan Meier ◽  
Neurologic Disability

OBJECTIVES/SPECIFIC AIMS: A mimic of congenital infections and a rare genetic cause of interferon overproduction, Aicardi Goutières Syndrome (AGS) results in significant neurologic disability. AGS is caused by pathogenic changes in the intracellular nucleic acid sensing machinery (TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1, and IFIH1). All affected individuals exhibit neurologic impairment: from mild spastic paraparesis to severe tetraparesis and global developmental delay. We hypothesize that genotype influences the heterogeneous developmental trajectory found in AGS. METHODS/STUDY POPULATION: To characterize this spectrum, age and symptoms at presentation and longitudinal developmental skill acquisition was collected from an international cohort of children (n=88) with genetically confirmed AGS. RESULTS/ANTICIPATED RESULTS: We found that individuals present at variable ages, with the largest range in SAMHD1, ADAR, and IFIH1. There are 3 clusters of symptoms at presentation: altered mental status (irritability or lethargy), systemic inflammatory symptoms, and acute neurologic symptoms, with variability across all genotypes. By creating Kaplan-Meier curves for developmental milestones, we were able to create genotype-based developmental trajectories for the children affected by the 5 most common genotypes: TREX1, IFIH1, SAMHD1, ADAR, and RNASEH2B. Individuals with AGS secondary to TREX1 were the most severely affected, significantly less likely to reach milestones compared to the other genotypes, including head control, sitting, and nonspecific mama/dada (p-value <0.005). Individuals affected by SAMHD1, IFIH1, and ADAR collectively attained the most advanced milestones, with 44% of the population achieving a minimum of a single word and 31% able to walk independently. Three retrospective scales were also applied: Gross Motor Function Classification System, Manual Ability Classification Scale, and Communication Function Classification System. Within each genotypic cohort, there was pronounced heterogeneity. DISCUSSION/SIGNIFICANCE OF IMPACT: Our results demonstrate the influence of genotype on early development, but also suggest the importance of other unidentified variables. These results underscore the need for deep phenotyping to better characterize subcohorts within the AGS population.

scholarly journals Developmental trajectory of prehematopoietic stem cell formation from endothelium

Blood ◽  
2020 ◽  
Vol 136 (7) ◽  
pp. 845-856 ◽  
Author(s):  
Qin Zhu ◽  
Peng Gao ◽  
Joanna Tober ◽  
Laura Bennett ◽  
Changya Chen ◽  
...  
Keyword(s):  
Single Cell ◽  
Fetal Liver ◽  
Developmental Trajectories ◽  
Cell Formation ◽  
Intermediate Stage ◽  
Chromatin Accessibility ◽  
Small Population ◽  
Developmental Trajectory ◽  
Mammalian Embryo ◽  
Hematopoietic Stem

Abstract Hematopoietic stem and progenitor cells (HSPCs) in the bone marrow are derived from a small population of hemogenic endothelial (HE) cells located in the major arteries of the mammalian embryo. HE cells undergo an endothelial to hematopoietic cell transition, giving rise to HSPCs that accumulate in intra-arterial clusters (IAC) before colonizing the fetal liver. To examine the cell and molecular transitions between endothelial (E), HE, and IAC cells, and the heterogeneity of HSPCs within IACs, we profiled ∼40 000 cells from the caudal arteries (dorsal aorta, umbilical, vitelline) of 9.5 days post coitus (dpc) to 11.5 dpc mouse embryos by single-cell RNA sequencing and single-cell assay for transposase-accessible chromatin sequencing. We identified a continuous developmental trajectory from E to HE to IAC cells, with identifiable intermediate stages. The intermediate stage most proximal to HE, which we term pre-HE, is characterized by increased accessibility of chromatin enriched for SOX, FOX, GATA, and SMAD motifs. A developmental bottleneck separates pre-HE from HE, with RUNX1 dosage regulating the efficiency of the pre-HE to HE transition. A distal candidate Runx1 enhancer exhibits high chromatin accessibility specifically in pre-HE cells at the bottleneck, but loses accessibility thereafter. Distinct developmental trajectories within IAC cells result in 2 populations of CD45+ HSPCs; an initial wave of lymphomyeloid-biased progenitors, followed by precursors of hematopoietic stem cells (pre-HSCs). This multiomics single-cell atlas significantly expands our understanding of pre-HSC ontogeny.

Perinatal photoperiod organizes adult immune responses in Siberian hamsters (Phodopus sungorus)

2006 ◽  
Vol 290 (6) ◽  
pp. R1714-R1719 ◽  
Author(s):  
Zachary M. Weil ◽  
Leah M. Pyter ◽  
Lynn B. Martin ◽  
Randy J. Nelson
Keyword(s):  
Immune System ◽  
Immune Function ◽  
Breeding Season ◽  
Somatic Growth ◽  
Developmental Trajectory ◽  
Day Length ◽  
Phodopus Sungorus ◽  
Siberian Hamsters ◽  
Time Of Year ◽  
Induced Changes

Individuals of many nontropical rodent species display reproductive, immunological, and somatic responses to day length. In general, short day (SD) lengths inhibit reproduction and enhance immune function in the laboratory when all other conditions are held constant. Most studies to date have focused on seasonal variation in immune function in adulthood. However, perinatal photoperiods also communicate critical day length information and serve to establish a developmental trajectory appropriate for the time of year. Nontropical rodents born early in the breeding season undergo rapid reproductive development, presumably to promote mating success during their first reproductive season. Rodents born late in the breeding season suspend somatic growth and puberty until the following vernal breeding season. We tested the hypothesis that perinatal day lengths have similar enduring effects on the immune system of rodents. Siberian hamsters ( Phodopus sungorus) were maintained prenatally and until weaning (21 days) in either SDs (8 h light:16 h dark) or long days (LD) (16 h light:8 h dark), then they were weaned into either the opposite photoperiod or maintained in their natal photoperiod, forming four groups (LD-LD, LD-SD, SD-LD, and SD-SD). After 8-wk in these conditions, cell-mediated immune activity was compared among groups. SD-SD hamsters of both sexes enhanced immune function relative to all other groups. The reproductive effects of perinatal photoperiod were not evident by the end of the experiment; circulating testosterone and cortisol sampled at the end of the experiment reflected the postweaning, but not the perinatal photoperiod. This experiment demonstrates long-lasting organizational effects of perinatal photoperiod on the rodent immune system and indicates that photoperiod-induced changes in the immune system are dissociable from changes in the reproductive system.

scholarly journals Functional reorganization in the developing lexicon: separable and changing influences of lexical and phonological variables on children's fast-mapping

2012 ◽  
Vol 40 (2) ◽  
pp. 307-335 ◽  
Author(s):  
CRISTINA MCKEAN ◽  
CAROLYN LETTS ◽  
DAVID HOWARD
Keyword(s):  
Word Learning ◽  
Developmental Trajectories ◽  
Developmental Trajectory ◽  
Fast Mapping ◽  
Lexical Knowledge ◽  
Phonotactic Probability ◽  
Cross Sectional ◽  
Functional Reorganization ◽  
Phonological Knowledge ◽  
English Speaking

ABSTRACTNeighbourhood Density (ND) and Phonotactic Probability (PP) influence word learning in children. This influence appears to change over development but the separate developmental trajectories of influence of PP and ND on word learning have not previously been mapped. This study examined the cross-sectional developmental trajectories of influence of PP and ND on fast-mapping in thirty-eight English-speaking children aged 3 ; 01–5 ; 02, in a task varying PP and ND orthogonally. PP and ND exerted separable influences on fast-mapping. Overall, low ND supported better fast-mapping. The influence of PP changed across the developmental trajectory, ‘switching’ from a high to a low PP advantage. A potential explanation for this ‘switch’ is advanced, suggesting that it represents functional reorganization in the developing lexicon, which emerges from changes in the developing lexicon, as phonological knowledge is abstracted from lexical knowledge, over development.

A method for induction and quantification of diapause entry in the swede midge (Diptera: Cecidomyiidae)

2012 ◽  
Vol 144 (6) ◽  
pp. 792-800 ◽  
Author(s):  
Lauren E. Des Marteaux ◽  
Marc B. Habash ◽  
Jonathan M. Schmidt ◽  
Rebecca H. Hallett
Keyword(s):  
Diapause Induction ◽  
Day Length ◽  
Retrieval Method ◽  
Short Day ◽  
Long Day ◽  
Rearing Conditions ◽  
Swede Midge ◽  
Pupal Mortality ◽  
Contarinia Nasturtii ◽  
Cool Conditions

AbstractInduction of diapause under laboratory conditions is a valuable tool for the study of dormancy in economic pests such as the swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae). In the present study, diapause in larval swede midge was achieved via manipulation of rearing photoperiod and temperature. Frequency of diapause was assessed by sieve separation of diapause cocoons from pre-sifted peat substrate following emergence of pupating individuals. Mean diapause frequency for swede midge larvae reared under cool conditions with short day length or cool conditions with decreasing day lengths were 45.2% and 19.5%, respectively. Only 1.2% of swede midge reared under warm, long day length conditions entered diapause. A small percentage of larvae neither pupated nor entered diapause and remained in substrate long after other individuals had emerged as adults. This behaviour was more prevalent under cool and short or decreasing day length rearing conditions. Approximately 76% of the larvae used for diapause induction were recovered with the present larval and cocoon retrieval method, and premature (larval and pupal) mortality averaged 18.2%. Although diapause occurred in the present study, conditions resulting in higher diapause frequencies should be investigated and attempts should be made to improve survival and recovery of individuals.

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