Mercury speciation and subcellular distribution in experimentally dosed and wild birds.

PubMed

Perkins, Marie; Barst, Benjamin D; Hadrava, Justine; Basu, Niladri

2017-12-01

Many bird species are exposed to methylmercury (MeHg) at levels shown to cause sublethal effects. Although MeHg sensitivity and assimilation can vary among species and developmental stages, the underlying reasons (such as MeHg toxicokinetics) are poorly understood. We investigated Hg distribution at the tissue and cellular levels in birds by examining Hg speciation in blood, brain, and liver and Hg subcellular distribution in liver. We used MeHg egg injection of white leghorn chicken (Gallus gallus domesticus), sampled at 3 early developmental stages, and embryonic ring-billed gulls (Larus delawarensis) exposed to maternally deposited MeHg. The percentage of MeHg (relative to total Hg [THg]) in blood, brain, and liver ranged from 94 to 121%, indicating little MeHg demethylation. A liver subcellular partitioning procedure was used to determine how THg was distributed between potentially sensitive and detoxified compartments. The distributions of THg among subcellular fractions were similar among chicken time points, and between embryonic chicken and ring-billed gulls. A greater proportion of THg was associated with metal-sensitive fractions than detoxified fractions. Within the sensitive compartment, THg was found predominately in heat-denatured proteins (∼42-46%), followed by mitochondria (∼15-18%). A low rate of MeHg demethylation and high proportion of THg in metal-sensitive subcellular fractions further indicates that embryonic and hatchling time points are Hg-sensitive developmental stages, although further work is needed across a range of additional species and life stages. Environ Toxicol Chem 2017;36:3289-3298. © 2017 SETAC. © 2017 SETAC.

The effects of mercury on developing larvae of Rhithropanopeus harrisii (Gould) . I. Interactions of temperature, salinity and mercuryon larval development

NASA Astrophysics Data System (ADS)

McKenney, C. L.; Costlow, J. D.

1982-02-01

Larvae of the estuarine xanthid crab Rhithropanopeus harrisii were reared inthe laboratory from hatch through completion of metamorphosis to postlarva in 64 combinations of temperature (20-35°C), salinity (10-40‰) and mercury (0-20 parts 10 -9 Hg 2+). Multiple linear regression analysis and response surface methodology were used to determine and visually display the individual and interactive effects of the various constant temperature-salinity-mercury combinations on both survival and developmental rates of developing larvae throughout total larval development and for zoeae and megalopae separately, to distinguish any differential sensitivity between the two larval forms. Survival capacity of larvae under a broad range of salinities and temperatures characteristic of temperate estuarine conditions was progressively reduced upon continual exposure to mercury ranging from 5 to 20 parts 10 -9 Hg 2+. Exposure concentrations as low as 5 parts 10 -9 Hg 2+ reduced the salinity and temperature plasciticity of the normally euryhalinic and eurythermal larvae. Larval survival from hatch to postlarva was affected by both mercury-salinity and mercury-temperature interactions with mercury toxicity increasing under suboptimal temperatures and salinities. Viability of early zoeal stages proved more sensitive to mercury exposure than the final megalopa stage. Exposure to mercury concentrations from 5-20 parts 10 -9, Hg 2+ prolonged complete developmental duration by 3 to 4 days with zoeal developmental rates retarded more than megalopal rates. Developmental rates of the megalopa were more reduced by mercury at higher salinities, and both zoeal and megalopal developmental rates were more retarded by mercury at lower temperatures. The reduced plasticity of larvae to estuarine conditions, and retarded developmental rates by low mercury concentrations may reduce recruitment into adult benthic populations and alter the distributional patterns of pelagic R. harrisii larvae.

Direct and indirect effects of development temperature on adult water balance traits of Eldana saccharina (Lepidoptera: Pyralidae).

PubMed

Kleynhans, Elsje; Conlong, Des E; Terblanche, John S

2014-09-01

For water balance physiology, prior thermal history may pre-condition individuals to be more sparing in their water consumption at a given temperature upon subsequent exposure, or alternatively, may relax constraints on water economy leading to more frivolous use of water at a later stage. Here we test these two major alternative hypotheses on the adult life stage of Eldana saccharina Walker (Lepidoptera: Pyralidae) by exposing them to different rearing temperatures (acclimation treatments) during immature stage development and comparing adult physiological performance (water loss rates, time to death) and water-balance related traits (body size, water content). Developmental acclimation at 20°C, 25°C or 30°C throughout the larval and pupal stage resulted in significant effects on water balance traits of two-day old adult male and female E. saccharina. In summary, lower developmental acclimation resulted in a 61% increase in water loss rate (range: 0.78mg/h) and a 26% reduction in survival time (6.8h). Initial body water content and initial body mass generally remained similar across male acclimation groups while higher developmental acclimation reduced female body mass significantly. High developmental acclimation resulted in significantly higher (∼23%) body water content at death possibly indicating a better overall ability to withstand desiccating conditions, although there was no difference in time to death compared to the intermediate group. The relationship between time to death and body mass was altered from negative at 25°C and 30°C acclimation, to positive at 20°C acclimation. These results show pervasive effects of rearing temperature on adult physiological performance, with low temperature relaxing what appear to be substantial constraints on water economy at higher temperatures for E. saccharina. Furthermore, they are significant for understanding the recent range expansion of E. saccharina into cooler environments in southern Africa and for management of the species. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Lifespan Developmental-Stage Approach to Tobacco and Other Drug Abuse Prevention

PubMed Central

2013-01-01

At least by informal design, tobacco and other drug abuse prevention programs are tailored to human developmental stage. However, few papers have been written to examine how programming has been formulated as a function of developmental stage throughout the lifespan. In this paper, I briefly define lifespan development, how it pertains to etiology of tobacco and other drug use, and how prevention programming might be constructed by five developmental stages: (a) young child, (b) older child, (c) young teen, (d) older teen, and (e) adult (emerging, young-to-middle and older adult substages). A search of the literature on tobacco and other drug abuse prevention by developmental stage was conducted, and multiple examples of programs are provided for each stage. A total of 34 programs are described as examples of each stage (five-young children, 12-older children, eight-young teens, four-older teens, and five-adults). Implications for future program development research are stated. In particular, I suggest that programming continue to be developed for all stages in the lifespan, as opposed to focusing on a single stage and that developmentally appropriate features continues to be pursued to maximize program impact. PMID:25298961

Maturation of the immune system of the male house cricket, Acheta domesticus.

PubMed

Piñera, Angelica V; Charles, Heather M; Dinh, Tracy A; Killian, Kathleen A

2013-08-01

The immune system functions to counteract the wide range of pathogens an insect may encounter during its lifespan, ultimately maintaining fitness and increasing the likelihood of survival to reproductive maturity. In this study, we describe the maturation of the innate immune system of the male house cricket Acheta domesticus during the last two nymphal stages, and during early and late adulthood. Total hemolymph phenoloxidase enzyme activity, lysozyme-like enzyme activity, the number of circulating hemocytes, and encapsulation ability were all determined for each developmental stage or age examined. The number of circulating hemocytes and lysozyme-like enzyme activity were similar for all developmental stages examined. Nymphs and newly molted adult males, however, had significantly lower total phenoloxidase activity than later adult stages, yet nymphs were able to encapsulate a nylon thread just as well as adults. Encapsulation ability would thus appear to be independent of total phenoloxidase activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dynamic Organization of lncRNA and Circular RNA Regulators Collectively Controlled Cardiac Differentiation in Humans.

PubMed

Li, Yongsheng; Zhang, Jinwen; Huo, Caiqin; Ding, Na; Li, Junyi; Xiao, Jun; Lin, Xiaoyu; Cai, Benzhi; Zhang, Yunpeng; Xu, Juan

2017-10-01

Advances in developmental cardiology have increased our understanding of the early aspects of heart differentiation. However, understanding noncoding RNA (ncRNA) transcription and regulation during this process remains elusive. Here, we constructed transcriptomes for both long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) in four important developmental stages ranging from early embryonic to cardiomyocyte based on high-throughput sequencing datasets, which indicate the high stage-specific expression patterns of two ncRNA types. Additionally, higher similarities of samples within each stage were found, highlighting the divergence of samples collected from distinct cardiac developmental stages. Next, we developed a method to identify numerous lncRNA and circRNA regulators whose expression was significantly stage-specific and shifted gradually and continuously during heart differentiation. We inferred that these ncRNAs are important for the stages of cardiac differentiation. Moreover, transcriptional regulation analysis revealed that the expression of stage-specific lncRNAs is controlled by known key stage-specific transcription factors (TFs). In addition, circRNAs exhibited dynamic expression patterns independent from their host genes. Functional enrichment analysis revealed that lncRNAs and circRNAs play critical roles in pathways that are activated specifically during heart differentiation. We further identified candidate TF-ncRNA-gene network modules for each differentiation stage, suggesting the dynamic organization of lncRNAs and circRNAs collectively controlled cardiac differentiation, which may cause heart-related diseases when defective. Our study provides a foundation for understanding the dynamic regulation of ncRNA transcriptomes during heart differentiation and identifies the dynamic organization of novel key lncRNAs and circRNAs to collectively control cardiac differentiation. Copyright © 2017. Published by Elsevier B.V.

Assessment of Growth Using Mandibular Canine Calcification Stages and Its Correlation with Modified MP3 Stages.

PubMed

Nayak, Reshma; Nayak, Us Krishna; Hegde, Gautam

2010-01-01

Orthodontic diagnosis and treatment planning for growing children must involve growth prediction, especially in the treatment of skeletal problems. Studies have shown that a strong association exists between skeletal maturity and dental calcification stages. The present study was therefore taken up to provide a simple and practical method for assessing skeletal maturity using a dental periapical film and standard dental X-ray machine, to compare the developmental stages of the mandibular canine with that of developmental stages of modified MP3 and to find out if any correlation exists, to determine if the developmental stages of the mandibular canine alone can be used as a reliable indicator for assessment of skeletal maturity. A total of 160 periapical radiographs (80 males and 80 females), of the mandibular right canine and the MP3 region was taken and assessed according to the Dermirjian's stages of dental calcification and the modified MP3 stages. The correlation between the developmental stages of MP3 and the mandibular right canine in male and female groups, is of high statistical significance (p = 0.001). The correlation coefficient between MP3 stages and developmental stages of mandibular canine and chronological age in male and females was found to be not significant. The correlation between the mandibular canine calcification stages and MP3 stages was found to be significant. The developmental stages of the mandibular canine could be used very reliably as a sole indicator for assessment of skeletal maturity.

Historical range of variability in live and dead wood biomass: a regional-scale simulation study

Treesearch

Etsuko Nonaka; Thomas A. Spies; Michael C. Wimberly; Janet L. Ohmann

2007-01-01

The historical range of variability (HRV) in landscape structure and composition created by natural disturbance can serve as a general guide for evaluating ecological conditions of managed landscapes. HRV approaches to evaluating landscapes have been based on age classes or developmental stages, which may obscure variation in live and dead stand structure. Developing...

The Growth of Complexity and Accuracy in L2 French: Past Observations and Recent Applications of Developmental Stages

ERIC Educational Resources Information Center

Agren, Malin; Granfeldt, Jonas; Schlyter, Suzanne

2012-01-01

This chapter addresses the question of the growth of accuracy and complexity in L2 French from the perspective of developmental sequences of morphosyntax, developmental stages and linguistic profiling. The six developmental stages for L2 French proposed by Bartning and Schlyter (2004) are presented and exemplified and new results are added to the…

Developmental Patterns of the Invasive Bramble (Rubus alceifolius Poiret, Rosaceae) in Réunion Island: an Architectural and Morphometric Analysis

PubMed Central

BARET, STÉPHANE; NICOLINI, ERIC; LE BOURGEOIS, THOMAS; STRASBERG, DOMINIQUE

2003-01-01

The aim of this study was to identify the developmental stages of Rubus alceifolius and to determine one or more characteristic morphological markers for each stage. The developmental reconstitution method used involved a detailed description of many individuals throughout the different stages of growth, from germination to the development of an adult shoot capable of fruiting. Results revealed that R. alceifolius passes through five developmental stages that can be distinguished by changes in several morphological markers such as internode length and diameter, pith diameter and plant shape. This analysis indicated that R. alceifolius has a heteroblastic developmental pattern, midway between that of a bush and a liana. Moreover, results showed that this species taps environmental resources early in its development, i.e. foliarization is high (the foliar component overrides the caulinary component) and an autotrophic stage is rapidly reached, whereas it ‘explores’ the environment during the adult stage, i.e. axialization is substantial (the caulinary component overrides the foliar component) and autotrophy occurs at a later stage. The morphological markers identified could benefit land‐use managers attempting to control this species before it reaches its optimum developmental stage. PMID:12495918

Developmental stage related patterns of codon usage and genomic GC content: searching for evolutionary fingerprints with models of stem cell differentiation

PubMed Central

2007-01-01

Background The usage of synonymous codons shows considerable variation among mammalian genes. How and why this usage is non-random are fundamental biological questions and remain controversial. It is also important to explore whether mammalian genes that are selectively expressed at different developmental stages bear different molecular features. Results In two models of mouse stem cell differentiation, we established correlations between codon usage and the patterns of gene expression. We found that the optimal codons exhibited variation (AT- or GC-ending codons) in different cell types within the developmental hierarchy. We also found that genes that were enriched (developmental-pivotal genes) or specifically expressed (developmental-specific genes) at different developmental stages had different patterns of codon usage and local genomic GC (GCg) content. Moreover, at the same developmental stage, developmental-specific genes generally used more GC-ending codons and had higher GCg content compared with developmental-pivotal genes. Further analyses suggest that the model of translational selection might be consistent with the developmental stage-related patterns of codon usage, especially for the AT-ending optimal codons. In addition, our data show that after human-mouse divergence, the influence of selective constraints is still detectable. Conclusion Our findings suggest that developmental stage-related patterns of gene expression are correlated with codon usage (GC3) and GCg content in stem cell hierarchies. Moreover, this paper provides evidence for the influence of natural selection at synonymous sites in the mouse genome and novel clues for linking the molecular features of genes to their patterns of expression during mammalian ontogenesis. PMID:17349061

Dynamic expression of ancient and novel molluscan shell genes during ecological transitions

PubMed Central

Jackson, Daniel J; Wörheide, Gert; Degnan, Bernard M

2007-01-01

Background The Mollusca constitute one of the most morphologically and ecologically diverse metazoan phyla, occupying a wide range of marine, terrestrial and freshwater habitats. The evolutionary success of the molluscs can in part be attributed to the evolvability of the external shell. Typically, the shell first forms during embryonic and larval development, changing dramatically in shape, colour and mineralogical composition as development and maturation proceeds. Major developmental transitions in shell morphology often correlate with ecological transitions (e.g. from a planktonic to benthic existence at metamorphosis). While the genes involved in molluscan biomineralisation are beginning to be identified, there is little understanding of how these are developmentally regulated, or if the same genes are operational at different stages of the mollusc's life. Results Here we relate the developmental expression of nine genes in the tissue responsible for shell production – the mantle – to ecological transitions that occur during the lifetime of the tropical abalone Haliotis asinina (Vetigastropoda). Four of these genes encode evolutionarily ancient proteins, while four others encode secreted proteins with little or no identity to known proteins. Another gene has been previously described from the mantle of another haliotid vetigastropod. All nine genes display dynamic spatial and temporal expression profiles within the larval shell field and juvenile mantle. Conclusion These expression data reflect the regulatory complexity that underlies molluscan shell construction from larval stages to adulthood, and serves to highlight the different ecological demands placed on each stage. The use of both ancient and novel genes in all stages of shell construction also suggest that a core set of shell-making genes was provided by a shared metazoan ancestor, which has been elaborated upon to produce the range of molluscan shell types we see today. PMID:17845714

A comparative ultrastructural study of pit membranes with plasmodesmata associated thickenings in four angiosperm species.

PubMed

Rabaey, David; Lens, Frederic; Huysmans, Suzy; Smets, Erik; Jansen, Steven

2008-11-01

Recent micromorphological observations of angiosperm pit membranes have extended the number and range of taxa with pseudo-tori in tracheary elements. This study investigates at ultrastructural level (TEM) the development of pseudo-tori in the unrelated Malus yunnanensis, Ligustrum vulgare, Pittosporum tenuifolium, and Vaccinium myrtillus in order to determine whether these plasmodesmata associated thickenings have a similar developmental pattern across flowering plants. At early ontogenetic stages, the formation of a primary thickening was observed, resulting from swelling of the pit membrane in fibre-tracheids and vessel elements. Since plasmodesmata appear to be frequently, but not always, associated with these primary pit membrane thickenings, it remains unclear which ultrastructural characteristics control the formation of pseudo-tori. At a very late stage during xylem differentiation, a secondary thickening is deposited on the primary pit membrane thickening. Plasmodesmata are always associated with pseudo-tori at these final developmental stages. After autolysis, the secondary thickening becomes electron-dense and persistent, while the primary thickening turns transparent and partially or entirely dissolves. The developmental patterns observed in the species studied are similar and agree with former ontogenetic studies in Rosaceae, suggesting that pseudo-tori might be homologous features across angiosperms.

Assessing the Development of Cross-Cultural Competence in Soldiers

DTIC Science & Technology

2010-11-01

five stages of CQ development based on models from developmental psychology including Piaget’s Model of Cognitive Development ( Piaget , 1985) and...and competence development , the Stage Model of Cognitive Skill Acquisition (Ross et al., 2005), and the Bennett Developmental Model of... developmental stages of proficiency and expertise (see the Stage Model of Cognitive Development ). At this level, cross-cultural competence is highly refined and

Assessment of Growth Using Mandibular Canine Calcification Stages and Its Correlation with Modified MP3 Stages

PubMed Central

Nayak, US Krishna; Hegde, Gautam

2010-01-01

Background and objectives Orthodontic diagnosis and treatment planning for growing children must involve growth prediction, especially in the treatment of skeletal problems. Studies have shown that a strong association exists between skeletal maturity and dental calcification stages. The present study was therefore taken up to provide a simple and practical method for assessing skeletal maturity using a dental periapical film and standard dental X-ray machine, to compare the developmental stages of the mandibular canine with that of developmental stages of modified MP3 and to find out if any correlation exists, to determine if the developmental stages of the mandibular canine alone can be used as a reliable indicator for assessment of skeletal maturity. Methods A total of 160 periapical radiographs (80 males and 80 females), of the mandibular right canine and the MP3 region was taken and assessed according to the Dermirjian’s stages of dental calcification and the modified MP3 stages. Results The correlation between the developmental stages of MP3 and the mandibular right canine in male and female groups, is of high statistical significance (p = 0.001). The correlation coefficient between MP3 stages and developmental stages of mandibular canine and chronological age in male and females was found to be not significant. Conclusions The correlation between the mandibular canine calcification stages and MP3 stages was found to be significant. The developmental stages of the mandibular canine could be used very reliably as a sole indicator for assessment of skeletal maturity. PMID:27625553

Why Are There Developmental Stages in Language Learning? A Developmental Robotics Model of Language Development

ERIC Educational Resources Information Center

Morse, Anthony F.; Cangelosi, Angelo

2017-01-01

Most theories of learning would predict a gradual acquisition and refinement of skills as learning progresses, and while some highlight exponential growth, this fails to explain why natural cognitive development typically progresses in stages. Models that do span multiple developmental stages typically have parameters to "switch" between…

Prevalence of entomophthoralean fungi (Entomophthoromycota) of aphids in relation to developmental stages.

PubMed

Manfrino, Romina G; Gutierrez, Alejandra C; Rueda Páramo, Manuel E; Salto, César E; López Lastra, Claudia C

2016-08-01

Transmission of fungal pathogens of aphids may be affected by the host developmental stage. Brassica and Lactuca sativa L. crops were sampled in Santa Fe, Argentina, to determine the prevalence of fungal-diseased aphids and investigate the differences between developmental stages of aphids. The fungal pathogens identified were Zoophthora radicans (Bref.) A. Batko, Pandora neoaphidis (Remaud. & Hennebert) Humber and Entomophthora planchoniana Cornu. Their prevalence on each crop was calculated. The numbers of infected aphids were significantly different between the different developmental stages on all crops except B. oleracea var. botrytis L. The entomophthoralean fungi identified are important mortality factors of aphids on horticultural crops in Santa Fe. The numbers of infected nymphs and adults were significantly different, nymphs being the most affected developmental stage. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

THE YOUNG ADULT--A CONCEPTUAL FRAMEWORK. SUMMARY.

ERIC Educational Resources Information Center

CHICKERING, ARTHUR W.

THE DEVELOPMENTAL STAGE SPANNING THE YEARS FROM 18 TO 25 MUST BE STUDIED SEPARATELY FROM OTHER DEVELOPMENTAL STAGES. THE DEVELOPMENTAL TASKS OF THIS PERIOD ARE RELATED TO, BUT SUBSTANTIALLY DIFFERENT FROM, THOSE OF BOTH ADOLESCENCE AND ADULTHOOD. THE SEVEN MAJOR DEVELOPMENTAL VECTORS FOR THE YOUNG ADULT INCLUDE DEVELOPMENT OF COMPETENCE,…

Embryotoxicity of Corexit 9500 in mallard ducks (Anas platyrhynchos).

PubMed

Wooten, Kimberly J; Finch, Bryson E; Smith, Philip N

2012-04-01

Embryotoxicity of the oil dispersant Corexit 9500 was examined using fertilized mallard duck eggs. Corexit 9500 was topically applied below the air cell to eggs in volumes ranging from 0 to 100 μL on day 3 of incubation. The highest incidence of mortality occurred at developmental stage 4, one day post-Corexit 9500 application. Hatching success was significantly decreased among eggs treated with ≥ 20 μL of Corexit 9500 as compared to controls (P ≤ 0.047). No egg treated with ≥ 40 μL successfully hatched. The application volume resulting in 50% mortality (corrected for control survival) was determined to be 15.5 μL. Developmental stage at embryo death was also significantly decreased compared to controls in eggs exposed to 40 μL (P = 0.0042) and above.

Developmental rate and behavior of early life stages of bighead carp and silver carp

USGS Publications Warehouse

Chapman, Duane C.; George, Amy E.

2011-01-01

The early life stages of Asian carp are well described by Yi and others (1988), but since these descriptions are represented by line drawings based only on live individuals and lacked temperature controls, further information on developmental time and stages is of use to expand understanding of early life stages of these species. Bighead carp and silver carp were cultured under two different temperature treatments to the one-chamber gas bladder stage, and a photographic guide is provided for bighead carp and silver carp embryonic and larval development, including notes about egg morphology and larval swimming behavior. Preliminary information on developmental time and hourly thermal units for each stage is also provided. Both carp species developed faster under warmer conditions. Developmental stages and behaviors are generally consistent with earlier works with the exception that strong vertical swimming immediately after hatching was documented in this report.

Roots from distinct plant developmental stages are capable of rapidly selecting their own microbiome without the influence of environmental and soil edaphic factors

USDA-ARS?s Scientific Manuscript database

Soil microbes live in close association with plants and are crucial for plant health and fitness. Recent literature revealed that specific microbes were cultured at distinct developmental stages of Arabidopsis. It is not clear how fast the roots, depending on their developmental stage, can alter the...

Transcriptome profiles of embryos before and after cleavage in Eriocheir sinensis: identification of developmental genes at the earliest stages

NASA Astrophysics Data System (ADS)

Hui, Min; Cui, Zhaoxia; Liu, Yuan; Song, Chengwen

2017-07-01

In crab, embryogenesis is a complicated developmental program marked by a series of critical events. RNA-Sequencing technology offers developmental biologists a way to identify many more developmental genes than ever before. Here, we present a comprehensive analysis of the transcriptomes of Eriocheir sinensis oosperms (Os) and embryos at the 2-4 cell stage (Cs), which are separated by a cleavage event. A total of 18 923 unigenes were identified, and 403 genes matched with gene ontology (GO) terms related to developmental processes. In total, 432 differentially expressed genes (DEGs) were detected between the two stages. Nine DEGs were specifically expressed at only one stage. These DEGs may be relevant to stage-specific molecular events during development. A number of DEGs related to `hedgehog signaling pathway', `Wnt signaling pathway' `germplasm', `nervous system', `sensory perception' and `segment polarity' were identified as being up-regulated at the Cs stage. The results suggest that these embryonic developmental events begin before the early cleavage event in crabs, and that many of the genes expressed in the two transcriptomes might be maternal genes. Our study provides ample information for further research on the molecular mechanisms underlying crab development.

Part II: morphological analysis of embryonic development following femtosecond laser manipulation

NASA Astrophysics Data System (ADS)

Kohli, V.; Elezzabi, A. Y.

2008-02-01

The zebrafish (Danio rerio) is an attractive model system that has received wide attention for its usefulness in the study of development and disease. This organism represents a closer analog to humans than the common invetebrates Drosophila melanogaster and Caenorhabditis elegans, making this species an ideal model for human health research. Non-invasive manipulation of the zebrafish has been challenging, owing to the outer proteinaceous membrane and multiple embryonic barriers. A novel tool capable of manipulating early cleavage stage embryonic cells would be important for future advancements in medial research and the aquaculture industry. Herein, we demonstrate the laser surgery of early cleavage stage (2-cell) blastomere cells using a range of average laser powers and beam dwell times. Since the novelty of this manipulation tool depends on its non-invasive application, we examined short- and long-term laser-induced developmental defects following embryonic surgery. Laser-manipulated embryos were reared to 2 and 7 days post-fertilization and compared to control embryos at the same developmental stages. Morphological analysis was performed using light microscopy and scanning electron microscopy. Developmental features that were examined included the antero- and dorsal-lateral whole body views of the larvae, the olfactory pit, dorsal, ventral and pectoral fins, notochord, pectoral fin buds, otic capsule, otic vesicle, neuromast patterning, and kinocilia of the olfactory pit rim and cristae of the lateral wall of the ear. Laser-manipulated embryos developed normally relative to the controls, with developmental patterning and morphology at 2 and 7 days indistinguishable from control larvae.

Evidence for a conserved microbiota across the different developmental stages of Plodia interpunctella.

PubMed

Mereghetti, Valeria; Chouaia, Bessem; Limonta, Lidia; Locatelli, Daria Patrizia; Montagna, Matteo

2017-11-01

Diversity and composition of lepidopteran microbiotas are poorly investigated, especially across the different developmental stages. To improve this knowledge, we characterize the microbiota among different developmental stages of the Indian meal moth, Plodia interpunctella, which is considered one of the major pest of commodities worldwide. Using culture-independent approach based on Illumina 16S rRNA gene sequencing we characterized the microbiota of four developmental stages: eggs, first-, and last-instar larvae, and adult. A total of 1022 bacterial OTUs were obtained, showing a quite diversified microbiota associated to all the analyzed stages. The microbiotas associated with P. interpunctella resulted almost constant throughout the developmental stages, with approximately 77% of bacterial OTUs belonging to the phylum of Proteobacteria. The dominant bacterial genus is represented by Burkholderia (∼64%), followed by Propionibacterium, Delftia, Pseudomonas, and Stenotrophomonas. A core bacterial community, composed of 139 OTUs, was detected in all the developmental stages, among which 112 OTUs were assigned to the genus Burkholderia. A phylogenetic reconstruction, based on the 16S rRNA, revealed that our Burkholderia OTUs clustered with Burkholderia cepacia complex, in the same group of those isolated from the hemipterans Gossyparia spuria and Acanthococcus aceris. The functional profiling, predicted on the base of the bacterial 16S rRNA, indicates differences in the metabolic pathways related to metabolism of amino acids between preimaginal and adult stages. We can hypothesize that bacteria may support the insect host during preimaginal stages. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Molecular investigations of Hepatozoon species in dogs and developmental stages of Rhipicephalus sanguineus.

PubMed

Aktas, Munir; Ozübek, Sezayi; Ipek, Duygu Neval Sayın

2013-06-01

The occurrence and distribution of Hepatozoon species in stray dogs, and the developmental stages of Rhipicephalus sanguineus detached from the same dogs in Diyarbakır Province, Turkey is reported. A total of 328 ticks, including 133 adults (55 males and 75 females consist of 63 partially engorged and 15 fully engorged) and 195 nymphs (91 partially engorged and 104 fully engorged) were detached from the dogs. Fully engorged nymphs and females were incubated at 27 °C and relative humidity of 85 % to molt to adult stage and recover eggs. The ticks were pooled according to sex and developmental stage. No Hepatozoon gamonts were found, whereas, by PCR, 15.87 % (10/63) of the dogs were infected with Hepatozoon canis. Of the 68 tick pools tested, 14 (20.58 %) pools were infected with Hepatozoon spp., an overall maximum likelihood estimation of prevalence of 4.9 % (95 % confidence intervals (CI) = 2.85-7.93 %) per 100 ticks. Maximum likelihood estimation of the infection rate varied by tick sex and developmental categories, ranging from 1.75 % (95 % CI = 0.11-8.11 %) in fed males to 6.81 % (95 % CI = 2.07-17.46 %) in unfed females. One amplicon from a fed adult female was 99 % identical to the sequence for Hepatozoon felis. The remaining sequences isolated from both dogs and ticks shared 99-100 % similarity with the corresponding H. canis isolates. This is the first detection of H. canis and H. felis in the tick R. sanguineus in Turkey.

RNA-Seq analysis of nodule development at five different developmental stages of soybean (Glycine max) inoculated with Bradyrhizobium japonicum strain 113-2

PubMed Central

Yuan, Song L.; Li, Rong; Chen, Hai F.; Zhang, Chan J.; Chen, Li M.; Hao, Qing N.; Chen, Shui L.; Shan, Zhi H.; Yang, Zhong L.; Zhang, Xiao J.; Qiu, De Z.; Zhou, Xin A.

2017-01-01

Nodule development directly affects nitrogen fixation efficiency during soybean growth. Although abundant genome-based information related to nodule development has been released and some studies have reported the molecular mechanisms that regulate nodule development, information on the way nodule genes operate in nodule development at different developmental stages of soybean is limited. In this report, notably different nodulation phenotypes in soybean roots inoculated with Bradyrhizobium japonicum strain 113-2 at five developmental stages (branching stage, flowering stage, fruiting stage, pod stage and harvest stage) were shown, and the expression of nodule genes at these five stages was assessed quantitatively using RNA-Seq. Ten comparisons were made between these developmental periods, and their differentially expressed genes were analysed. Some important genes were identified, primarily encoding symbiotic nitrogen fixation-related proteins, cysteine proteases, cystatins and cysteine-rich proteins, as well as proteins involving plant-pathogen interactions. There were no significant shifts in the distribution of most GO functional annotation terms and KEGG pathway enrichment terms between these five development stages. A cystatin Glyma18g12240 was firstly identified from our RNA-seq, and was likely to promote nodulation and delay nodule senescence. This study provides molecular material for further investigations into the mechanisms of nitrogen fixation at different soybean developmental stages. PMID:28169364

Sexual dysfunction within an adult developmental perspective.

PubMed

Fagan, P J; Meyer, J K; Schmidt, C W

1986-01-01

The focus of this paper is on the adult who has adequately mastered the oedipal stage of psychosexual development and who presents with a sexual dysfunction. Drawing on the developmental sequence of Erik Erikson, the authors suggest that failure to address adequately an adult psychosocial crisis may result in sexual dysfunction. There may be both adult developmental deficits and regression to adolescent and adult stages previously negotiated. Both may be symptomatically represented by sexual dysfunction. The authors urge that the sexual and marital problems be evaluated within an adult developmental framework and that the therapy address the psychosocial issues which are appropriate to the developmental stage of the patient.

Teaching and Technologies for Human Development.

ERIC Educational Resources Information Center

Chickering, Arthur W.; Payne, Carla; Poitras, Gail

2001-01-01

Discusses the potential of emerging communication and information technologies in terms of human development. Topics include distinctions between training and education, instrumental and developmental purposes, and differentiation and integration; developmental stages theory; a leadership seminar based on developmental stages; and uses of…

Integrating and Analyzing Psychosocial and Stage Theories To Challenge the Development of the Injured Collegiate Athlete.

ERIC Educational Resources Information Center

Harris, Laura L.

2003-01-01

Integrated a psychosocial developmental theory (the Kubler-Ross Stage Theory) and a psychological stage theory (the Ross Stage Theory) and a psychological stage theory (the Chickering and Reisser psychosocial and developmental theory) for challenging injured collegiate student-athletes' personal development. A search of online databases from…

Microanatomy and Development of the Dwarf Male of Symbion pandora (Phylum Cycliophora): New Insights from Ultrastructural Investigation Based on Serial Section Electron Microscopy

PubMed Central

Neves, Ricardo Cardoso; Reichert, Heinrich

2015-01-01

Cycliophorans have a complex life cycle that involves several sexual and asexual stages. One of the sexual stages is the 40 μm-long dwarf male, which is among the smallest free-living metazoans. Although the dwarf male has a highly complex body plan, this minute organism is composed of a very low number of somatic cells (~50). The developmental processes that give rise to this unique phenotype are largely unknown. Here we use high resolution serial block face—scanning electron microscopy to analyze the anatomy and morphogenesis of three cycliophoran dwarf males at different developmental stages ranging from internal bud to mature male. The anatomical and morphological features of the mature dwarf male stage reported here largely correspond to those reported in earlier studies. Interestingly, the organs that typically characterize the anatomy of the mature dwarf male, e.g., muscles, brain, testis and glands, are already formed in the young male. However, there are striking differences between the mature male and young male stages at the level of cellular architecture. Thus, while the young male stage, like the internal bud stage, possesses approximately 200 nucleated cells, the mature male stage comprises only around 50 nucleated cells; muscle and epidermal cells of the mature male lack nuclei. Moreover, the total body volume of the mature male is only 63% of the body of the young male implying that the maturation of the young male into a mature male involves a marked reduction of internal body volume, mainly by massive nuclei loss. Our comparative analysis of these dwarf male specimens reveals unprecedented insight into the striking morphological and developmental differences that characterize these highly miniaturized male stages both at the level of body organization and at the level of cellular ultrastructure. PMID:25875482

Effect of water temperature on the development, release and survival of the triactinomyxon stage of Myxobolus cerebralis in its oligochaete host.

PubMed

El-Matbouli, M; McDowell, T S; Antonio, D B; Andree, K B; Hedrick, R P

1999-04-01

The development of the triactinomyxon stage of Myxobolus cerebralis and release of mature spores from Tubifex tubifex were shown to be temperature dependent. In the present work, the effect of temperature over a range of 5-30 degrees C on the development and release of the triactinomyxon stages of M. cerebralis was studied. Infected T. tubifex stopped releasing triactinomyxon spores 4 days after transfer from 15 degrees C to 25 degrees C or 30 degrees C. Transmission electron microscopic examinations of the tubificids held at 25 degrees C and 30 degrees C for 3 days showed that all developmental stages degenerated and transformed to electron-dense clusters between the gut epithelial cells of T. tubifex. In contrast, tubificid worms held at 5 degrees C and 10 degrees C examined at the same time were heavily infected with many early developmental stages of triactinomyxon. At 15 degrees C, the optimal temperature for development, maturing and mature stages of the parasite were evident. Infected T. tubifex transferred from 15 degrees C to 20 degrees C stopped producing triactinomyxon spores after 15 days. However, 15 days at 20 degrees C was not sufficient to destroy all developmental stages of the parasite. When the tubificid worms were returned to 15 degrees C, the one-cell stages and the binucleate-cell stages resumed normal growth. It was also demonstrated that T. tubifex cured of infection by holding at 30 degrees C for 3 weeks and shifted to 15 degrees C could be re-infected with M. cerebralis spores. The waterborne triactinomyxon spores of M. cerebralis did not appear to be as short-lived as previously reported. More than 60% of experimentally produced waterborne triactinomyxon spores survived and maintained their infectivity for rainbow trout for 15 days at water temperatures up to 15 degrees C. In natural aquatic systems, the triactinomyxon spores may survive and keep their infectivity for periods even longer than 15 days.

A new method of estimating thermal performance of embryonic development rate yields accurate prediction of embryonic age in wild reptile nests.

PubMed

Rollinson, Njal; Holt, Sarah M; Massey, Melanie D; Holt, Richard C; Nancekivell, E Graham; Brooks, Ronald J

2018-05-01

Temperature has a strong effect on ectotherm development rate. It is therefore possible to construct predictive models of development that rely solely on temperature, which have applications in a range of biological fields. Here, we leverage a reference series of development stages for embryos of the turtle Chelydra serpentina, which was described at a constant temperature of 20 °C. The reference series acts to map each distinct developmental stage onto embryonic age (in days) at 20 °C. By extension, an embryo taken from any given incubation environment, once staged, can be assigned an equivalent age at 20 °C. We call this concept "Equivalent Development", as it maps the development stage of an embryo incubated at a given temperature to its equivalent age at a reference temperature. In the laboratory, we used the concept of Equivalent Development to estimate development rate of embryos of C. serpentina across a series of constant temperatures. Using these estimates of development rate, we created a thermal performance curve measured in units of Equivalent Development (TPC ED ). We then used the TPC ED to predict developmental stage of embryos in several natural turtle nests across six years. We found that 85% of the variation of development stage in natural nests could be explained. Further, we compared the predictive accuracy of the model based on the TPC ED to the predictive accuracy of a degree-day model, where development is assumed to be linearly related to temperature and the amount of accumulated heat is summed over time. Information theory suggested that the model based on the TPC ED better describes variation in developmental stage in wild nests than the degree-day model. We suggest the concept of Equivalent Development has several strengths and can be broadly applied. In particular, studies on temperature-dependent sex determination may be facilitated by the concept of Equivalent Development, as development age maps directly onto the developmental series of the organism, allowing critical periods of sex determination to be delineated without invasive sampling, even under fluctuating temperature. Copyright © 2018 Elsevier Ltd. All rights reserved.

Immunocompetence of the red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae): variation between developmental stages and sexes in populations in China.

PubMed

Shi, Zhang-Hong; Sun, Jiang-Hua

2010-11-01

Immune defense imposes fitness costs as well as benefits, so organisms should optimize, not maximize, their immune function through their life cycle. We investigated this issue in the red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae), which is a pine-killing invasive beetle in China, though it is usually considered as a secondary pest in its native range of North America. We hypothesized that pathogen pressure may affect these beetles differently throughout their life history. We measured the insect's immunocompetence throughout life, determining encapsulation ability and phenoloxidase activity in larval stages, pupae and adults. Pupae had the highest encapsulation ability, but encapsulation was not different between final instar larvae and adults. Phenoloxidase (PO) activity was highest in final instar larvae and pupae, followed by the second instar larvae and adults. Total phenoloxidase activity increased significantly from the second instar larval stage to pupae, and then decreased in adults. Although the second instar larvae had the lowest phenoloxidase activity, more than 90% of total PO existed in the hemolymph in the form of the active enzyme, as compared with pupae, in which over 60% of PO occurred as a proenzyme. Both active PO and total PO were much higher in females than in males, though no significant differences were detected between the encapsulation ability of male and female adults. This result suggests the existence of a sexual dimorphism of immunocompetence in D. valens adults. Variations in immunocompetence across developmental stages suggest that D. valens adopts diverse investment strategies in immunocompetence during different stages. Potential reasons for variation in immunocompetence among developmental stages and between the sexes of D. valens are discussed. Copyright 2010 Elsevier Ltd. All rights reserved.

Differential Expression of Hox and Notch Genes in Larval and Adult Stages of Echinococcus granulosus.

PubMed

Dezaki, Ebrahim Saedi; Yaghoobi, Mohammad Mehdi; Taheri, Elham; Almani, Pooya Ghaseminejad; Tohidi, Farideh; Gottstein, Bruno; Harandi, Majid Fasihi

2016-10-01

This investigation aimed to evaluate the differential expression of HoxB7 and notch genes in different developmental stages of Echinococcus granulosus sensu stricto. The expression of HoxB7 gene was observed at all developmental stages. Nevertheless, significant fold differences in the expression level was documented in the juvenile worm with 3 or more proglottids, the germinal layer from infected sheep, and the adult worm from an experimentally infected dog. The notch gene was expressed at all developmental stages of E. granulosus ; however, the fold difference was significantly increased at the microcysts in monophasic culture medium and the germinal layer of infected sheep in comparison with other stages. The findings demonstrated that the 2 aforementioned genes evaluated in the present study were differentially expressed at different developmental stages of the parasite and may contribute to some important biological processes of E. granulosus .

OVERVIEW OF EXPOSURE TO DIOXIN-LIKE COMPOUNDS AND PCBS ON DEVELOPMENTAL, IMMUNOSUPPRESSIVE, AND HORMONE-RELATED EFFECTS IN MAMMALS, INCLUDING HUMANS

EPA Science Inventory

Exposure to TCDD and related compounds leads to a plethora of effects in multiple species, tissues and stages of development. The response spectrum ranges from simple biochemical alterations to overtly toxic responses, including lethality. Many of the effects of TCDD and relate...

Variation in chemical composition and allelopathic potential of mixoploid Trigonella foenum-graecum L. with developmental stages.

PubMed

Omezzine, Faten; Bouaziz, Mohamed; Simmonds, Monique S J; Haouala, Rabiaa

2014-04-01

This study was conducted to evaluate the influence of developmental stages (vegetative, flowering and fruiting) of mixoploid fenugreek aerial parts on their chemical composition and allelopathic potential, assessed on lettuce germination and seedling growth. Aqueous and organic extracts significantly delayed germination, reduced its rate and affected seedling growth. Ethyl acetate and methanol extracts of aerial parts harvested at vegetative stage were the most toxic for lettuce germination and seedling growth, respectively. LC-MS/MS analysis of T. foenum-graecum aerial parts methanolic extract showed nine different flavonol glycosides (quercetin and kaempferol glucosides). Chemical composition of aerial parts differed with the developmental stage; indeed, at the vegetative and fruiting stages, analysis revealed the presence of 9 compounds as compared to only 6 compounds at the flowering stage. Thus, it is necessary to follow the qualitative changes of allelochemicals production at different developmental stages to identify the most productive one. Copyright © 2013 Elsevier Ltd. All rights reserved.

Determination of male strobilus developmental stages by cytological and gene expression analyses in Japanese cedar (Cryptomeria japonica).

PubMed

Tsubomura, Miyoko; Kurita, Manabu; Watanabe, Atsushi

2016-05-01

The molecular mechanisms that control male strobilus development in conifers are largely unknown because the developmental stages and related genes have not yet been characterized. The determination of male strobilus developmental stages will contribute to genetic research and reproductive biology in conifers. Our objectives in this study were to determine the developmental stages of male strobili by cytological and transcriptome analysis, and to determine the stages at which aberrant morphology is observed in a male-sterile mutant of Cryptomeria japonica D. Don to better understand the molecular mechanisms that control male strobilus and pollen development. Male strobilus development was observed for 8 months, from initiation to pollen dispersal. A set of 19,209 expressed sequence tags (ESTs) collected from a male reproductive library and a pollen library was used for microarray analysis. We divided male strobilus development into 10 stages by cytological and transcriptome analysis. Eight clusters (7324 ESTs) exhibited major changes in transcriptome profiles during male strobili and pollen development in C. japonica Two clusters showed a gradual increase and decline in transcript abundance, respectively, while the other six clusters exhibited stage-specific changes. The stages at which the male sterility trait of Sosyun was expressed were identified using information on male strobilus and pollen developmental stages and gene expression profiles. Aberrant morphology was observed cytologically at Stage 6 (microspore stage), and differences in expression patterns compared with wild type were observed at Stage 4 (tetrad stage). © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Developmental Screening Using the Ages and Stages Questionnaire: Standardized versus Real-World Conditions

ERIC Educational Resources Information Center

San Antonio, Marianne C.; Fenick, Ada M.; Shabanova, Veronika; Leventhal, John M.; Weitzman, Carol C.

2014-01-01

Developmental screens are often used in nonstandardized conditions, such as pediatric waiting rooms, despite validation under standardized conditions. We examined the reproducibility of the Ages and Stages Questionnaire (ASQ), a developmental screening instrument commonly used in pediatric practices, under standardized versus nonstandardized…

Characterization and potential role of microRNA in the Chinese dominant malaria mosquito Anopheles sinensis (Diptera: Culicidae) throughout four different life stages.

PubMed

Feng, Xinyu; Wu, Jiatong; Zhou, Shuisen; Wang, Jingwen; Hu, Wei

2018-01-01

microRNAs (miRNAs) are one kind of small non-coding RNAs widely distributed in insects. Many studies have shown that miRNAs play critical roles in development, differentiation, apoptosis, and innate immunity. However, there are a few reports describing miRNAs in Anopheles sinensis , the most common, and one of the dominant malaria mosquito in China. Here, we investigated the global miRNA expression profile across four different developmental stages including embryo, larval, pupal, and adult stages using Illumina Hiseq 2500 sequencing. In total, 164 miRNAs were obtained out of 107.46 million raw sequencing reads. 99 of them identified as known miRNAs, and the remaining 65 miRNAs were considered as novel. By analyzing the read counts of miRNAs in all developmental stages, 95 miRNAs showed stage-specific expression (q < 0.01 and |log2 (fold change)| > 1) in consecutive stages, indicating that these miRNAs may be involved in critical physiological activity during development. Sixteen miRNAs were identified to be commonly dysregulated throughout four developmental stages. Many miRNAs showed stage-specific expression, such as asi-miR-2943 was exclusively expressed in the embryo stage, and asi-miR-1891 could not be detected in larval stage. The expression of six selected differentially expressed miRNAs identified by qRT-PCR were consistent with our sequencing results. Furthermore, 5296 and 1902 target genes were identified for the dysregulated 68 known and 27 novel miRNAs respectively by combining miRanda and RNAhybrid prediction. GO annotation and KEGG pathway analysis for the predicted genes of dysregulated miRNAs revealed that they might be involved in a broad range of biological processes related with the development, such as membrane, organic substance transport and several key pathways including protein processing in endoplasmic reticulum, propanoate metabolism and folate biosynthesis. Thirty-two key miRNAs were identified by microRNA-gene network analysis. The present study represents the first global characterization of An. sinensis miRNAs in its four developmental stages. The presence and differential expression of An. sinensis miRNAs imply that such miRNAs may play critical roles in An. sinensis life cycle. A better understanding of the functions of these miRNAs will have great implication for the effective control of vector population and therefore interrupting malaria transmission.

The Developmental Cycle: Teachings on the Eight Stages of Growth of a Human Being.

ERIC Educational Resources Information Center

Coyhis, Don

1997-01-01

Ties Native American Medicine Wheel teachings on the cycle of life to Eric Erickson's work on the eight developmental stages: trust, autonomy, initiative, accomplishment, identity, intimacy, generativity, and integrity. To have healthy communities, people need to move successfully through these stages. Knowing about these stages can help a person…

The developmental transcriptome atlas of the spoon worm Urechis unicinctus (Echiurida: Annelida).

PubMed

Park, Chungoo; Han, Yong-Hee; Lee, Sung-Gwon; Ry, Kyoung-Bin; Oh, Jooseong; Kern, Elizabeth M A; Park, Joong-Ki; Cho, Sung-Jin

2018-03-01

Echiurida is one of the most intriguing major subgroups of annelida because, unlike most other annelids, echiurids lack metameric body segmentation as adults. For this reason, transcriptome analyses from various developmental stages of echiurid species can be of substantial value for understanding precise expression levels and the complex regulatory networks during early and larval development. A total of 914 million raw RNA-Seq reads were produced from 14 developmental stages of Urechis unicinctus and were de novo assembled into contigs spanning 63,928,225 bp with an N50 length of 2700 bp. The resulting comprehensive transcriptome database of the early developmental stages of U. unicinctus consists of 20,305 representative functional protein-coding transcripts. Approximately 66% of unigenes were assigned to superphylum-level taxa, including Lophotrochozoa (40%). The completeness of the transcriptome assembly was assessed using benchmarking universal single-copy orthologs; 75.7% of the single-copy orthologs were presented in our transcriptome database. We observed 3 distinct patterns of global transcriptome profiles from 14 developmental stages and identified 12,705 genes that showed dynamic regulation patterns during the differentiation and maturation of U. unicinctus cells. We present the first large-scale developmental transcriptome dataset of U. unicinctus and provide a general overview of the dynamics of global gene expression changes during its early developmental stages. The analysis of time-course gene expression data is a first step toward understanding the complex developmental gene regulatory networks in U. unicinctus and will furnish a valuable resource for analyzing the functions of gene repertoires in various developmental phases.

Molecular cloning and mRNA expression pattern of Sox10 in Paramisgurnus dabryanus.

PubMed

Xia, Xiaohua; Chen, Jianjun; Zhang, Linxia; Du, Qiyan; Sun, Jinsheng; Chang, Zhongjie

2013-04-01

A number of genetic studies have established that Sox10 involved in a wide range of developmental processes including sex differentiation and neurogenesis in vertebrates. A Sox10 homologue was cloned from brain of Paramisgurnus dabryanus by using homologous cloning and RACE method, designated as PdSox10. The full-length cDNA of PdSox10 contains a 312 bp 5' UTR, a 1,476 bp open reading frame (ORF) encoding 492 amino acids and a 262 bp 3' UTR (Accession no.: JQ217143). The overall topology of the phylogenetic tree shows that the PdSox10 fits within the Sox10 clade. During embryogenesis, PdSox10 gene seemed to be de novo synthesized in the embryos from gastrulae stage. From the somitogenesis stage and thereafter, distinct expression of PdSox10 was observed in the medial neural tube, extending from the hindbrain through the posterior trunk. In adult, PdSox10 mRNA was detected primarily in the gonads, as well as in brain and heart by RT-PCR. In situ hybridization on gonadal sections further demonstrated that PdSox10 is expressed especially in premature germ cells, in early perinucleolus stage oocytes and cortical-alveolar stage oocytes in ovaries and in spermatogonia and spermatocytes in testes. These preliminary findings suggested that PdSox10 is highly conserved during vertebrate evolution and involved in a wide range of developmental processes including neurogenesis and sex differentiation in vertebrates.

Violent Victimization and Perpetration during Adolescence: Developmental Stage Dependent Ecological Models

ERIC Educational Resources Information Center

Matjasko, Jennifer L.; Needham, Belinda L.; Grunden, Leslie N.; Farb, Amy Feldman

2010-01-01

Using a variant of the ecological-transactional model and developmental theories of delinquency on a nationally representative sample of adolescents, the current study explored the ecological predictors of violent victimization, perpetration, and both for three different developmental stages during adolescence. We examined the relative influence…

Developmental perspectives on personality: implications for ecological and evolutionary studies of individual differences.

PubMed

Stamps, Judy A; Groothuis, Ton G G

2010-12-27

Developmental processes can have major impacts on the correlations in behaviour across contexts (contextual generality) and across time (temporal consistency) that are the hallmarks of animal personality. Personality can and does change: at any given age or life stage it is contingent upon a wide range of experiential factors that occurred earlier in life, from prior to conception through adulthood. We show how developmental reaction norms that describe the effects of prior experience on a given behaviour can be used to determine whether the effects of a given experience at a given age will affect contextual generality at a later age, and to illustrate how variation within individuals in developmental plasticity leads to variation in contextual generality across individuals as a function of experience. We also show why niche-picking and niche-construction, behavioural processes which allow individuals to affect their own developmental environment, can affect the contextual generality and the temporal consistency of personality. We conclude by discussing how an appreciation of developmental processes can alert behavioural ecologists studying animal personality to critical, untested assumptions that underlie their own research programmes, and outline situations in which a developmental perspective can improve studies of the functional significance and evolution of animal personality.

Description of Rhagoletis cerasi (Diptera: Tephritidae) Pupal Developmental Stages: Indications of Prolonged Diapause

PubMed Central

Papanastasiou, Stella A.; Papadopoulos, Nikos T.

2014-01-01

Abstract The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is the key pest of sweet and sour cherries in many European countries and west Asia. It is a univoltine species of the west Palaearctic zone that undergoes obligatory pupal diapause. In this study, the development of R. cerasi pupae that were brought to an optimum temperature for postdiapause development following a long chilling period is described. The six most representative developmental stages within the puparium are illustrated, and the developmental progression among the stages after the end of the chilling period is quantified. Within 20 d postchilling, there was a gradual progress from stage I to pharate adult. However, ∼30% of the pupae remained at the transitional stage II, after 20 d at 25°C (optimum temperature for development). This suggests that a proportion of pupae remain at an intermediate developmental stage for an extended period of time that goes beyond 20 d postchilling. The pupal stage II might be related to diapause termination and responsiveness to environmental cues. It may also define the time before developmental progress to pharate adult. This finding agrees with previous studies proposing that a number of R. cerasi pupae undergo prolonged diapause, though the morphological characteristics of these pupae have never been described before. PMID:25399427

Why Are There Developmental Stages in Language Learning? A Developmental Robotics Model of Language Development.

PubMed

Morse, Anthony F; Cangelosi, Angelo

2017-02-01

Most theories of learning would predict a gradual acquisition and refinement of skills as learning progresses, and while some highlight exponential growth, this fails to explain why natural cognitive development typically progresses in stages. Models that do span multiple developmental stages typically have parameters to "switch" between stages. We argue that by taking an embodied view, the interaction between learning mechanisms, the resulting behavior of the agent, and the opportunities for learning that the environment provides can account for the stage-wise development of cognitive abilities. We summarize work relevant to this hypothesis and suggest two simple mechanisms that account for some developmental transitions: neural readiness focuses on changes in the neural substrate resulting from ongoing learning, and perceptual readiness focuses on the perceptual requirements for learning new tasks. Previous work has demonstrated these mechanisms in replications of a wide variety of infant language experiments, spanning multiple developmental stages. Here we piece this work together as a single model of ongoing learning with no parameter changes at all. The model, an instance of the Epigenetic Robotics Architecture (Morse et al 2010) embodied on the iCub humanoid robot, exhibits ongoing multi-stage development while learning pre-linguistic and then basic language skills. Copyright © 2016 Cognitive Science Society, Inc.

Leaf area and net photosynthesis during development of Prunus serotina seedlings

Treesearch

Stephen B. Horsley; Kurt W. Gottschalk

1993-01-01

We used the plastochron index to study the relationship between plant age, leaf age and development, and net photosynthesis of black cherry (Prtmus serotina Ehrh.) seedlings. Leaf area and net photosynthesis were measured on all leaves >=75 mm of plants ranging in age from 7 to 20 plastochrons. Effects of plant developmental stage...

Specificity of Putative Psychosocial Risk Factors for Psychiatric Disorders in Children and Adolescents

ERIC Educational Resources Information Center

Shanahan, Lilly; Copeland, William; Costello, E. Jane; Angold, Adrian

2008-01-01

Background: Most psychosocial risk factors appear to have general rather than specific patterns of association with common childhood and adolescence disorders. However, previous research has typically failed to 1) control for comorbidity among disorders, 2) include a wide range of risk factors, and 3) examine sex by developmental stage effects on…

Efficient embryonic culture method for the Japanese striped snake, Elaphe quadrivirgata, and its early developmental stages.

PubMed

Matsubara, Yoshiyuki; Sakai, Atsushi; Kuroiwa, Atsushi; Suzuki, Takayuki

2014-10-01

The morphogenesis of snake embryos is an elusive yet fascinating research target for developmental biologists. However, few data exist on development of early snake embryo due to limited availability of pregnant snakes, and the need to harvest early stage embryos directly from pregnant snakes before oviposition without knowing the date of fertilization. We established an ex vivo culture method for early snake embryos using the Japanese striped snake, Elaphe quadrivirgata. This method, which we named "sausage-style (SS) culture", allows us to harvest snake embryos at specific stages for each experiment. Using this SS culture system, we calculated somite formation rate at early stages before oviposition. The average somite formation rate between 6/7 and 12/13 somite stages was 145.9 min, between 60/70 and 80/91 somite stages 42.4 min, and between 113-115 and 126/127 somite stages 71 min. Thus, somite formation rate that we observed during early snake embryogenesis was changed over time. We also describe a developmental staging series for E. quadrivirgata. This is the first report of a developmental series of early snake embryogenesis prior to oviposition by full-color images with high-resolution. We propose that the SS culture system is an easy method for treating early snake embryos ex vivo. © 2014 The Authors Development, Growth & Differentiation © 2014 Japanese Society of Developmental Biologists.

A new system for assessment of growth using mandibular canine calcification stages and its correlation with modified MP3 stages.

PubMed

Hegde, Gautham; Hegde, Nanditha; Kumar, Anil; Keshavaraj

2014-07-01

Orthodontic diagnosis and treatment planning for growing children must involve growth prediction, especially in the treatment of skeletal problems. Studies have shown that a strong association exists between skeletal maturity and dental calcification stages. The present study was therefore taken up to provide a simple and practical method for assessing skeletal maturity using a dental periapical film and standard dental X-ray machine, to compare the developmental stages of the mandibular canine with that of developmental stages of modified MP3 and to find out if any correlation exists, to determine if the developmental stages of the mandibular canine alone can be used as a reliable indicator for assessment of skeletal maturity. A total of 160 periapical radiographs, of the mandibular right canine and the MP3 region was taken and assessed according to the Dermirjian's stages of dental calcification and the modified MP3 stages. The correlation coefficient between MP3 stages and developmental stages of mandibular canine was found to be significant in both male and female groups. When the canine calcification stages were compared with the MP3 stages it was found that with the exception of the D stage of canine calcification the remaining stages showed a very high correlation with the modified MP3 stages. The correlation between the mandibular canine calcification stages, and the MP3 stages was found to be significant. The canine calcification could be used as a sole indicator for assessment of skeletal maturity.

Selection of Lecanicillium Strain with High Virulence against Developmental Stages of Bemisia tabaci

PubMed Central

Park, Heeyong

2010-01-01

Selection of fungal strains with high virulence against the developmental stages of Bemisia tabaci was performed using internal transcribed spacer regions. The growth rate of hyphae was measured and bioassay of each developmental stage of B. tabaci was conducted for seven days. All of the fungal strains tested were identified as Lecanicillium spp., with strain 4078 showing the fastest mycelium growth rate (colony diameter, 16.3 ± 0.9 mm) among the strains. Compared to strain 4075, which showed the slowest growth rate, the growth rate of strain 4078 was increased almost 2-fold after seven days. Strains 4078 and Btab01 were most virulent against the egg and larva stages, respectively. The virulence of fungal strains against the adult stage was high, except for strains 41185 and 3387. Based on the growth rate of mycelium and level of virulence, strains 4078 and Btab01 were selected as the best fungal strains for application to B. tabaci, regardless of developmental stage. PMID:23956657

[Study on the histological anatomy on medicinal parts of Semiaquilegia adoxoides in different developmental stages].

PubMed

Yang, Jun; Peng, Hua-Sheng; Wang, De-Qun; Sun, Jing

2012-08-01

To study the structural characteristics of medicinal parts at different developmental stages of Semiaquilegia adoxoides. Observed on sections of medicinal parts of Semiaquilegia adoxoides at various developmental stages during growth periods. There was a great difference between the upper and bottom of the medicinal parts of Semiaquilegia adoxoides: rhizome at the top of root had the structure of rhizome with pith; The upper one third of enlarged root was root-stem transition zone, also with pith; And the other two thirds of enlarged root had the structure of root without pith. The microscopic structures of the medicinal parts of Semiaquilegia adoxoides at various developmental stages presented great disparities, the structures regularly increased as the size of plant increased. It was the first time to find that there were structure of growth rings in xylem of the root and rhizome of Semiaquilegia adoxoides. The method of identification of characteristics and histology of medicinal parts of Semiaquilegia adoxoides at different developmental stages is established, and the results provide a basis for identification of Semiaquilegia adoxoides medicinal materials.

Telomere length of the colonial coral Galaxea fascicularis at different developmental stages

NASA Astrophysics Data System (ADS)

Tsuta, H.; Hidaka, M.

2013-06-01

The ability to estimate coral age using soft tissue would be useful for population biology or aging studies on corals. In this study, we investigated whether telomere length can be used to estimate coral age. We applied single telomere length analysis to a colonial coral, Galaxea fascicularis, and estimated telomere lengths of specific coral chromosomes at different developmental stages. If the telomere shortened at each cell division, the telomere length of the coral would be longest in sperm and shortest in adult colonies. However, the mean telomere length of sperm, planula larvae, and polyps was approximately 4 kb, with no significant differences among the developmental stages. The telomerase restriction fragment (TRF) analysis also showed no significant difference in the mean TRF length among the developmental stages. Our results suggested that telomere length is maintained during developmental stages and that estimating the age of colonial coral based on telomere length may not be possible. However, our findings can be used to examine avoidance of aging and rejuvenation during regeneration and asexual reproduction in colonial corals.

Sub-lethal and lethal toxicities of elevated CO2 on embryonic, juvenile, and adult stages of marine medaka Oryzias melastigma.

PubMed

Lee, Changkeun; Kwon, Bong-Oh; Hong, Seongjin; Noh, Junsung; Lee, Junghyun; Ryu, Jongseong; Kang, Seong-Gil; Khim, Jong Seong

2018-06-06

The potential leakage from marine CO 2 storage sites is of increasing concern, but few studies have evaluated the probable adverse effects on marine organisms. Fish, one of the top predators in marine environments, should be an essential representative species used for water column toxicity testing in response to waterborne CO 2 exposure. In the present study, we conducted fish life cycle toxicity tests to fully elucidate CO 2 toxicity mechanism effects. We tested sub-lethal and lethal toxicities of elevated CO 2 concentrations on marine medaka (Oryzias melastigma) at different developmental stages. At each developmental stage, the test species was exposed to varying concentrations of gaseous CO 2 (control air, 5%, 10%, 20%, and 30%), with 96 h of exposure at 0-4 d (early stage), 4-8 d (middle stage), and 8-12 d (late stage). Sub-lethal and lethal effects, including early developmental delays, cardiac edema, tail abnormalities, abnormal pigmentation, and mortality were monitored daily during the 14 d exposure period. At the embryonic stage, significant sub-lethal and lethal effects were observed at pH < 6.30. Hypercapnia can cause long-term and/or delayed developmental embryonic problems, even after transfer back to clean seawater. At fish juvenile and adult stages, significant mortality was observed at pH < 5.70, indicating elevated CO 2 exposure might cause various adverse effects, even during short-term exposure periods. It should be noted the early embryonic stage was found more sensitive to CO 2 exposure than other developmental stages of the fish life cycle. Overall, the present study provided baseline information for potential adverse effects of high CO 2 concentration exposure on fish developmental processes at different life cycle stages in marine ecosystems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Large-scale gene expression profiling data for the model moss Physcomitrella patens aid understanding of developmental progression, culture and stress conditions.

PubMed

Hiss, Manuel; Laule, Oliver; Meskauskiene, Rasa M; Arif, Muhammad A; Decker, Eva L; Erxleben, Anika; Frank, Wolfgang; Hanke, Sebastian T; Lang, Daniel; Martin, Anja; Neu, Christina; Reski, Ralf; Richardt, Sandra; Schallenberg-Rüdinger, Mareike; Szövényi, Peter; Tiko, Theodhor; Wiedemann, Gertrud; Wolf, Luise; Zimmermann, Philip; Rensing, Stefan A

2014-08-01

The moss Physcomitrella patens is an important model organism for studying plant evolution, development, physiology and biotechnology. Here we have generated microarray gene expression data covering the principal developmental stages, culture forms and some environmental/stress conditions. Example analyses of developmental stages and growth conditions as well as abiotic stress treatments demonstrate that (i) growth stage is dominant over culture conditions, (ii) liquid culture is not stressful for the plant, (iii) low pH might aid protoplastation by reduced expression of cell wall structure genes, (iv) largely the same gene pool mediates response to dehydration and rehydration, and (v) AP2/EREBP transcription factors play important roles in stress response reactions. With regard to the AP2 gene family, phylogenetic analysis and comparison with Arabidopsis thaliana shows commonalities as well as uniquely expressed family members under drought, light perturbations and protoplastation. Gene expression profiles for P. patens are available for the scientific community via the easy-to-use tool at https://www.genevestigator.com. By providing large-scale expression profiles, the usability of this model organism is further enhanced, for example by enabling selection of control genes for quantitative real-time PCR. Now, gene expression levels across a broad range of conditions can be accessed online for P. patens. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

It Is Only a Stage They Are Going Through: The Development of Student Teachers.

ERIC Educational Resources Information Center

Piland, Diane E.; Anglin, Jacqueline M.

1993-01-01

Describes student teachers' developmental stages. After reviewing pertinent literature, the paper examines a recent study that qualitatively and quantitatively outlined stages of development applicable to contemporary student teaching contexts. The study found that each of five student teachers passed through four developmental stages…

Adolescent and Parent: Interaction between Developmental Stages.

ERIC Educational Resources Information Center

Smith, Barbara

1976-01-01

The focus of this newsletter is on the interaction between two major developmental stages: adolescence and middle age. Research and theories about each stage are presented separately, followed by a discussion of how the two occur within the family structure. This discussion may be useful to teachers, counselors, employers, or researchers working…

Morphogenesis of the human excretory lacrimal system

PubMed Central

de la Cuadra-Blanco, C; Peces-Peña, M D; Jáñez-Escalada, L; Mérida-Velasco, J R

2006-01-01

The aim of this study was to determine the principal developmental stages in the formation of the excretory lacrimal system in humans and to establish its morphogenetic period. The study was performed using light microscopy on serial sections of 51 human specimens: 33 embryos and 18 fetuses ranging from 8 to 137 mm crown–rump length (CR; 5–16 weeks of development). Three stages were identified in the morphogenesis of the excretory lacrimal system: (1) the formative stage of the lacrimal lamina (Carnegie stages 16–18); (2) the formative stage of the lacrimal cord (Carnegie stages 19–23); and (3) the maturative stage of the excretory lacrimal system, from the 9th week of development onward. A three-dimensional reconstruction of the excretory lacrimal system was performed from serial sections of an embryo at the end of the embryonic period (27 mm CR). PMID:16879594

A new system for assessment of growth using mandibular canine calcification stages and its correlation with modified MP3 stages

PubMed Central

Hegde, Gautham; Hegde, Nanditha; Kumar, Anil; Keshavaraj

2014-01-01

Objective: Orthodontic diagnosis and treatment planning for growing children must involve growth prediction, especially in the treatment of skeletal problems. Studies have shown that a strong association exists between skeletal maturity and dental calcification stages. The present study was therefore taken up to provide a simple and practical method for assessing skeletal maturity using a dental periapical film and standard dental X-ray machine, to compare the developmental stages of the mandibular canine with that of developmental stages of modified MP3 and to find out if any correlation exists, to determine if the developmental stages of the mandibular canine alone can be used as a reliable indicator for assessment of skeletal maturity. Materials and Methods: A total of 160 periapical radiographs, of the mandibular right canine and the MP3 region was taken and assessed according to the Dermirjian's stages of dental calcification and the modified MP3 stages. Results and Discussion: The correlation coefficient between MP3 stages and developmental stages of mandibular canine was found to be significant in both male and female groups. When the canine calcification stages were compared with the MP3 stages it was found that with the exception of the D stage of canine calcification the remaining stages showed a very high correlation with the modified MP3 stages. Conclusion: The correlation between the mandibular canine calcification stages, and the MP3 stages was found to be significant. The canine calcification could be used as a sole indicator for assessment of skeletal maturity. PMID:25210386

Description of Rhagoletis cerasi (Diptera: Tephritidae) pupal developmental stages: indications of prolonged diapause.

PubMed

Papanastasiou, Stella A; Papadopoulos, Nikos T

2014-01-01

The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is the key pest of sweet and sour cherries in many European countries and west Asia. It is a univoltine species of the west Palaearctic zone that undergoes obligatory pupal diapause. In this study, the development of R. cerasi pupae that were brought to an optimum temperature for postdiapause development following a long chilling period is described. The six most representative developmental stages within the puparium are illustrated, and the developmental progression among the stages after the end of the chilling period is quantified. Within 20 d postchilling, there was a gradual progress from stage I to pharate adult. However, ∼30% of the pupae remained at the transitional stage II, after 20 d at 25°C (optimum temperature for development). This suggests that a proportion of pupae remain at an intermediate developmental stage for an extended period of time that goes beyond 20 d postchilling. The pupal stage II might be related to diapause termination and responsiveness to environmental cues. It may also define the time before developmental progress to pharate adult. This finding agrees with previous studies proposing that a number of R. cerasi pupae undergo prolonged diapause, though the morphological characteristics of these pupae have never been described before. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

A systematic study on hemocyte identification and plasma prophenoloxidase from Culex pipiens quinquefasciatus at different developmental stages.

PubMed

Wang, Zhixiang; Lu, Anrui; Li, Xuquan; Shao, Qimiao; Beerntsen, Brenda T; Liu, Chaoliang; Ma, Yajun; Huang, Yamin; Zhu, Huaimin; Ling, Erjun

2011-01-01

Culexpipiens quinquefasciatus (C. quinquefasciatus) is an important vector that can transmit human diseases such as West Nile virus, lymphatic filariasis, Japanese encephalitis and St. Louis encephalitis. However, very limited research concerning the humoral and cellular immune defenses of C. quinquefasciatus has been done. Here we present the research on hemocyte identification and plasma including hemocyte prophenoloxidase from C. quinquefasciatus at all developmental stages in order to obtain a complete picture of C. quinquefasciatus innate immunity. We identified hemocytes into four types: prohemocytes, oenocytoids, plasmatocytes and granulocytes. Prophenoloxidase (PPO) is an essential enzyme to induce melanization after encapsulation. PPO-positive hemocytes and plasma PPO were observed at all developmental stages. As for specific hemocyte types, prophenoloxidase was found in the plasmatocytes at larval stage alone and in the smallest prohemocytes during almost all developmental stages. Moreover, the granulocytes were PPO-positive from blood-fed female mosquitoes and oenocytoids were observed PPO-positive in pupae and in adult females after blood-feeding. As for plasma, there were different patterns of PPO in C. quinquefasciatus at different developmental stages. These results are forming a basis for further studies on the function of C. quinquefasciatus hemocytes and prophenoloxidase as well as their involvement in fighting against mosquito-borne pathogens. Copyright © 2010 Elsevier Inc. All rights reserved.

BLIND ordering of large-scale transcriptomic developmental timecourses.

PubMed

Anavy, Leon; Levin, Michal; Khair, Sally; Nakanishi, Nagayasu; Fernandez-Valverde, Selene L; Degnan, Bernard M; Yanai, Itai

2014-03-01

RNA-Seq enables the efficient transcriptome sequencing of many samples from small amounts of material, but the analysis of these data remains challenging. In particular, in developmental studies, RNA-Seq is challenged by the morphological staging of samples, such as embryos, since these often lack clear markers at any particular stage. In such cases, the automatic identification of the stage of a sample would enable previously infeasible experimental designs. Here we present the 'basic linear index determination of transcriptomes' (BLIND) method for ordering samples comprising different developmental stages. The method is an implementation of a traveling salesman algorithm to order the transcriptomes according to their inter-relationships as defined by principal components analysis. To establish the direction of the ordered samples, we show that an appropriate indicator is the entropy of transcriptomic gene expression levels, which increases over developmental time. Using BLIND, we correctly recover the annotated order of previously published embryonic transcriptomic timecourses for frog, mosquito, fly and zebrafish. We further demonstrate the efficacy of BLIND by collecting 59 embryos of the sponge Amphimedon queenslandica and ordering their transcriptomes according to developmental stage. BLIND is thus useful in establishing the temporal order of samples within large datasets and is of particular relevance to the study of organisms with asynchronous development and when morphological staging is difficult.

Radiographic evaluation of third molar development in 6- to 24-year-olds

PubMed Central

Jung, Yun-Hoa

2014-01-01

Purpose This study investigated the developmental stages of third molars in relation to chronological age and compared third molar development according to location and gender. Materials and Methods A retrospective analysis of panoramic radiographs of 2490 patients aged between 6 and 24 years was conducted, and the developmental stages of the third molars were evaluated using the modified Demirjian's classification. The mean age, standard deviation, minimal and maximal age, and percentile distributions were recorded for each stage of development. A Mann-Whitney U test was performed to test the developmental differences in the third molars between the maxillary and mandibular arches and between genders. A linear regression analysis was used for assessing the correlation between the third molar development and chronological age. Results The developmental stages of the third molars were more advanced in the maxillary arch than the mandibular arch. Males reached the developmental stages earlier than females. The average age of the initial mineralization of the third molars was 8.57 years, and the average age at apex closure was 21.96 years. The mean age of crown completion was 14.52 and 15.04 years for the maxillary and the mandibular third molars, respectively. Conclusion The developmental stages of the third molars clearly showed a strong correlation with age. The third molars developed earlier in the upper arch than the lower arch; further, they developed earlier in males than in females. PMID:25279338

Key Facts about Children in Utah. Children and Families at Risk: A Status Report of Our Children, 1994.

ERIC Educational Resources Information Center

Utah Children, Salt Lake City.

The Utah KIDS COUNT program provides information about child well-being to enhance discussions on securing better futures for children. Indicators of children's quality of life are chosen to reflect a range of influences on children, conditions across developmental stages, and comparisons across time. Ten indicators examined included: (1) low…

Cole-Cole parameters for the dielectric properties of porcine tissues as a function of age at microwave frequencies.

PubMed

Peyman, A; Gabriel, C

2010-08-07

We have applied the Cole-Cole expression to the dielectric properties of tissues in the frequency range 0.4-10 GHz. The data underpinning the model relate to pig tissue as a function of age. Altogether, we provide the Cole-Cole parameters for 14 tissue types at three developmental stages.

Can Early Years Professionals Determine Which Preschoolers Have Comprehension Delays? A Comparison of Two Screening Tools

ERIC Educational Resources Information Center

Seager, Emily; Abbot-Smith, Kirsten

2017-01-01

Language comprehension delays in pre-schoolers are predictive of difficulties in a range of developmental domains. In England, early years practitioners are required to assess the language comprehension of 2-year-olds in their care. Many use a format based on the Early Years Foundation Stage Unique Child Communication Sheet (EYFS:UCCS) in which…

Developmental changes in the distribution of cecal lectin-binding sites of Balb-c mice.

PubMed

Doehrn, S; Breipohl, W; Lierse, W; Romaniuk, K; Young, W

1992-01-01

The existence of lectin-binding sites was investigated in the cecum of Balb-c mice at seven developmental stages ranging from 18 days post conception (p.c.) to 8 weeks after birth. Nine horseradish-peroxidase-conjugated lectins (concanavalin A, Triticum vulgaris, Dolichus biflorus, Helix pomatia, Arachis hypogaea, Glycine maximus, Lotus tetragonolobus, Ulex europaeus, Limulus polyphemus) were applied to 5- to 7-microns thin paraffin sections of Bouin-fixed tissue. After DAB staining the sections were evaluated by light microscopy. It was shown that each lectin exhibits a unique developmental pattern. The adult binding patterns were established at the age of 3-4 weeks with only minor changes occurring thereafter. Considerable differences in binding patterns occurred not only between lectins of different groups but also between lectins with the same nominal monosaccharide specificity.

Developmental stages of cultivated strawberry flowers in relation to chilling sensitivity

PubMed Central

Ariza, Maria Teresa; Soria, Carmen; Martínez-Ferri, Elsa

2015-01-01

Environmental factors affecting flower development may limit the yields of fruiting crops worldwide. In temperate regions, chilling temperatures during flower development can compromise fruit production, but their negative effects vary depending on the differing susceptibilities of each developmental stage. The cultivated strawberry (Fragaria× ananassa Duch.) is widely grown worldwide but financial returns are influenced by sudden shifts to chilling temperatures occurring during the cropping cycle. Despite this important limitation, knowledge of F.× ananassa flower development is lacking, in contrast to the diploid wild-type strawberry (F. vesca). In this study we describe steps in floral development of cultivated strawberry and define their vulnerability to chilling temperatures. To achieve this, flower buds from strawberry plants of cv. ‘Camarosa’ were labelled and monitored from bud initiation until anthesis. Description of morphological and functional changes during flower development was based on histological sections and scanning electron microscopy. To determine the impact of low temperatures at different developmental stages, plants carrying buds of different sizes were chilled at 2 °C for 24 h. Several parameters related to male and female gametophyte development were later evaluated in flowers as they approached anthesis. Fragaria× ananassa flower development was divided into 16 stages according to landmark events. These stages were similar to those documented for F. vesca but three new additional intermediate stages were described. Timing of developmental processes was achieved by correlating developmental staging with specific bud sizes and days before anthesis. Time to reach anthesis from early bud stages was 17–18 days. During this period, we detected four critical periods vulnerable to low temperatures. These were mostly related to male gametophyte development but also to injury to female organs at late developmental stages. These results provide the essential groundwork on floral biology of cultivated strawberry that is a prerequisite for successful comparative studies of cold tolerance among genotypes during flower formation. PMID:25661200

Children's understanding of the immune system: Integrating the cognitive-developmental and intuitive theories' perspectives

NASA Astrophysics Data System (ADS)

Landry-Boozer, Kristine L.

Traditional cognitive-developmental researchers have provided a large body of evidence supporting the stage-like progression of children's cognitive development. Further, from this body of research comes evidence that children's understanding of HIV/AIDS develops in much the same way as their understanding of other illness-related concepts. Researchers from a newer perspective assert that biological concepts develop from intuitive theories. In general, as children are exposed to relevant content and have opportunities to organize this information, their theories become more accurate and differentiated. According to this perspective, there are no broad structural constraints on developing concepts, as asserted by cognitive developmental theorists. The purpose of the current study was two-fold: to provide support for both theoretical perspectives, while at the same time to explore children's conceptualizations of the immune system, which has not been done previously in the cognitive-developmental literature. One hundred ninety children ranging in age from 4 years old through 11 years old, and a group of adults, participated. Each participant was interviewed regarding health concepts and the body's function in maintaining health. Participants were also asked to report if they had certain experiences that would have led to relevant content exposure. Qualitative analyses were utilized to code the interviews with rubrics based on both theoretical perspectives. Quantitative analyses consisted of a series of univariate ANOVAs (and post hoc tests when appropriate) examining all three coding variables (accuracy, differentiation, and developmental level) across various age-group combinations and exposure groups. Results of these analyses provided support for both theoretical perspectives. When the data were analyzed for developmental level by all ages, a stage-like progression consistent with Piagetian stages emerged. When accuracy and differentiation were examined (intuitive theories perspective), discrete groups could not be formed. Instead, a gradual increase in accuracy and differentiation was observed. Additional support for this perspective was found when the responses of participants who had additional exposure provided responses that were more accurate, differentiated, and sophisticated than those of participants with no additional exposure. Theoretical and educational implications of these findings are discussed.

Quantitative assessment of pheromone-induced Dauer formation in Caenorhabditis elegans.

PubMed

Neal, Scott J; Kim, Kyuhyung; Sengupta, Piali

2013-01-01

Environmental conditions experienced during early larval stages dictate the developmental trajectory of the nematode C. elegans. Favorable conditions such as low population density, abundant food, and lower temperatures allow reproductive growth, while stressful conditions promote entry of second-stage (L2) larvae into the alternate dauer developmental stage. Population density is signaled by the concentration and composition of a complex mixture of small molecules that is produced by all stages of animals, and is collectively referred to as dauer pheromone; pheromone concentration is a major trigger for dauer formation. Here, we describe a quantitative dauer formation assay that provides a measure of the potency of single or mixtures of pheromone components in regulating this critical developmental decision.

Biochemical and transcriptomic analyses reveal different metabolite biosynthesis profiles among three color and developmental stages in 'Anji Baicha' (Camellia sinensis).

PubMed

Li, Chun-Fang; Xu, Yan-Xia; Ma, Jian-Qiang; Jin, Ji-Qiang; Huang, Dan-Juan; Yao, Ming-Zhe; Ma, Chun-Lei; Chen, Liang

2016-09-08

The new shoots of the albino tea cultivar 'Anji Baicha' are yellow or white at low temperatures and turn green as the environmental temperatures increase during the early spring. 'Anji Baicha' metabolite profiles exhibit considerable variability over three color and developmental stages, especially regarding the carotenoid, chlorophyll, and theanine concentrations. Previous studies focused on physiological characteristics, gene expression differences, and variations in metabolite abundances in albino tea plant leaves at specific growth stages. However, the molecular mechanisms regulating metabolite biosynthesis in various color and developmental stages in albino tea leaves have not been fully characterized. We used RNA-sequencing to analyze 'Anji Baicha' leaves at the yellow-green, albescent, and re-greening stages. The leaf transcriptomes differed considerably among the three stages. Functional classifications based on Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that differentially expressed unigenes were mainly related to metabolic pathways, biosynthesis of secondary metabolites, phenylpropanoid biosynthesis, and carbon fixation in photosynthetic organisms. Chemical analyses revealed higher β-carotene and theanine levels, but lower chlorophyll a levels, in the albescent stage than in the green stage. Furthermore, unigenes involved in carotenoid, chlorophyll, and theanine biosyntheses were identified, and the expression patterns of the differentially expressed unigenes in these biosynthesis pathways were characterized. Through co-expression analyses, we identified the key genes in these pathways. These genes may be responsible for the metabolite biosynthesis differences among the different leaf color and developmental stages of 'Anji Baicha' tea plants. Our study presents the results of transcriptomic and biochemical analyses of 'Anji Baicha' tea plants at various stages. The distinct transcriptome profiles for each color and developmental stage enabled us to identify changes to biosynthesis pathways and revealed the contributions of such variations to the albino phenotype of tea plants. Furthermore, comparisons of the transcriptomes and related metabolites helped clarify the molecular regulatory mechanisms underlying the secondary metabolic pathways in different stages.

Extraction and Refinement Strategy for detection of autism in 18-month-olds: a guarantee of higher sensitivity and specificity in the process of mass screening.

PubMed

Honda, Hideo; Shimizu, Yasuo; Nitto, Yukari; Imai, Miho; Ozawa, Takeshi; Iwasa, Mitsuaki; Shiga, Keiko; Hira, Tomoko

2009-08-01

For early detection of autism, it is difficult to maintain an efficient level of sensitivity and specificity based on observational data from a single screening. The Extraction and Refinement (E&R) Strategy utilizes a public children's health surveillance program to produce maximum efficacy in early detection of autism. In the extraction stage, all cases at risk of childhood problems, including developmental abnormality, are identified; in the refinement stage, cases without problems are excluded, leaving only cases with conclusive diagnoses. The city of Yokohama, Japan, conducts a routine child health surveillance program for children at 18 months in which specialized public health nurses administer YACHT-18 (Young Autism and other developmental disorders CHeckup Tool), a screening instrument to identify children at risk for developmental disorders. Children who screen positive undergo further observation, and those without disorders are subsequently excluded. To study the efficacy of early detection procedures for developmental disorders, including autism, 2,814 children born in 1988, examined at 18 months of age, and not already receiving treatment for diseases or disorders were selected. In the extraction stage, 402 (14.3%) children were identified for follow-up. In the refinement stage, 19 (.7%) of these were referred to the Yokohama Rehabilitation Center and diagnosed with developmental disorders. The extraction stage produced four false negatives, bringing total diagnoses of developmental disorders to 23 (.8%) - including 5 with autistic disorder and 9 with pervasive developmental disorder - not otherwise specified (PDDNOS). Sensitivity was 60% for autistic disorder and 82.6% for developmental disorders. Specificity for developmental disorders rose to 100% with the E&R Strategy. Picture cards used in YACHT-18 provided a finer screen that excluded some false positive cases. An extraction and refinement methodology utilizing child health surveillance programs achieve high efficacy for early detection of autism.

Host species and developmental stage, but not host social structure, affects bacterial community structure in socially polymorphic bees.

PubMed

McFrederick, Quinn S; Wcislo, William T; Hout, Michael C; Mueller, Ulrich G

2014-05-01

Social transmission and host developmental stage are thought to profoundly affect the structure of bacterial communities associated with honey bees and bumble bees, but these ideas have not been explored in other bee species. The halictid bees Megalopta centralis and M. genalis exhibit intrapopulation social polymorphism, which we exploit to test whether bacterial communities differ by host social structure, developmental stage, or host species. We collected social and solitary Megalopta nests and sampled bees and nest contents from all stages of host development. To survey these bacterial communities, we used 16S rRNA gene 454 pyrosequencing. We found no effect of social structure, but found differences by host species and developmental stage. Wolbachia prevalence differed between the two host species. Bacterial communities associated with different developmental stages appeared to be driven by environmentally acquired bacteria. A Lactobacillus kunkeei clade bacterium that is consistently associated with other bee species was dominant in pollen provisions and larval samples, but less abundant in mature larvae and pupae. Foraging adults appeared to often reacquire L. kunkeei clade bacteria, likely while foraging at flowers. Environmental transmission appears to be more important than social transmission for Megalopta bees at the cusp between social and solitary behavior. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

The developmental race between maturing host plants and their butterfly herbivore - the influence of phenological matching and temperature.

PubMed

Posledovich, Diana; Toftegaard, Tenna; Wiklund, Christer; Ehrlén, Johan; Gotthard, Karl

2015-11-01

Interactions between herbivorous insects and their host plants that are limited in time are widespread. Therefore, many insect-plant interactions result in a developmental race, where herbivores need to complete their development before plants become unsuitable, while plants strive to minimize damage from herbivores by outgrowing them. When spring phenologies of interacting species change asymmetrically in response to climate warming, there will be a change in the developmental state of host plants at the time of insect herbivore emergence. In combination with altered temperatures during the subsequent developmental period, this is likely to affect interaction strength as well as fitness of interacting species. Here, we experimentally explore whether the combined effect of phenological matching and thermal conditions influence the outcome of an insect-host interaction. We manipulated both developmental stages of the host plants at the start of the interaction and temperature during the subsequent developmental period in a model system of a herbivorous butterfly, Anthocharis cardamines, and five of its Brassicaceae host plant species. Larval performance characteristics were favoured by earlier stages of host plants at oviposition as well as by higher developmental temperatures on most of the host species. The probability of a larva needing a second host plant covered the full range from no influence of either phenological matching or temperature to strong effects of both factors, and complex interactions between them. The probability of a plant outgrowing a larva was dependent only on the species identity. This study demonstrates that climatic variation can influence the outcome of consumer-resource interactions in multiple ways and that its effects differ among host plant species. Therefore, climate warming is likely to change the temporal match between larval and plant development in some plant species, but not in the others. This is likely to have important implications for host plant use and possibly influence competitive relationships. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

A Comparison of the Developmental Stages Proposed by L. S. Vygotsky and J. Piaget.

ERIC Educational Resources Information Center

Stewin, L. L.; Martin, Jan

The present study was designed to explore the relationship between the theoretical models of cognitive development proposed by L. S. Vygotsky and J. Piaget. One hundred and four subjects aged four to sixteen years were selected. All subjects were in the average range of intelligence, were in the usual school grade for their age, and had no history…

Classification, description, and dynamics of plant communities after fire in the taiga of interior Alaska.

Treesearch

M. Joan Foote

1983-01-01

One hundred thirty forest stands ranging in age from I month postfire to 200 years were sampled and described by successional series (white spruce and black spruce) and by developmental stage (newly burned, moss-herb, tall shrub-sapling, dense tree, hardwood, and spruce). Patterns of change in the two successional series are described. In addition, 12 mature forest...

The vertebrate phylotypic stage and an early bilaterian-related stage in mouse embryogenesis defined by genomic information.

PubMed

Irie, Naoki; Sehara-Fujisawa, Atsuko

2007-01-12

Embryos of taxonomically different vertebrates are thought to pass through a stage in which they resemble one another morphologically. This "vertebrate phylotypic stage" may represent the basic vertebrate body plan that was established in the common ancestor of vertebrates. However, much controversy remains about when the phylotypic stage appears, and whether it even exists. To overcome the limitations of studies based on morphological comparison, we explored a comprehensive quantitative method for defining the constrained stage using expressed sequence tag (EST) data, gene ontologies (GO), and available genomes of various animals. If strong developmental constraints occur during the phylotypic stage of vertebrate embryos, then genes conserved among vertebrates would be highly expressed at this stage. We established a novel method for evaluating the ancestral nature of mouse embryonic stages that does not depend on comparative morphology. The numerical "ancestor index" revealed that the mouse indeed has a highly conserved embryonic period at embryonic day 8.0-8.5, the time of appearance of the pharyngeal arch and somites. During this period, the mouse prominently expresses GO-determined developmental genes shared among vertebrates. Similar analyses revealed the existence of a bilaterian-related period, during which GO-determined developmental genes shared among bilaterians are markedly expressed at the cleavage-to-gastrulation period. The genes associated with the phylotypic stage identified by our method are essential in embryogenesis. Our results demonstrate that the mid-embryonic stage of the mouse is indeed highly constrained, supporting the existence of the phylotypic stage. Furthermore, this candidate stage is preceded by a putative bilaterian ancestor-related period. These results not only support the developmental hourglass model, but also highlight the hierarchical aspect of embryogenesis proposed by von Baer. Identification of conserved stages and tissues by this method in various animals would be a powerful tool to examine the phylotypic stage hypothesis, and to understand which kinds of developmental events and gene sets are evolutionarily constrained and how they limit the possible variations of animal basic body plans.

Great talent, excellent voices-no problem for pubertal girls?

PubMed

Decoster, Wivine; Ghesquiere, Sofie; Van Steenberge, Sebastiaan

2008-01-01

This research on 17 girls (aged 9;9 y to 16;11 y) singing in an established choir was focused on two issues: 1) the variety in physical and vocal development using Gackle's model, and 2) the matching of vocal demands and abilities. Developmental and acoustical data on the speaking and singing voice revealed considerable variation between individual girl singers. The model was greatly applicable. However, all girls had a greater total singing range, mainly in favour of the lower tones, and 11 girls used a lower speaking fundamental frequency. A third of the girls met the vocal and developmental features of their stage at a younger age. Next the lower limit of the frequency range of all girls was several semitones below the lowest notes of the pieces being worked on at the time of the experiment. However the upper limit of the pieces coincided with or exceeded their upper frequency limit.

[Crucial stages of embryogenesis of R. arvalis: Part 1. Linear measurements of embryonic structures].

PubMed

Severtsova, E A; Severtsov, A S

2011-01-01

Investigations of individual variability have allowed us to reveal the crucial (= nodal) stages in embryogenesis of the moor frog (Rana arvalis Nills.). These crucial stages are: the late gastrula stage (stages 18-20), the hatching stages (stages 32-33) and, apparently, early metamorphosis (stage 39). Moreover, we have found that each embryonic structure passes through its specific crucial stages. For example, stage 34 is crucial for the trait "tail width" but is internodal for all other embryonic traits. At this stage, larva passes from an attached to a free-swimming life style. We also found considerable differences between the different frog populations in the the level of developmental variability. These differences were associated with internodal developmental stages.

Not a Stage! A Critical Re-Conception of Young Adolescent Education. Adolescent Cultures, School and Society. Volume 60

ERIC Educational Resources Information Center

Vagle, Mark D., Ed.

2012-01-01

"Not a Stage!" is written for teachers, students, and scholars interested in the academic, social, and emotional needs of young adolescents. It is unique because it actively resists basing the practice, research, and theory of young adolescent education on developmentalism and the developmental stage of young adolescence. The purpose of…

Maternal nutrition, fetal weight, body composition and disease in later life.

PubMed

Zadik, Z

2003-09-01

Nutritional and hormonal milieu in utero affect fetal growth. Both parties involved have an independent chance, for the occurrence of a developmental error at any stage of their constant developing system. Studies suggest that pregnancy outcome is associated with fetal demand for nutrients and the materno-placental capacity to meet that demand. Failure of the materno-placental supply line to satisfy fetal nutrient requirements results in a range of fetal adaptations and developmental changes, and may lead to permanent alterations in the body's structure and metabolism, and thereby to cardiovascular and metabolic disease in adult life. Changes in the in-utero homeostasis may lead to programming of endocrine and metabolic systems so that feedback systems and reactions are permanently changed. At the present stage, short- and long-term hazards of intra-uterine growth retardation (IUGR) have been identified, but preventive strategies are still lacking. It is unlikely that a single factor will reduce a multi-causal outcome like IUGR. Appropriate population-specific interventions should be a priority.

Effects of chronic crude oil exposure on early developmental stages of the Northern krill (Meganyctiphanes norvegica).

PubMed

Arnberg, Maj; Moodley, Leon; Dunaevskaya, Evgenia; Ramanand, Sreerekha; Ingvarsdóttir, Anna; Nilsen, Marianne; Ravagnan, Elisa; Westerlund, Stig; Sanni, Steinar; Tarling, Geraint A; Bechmann, Renée K

2017-01-01

Rising oil and gas activities in northern high latitudes have led to an increased risk of petroleum pollution in these ecosystems. Further, seasonal high UV radiation at high latitudes may elevate photo-enhanced toxicity of petroleum pollution to marine organisms. Zooplanktons are a key ecological component of northern ecosystems; therefore, it is important to assess their sensitivity to potential pollutants of oil and gas activity. As ontogenetic development may be particularly sensitive, the aim of this study was to examine the impact of chronic exposure to oil water dispersion (OWD) on development and feeding of early life stages of the Northern krill, Meganyctiphanes norvegica. In a range of experiments, embryonic, nonfeeding, and feeding larval stages were exposed to concentrations of between 0.01 and 0.1 mg/L of oil or photo-modified oil for 19 and 21 d. No significant effects on egg respiration, hatching success, development, length and larval survival were observed from these treatments. Similarly, evolution of fatty acid composition patterns during ontogenetic development was unaffected. The results indicates a high degree of resilience of these early developmental stages to such types and concentrations of pollutants. However, feeding and motility in later calyptopis-stage larvae were significantly impaired at exposure of 0.1 mg/L oil. Data indicate that feeding larval stage of krill was more sensitive to OWD than early nonfeeding life stages. This might be attributed to the narcotic effects of oil pollutants, their direct ingestion, or accumulated adverse effects over early development.

Personality in the cockroach Diploptera punctata: Evidence for stability across developmental stages despite age effects on boldness.

PubMed

Stanley, Christina R; Mettke-Hofmann, Claudia; Preziosi, Richard F

2017-01-01

Despite a recent surge in the popularity of animal personality studies and their wide-ranging associations with various aspects of behavioural ecology, our understanding of the development of personality over ontogeny remains poorly understood. Stability over time is a central tenet of personality; ecological pressures experienced by an individual at different life stages may, however, vary considerably, which may have a significant effect on behavioural traits. Invertebrates often go through numerous discrete developmental stages and therefore provide a useful model for such research. Here we test for both differential consistency and age effects upon behavioural traits in the gregarious cockroach Diploptera punctata by testing the same behavioural traits in both juveniles and adults. In our sample, we find consistency in boldness, exploration and sociality within adults whilst only boldness was consistent in juveniles. Both boldness and exploration measures, representative of risk-taking behaviour, show significant consistency across discrete juvenile and adult stages. Age effects are, however, apparent in our data; juveniles are significantly bolder than adults, most likely due to differences in the ecological requirements of these life stages. Size also affects risk-taking behaviour since smaller adults are both bolder and more highly explorative. Whilst a behavioural syndrome linking boldness and exploration is evident in nymphs, this disappears by the adult stage, where links between other behavioural traits become apparent. Our results therefore indicate that differential consistency in personality can be maintained across life stages despite age effects on its magnitude, with links between some personality traits changing over ontogeny, demonstrating plasticity in behavioural syndromes.

Personality in the cockroach Diploptera punctata: Evidence for stability across developmental stages despite age effects on boldness

PubMed Central

Mettke-Hofmann, Claudia; Preziosi, Richard F.

2017-01-01

Despite a recent surge in the popularity of animal personality studies and their wide-ranging associations with various aspects of behavioural ecology, our understanding of the development of personality over ontogeny remains poorly understood. Stability over time is a central tenet of personality; ecological pressures experienced by an individual at different life stages may, however, vary considerably, which may have a significant effect on behavioural traits. Invertebrates often go through numerous discrete developmental stages and therefore provide a useful model for such research. Here we test for both differential consistency and age effects upon behavioural traits in the gregarious cockroach Diploptera punctata by testing the same behavioural traits in both juveniles and adults. In our sample, we find consistency in boldness, exploration and sociality within adults whilst only boldness was consistent in juveniles. Both boldness and exploration measures, representative of risk-taking behaviour, show significant consistency across discrete juvenile and adult stages. Age effects are, however, apparent in our data; juveniles are significantly bolder than adults, most likely due to differences in the ecological requirements of these life stages. Size also affects risk-taking behaviour since smaller adults are both bolder and more highly explorative. Whilst a behavioural syndrome linking boldness and exploration is evident in nymphs, this disappears by the adult stage, where links between other behavioural traits become apparent. Our results therefore indicate that differential consistency in personality can be maintained across life stages despite age effects on its magnitude, with links between some personality traits changing over ontogeny, demonstrating plasticity in behavioural syndromes. PMID:28489864

A Pilot Study of the Normative Range of Overnight Urinary Free Cortisol Corrected for Creatinine in Children.

PubMed

Wolthers, Ole D; Mersmann, Sabine; Dissanayake, Sanjeeva

2018-04-01

For more than a decade, urinary free cortisol corrected for creatinine (OUFCC) has been used to assess the systemic bioactivity of inhaled corticosteroids in children with asthma. Paediatric normative ranges, however, have not been established. The aim of the present study was to define a preliminary range for OUFCC in Tanner stage 1 children. A post hoc analysis was performed of 26 Tanner stage one children (aged 5-11 years) with mild asthma only requiring prn (pro re nata) treatment with short-acting β 2 -agonists, who participated in a 3-way cross-over knemometry study. The study comprised a run-in, two washout periods and three treatment periods (2 weeks each). Urine was collected at the end of each period. A normative range was derived using the 95% prediction interval for the geometric mean OUFCC, calculated from run-in and washout periods. Twenty-six children contributed 41 OUFCC values. The geometric mean OUFCC was 9.0 nmol/mmol (95% PI: 3.6, 22.7 nmol/mmol). The OUFCC preliminary normative range was 3.6 to 22.7 nmol/mmol in Tanner stage one children. A larger study in healthy children is warranted to confirm these findings and to assess potential differences in OUFCC across developmental stages and age groups, and by gender and race. 2013-004719-32, CLINICALTRIALS. NCT02063139.

Swimming speed alteration in the early developmental stages of Paracentrotus lividus sea urchin as ecotoxicological endpoint.

PubMed

Morgana, Silvia; Gambardella, Chiara; Falugi, Carla; Pronzato, Roberto; Garaventa, Francesca; Faimali, Marco

2016-04-01

Behavioral endpoints have been used for decades to assess chemical impacts at concentrations unlikely to cause mortality. With recently developed techniques, it is possible to investigate the swimming behavior of several organisms under laboratory conditions. The aims of this study were: i) assessing for the first time the feasibility of swimming speed analysis of the early developmental stage sea urchin Paracentrotus lividus by an automatic recording system ii) investigating any Swimming Speed Alteration (SSA) on P. lividus early stages exposed to a chemical reference; iii) identifying the most suitable stage for SSA test. Results show that the swimming speed of all the developmental stages was easily recorded. The swimming speed was inhibited as a function of toxicant concentration. Pluteus were the most appropriate stage for evaluating SSA in P. lividus as ecotoxicological endpoint. Finally, swimming of sea urchin early stages represents a sensitive endpoint to be considered in ecotoxicological investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Variable sensitivity of US maize yield to high temperatures across developmental stages

NASA Astrophysics Data System (ADS)

Butler, E. E.; Huybers, P. J.

2013-12-01

The sensitivity of maize to high temperatures has been widely demonstrated. Furthermore, field work has indicated that reproductive development stages are particularly sensitive to stress, but this relationship has not been quantified across a wide geographic region. Here, the relationship between maize yield and temperature variations is examined as a function of developmental stage. US state-level data from the National Agriculture Statistics Service provide dates for six growing stages: planting, silking, doughing, dented, mature, and harvested. Temperatures that correspond to each developmental stage are then inferred from a network of weather station observations interpolated to the county level, and a multiple linear regression technique is employed to estimate the sensitivity of county yield outcomes to variations in growing-degree days and an analogous measure of high temperatures referred to as killing-degree days. Uncertainties in the transition times between county-level growth stages are accounted for. Results indicate that the silking and dented stages are generally the most sensitive to killing degree days, with silking the most sensitive stage in the US South and dented the most sensitive in the US North. These variable patterns of sensitivity aid in interpreting which weather events are of greatest significance to maize yields and provide some insight into how shifts in planting time or changes in developmental timing would influence the risks associated with exposure to high temperatures.

Deep sequencing of small RNA libraries reveals dynamic expression patterns of microRNAs in multiple developmental stages of Bactrocera dorsalis.

PubMed

Huang, Y; Dou, W; Liu, B; Wei, D; Liao, C Y; Smagghe, G; Wang, J-J

2014-10-01

In eukaryotes, microRNAs (miRNAs) are small, conserved, noncoding RNAs that have emerged as critical regulators of gene expression. The oriental fruit fly Bactrocera dorsalis is one of the most economically important fruit fly pests in East Asia and the Pacific. Although transcriptome analyses have greatly enriched our knowledge of its structural genes, little is known about post-transcriptional regulation by miRNAs in this dipteran species. In this study, small RNA libraries corresponding to four B. dorsalis developmental stages (eggs, larvae, pupae and adults) were constructed and sequenced. Approximately 30.7 million reads of 18-30 nucleotides were obtained, with 123 known miRNAs and 60 novel miRNAs identified amongst these libraries. More than half of the miRNAs were stage-specific during the four developmental stages. A set of miRNAs was found to be up- or down-regulated during development by comparison of their reads at different developmental stages. Moreover, a small part of miRNAs owned both miR-#-3p and miR-#-5p types, with enormously variable miR-#-3p/miR-#-5p ratios in the same library and amongst different developmental stages for each miRNA. Taking these findings together, the current study has uncovered a number of miRNAs and provided insights into their possible involvement in developmental regulation by expression profiling of miRNAs. Further analyses of the expression and function of these miRNAs could increase our understanding of regulatory networks in this insect and lead to novel approaches for its control. © 2014 The Royal Entomological Society.

A dysmorphology score system for assessing embryo abnormalities in rat whole embryo culture.

PubMed

Zhang, Cindy X; Danberry, Tracy; Jacobs, Mary Ann; Augustine-Rauch, Karen

2010-12-01

The rodent whole embryo culture (WEC) system is a well-established model for characterizing developmental toxicity of test compounds and conducting mechanistic studies. Laboratories have taken various approaches in describing type and severity of developmental findings of organogenesis-stage rodent embryos, but the Brown and Fabro morphological score system is commonly used as a quantitative approach. The associated score criteria is based upon developmental stage and growth parameters, where a series of embryonic structures are assessed and assigned respective scores relative to their gestational stage, with a Total Morphological Score (TMS) assigned to the embryo. This score system is beneficial because it assesses a series of stage-specific anatomical landmarks, facilitating harmonized evaluation across laboratories. Although the TMS provides a quantitative approach to assess growth and determine developmental delay, it is limited to its ability to identify and/or delineate subtle or structure-specific abnormalities. Because of this, the TMS may not be sufficiently sensitive for identifying compounds that induce structure or organ-selective effects. This study describes a distinct morphological score system called the "Dysmorphology Score System (DMS system)" that has been developed for assessing gestation day 11 (approximately 20-26 somite stage) rat embryos using numerical scores to differentiate normal from abnormal morphology and define the respective severity of dysmorphology of specific embryonic structures and organ systems. This method can also be used in scoring mouse embryos of the equivalent developmental stage. The DMS system enhances capabilities to rank-order compounds based upon teratogenic potency, conduct structure- relationships of chemicals, and develop statistical prediction models to support abbreviated developmental toxicity screens. © 2010 Wiley-Liss, Inc.

Maturation experiments reveal bias in the fossil record of feathers

NASA Astrophysics Data System (ADS)

McNamara, Maria; Field, Daniel

2016-04-01

The evolutionary history of birds and feathers is a major focus in palaeobiology and evolutionary biology. Diverse exceptionally preserved birds and feathered dinosaurs from Jurassic and Cretaceous biotas in China have provided pivotal evidence of early feathers and feather-like integumentary features, but the true nature of many of these fossil soft tissues is still debated. Interpretations of feathers at intermediate developmental stages (i.e. Stages II, III and IV) and of simple quill-like (Stage I) feathers are particularly controversial. This reflects key uncertainties relating to the preservation potential of feathers at different evolutionary-developmental stages, and to the relative preservation potential of diagnostic features of Stage I feathers and hair. To resolve these issues, we used high pressure-high temperature autoclave experiments to simulate the effects of burial on modern feathers from the Black Coucal (Centropus grilii) and Common Starling (Sturnus vulgaris), and on human hair. Our results reveal profound differences in the recalcitrance of feathers of different types during maturation: Stage I and Stage V feathers retain diagnostic morphological and ultrastructural details following maturation, whereas other feather types do not. Further, the morphology and arrangement of certain ultrastructural features diagnostic of Stages III and IV, e.g. barbules, are preferentially lost during maturation. These results indicate a pervasive bias in the fossil record of feathers, whereby preservation of feathers at Stages I and V is favored. Critical stages in the evolution of feathers, i.e. Stages II, III and IV, are less likely to be preserved and more likely to be misinterpreted as feathers at earlier developmental stages. Our discovery has major implications for our understanding of the fidelity of the fossil record of feathers and provides a framework for testing the significance of putative examples of fossil feathers at different developmental stages.

DEVELOPMENTAL PALEOBIOLOGY OF THE VERTEBRATE SKELETON.

PubMed

Rücklin, Martin; Donoghue, Philip C J; Cunningham, John A; Marone, Federica; Stampanoni, Marco

2014-07-01

Studies of the development of organisms can reveal crucial information on homology of structures. Developmental data are not peculiar to living organisms, and they are routinely preserved in the mineralized tissues that comprise the vertebrate skeleton, allowing us to obtain direct insight into the developmental evolution of this most formative of vertebrate innovations. The pattern of developmental processes is recorded in fossils as successive stages inferred from the gross morphology of multiple specimens and, more reliably and routinely, through the ontogenetic stages of development seen in the skeletal histology of individuals. Traditional techniques are destructive and restricted to a 2-D plane with the third dimension inferred. Effective non-invasive methods of visualizing paleohistology to reconstruct developmental stages of the skeleton are necessary. In a brief survey of paleohistological techniques we discuss the pros and cons of these methods. The use of tomographic methods to reconstruct development of organs is exemplified by the study of the placoderm dentition. Testing evidence for the presence of teeth in placoderms, the first jawed vertebrates, we compare the methods that have been used. These include inferring the development from morphology, and using serial sectioning, microCT or synchrotron X-ray tomographic microscopy (SRXTM) to reconstruct growth stages and directions of growth. The ensuing developmental interpretations are biased by the methods and degree of inference. The most direct and reliable method is using SRXTM data to trace sclerochronology. The resulting developmental data can be used to resolve homology and test hypotheses on the origin of evolutionary novelties.

SLA Developmental Stages and Teachers' Assessment of Written French: Exploring Direkt Profil as a Diagnostic Assessment Tool

ERIC Educational Resources Information Center

Granfeldt, Jonas; Ågren, Malin

2014-01-01

One core area of research in Second Language Acquisition is the identification and definition of developmental stages in different L2s. For L2 French, Bartning and Schlyter (2004) presented a model of six morphosyntactic stages of development in the shape of grammatical profiles. The model formed the basis for the computer program Direkt Profil…

The Historical Emergence of Adolescence: Perspectives from Developmental Psychology and Adolescent Literature.

ERIC Educational Resources Information Center

Matter, Roxana Marie

1984-01-01

Reviews the literature from two distinct disciplines, developmental psychology and literature, reflecting the emergence of adolescence as a recognized stage in human development. Describes both cognitive and stage theories of adolescence and medieval concerns as well as twentieth century interest. (JAC)

The Association of Parent Mindfulness with Parenting and Youth Psychopathology Across Three Developmental Stages.

PubMed

Parent, Justin; McKee, Laura G; N Rough, Jennifer; Forehand, Rex

2016-01-01

The primary purpose of the current study was to test a model examining the process by which parent dispositional mindfulness relates to youth psychopathology through mindful parenting and parenting practices. The universality of the model across youth at three developmental stages was examined: young childhood (3-7 years; n = 210), middle childhood (8-12 years; n = 200), and adolescence (13-17 years; n = 205). Overall, participants were 615 parents (55% female) and one of their 3-to-17 year old children (45% female). Parents reported on their dispositional mindfulness, mindful parenting, positive and negative parenting practices and their child's or adolescent's internalizing and externalizing problems. Consistent findings across all three developmental stages indicated that higher levels of parent dispositional mindfulness were indirectly related to lower levels of youth internalizing and externalizing problems through higher levels of mindful parenting and lower levels of negative parenting practices. Replication of these findings across families with children at different developmental stages lends support to the generalizability of the model.

Comparison of glucose metabolism in in vivo- and in vitro-matured tammar wallaby oocytes and its relationship to developmental potential following intracytoplasmic sperm injection.

PubMed

Magarey, Genevieve M; Mate, Karen E

2004-01-01

Although marsupial oocytes undergo nuclear maturation in vitro, there is, at present, no indication of their developmental potential, largely owing to the lack of in vitro fertilisation and related technologies for marsupials. Glucose metabolism has proven a useful indicator of oocyte cytoplasmic maturation and developmental potential in several eutherian species. Therefore, the aims of the present study were to compare: (1) the rates of glycolysis and glucose oxidation in immature, in vitro-matured and in vivo-matured tammar wallaby oocytes; and (2) the metabolic rate of individual oocytes with their ability to form pronuclei after intracytoplasmic sperm injection. The rates of glycolysis measured in immature (2.18 pmol oocyte(-1) h(-1)), in vitro- matured (0.93 pmol oocyte(-1) h(-1)) and in vivo-matured tammar wallaby oocytes (0.54 pmol oocyte(-1) h(-1)) were within a similar range to values obtained in eutherian species. However, unlike the trend observed in eutherian oocytes, the glycolytic rate was significantly higher in immature oocytes compared with either in vivo- or in vitro-matured oocytes (P < 0.001) and significantly higher in in vitro-matured oocytes compared with in vivo-matured oocytes (P < 0.001). No relationship was identified between glucose metabolism and the developmental capacity of oocytes after intracytoplasmic sperm injection when assessed after 17-19 h. Oocytes that became fertilised (two pronuclei) or activated (one or more pronucleus) were not distinguished from others by their metabolic rates. Longer culture after intracytoplasmic sperm injection (e.g. blastocyst stage) may show oocyte glucose metabolism to be predictive of developmental potential; however, culture to the single-cell stage did not reveal any significant differences in normally developing embryos.

Ascaroside expression in Caenorhabditis elegans is strongly dependent on diet and developmental stage

USDA-ARS?s Scientific Manuscript database

A group of small signaling molecules called ascarosides, associated with dauer formation, male attraction and social behavior in the nematode Caenorhabditis elegans, are shown to be regulated by developmental stage and environmental factors. The concentration of dauer-inducing ascaroside, ascr#2, i...

The Lunar CELSS Test Module

NASA Technical Reports Server (NTRS)

Hoehn, Alexander; Gomez, Shawn; Luttges, Marvin W.

1992-01-01

The evolutionarily-developed Lunar Controlled Ecological Life Support System (CELSS) Test Module presented can address questions concerning long-term human presence-related issues both at LEO and in the lunar environment. By achieving well-defined research goals at each of numerous developmental stages (each economically modest), easily justifiable operations can be undertaken. Attention is given to the possibility of maximizing non-NASA involvement in these CELSS developmental efforts via the careful definability and modest risk of each developmental stage.

Comparative transcriptome analysis reveals vertebrate phylotypic period during organogenesis

PubMed Central

Irie, Naoki; Kuratani, Shigeru

2011-01-01

One of the central issues in evolutionary developmental biology is how we can formulate the relationships between evolutionary and developmental processes. Two major models have been proposed: the 'funnel-like' model, in which the earliest embryo shows the most conserved morphological pattern, followed by diversifying later stages, and the 'hourglass' model, in which constraints are imposed to conserve organogenesis stages, which is called the phylotypic period. Here we perform a quantitative comparative transcriptome analysis of several model vertebrate embryos and show that the pharyngula stage is most conserved, whereas earlier and later stages are rather divergent. These results allow us to predict approximate developmental timetables between different species, and indicate that pharyngula embryos have the most conserved gene expression profiles, which may be the source of the basic body plan of vertebrates. PMID:21427719

Shotgun proteomics approach to characterizing the embryonic proteome of the silkworm, Bombyx mori, at labrum appearance stage.

PubMed

Li, J-Y; Chen, X; Hosseini Moghaddam, S H; Chen, M; Wei, H; Zhong, B-X

2009-10-01

The shotgun approach has gained considerable acknowledgement in recent years as a dominant strategy in proteomics. We observed a dramatic increase of specific protein spots in two-dimensional electrophoresis (2-DE) gels of the silkworm (Bombyx mori) embryo at labrum appearance, a characteristic stage during embryonic development of silkworm which is involved with temperature increase by silkworm raiser. We employed shotgun liquid chromatography tandem mass spectrometry (LC-MS/MS) technology to analyse the proteome of B. mori embryos at this stage. A total of 2168 proteins were identified with an in-house database. Approximately 47% of them had isoelectric point (pI) values distributed theoretically in the range pI 5-7 and approximately 60% of them had molecular weights of 15-45 kDa. Furthermore, 111 proteins had an pI greater than 10 and were difficult to separate by 2-DE. Many important functional proteins related to embryonic development, stress response, DNA transcription/translation, cell growth, proliferation and differentiation, organogenesis and reproduction were identified. Among them proteins related to nervous system development were noticeable. All known heat shock proteins (HSPs) were detected in this developmental stage of B. mori embryo. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed energetic metabolism at this stage. These results were expected to provide more information for proteomic monitoring of the insect embryo and better understanding of the spatiotemporal expression of genes during embryonic developmental processes.

Mutagen-induced fetal anomalies and death following treatment of females within hours after mating.

PubMed

Generoso, W M; Rutledge, J C; Cain, K T; Hughes, L A; Downing, D J

1988-05-01

In an earlier study (Generoso et al., 1987), it was observed that the mutagen, ethylene oxide (EtO), produced remarkable increases in the incidence of developmental abnormalities and death of fetuses when early zygotic stages were exposed. This is a major finding in experimental induction of embryopathy, implicating genetic damage to the zygotes as the likely cause. In the subsequent study reported here, 3 other mutagens--ethyl methanesulfonate (EMS), ethyl nitrosourea (ENU), and triethylene melamine (TEM), were studied for embryopathic effects following exposure of dictyate oocytes, prefertilization oviducal eggs and sperm, early pronuclear zygotes, zygotes undergoing pronuclear DNA synthesis, and two-cell embryos. All 4 mutagens produced developmental abnormalities among living fetuses following exposure of early pronuclear zygotes (the only stage studied for this endpoint in this report). With respect to stage specificity and gestational timing of death of conceptuses, EMS and EtO on one hand and ENU and TEM on the other, are very similar to one another. EMS, like EtO, produced a high incidence of midgestation and late fetal deaths only in prefertilization oviducal eggs and sperm and in early pronuclear eggs. In contrast, ENU and TEM produced high losses of conceptuses in all postmating stages studied but death occurred primarily prior to or around the time of implantation. Thus, the frequency of induction and the expression of embryopathy, which ranged from early embryonic preimplantation and late fetal deaths to subtle fetal anomalies, are dependent upon the stage exposed and the mutagen used.

The Developmental Stages of a Community–University Partnership

PubMed Central

Allen, Michele L.; Svetaz, María Veronica; Hurtado, G. Ali; Linares, Roxana; Garcia-Huidobro, Diego; Hurtado, Monica

2013-01-01

Background: Strong and sustained community–university partnerships are necessary for community-based participatory translational research. Little attention has been paid to understanding the trajectory of research partnerships from a developmental perspective. Objective: To propose a framework describing partnership development and maturation based on Erikson’s eight stages of psychosocial development and describe how our collaboration is moving through those stages. Methods: Collaborators engaged in three rounds of iterative reflection regarding characteristics and contributors to the maturation of the Padres Informados/Jovenes Preparados (Informed Parents/Prepared Youth [PI/JP]) partnership. Lessons Learned: Each stage is characterized by broad developmental partnership tasks. Conflict or tension within the partnership is often a part of achieving the associated tasks. The strengths developed at each stage prepare the partnership for challenges associated with subsequent stages. Conclusions: This framework could provide a means for partnerships to reflect on their strengths and challenges at a given time point, and to help understand why some partnerships fail whereas others achieve maturity. PMID:24056509

The developmental stages of a community-university partnership: the experience of Padres Informados/Jovenes Preparados.

PubMed

Allen, Michele L; Svetaz, A Veronica; Hurtado, G Ali; Linares, Roxana; Garcia-Huidobro, Diego; Hurtado, Monica

2013-01-01

Strong and sustained community-university partnerships are necessary for community-based participatory translational research. Little attention has been paid to understanding the trajectory of research partnerships from a developmental perspective. To propose a framework describing partnership development and maturation based on Erikson's eight stages of psychosocial development and describe how our collaboration is moving through those stages. Collaborators engaged in three rounds of iterative reflection regarding characteristics and contributors to the maturation of the Padres Informados/Jovenes Preparados (Informed Parents/Prepared Youth [PI/JP]) partnership. Each stage is characterized by broad developmental partnership tasks. Conflict or tension within the partnership is often a part of achieving the associated tasks. The strengths developed at each stage prepare the partnership for challenges associated with subsequent stages. This framework could provide a means for partnerships to reflect on their strengths and challenges at a given time point, and to help understand why some partnerships fail whereas others achieve maturity.

Coherence of Personal Narratives across the Lifespan: A Multidimensional Model and Coding Method

PubMed Central

Reese, Elaine; Haden, Catherine A.; Baker-Ward, Lynne; Bauer, Patricia; Fivush, Robyn; Ornstein, Peter A.

2012-01-01

Personal narratives are integral to autobiographical memory and to identity, with coherent personal narratives being linked to positive developmental outcomes across the lifespan. In this article, we review the theoretical and empirical literature that sets the stage for a new lifespan model of personal narrative coherence. This new model integrates context, chronology, and theme as essential dimensions of personal narrative coherence, each of which relies upon different developmental achievements and has a different developmental trajectory across the lifespan. A multidimensional method of coding narrative coherence (the Narrative Coherence Coding Scheme or NaCCS) was derived from the model and is described here. The utility of this approach is demonstrated by its application to 498 narratives that were collected in six laboratories from participants ranging in age from 3 years to adulthood. The value of the model is illustrated further by a discussion of its potential to guide future research on the developmental foundations of narrative coherence and on the benefits of personal narrative coherence for different aspects of psychological functioning. PMID:22754399

Does playing pay? The fitness-effect of free play during childhood.

PubMed

Greve, Werner; Thomsen, Tamara; Dehio, Cornelia

2014-04-29

Evolutionary developmental psychology claims that the sequences and processes of human development, in fact the mere fact of ontogeny itself, have to be viewed as evolutionary products. However, although the functional benefits of childish behavior (child playing) for cognitive and emotional development have been shown repeatedly, claiming evolutionary adaptiveness of playing in childhood suggests that childish play supports evolutionary success in mature stages of development. This hypothesis is tested in a study with N=134 adults (93 females; age range 20-66 years). Participants were asked to recollect their play experiences during childhood in detail, and to report their current developmental status with respect to several aspects of social success. Results show that the opportunity for and the promotion of free play in childhood significantly predict some indicators of social success. Additional analyses strive to explore mediating processes for this relationship. In particular, the mediating role of individual adaptivity (flexibility of goal adjustment) is investigated. Results suggest that freely playing in childhood promotes developmental resources, in particular individual adaptivity in adulthood, which, in turn, promote developmental success.

Perspectives of Young Children: How Do They Really Think?

ERIC Educational Resources Information Center

Costley, Kevin C.

2010-01-01

In his monumental research, although Piaget primarily relayed information about children's developmental stages of cognitive growth, Marian Marion goes on to discuss not only the developmental stages, yet focuses on how children think. In her textbook, "Guidance of Young Children", Marion conveys how teachers need to understand children and help…

Fine Sediment Effects on Brook Trout Eggs in Laboratory Streams

Treesearch

David G. Argent; Patricia A. Flebbe

1999-01-01

This study was designed to determine effects of different fine sediments (0.43-0.85 mm in diameter) on survival of brook trout (Salvelinus fontinalis) eggs during early developmental stages under laboratory conditions. Intragravel permeability and dissolved oxygen declined with increasing fine sediment amounts. Survival at each developmental stage...

Attachment in Middle Childhood: An Evolutionary-Developmental Perspective

ERIC Educational Resources Information Center

Del Giudice, Marco

2015-01-01

Middle childhood is a key transitional stage in the development of attachment processes and representations. Here I discuss the middle childhood transition from an evolutionary-developmental perspective and show how this approach offers fresh insight into the function and organization of attachment in this life stage. I begin by presenting an…

Massive shift in gene expression during transitions between developmental stages of the Gall Midge, Mayetiola destructor

USDA-ARS?s Scientific Manuscript database

The gall midge Mayetiola destructor is a destructive pest of wheat worldwide and a model organism for studying plant – insect interactions. The insect has six different developmental stages including eggs, three instars of larvae, pupae, and adults. Molecular mechanisms controlling the transition ...

Oral Care for Developmentally Disabled Children: The Primary Dentition Stage.

ERIC Educational Resources Information Center

Kenny, David J.; Judd, Peter L.

1988-01-01

Developmental disabilities and chronic illness can impact the oral health of children in the preeruptive and primary dentition stages. The article covers prevention and management of dental caries; gingival changes; trauma to the primary dentition; sucking, swallowing, and mastication; extraorally fed patients; and factitial injuries. Home-care…

47 CFR 2.803 - Marketing of radio frequency devices prior to equipment authorization.

Code of Federal Regulations, 2010 CFR

2010-10-01

... device that is in the conceptual, developmental, design or pre-production stage is permitted prior to... operation takes place at the manufacturer's facilities during developmental, design, or pre-production... development, design or pre-production stages. A product operated under this provision shall be labelled, in a...

47 CFR 2.803 - Marketing of radio frequency devices prior to equipment authorization.

Code of Federal Regulations, 2012 CFR

2012-10-01

... device that is in the conceptual, developmental, design or pre-production stage is permitted prior to... operation takes place at the manufacturer's facilities during developmental, design, or pre-production... development, design or pre-production stages. A product operated under this provision shall be labelled, in a...

47 CFR 2.803 - Marketing of radio frequency devices prior to equipment authorization.

Code of Federal Regulations, 2011 CFR

2011-10-01

... device that is in the conceptual, developmental, design or pre-production stage is permitted prior to... operation takes place at the manufacturer's facilities during developmental, design, or pre-production... development, design or pre-production stages. A product operated under this provision shall be labelled, in a...

Metabolic Profiles and Free Radical Scavenging Activity of Cordyceps bassiana Fruiting Bodies According to Developmental Stage

PubMed Central

Hyun, Sun-Hee; Lee, Seok-Young; Sung, Gi-Ho; Kim, Seong Hwan; Choi, Hyung-Kyoon

2013-01-01

The metabolic profiles of Cordyceps bassiana according to fruiting body developmental stage were investigated using gas chromatography-mass spectrometry. We were able to detect 62 metabolites, including 48 metabolites from 70% methanol extracts and 14 metabolites from 100% n-hexane extracts. These metabolites were classified as alcohols, amino acids, organic acids, phosphoric acids, purine nucleosides and bases, sugars, saturated fatty acids, unsaturated fatty acids, or fatty amides. Significant changes in metabolite levels were found according to developmental stage. Relative levels of amino acids, purine nucleosides, and sugars were higher in development stage 3 than in the other stages. Among the amino acids, valine, isoleucine, lysine, histidine, glutamine, and aspartic acid, which are associated with ABC transporters and aminoacyl-tRNA biosynthesis, also showed higher levels in stage 3 samples. The free radical scavenging activities, which were significantly higher in stage 3 than in the other stages, showed a positive correlation with purine nucleoside metabolites such as adenosine, guanosine, and inosine. These results not only show metabolic profiles, but also suggest the metabolic pathways associated with fruiting body development stages in cultivated C. bassiana. PMID:24058459

Effects of ionizing radiation on embryos of the tardigrade Milnesium cf. tardigradum at different stages of development.

PubMed

Beltrán-Pardo, Eliana; Jönsson, K Ingemar; Wojcik, Andrzej; Haghdoost, Siamak; Harms-Ringdahl, Mats; Bermúdez-Cruz, Rosa M; Bernal Villegas, Jaime E

2013-01-01

Tardigrades represent one of the most desiccation and radiation tolerant animals on Earth, and several studies have documented their tolerance in the adult stage. Studies on tolerance during embryological stages are rare, but differential effects of desiccation and freezing on different developmental stages have been reported, as well as dose-dependent effect of gamma irradiation on tardigrade embryos. Here, we report a study evaluating the tolerance of eggs from the eutardigrade Milnesium cf. tardigradum to three doses of gamma radiation (50, 200 and 500 Gy) at the early, middle, and late stage of development. We found that embryos of the middle and late developmental stages were tolerant to all doses, while eggs in the early developmental stage were tolerant only to a dose of 50 Gy, and showed a declining survival with higher dose. We also observed a delay in development of irradiated eggs, suggesting that periods of DNA repair might have taken place after irradiation induced damage. The delay was independent of dose for eggs irradiated in the middle and late stage, possibly indicating a fixed developmental schedule for repair after induced damage. These results show that the tolerance to radiation in tardigrade eggs changes in the course of their development. The mechanisms behind this pattern are unknown, but may relate to changes in mitotic activities over the embryogenesis and/or to activation of response mechanisms to damaged DNA in the course of development.

Effects of Ionizing Radiation on Embryos of the Tardigrade Milnesium cf. tardigradum at Different Stages of Development

PubMed Central

Beltrán-Pardo, Eliana; Jönsson, K. Ingemar; Wojcik, Andrzej; Haghdoost, Siamak; Harms-Ringdahl, Mats; Bermúdez-Cruz, Rosa M.; Bernal Villegas, Jaime E.

2013-01-01

Tardigrades represent one of the most desiccation and radiation tolerant animals on Earth, and several studies have documented their tolerance in the adult stage. Studies on tolerance during embryological stages are rare, but differential effects of desiccation and freezing on different developmental stages have been reported, as well as dose-dependent effect of gamma irradiation on tardigrade embryos. Here, we report a study evaluating the tolerance of eggs from the eutardigrade Milnesium cf. tardigradum to three doses of gamma radiation (50, 200 and 500 Gy) at the early, middle, and late stage of development. We found that embryos of the middle and late developmental stages were tolerant to all doses, while eggs in the early developmental stage were tolerant only to a dose of 50 Gy, and showed a declining survival with higher dose. We also observed a delay in development of irradiated eggs, suggesting that periods of DNA repair might have taken place after irradiation induced damage. The delay was independent of dose for eggs irradiated in the middle and late stage, possibly indicating a fixed developmental schedule for repair after induced damage. These results show that the tolerance to radiation in tardigrade eggs changes in the course of their development. The mechanisms behind this pattern are unknown, but may relate to changes in mitotic activities over the embryogenesis and/or to activation of response mechanisms to damaged DNA in the course of development. PMID:24039737

Quantitative developmental transcriptomes of the Mediterranean sea urchin Paracentrotus lividus.

PubMed

Gildor, Tsvia; Malik, Assaf; Sher, Noa; Avraham, Linor; Ben-Tabou de-Leon, Smadar

2016-02-01

Embryonic development progresses through the timely activation of thousands of differentially activated genes. Quantitative developmental transcriptomes provide the means to relate global patterns of differentially expressed genes to the emerging body plans they generate. The sea urchin is one of the classic model systems for embryogenesis and the models of its developmental gene regulatory networks are of the most comprehensive of their kind. Thus, the sea urchin embryo is an excellent system for studies of its global developmental transcriptional profiles. Here we produced quantitative developmental transcriptomes of the sea urchin Paracentrotus lividus (P. lividus) at seven developmental stages from the fertilized egg to prism stage. We generated de-novo reference transcriptome and identified 29,817 genes that are expressed at this time period. We annotated and quantified gene expression at the different developmental stages and confirmed the reliability of the expression profiles by QPCR measurement of a subset of genes. The progression of embryo development is reflected in the observed global expression patterns and in our principle component analysis. Our study illuminates the rich patterns of gene expression that participate in sea urchin embryogenesis and provide an essential resource for further studies of the dynamic expression of P. lividus genes. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of increased temperature on metabolic activity and oxidative stress in the first life stages of marble trout (Salmo marmoratus).

PubMed

Simčič, Tatjana; Jesenšek, Dušan; Brancelj, Anton

2015-08-01

Climate change may result in future alterations in thermal regime which could markedly affect the early developmental stages of cold water fish due to their expected high sensitivity to increasing temperature. In the present study, the effect of temperature increase of 2, 4 and 6°C on the oxygen consumption rate (R), the activity of respiratory electron transport system (ETS) and oxidative stress have been studied in four developmental stages of the marble trout (Salmo marmoratus)-eyed eggs, yolk-sac larvae and juveniles of 1 and 3 months. Oxygen consumption rate and ETS activity increased with level of development and with temperature in all four stages. ETS/R ratios decreased during development and correlated with temperature in eyed eggs, larvae and juveniles of 1 month, but not in juveniles of 3 months. Low ETS/R ratios at higher temperatures indicate stress response in eyed eggs, the most temperature sensitive developmental stage. Catalase (CAT) and glutathione reductase (GR) activities increased during development, but responded differently to elevated temperature in the different developmental stages. Stress in eyed eggs, caused by higher temperatures, resulted in increased oxygen consumption rate and increased activities of CAT and GR. Larvae were sensitive to increased temperature only at the highest experimental temperature of 16°C. Increased temperature did not stress the metabolism of the juveniles, since they were able to compensate their metabolic activity. The earlier developmental stages of marble trout are thus more sensitive to temperature increase than juveniles and therefore more endangered by higher water temperatures. This is the first report connecting oxygen consumption, ETS activity and ETS/R ratio with the activities of antioxidant enzymes in relation to increased temperature in salmonids.

A systematic literature review of sex differences in childhood language and brain development.

PubMed

Etchell, Andrew; Adhikari, Aditi; Weinberg, Lauren S; Choo, Ai Leen; Garnett, Emily O; Chow, Ho Ming; Chang, Soo-Eun

2018-06-01

The extent of sex differences in childhood language development is unclear. We conducted a systematic literature review synthesizing results from studies examining sex differences in brain structure and function relevant to language development during childhood. We searched PubMed and Scopus databases, and this returned a total of 46 published studies meeting criteria for inclusion that directly examined sex differences in brain development relevant to language function in children. The results indicate that: (a) sex differences in brain structure or function do not necessarily lead to differences in language task performance; (b) evidence for sex differences in brain and language development are limited; (c) when present, sex differences often interact with a variety of factors such as age and task. Overall, the magnitude of sexual dimorphism of brain developmental trajectories associated with language is not as significant as previously thought. Sex differences were found, however, in studies employing tighter age ranges. This suggests that sex differences may be more prominent during certain developmental stages but are negligible in other stages, likely due to different rates of maturation between the sexes. More research is needed to improve our understanding of how sex differences may arise due to the influence of sex hormones and developmental stages, and how these differences may lead to differences in various language task performance. These studies are expected to provide normative information that may be used in studies examining neurodevelopmental disorders that frequently affect more males than females, and also often affect language development. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of experimental warming on survival, phenology and morphology of an aquatic insect (Odonata)

PubMed Central

McCauley, Shannon J.; Hammond, John I.; Frances, Dachin N.; Mabry, Karen E.

2014-01-01

1. Organisms can respond to changing climatic conditions in multiple ways including changes in phenology, body size or morphology, and range shifts. Understanding how developmental temperatures affect insect life-history timing and morphology is crucial because body size and morphology affect multiple aspects of life history, including dispersal ability, while phenology can shape population performance and community interactions. 2. We experimentally assessed how developmental temperatures experienced by aquatic larvae affected survival, phenology, and adult morphology of dragonflies (Pachydiplax longipennis). Larvae were reared under 3 environmental temperatures: ambient, +2.5 °C, and +5 °C, corresponding to temperature projections for our study area 50 and 100 years in the future, respectively. Experimental temperature treatments tracked naturally-occurring variation. 3. We found clear effects of temperature in the rearing environment on survival and phenology: dragonflies reared at the highest temperatures had the lowest survival rates, and emerged from the larval stage approximately 3 weeks earlier than animals reared at ambient temperatures. There was no effect of rearing temperature on overall body size. Although neither the relative wing nor thorax size was affected by warming, a non-significant trend towards an interaction between sex and warming in relative thorax size suggests that males may be more sensitive to warming than females, a pattern that should be investigated further. 4. Warming strongly affected survival in the larval stage and the phenology of adult emergence. Understanding how warming in the developmental environment affects later life-history stages is critical to interpreting the consequences of warming for organismal performance. PMID:26028806

Stage-Dependent Expression of Deltamethrin Toxicity and Resistance in Triatoma infestans (Hemiptera: Reduviidae) From Argentina.

PubMed

Germano, Mónica D; Picollo, María I

2018-02-20

Triatoma infestans Klug (Hemiptera: Reduviidae) is the main vector of Chagas disease in Latin America. This insect has been controlled with pyrethroids since the 1980s, although the emergence of resistance to deltamethrin has decreased control success in some areas of the Gran Chaco ecoregion. The response of T. infestans to deltamethrin was evaluated per developmental stage. In addition, we evaluated the possible stage-dependent expression of deltamethrin resistance. The bioassays were conducted by topical application of the insecticide in acetone. The drop size, age at the time of exposure, and mortality measuring time were standardized per stage. The lethal dose of deltamethrin moderately increased with the developmental stage. The resistance to deltamethrin was expressed in every instar, and was the highest in the fourth- and fifth-instar nymphs. While increasing, weight plays a relevant role in lethal dose stage dependency, a number of contributing factors such as degradative metabolism are probably involved in the variability of insecticide effect and resistance described for different T. infestans developmental stages. Possible explanations for these differences and their implications on resistance management and chemical control are discussed.

Phenoloxidase activity among developmental stages and pupal cell types of the ground beetle Carabus (Chaetocarabus) lefebvrei (Coleoptera, Carabidae).

PubMed

Giglio, Anita; Giulianini, Piero Giulio

2013-04-01

In ecological immunology is of great importance the study of the immune defense plasticity as response to a variable environment. In holometabolous insects the fitness of each developmental stage depends on the capacity to mount a response (i.e. physiological, behavioral) under environmental pressure. The immune response is a highly dynamic trait closely related to the ecology of organism and the variation in the expression of an immune system component may affect another fitness relevant trait of organism (i.e. growth, reproduction). The present research quantified immune function (total and differential number of hemocytes, phagocytosis in vivo and activity of phenoloxidase) in the pupal stage of Carabus (Chaetocarabus) lefebvrei. Moreover, the cellular and humoral immune function was compared across the larval, pupal and adult stages to evaluate the changes in immunocompetence across the developmental stages. Four types of circulating hemocytes were characterized via transmission electron microscopy in the pupal stage: prohemocytes, plasmatocytes, granulocytes and oenocytoids. The artificial non-self-challenge treatments performed in vivo have shown that plasmatocytes and granulocytes are responsible for phagocytosis. The level of active phenoloxidase increases with the degree of pigmentation of the cuticle in each stage. In C. lefebvrei, there are different strategies in term of immune response to enhance the fitness of each life stage. The results have shown that the variation in speed and specificity of immune function across the developmental stages is correlated with differences in infection risk, life expectancy and biological function of the life cycle. Copyright © 2013 Elsevier Ltd. All rights reserved.

Insulin/Insulin-like growth factor signaling controls non-Dauer developmental speed in the nematode Caenorhabditis elegans.

PubMed

Ruaud, Anne-Françoise; Katic, Iskra; Bessereau, Jean-Louis

2011-01-01

Identified as a major pathway controlling entry in the facultative dauer diapause stage, the DAF-2/Insulin receptor (InsR) signaling acts in multiple developmental and physiological regulation events in Caenorhabditis elegans. Here we identified a role of the insulin-like pathway in controlling developmental speed during the C. elegans second larval stage. This role relies on the canonical DAF-16/FOXO-dependent branch of the insulin-like signaling and is largely independent of dauer formation. Our studies provide further evidence for broad conservation of insulin/insulin-like growth factor (IGF) functions in developmental speed control.

Why did the savant syndrome not spread in the population? A psychiatric example of a developmental constraint.

PubMed

Ploeger, Annemie; van der Maas, Han L J; Raijmakers, Maartje E J; Galis, Frietson

2009-03-31

A developmental constraint is a mechanism that limits the possibility of a phenotype to evolve. There is growing evidence for the existence of developmental constraints in the biological literature. We hypothesize that a developmental constraint prevents the savant syndrome, despite its positive aspects, from spreading in the population. Here, the developmental constraint is the result of the high interactivity among body parts in an early stage in embryological development, namely early organogenesis or the phylotypic stage. The interactivity during this stage involves all components of the embryo, and as a result mutations that affect one part of the embryo also affect other parts. We hypothesize that a mutation, which gives rise to the development of the positive aspects of the savant syndrome (e.g., an impressive memory capacity), will virtually always have a deleterious effect on the development of other phenotypic traits (e.g., resulting in autism and/or impaired motor coordination). Thus, our hypothesis states that the savant syndrome cannot spread in the population because of this developmental constraint. The finding that children with savant syndrome often have autism and physical anomalies, which are known to be established during early organogenesis, supports our hypothesis.

Analysis of gene expression in a developmental context emphasizes distinct biological leitmotifs in human cancers

PubMed Central

Naxerova, Kamila; Bult, Carol J; Peaston, Anne; Fancher, Karen; Knowles, Barbara B; Kasif, Simon; Kohane, Isaac S

2008-01-01

Background In recent years, the molecular underpinnings of the long-observed resemblance between neoplastic and immature tissue have begun to emerge. Genome-wide transcriptional profiling has revealed similar gene expression signatures in several tumor types and early developmental stages of their tissue of origin. However, it remains unclear whether such a relationship is a universal feature of malignancy, whether heterogeneities exist in the developmental component of different tumor types and to which degree the resemblance between cancer and development is a tissue-specific phenomenon. Results We defined a developmental landscape by summarizing the main features of ten developmental time courses and projected gene expression from a variety of human tumor types onto this landscape. This comparison demonstrates a clear imprint of developmental gene expression in a wide range of tumors and with respect to different, even non-cognate developmental backgrounds. Our analysis reveals three classes of cancers with developmentally distinct transcriptional patterns. We characterize the biological processes dominating these classes and validate the class distinction with respect to a new time series of murine embryonic lung development. Finally, we identify a set of genes that are upregulated in most cancers and we show that this signature is active in early development. Conclusion This systematic and quantitative overview of the relationship between the neoplastic and developmental transcriptome spanning dozens of tissues provides a reliable outline of global trends in cancer gene expression, reveals potentially clinically relevant differences in the gene expression of different cancer types and represents a reference framework for interpretation of smaller-scale functional studies. PMID:18611264

Gene expression during blow fly development: improving the precision of age estimates in forensic entomology.

PubMed

Tarone, Aaron M; Foran, David R

2011-01-01

Forensic entomologists use size and developmental stage to estimate blow fly age, and from those, a postmortem interval. Since such estimates are generally accurate but often lack precision, particularly in the older developmental stages, alternative aging methods would be advantageous. Presented here is a means of incorporating developmentally regulated gene expression levels into traditional stage and size data, with a goal of more precisely estimating developmental age of immature Lucilia sericata. Generalized additive models of development showed improved statistical support compared to models that did not include gene expression data, resulting in an increase in estimate precision, especially for postfeeding third instars and pupae. The models were then used to make blind estimates of development for 86 immature L. sericata raised on rat carcasses. Overall, inclusion of gene expression data resulted in increased precision in aging blow flies. © 2010 American Academy of Forensic Sciences.

Transcriptome analysis on the exoskeleton formation in early developmetal stages and reconstruction scenario in growth-moulting in Litopenaeus vannamei.

PubMed

Gao, Yi; Wei, Jiankai; Yuan, Jianbo; Zhang, Xiaojun; Li, Fuhua; Xiang, Jianhai

2017-04-24

Exoskeleton construction is an important issue in shrimp. To better understand the molecular mechanism of exoskeleton formation, development and reconstruction, the transcriptome of the entire developmental process in Litopenaeus vannamei, including nine early developmental stages and eight adult-moulting stages, was sequenced and analysed using Illumina RNA-seq technology. A total of 117,539 unigenes were obtained, with 41.2% unigenes predicting the full-length coding sequence. Gene Ontology, Clusters of Orthologous Group (COG), the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and functional annotation of all unigenes gave a better understanding of the exoskeleton developmental process in L. vannamei. As a result, more than six hundred unigenes related to exoskeleton development were identified both in the early developmental stages and adult-moulting. A cascade of sequential expression events of exoskeleton-related genes were summarized, including exoskeleton formation, regulation, synthesis, degradation, mineral absorption/reabsorption, calcification and hardening. This new insight on major transcriptional events provide a deep understanding for exoskeleton formation and reconstruction in L. vannamei. In conclusion, this is the first study that characterized the integrated transcriptomic profiles cover the entire exoskeleton development from zygote to adult-moulting in a crustacean, and these findings will serve as significant references for exoskeleton developmental biology and aquaculture research.

Applying Piaget's Theory of Cognitive Development to Mathematics Instruction

ERIC Educational Resources Information Center

Ojose, Bobby

2008-01-01

This paper is based on a presentation given at National Council of Teachers of Mathematics (NCTM) in 2005 in Anaheim, California. It explicates the developmental stages of the child as posited by Piaget. The author then ties each of the stages to developmentally appropriate mathematics instruction. The implications in terms of not imposing…

Conceptualising Teacher Practice and Pupil Group Learning through Developmental Stages and Integration Factors

ERIC Educational Resources Information Center

Saito, Eisuke; Atencio, Matthew

2014-01-01

This article proposes four key developmental stages and various underpinning factors pertaining to the practices of setting up and supporting group learning in the classroom setting. The discussion is mostly explained conceptually, with some compelling examples from the field. The authors subsequently advise that three elements of…

Developmental Theories and Instructional Strategies: A Summary Paper. SIDRU Research Report No. 5.

ERIC Educational Resources Information Center

Bailey, Beeke

This paper provides curriculum makers with an overview of developmental theory and relates the theory to instructional strategies. The section on socioemotional development addresses Erikson's eight ages of man, Kohlberg's stages of moral development, motivation and Maslow's hierarchy of needs, Taylor's stage model of creative development, and…

Moral Dilemmas and the Environment.

ERIC Educational Resources Information Center

Piburn, Michael D.

Stages of moral reasoning through which children develop, as researched by developmental psychologists Jean Piaget and Lawrence Kohlberg, are outlined in the introduction of this paper. The six stages are defined and exemplified by the moral issue of the value of human life. The developmental model, as it is argued, is suitable for instruction in…

The Association of Parent Mindfulness with Parenting and Youth Psychopathology across Three Developmental Stages

PubMed Central

Parent, Justin; McKee, Laura G.; Mahon, Jennifer; Foreh, Rex

2015-01-01

The primary purpose of the current study was to test a model examining the process by which parent dispositional mindfulness relates to youth psychopathology through mindful parenting and parenting practices. The universality of the model across youth at three developmental stages was examined: young childhood (3 – 7 yrs.; n = 210), middle childhood (8 – 12 yrs.; n = 200), and adolescence (13 – 17 yrs.; n = 205). Overall, participants were 615 parents (55 % female) and one of their 3-to-17 year old children (45 % female). Parents reported on their dispositional mindfulness, mindful parenting, positive and negative parenting practices and their child's or adolescent's internalizing and externalizing problems. Consistent findings across all three developmental stages indicated that higher levels of parent dispositional mindfulness were indirectly related to lower levels of youth internalizing and externalizing problems through higher levels of mindful parenting and lower levels of negative parenting practices. Replication of these findings across families with children at different developmental stages lends support to the generalizability of the model. PMID:25633828

Differences in adjustment by child developmental stage among caregivers of children with disorders of sex development

PubMed Central

2011-01-01

Background The current study sought to compare levels of overprotection and parenting stress reported by caregivers of children with disorders of sex development at four different developmental stages. Methods Caregivers (N = 59) of children with disorders of sex development were recruited from specialty clinics and were asked to complete the Parent Protection Scale and Parenting Stress Index/Short Form as measures of overprotective behaviors and parenting stress, respectively. Results Analyses of covariance (ANCOVAs) were conducted to examine differences between caregiver report of overprotection and parenting stress. Results revealed that caregivers of infants and toddlers exhibited more overprotective behaviors than caregivers of children in the other age groups. Further, caregivers of adolescents experienced significantly more parenting stress than caregivers of school-age children, and this effect was driven by personal distress and problematic parent-child interactions, rather than having a difficult child. Conclusions These results suggest that caregivers of children with disorders of sex development may have different psychosocial needs based upon their child's developmental stage and based upon the disorder-related challenges that are most salient at that developmental stage. PMID:22074416

New features of triacylglycerol biosynthetic pathways of peanut seeds in early developmental stages.

PubMed

Yu, Mingli; Liu, Fengzhen; Zhu, Weiwei; Sun, Meihong; Liu, Jiang; Li, Xinzheng

2015-11-01

The peanut (Arachis hypogaea L.) is one of the three most important oil crops in the world due to its high average oil content (50 %). To reveal the biosynthetic pathways of seed oil in the early developmental stages of peanut pods with the goal of improving the oil quality, we presented a method combining deep sequencing analysis of the peanut pod transcriptome and quantitative real-time PCR (RT-PCR) verification of seed oil-related genes. From the sequencing data, approximately 1500 lipid metabolism-associated Unigenes were identified. The RT-PCR results quantified the different expression patterns of these triacylglycerol (TAG) synthesis-related genes in the early developmental stages of peanut pods. Based on these results and analysis, we proposed a novel construct of the metabolic pathways involved in the biosynthesis of TAG, including the Kennedy pathway, acyl-CoA-independent pathway and proposed monoacylglycerol pathway. It showed that the biosynthetic pathways of TAG in the early developmental stages of peanut pods were much more complicated than a simple, unidirectional, linear pathway.

What are the benefits of parental care? The importance of parental effects on developmental rate

PubMed Central

Klug, Hope; Bonsall, Michael B

2014-01-01

The evolution of parental care is beneficial if it facilitates offspring performance traits that are ultimately tied to offspring fitness. While this may seem self-evident, the benefits of parental care have received relatively little theoretical exploration. Here, we develop a theoretical model that elucidates how parental care can affect offspring performance and which aspects of offspring performance (e.g., survival, development) are likely to be influenced by care. We begin by summarizing four general types of parental care benefits. Care can be beneficial if parents (1) increase offspring survival during the stage in which parents and offspring are associated, (2) improve offspring quality in a way that leads to increased offspring survival and/or reproduction in the future when parents are no longer associated with offspring, and/or (3) directly increase offspring reproductive success when parents and offspring remain associated into adulthood. We additionally suggest that parental control over offspring developmental rate might represent a substantial, yet underappreciated, benefit of care. We hypothesize that parents adjust the amount of time offspring spend in life-history stages in response to expected offspring mortality, which in turn might increase overall offspring survival, and ultimately, fitness of parents and offspring. Using a theoretical evolutionary framework, we show that parental control over offspring developmental rate can represent a significant, or even the sole, benefit of care. Considering this benefit influences our general understanding of the evolution of care, as parental control over offspring developmental rate can increase the range of life-history conditions (e.g., egg and juvenile mortalities) under which care can evolve. PMID:25360271

Root Exudation of Phytochemicals in Arabidopsis Follows Specific Patterns That Are Developmentally Programmed and Correlate with Soil Microbial Functions

PubMed Central

Sugiyama, Akifumi; Manter, Daniel K.; Vivanco, Jorge M.

2013-01-01

Plant roots constantly secrete compounds into the soil to interact with neighboring organisms presumably to gain certain functional advantages at different stages of development. Accordingly, it has been hypothesized that the phytochemical composition present in the root exudates changes over the course of the lifespan of a plant. Here, root exudates of in vitro grown Arabidopsis plants were collected at different developmental stages and analyzed using GC-MS. Principle component analysis revealed that the composition of root exudates varied at each developmental stage. Cumulative secretion levels of sugars and sugar alcohols were higher in early time points and decreased through development. In contrast, the cumulative secretion levels of amino acids and phenolics increased over time. The expression in roots of genes involved in biosynthesis and transportation of compounds represented in the root exudates were consistent with patterns of root exudation. Correlation analyses were performed of the in vitro root exudation patterns with the functional capacity of the rhizosphere microbiome to metabolize these compounds at different developmental stages of Arabidopsis grown in natural soils. Pyrosequencing of rhizosphere mRNA revealed strong correlations (p<0.05) between microbial functional genes involved in the metabolism of carbohydrates, amino acids and secondary metabolites with the corresponding compounds released by the roots at particular stages of plant development. In summary, our results suggest that the root exudation process of phytochemicals follows a developmental pattern that is genetically programmed. PMID:23383346

Glue protein production can be triggered by steroid hormone signaling independent of the developmental program in Drosophila melanogaster

PubMed Central

Kaieda, Yuya; Masuda, Ryota; Nishida, Ritsuo; Shimell, MaryJane; O’Connor, Michael B.; Ono, Hajime

2018-01-01

Steroid hormones regulate life stage transitions, allowing animals to appropriately follow a developmental timeline. During insect development, the steroid hormone ecdysone is synthesized and released in a regulated manner by the prothoracic gland (PG) and then hydroxylated to the active molting hormone, 20-hydroxyecdysone (20E), in peripheral tissues. We manipulated ecdysteroid titers, through temporally controlled over-expression of the ecdysteroid-inactivating enzyme, CYP18A1, in the PG using the GeneSwitch-GAL4 system in the fruit fly Drosophila melanogaster. We monitored expression of a 20E-inducible glue protein gene, Salivary gland secretion 3 (Sgs3), using a Sgs3:GFP fusion transgene. In wild type larvae, Sgs3-GFP expression is activated at the midpoint of the third larval instar stage in response to the rising endogenous level of 20E. By first knocking down endogenous 20E levels during larval development and then feeding 20E to these larvae at various stages, we found that Sgs3-GFP expression could be triggered at an inappropriate developmental stage after a certain time lag. This stage-precocious activation of Sgs3 required expression of the Broad-complex, similar to normal Sgs3 developmental regulation, and a small level of nutritional input. We suggest that these studies provide evidence for a tissue-autonomic regulatory system for a metamorphic event independent from the primary 20E driven developmental progression. PMID:28782527

Glue protein production can be triggered by steroid hormone signaling independent of the developmental program in Drosophila melanogaster.

PubMed

Kaieda, Yuya; Masuda, Ryota; Nishida, Ritsuo; Shimell, MaryJane; O'Connor, Michael B; Ono, Hajime

2017-10-01

Steroid hormones regulate life stage transitions, allowing animals to appropriately follow a developmental timeline. During insect development, the steroid hormone ecdysone is synthesized and released in a regulated manner by the prothoracic gland (PG) and then hydroxylated to the active molting hormone, 20-hydroxyecdysone (20E), in peripheral tissues. We manipulated ecdysteroid titers, through temporally controlled over-expression of the ecdysteroid-inactivating enzyme, CYP18A1, in the PG using the GeneSwitch-GAL4 system in the fruit fly Drosophila melanogaster. We monitored expression of a 20E-inducible glue protein gene, Salivary gland secretion 3 (Sgs3), using a Sgs3:GFP fusion transgene. In wild type larvae, Sgs3-GFP expression is activated at the midpoint of the third larval instar stage in response to the rising endogenous level of 20E. By first knocking down endogenous 20E levels during larval development and then feeding 20E to these larvae at various stages, we found that Sgs3-GFP expression could be triggered at an inappropriate developmental stage after a certain time lag. This stage-precocious activation of Sgs3 required expression of the Broad-complex, similar to normal Sgs3 developmental regulation, and a small level of nutritional input. We suggest that these studies provide evidence for a tissue-autonomic regulatory system for a metamorphic event independent from the primary 20E driven developmental progression. Copyright © 2017 Elsevier Inc. All rights reserved.

Mortality Dynamics of Spodoptera frugiperda (Lepidoptera: Noctuidae) Immatures in Maize.

PubMed

Varella, Andrea Corrêa; Menezes-Netto, Alexandre Carlos; Alonso, Juliana Duarte de Souza; Caixeta, Daniel Ferreira; Peterson, Robert K D; Fernandes, Odair Aparecido

2015-01-01

We characterized the dynamics of mortality factors affecting immature developmental stages of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). Multiple decrement life tables for egg and early larval stages of S. frugiperda in maize (Zea mays L.) fields were developed with and without augmentative releases of Telenomus remus Nixon (Hymenoptera: Platygastridae) from 2009 to 2011. Total egg mortality ranged from 73 to 81% and the greatest egg mortality was due to inviability, dislodgement, and predation. Parasitoids did not cause significant mortality in egg or early larval stages and the releases of T. remus did not increase egg mortality. Greater than 95% of early larvae died from predation, drowning, and dislodgment by rainfall. Total mortality due to these factors was largely irreplaceable. Results indicate that a greater effect in reducing generational survival may be achieved by adding mortality to the early larval stage of S. frugiperda.

Mortality Dynamics of Spodoptera frugiperda (Lepidoptera: Noctuidae) Immatures in Maize

PubMed Central

Varella, Andrea Corrêa; Menezes-Netto, Alexandre Carlos; Alonso, Juliana Duarte de Souza; Caixeta, Daniel Ferreira; Peterson, Robert K. D.; Fernandes, Odair Aparecido

2015-01-01

We characterized the dynamics of mortality factors affecting immature developmental stages of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). Multiple decrement life tables for egg and early larval stages of S. frugiperda in maize (Zea mays L.) fields were developed with and without augmentative releases of Telenomus remus Nixon (Hymenoptera: Platygastridae) from 2009 to 2011. Total egg mortality ranged from 73 to 81% and the greatest egg mortality was due to inviability, dislodgement, and predation. Parasitoids did not cause significant mortality in egg or early larval stages and the releases of T. remus did not increase egg mortality. Greater than 95% of early larvae died from predation, drowning, and dislodgment by rainfall. Total mortality due to these factors was largely irreplaceable. Results indicate that a greater effect in reducing generational survival may be achieved by adding mortality to the early larval stage of S. frugiperda. PMID:26098422

Expression patterns of ABA and GA metabolism genes and hormone levels during rice seed development and imbibition: a comparison of dormant and non-dormant rice cultivars.

PubMed

Liu, Yang; Fang, Jun; Xu, Fan; Chu, Jinfang; Yan, Cunyu; Schläppi, Michael R; Wang, Youping; Chu, Chengcai

2014-06-20

Seed dormancy is an important agronomic trait in cereals. Using deep dormant (N22), medium dormant (ZH11), and non-dormant (G46B) rice cultivars, we correlated seed dormancy phenotypes with abscisic acid (ABA) and gibberellin (GA) metabolism gene expression profiles and phytohormone levels during seed development and imbibition. A time course analysis of ABA and GA content during seed development showed that N22 had a high ABA level at early and middle seed developmental stages, while at late developmental stage it declined to the level of ZH11; however, its ABA/GA ratio maintained at a high level throughout seed development. By contrast, G46B had the lowest ABA content during seed development though at early developmental stage its ABA level was close to that of ZH11, and its ABA/GA ratio peaked at late developmental stage that was at the same level of ZH11. Compared with N22 and G46B, ZH11 had an even and medium ABA level during seed development and its ABA/GA ratio peaked at the middle developmental stage. Moreover, the seed development time-point having high ABA/GA ratio also had relatively high transcript levels for key genes in ABA and GA metabolism pathways across three cultivars. These indicated that the embryo-imposed dormancy has been induced before the late developmental stage and is determined by ABA/GA ratio. A similar analysis during seed imbibition showed that ABA was synthesized in different degrees for the three cultivars. In addition, water uptake assay for intact mature seeds suggested that water could permeate through husk barrier into seed embryo for all three cultivars; however, all three cultivars showed distinct colors by vanillin-staining indicative of the existence of flavans in their husks, which are dormancy inhibition compounds responsible for the husk-imposed dormancy. Copyright © 2014. Published by Elsevier Ltd.

Developmental Transcriptomic Features of the Carcinogenic Liver Fluke, Clonorchis sinensis

PubMed Central

Cho, Pyo Yun; Kim, Tae Im; Cho, Shin-Hyeong; Choi, Sang-Haeng; Park, Hong-Seog; Kim, Tong-Soo; Hong, Sung-Jong

2011-01-01

Clonorchis sinensis is the causative agent of the life-threatening disease endemic to China, Korea, and Vietnam. It is estimated that about 15 million people are infected with this fluke. C. sinensis provokes inflammation, epithelial hyperplasia, and periductal fibrosis in bile ducts, and may cause cholangiocarcinoma in chronically infected individuals. Accumulation of a large amount of biological information about the adult stage of this liver fluke in recent years has advanced our understanding of the pathological interplay between this parasite and its hosts. However, no developmental gene expression profiles of C. sinensis have been published. In this study, we generated gene expression profiles of three developmental stages of C. sinensis by analyzing expressed sequence tags (ESTs). Complementary DNA libraries were constructed from the adult, metacercaria, and egg developmental stages of C. sinensis. A total of 52,745 ESTs were generated and assembled into 12,830 C. sinensis assembled EST sequences, and then these assemblies were further categorized into groups according to biological functions and developmental stages. Most of the genes that were differentially expressed in the different stages were consistent with the biological and physical features of the particular developmental stage; high energy metabolism, motility and reproduction genes were differentially expressed in adults, minimal metabolism and final host adaptation genes were differentially expressed in metacercariae, and embryonic genes were differentially expressed in eggs. The higher expression of glucose transporters, proteases, and antioxidant enzymes in the adults accounts for active uptake of nutrients and defense against host immune attacks. The types of ion channels present in C. sinensis are consistent with its parasitic nature and phylogenetic placement in the tree of life. We anticipate that the transcriptomic information on essential regulators of development, bile chemotaxis, and physico-metabolic pathways in C. sinensis that presented in this study will guide further studies to identify novel drug targets and diagnostic antigens. PMID:21738807

Localization and dynamics of Wolbachia infection in Asian citrus psyllid Diaphorina citri, the insect vector of the causal pathogens of Huanglongbing.

PubMed

Ren, Su-Li; Li, Yi-Han; Ou, Da; Guo, Yan-Jun; Qureshi, Jawwad A; Stansly, Philip A; Qiu, Bao-Li

2018-03-23

Wolbachia is a group of intracellular bacteria that infect a wide range of arthropods including the Asian citrus psyllid (ACP), Diaphorina citri Kuwayama. This insect is the vector of Candidatus Liberibacter asiaticus (CLas), the causal pathogen of Huanglongbing or citrus greening disease. Here, we investigated the localization pattern and infection dynamics of Wolbachia in different developmental stages of ACP. Results revealed that all developmental stages of ACP including egg, 1st-5th instar nymphs, and adults of both gender were infected with Wolbachia. FISH visualization of an ACP egg showed that Wolbachia moved from the egg stalk of newly laid eggs to a randomly distributed pattern throughout the egg prior to hatching. The infection rate varied between nymphal instars. The titers of Wolbachia in fourth and fifth instar nymphs were significantly higher than those in the first and second instar nymphs. Wolbachia were scattered in all nymphal stages, but with highest intensity in the U-shaped bacteriome located in the abdomen of the nymph. Wolbachia was confined to two symmetrical organizations in the abdomen of newly emerged female and male adults. The potential mechanisms of Wolbachia infection dynamics are discussed. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

The Activity of Carbohydrate-Degrading Enzymes in the Development of Brood and Newly Emerged workers and Drones of the Carniolan Honeybee, Apis mellifera carnica

PubMed Central

Żółtowska, Krystyna; Lipiński, Zbigniew; Łopieńska-Biernat, Elżbieta; Farjan, Marek; Dmitryjuk, Małgorzata

2012-01-01

The activity of glycogen Phosphorylase and carbohydrate hydrolyzing enzymes α-amylase, glucoamylase, trehalase, and sucrase was studied in the development of the Carniolan honey bee, Apis mellifera carnica Pollman (Hymenoptera: Apidae), from newly hatched larva to freshly emerged imago of worker and drone. Phosphorolytic degradation of glycogen was significantly stronger than hydrolytic degradation in all developmental stages. Developmental profiles of hydrolase activity were similar in both sexes of brood; high activity was found in unsealed larvae, the lowest in prepupae followed by an increase in enzymatic activity. Especially intensive increases in activity occurred in the last stage of pupae and newly emerged imago. Besides α-amylase, the activities of other enzymes were higher in drone than in worker broods. Among drones, activity of glucoamylase was particularly high, ranging from around three times higher in the youngest larvae to 13 times higher in the oldest pupae. This confirms earlier suggestions about higher rates of metabolism in drone broods than in worker broods. PMID:22943407

The activity of carbohydrate-degrading enzymes in the development of brood and newly emerged workers and drones of the Carniolan honeybee, Apis mellifera carnica.

PubMed

Żółtowska, Krystyna; Lipiński, Zbigniew; Łopieńska-Biernat, Elżbieta; Farjan, Marek; Dmitryjuk, Małgorzata

2012-01-01

The activity of glycogen Phosphorylase and carbohydrate hydrolyzing enzymes α-amylase, glucoamylase, trehalase, and sucrase was studied in the development of the Carniolan honey bee, Apis mellifera carnica Pollman (Hymenoptera: Apidae), from newly hatched larva to freshly emerged imago of worker and drone. Phosphorolytic degradation of glycogen was significantly stronger than hydrolytic degradation in all developmental stages. Developmental profiles of hydrolase activity were similar in both sexes of brood; high activity was found in unsealed larvae, the lowest in prepupae followed by an increase in enzymatic activity. Especially intensive increases in activity occurred in the last stage of pupae and newly emerged imago. Besides α-amylase, the activities of other enzymes were higher in drone than in worker broods. Among drones, activity of glucoamylase was particularly high, ranging from around three times higher in the youngest larvae to 13 times higher in the oldest pupae. This confirms earlier suggestions about higher rates of metabolism in drone broods than in worker broods.

Comparative anatomy and histology of developmental and parasitic stages in the life cycle of the lined sea anemone Edwardsiella lineata.

PubMed

Reitzel, Adam M; Daly, Marymegan; Sullivan, James C; Finnerty, John R

2009-02-01

The evolution of parasitism is often accompanied by profound changes to the developmental program. However, relatively few studies have directly examined the developmental evolution of parasitic species from free-living ancestors. The lined sea anemone Edwardsiella lineata is a relatively recently evolved parasite for which closely related free-living outgroups are known, including the starlet sea anemone Nematostella vectensis. The larva of E. lineata parasitizes the ctenophore Mnemiopsis leidyi, and, once embedded in its host, the anemone assumes a novel vermiform body plan. That we might begin to understand how the developmental program of this species has been transformed during the evolution of parasitism, we characterized the gross anatomy, histology, and cnidom of the parasitic stage, post-parasitic larval stage, and adult stage of the E. lineata life cycle. The distinct parasitic stage of the life cycle differs from the post-parasitic larva with respect to overall shape, external ciliation, cnida frequency, and tissue architecture. The parasitic stage and planula both contain holotrichs, a type of cnida not previously reported in Edwardsiidae. The internal morphology of the post-parasitic planula is extremely similar to the adult morphology, with a complete set of mesenterial tissue and musculature despite this stage having little external differentiation. Finally, we observed 2 previously undocumented aspects of asexual reproduction in E. lineata: (1) the parasitic stage undergoes transverse fission via physal pinching, the first report of asexual reproduction in a pre-adult stage in the Edwardsiidae; and (2) the juvenile polyp undergoes transverse fission via polarity reversal, the first time this form of fission has been reported in E. lineata.

Failed sperm development as a reproductive isolating barrier between species.

PubMed

Wünsch, Lisa K; Pfennig, Karin S

2013-01-01

Hybrid male sterility is a common reproductive isolating barrier between species. Yet, little is known about the actual developmental causes of this phenomenon, especially in naturally hybridizing species. We sought to evaluate the developmental causes of hybrid male sterility, using spadefoot toads as our study system. Plains spadefoot toads (Spea bombifrons) and Mexican spadefoot toads (S. multiplicata) hybridize where they co-occur in the southwestern USA. Hybrids are viable, but hybrid males suffer reduced fertility. We compared testes size and developmental stages of sperm cell maturation between hybrid males and males of each species. We found that testes of hybrid males did not differ in mean size from pure-species males. However, hybrids showed a greater range of within-individual variation in testes size than pure-species males. Moreover, although hybrids produced similar numbers of early stage sperm cells, hybrids produced significantly fewer mature spermatozoids than pure-species males. Interestingly, an introgressed individual produced numbers of live sperm comparable to pure-species males, but the majority of these sperm cells were abnormally shaped and non-motile. These results indicate that hybrid incompatibilities in late sperm development serve as a reproductive isolating barrier between species. The nature of this breakdown highlights the possibilities that hybrid males may vary in fertility and that fertility could possibly be recovered in introgressed males. © 2013 Wiley Periodicals, Inc.

From Early Embryonic to Adult Stage: Comparative Study of Action Potentials of Native and Pluripotent Stem Cell-Derived Cardiomyocytes.

PubMed

Peinkofer, Gabriel; Burkert, Karsten; Urban, Katja; Krausgrill, Benjamin; Hescheler, Jürgen; Saric, Tomo; Halbach, Marcel

2016-10-01

Cardiomyocytes (CMs) derived from induced pluripotent stem cells (iPS-CMs) are promising candidates for cell therapy, drug screening, and developmental studies. It is known that iPS-CMs possess immature electrophysiological properties, but an exact characterization of their developmental stage and subtype differentiation is hampered by a lack of knowledge of electrophysiological properties of native CMs from different developmental stages and origins within the heart. Thus, we sought to systematically investigate action potential (AP) properties of native murine CMs and to establish a database that allows classification of stem cell-derived CMs. Hearts from 129S2PasCrl mice were harvested at days 9-10, 12-14, and 16-18 postcoitum, as well as 1 day, 3-4 days, 1-2 weeks, 3-4 weeks, and 6 weeks postpartum. AP recordings in left and right atria and at apical, medial, and basal left and right ventricles were performed with sharp glass microelectrodes. Measurements revealed significant changes in AP morphology during pre- and postnatal murine development and significant differences between atria and ventricles, enabling a classification of developmental stage and subtype differentiation of stem cell-derived CMs based on their AP properties. For iPS-CMs derived from cell line TiB7.4, a typical ventricular phenotype was demonstrated at later developmental stages, while there were electrophysiological differences from atrial as well as ventricular native CMs at earlier stages. This finding supports that iPS-CMs can develop AP properties similar to native CMs, but points to differences in the maturation process between iPS-CMs and native CMs, which may be explained by dissimilar conditions during in vitro differentiation and in vivo development.

The Unique Dorsal Brood Pouch of Thermosbaenacea (Crustacea, Malacostraca) and Description of an Advanced Developmental Stage of Tulumella unidens from the Yucatan Peninsula (Mexico), with a Discussion of Mouth Part Homologies to Other Malacostraca

PubMed Central

Olesen, Jørgen; Boesgaard, Tom; Iliffe, Thomas M.

2015-01-01

The Thermosbaenacea, a small taxon of crustaceans inhabiting subterranean waters, are unique among malacostracans as they brood their offspring dorsally under the carapace. This habit is of evolutionary interest but the last detailed report on thermosbaenacean development is more than 40 years old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped) and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary ‘naupliar processes’ of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan) relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations. PMID:25901753

The Unique Dorsal Brood Pouch of Thermosbaenacea (Crustacea, Malacostraca) and Description of an Advanced Developmental Stage of Tulumella unidens from the Yucatan Peninsula (Mexico), with a Discussion of Mouth Part Homologies to Other Malacostraca.

PubMed

Olesen, Jørgen; Boesgaard, Tom; Iliffe, Thomas M

2015-01-01

The Thermosbaenacea, a small taxon of crustaceans inhabiting subterranean waters, are unique among malacostracans as they brood their offspring dorsally under the carapace. This habit is of evolutionary interest but the last detailed report on thermosbaenacean development is more than 40 years old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped) and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary 'naupliar processes' of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan) relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations.

Divergent methylation pattern in adult stage between two forms of Tetranychus urticae (Acari: Tetranychidae).

PubMed

Yang, Si-Xia; Guo, Chao; Zhao, Xiu-Ting; Sun, Jing-Tao; Hong, Xiao-Yue

2017-02-19

The two-spotted spider mite, Tetranychus urticae Koch has two forms: green form and red form. Understanding the molecular basis of how these two forms established without divergent genetic background is an intriguing area. As a well-known epigenetic process, DNA methylation has particularly important roles in gene regulation and developmental variation across diverse organisms that do not alter genetic background. Here, to investigate whether DNA methylation could be associated with different phenotypic consequences in the two forms of T. urticae, we surveyed the genome-wide cytosine methylation status and expression level of DNA methyltransferase 3 (Tudnmt3) throughout their entire life cycle. Methylation-sensitive amplification polymorphism (MSAP) analyses of 585 loci revealed variable methylation patterns in the different developmental stages. In particular, principal coordinates analysis (PCoA) indicates a significant epigenetic differentiation between female adults of the two forms. The gene expression of Tudnmt3 was detected in all examined developmental stages, which was significantly different in the adult stage of the two forms. Together, our results reveal the epigenetic distance between the two forms of T. urticae, suggesting that DNA methylation might be implicated in different developmental demands, and contribute to different phenotypes in the adult stage of these two forms. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Developmental Stages in Receptive Grammar Acquisition: A Processability Theory Account

ERIC Educational Resources Information Center

Buyl, Aafke; Housen, Alex

2015-01-01

This study takes a new look at the topic of developmental stages in the second language (L2) acquisition of morphosyntax by analysing receptive learner data, a language mode that has hitherto received very little attention within this strand of research (for a recent and rare study, see Spinner, 2013). Looking at both the receptive and productive…

Was Pre-Modern Man a Child? The Quintessence of the Psychometric and Developmental Approaches

ERIC Educational Resources Information Center

Oesterdiekhoff, Georg W.

2012-01-01

The essay integrates the psychometric intelligence approach with the cognitive-developmental approach or the stage theory erected by Piaget and his disciples. The latter led to Piagetian Cross-Cultural Psychology and the accumulation of an immense body of data. It shows that different IQ levels are indicative of the peculiar stages of cognitive…

The Lighthouse Project.

ERIC Educational Resources Information Center

LeRose, Barbara; And Others

1979-01-01

The project is based on a general systems approach. Developmental stage theory is employed as a starting point, and the developmental "minitasks" which act as stair risers from one developmental level to another are carried through with the use of Bloom's cognitive taxonomy. (Author/DLS)

Developmental perspectives on nutrition and obesity from gestation to adolescence.

PubMed

Esposito, Layla; Fisher, Jennifer O; Mennella, Julie A; Hoelscher, Deanna M; Huang, Terry T

2009-07-01

Obesity results from a complex combination of factors that act at many stages throughout a person's life. Therefore, examining childhood nutrition and obesity from a developmental perspective is warranted. A developmental perspective recognizes the cumulative effects of factors that contribute to eating behavior and obesity, including biological and socioenvironmental factors that are relevant at different stages of development. A developmental perspective considers family, school, and community context. During gestation, risk factors for obesity include maternal diet, overweight, and smoking. In early childhood, feeding practices, taste acquisition, and eating in the absence of hunger must be considered. As children become more independent during middle childhood and adolescence, school nutrition, food marketing, and social networks become focal points for obesity prevention or intervention. Combining a multilevel approach with a developmental perspective can inform more effective and sustainable strategies for obesity prevention.

Developmental Localization and Methylesterification of Pectin Epitopes during Somatic Embryogenesis of Banana (Musa spp. AAA)

PubMed Central

Xu, Chunxiang; Zhao, Lu; Pan, Xiao; Šamaj, Jozef

2011-01-01

Background The plant cell walls play an important role in somatic embryogenesis and plant development. Pectins are major chemical components of primary cell walls while homogalacturonan (HG) is the most abundant pectin polysaccharide. Developmental regulation of HG methyl-esterification degree is important for cell adhesion, division and expansion, and in general for proper organ and plant development. Methodology/Principal Findings Developmental localization of pectic homogalacturonan (HG) epitopes and the (1→4)-β-D-galactan epitope of rhamnogalacturonan I (RG-I) and degree of pectin methyl-esterification (DM) were studied during somatic embryogenesis of banana (Musa spp. AAA). Histological analysis documented all major developmental stages including embryogenic cells (ECs), pre-globular, globular, pear-shaped and cotyledonary somatic embryos. Histochemical staining of extracellularly secreted pectins with ruthenium red showed the most intense staining at the surface of pre-globular, globular and pear-shaped somatic embryos. Biochemical analysis revealed developmental regulation of galacturonic acid content and DM in diverse embryogenic stages. Immunodots and immunolabeling on tissue sections revealed developmental regulation of highly methyl-esterified HG epitopes recognized by JIM7 and LM20 antibodies during somatic embryogenesis. Cell walls of pre-globular/globular and late-stage embryos contained both low methyl-esterified HG epitopes as well as partially and highly methyl-esterified ones. Extracellular matrix which covered surface of early developing embryos contained pectin epitopes recognized by 2F4, LM18, JIM5, JIM7 and LM5 antibodies. De-esterification of cell wall pectins by NaOH caused a decrease or an elimination of immunolabeling in the case of highly methyl-esterified HG epitopes. However, immunolabeling of some low methyl-esterified epitopes appeared stronger after this base treatment. Conclusions/Significance These data suggest that both low- and highly-methyl-esterified HG epitopes are developmentally regulated in diverse embryogenic stages during somatic embryogenesis. This study provides new information about pectin composition, HG methyl-esterification and developmental localization of pectin epitopes during somatic embryogenesis of banana. PMID:21826225

The Silkworm (Bombyx mori) microRNAs and Their Expressions in Multiple Developmental Stages

PubMed Central

Luo, Qibin; Cai, Yimei; Lin, Wen-chang; Chen, Huan; Yang, Yue; Hu, Songnian; Yu, Jun

2008-01-01

Background MicroRNAs (miRNAs) play crucial roles in various physiological processes through post-transcriptional regulation of gene expressions and are involved in development, metabolism, and many other important molecular mechanisms and cellular processes. The Bombyx mori genome sequence provides opportunities for a thorough survey for miRNAs as well as comparative analyses with other sequenced insect species. Methodology/Principal Findings We identified 114 non-redundant conserved miRNAs and 148 novel putative miRNAs from the B. mori genome with an elaborate computational protocol. We also sequenced 6,720 clones from 14 developmental stage-specific small RNA libraries in which we identified 35 unique miRNAs containing 21 conserved miRNAs (including 17 predicted miRNAs) and 14 novel miRNAs (including 11 predicted novel miRNAs). Among the 114 conserved miRNAs, we found six pairs of clusters evolutionarily conserved cross insect lineages. Our observations on length heterogeneity at 5′ and/or 3′ ends of nine miRNAs between cloned and predicted sequences, and three mature forms deriving from the same arm of putative pre-miRNAs suggest a mechanism by which miRNAs gain new functions. Analyzing development-related miRNAs expression at 14 developmental stages based on clone-sampling and stem-loop RT PCR, we discovered an unusual abundance of 33 sequences representing 12 different miRNAs and sharply fluctuated expression of miRNAs at larva-molting stage. The potential functions of several stage-biased miRNAs were also analyzed in combination with predicted target genes and silkworm's phenotypic traits; our results indicated that miRNAs may play key regulatory roles in specific developmental stages in the silkworm, such as ecdysis. Conclusions/Significance Taking a combined approach, we identified 118 conserved miRNAs and 151 novel miRNA candidates from the B. mori genome sequence. Our expression analyses by sampling miRNAs and real-time PCR over multiple developmental stages allowed us to pinpoint molting stages as hotspots of miRNA expression both in sorts and quantities. Based on the analysis of target genes, we hypothesized that miRNAs regulate development through a particular emphasis on complex stages rather than general regulatory mechanisms. PMID:18714353

A proposed model of psychodynamic psychotherapy linked to Erik Erikson's eight stages of psychosocial development.

PubMed

Knight, Zelda Gillian

2017-09-01

Just as Freud used stages of psychosexual development to ground his model of psychoanalysis, it is possible to do the same with Erik Erikson's stages of development with regards to a model of psychodynamic psychotherapy. This paper proposes an eight-stage model of psychodynamic psychotherapy linked to Erik Erikson's eight stages of psychosocial development. Various suggestions are offered. One such suggestion is that as each of Erikson's developmental stages is triggered by a crisis, in therapy it is triggered by the client's search. The resolution of the search often leads to the development of another search, which implies that the therapy process comprises a series of searches. This idea of a series of searches and resolutions leads to the understanding that identity is developmental and therapy is a space in which a new sense of identity may emerge. The notion of hope is linked to Erikson's stage of Basic Trust and the proposed model of therapy views hope and trust as essential for the therapy process. Two clinical vignettes are offered to illustrate these ideas. Psychotherapy can be approached as an eight-stage process and linked to Erikson's eight stages model of development. Psychotherapy may be viewed as a series of searches and thus as a developmental stage resolution process, which leads to the understanding that identity is ongoing throughout the life span. Copyright © 2017 John Wiley & Sons, Ltd.

RNA-sequencing of the sturgeon Acipenser baeri provides insights into expression dynamics of morphogenic differentiation and developmental regulatory genes in early versus late developmental stages.

PubMed

Song, Wei; Jiang, Keji; Zhang, Fengying; Lin, Yu; Ma, Lingbo

2016-08-08

Acipenser baeri, one of the critically endangered animals on the verge of extinction, is a key species for evolutionary, developmental, physiology and conservation studies and a standout amongst the most important food products worldwide. Though the transcriptome of the early development of A. baeri has been published recently, the transcriptome changes occurring in the transition from embryonic to late stages are still unknown. The aim of this work was to analyze the transcriptomes of embryonic and post-embryonic stages of A. baeri and identify differentially expressed genes (DEGs) and their expression patterns using mRNA collected from specimens at big yolk plug, wide neural plate and 64 day old sturgeon developmental stages for RNA-Seq. The paired-end sequencing of the transcriptome of samples of A. baeri collected at two early (big yolk plug (T1, 32 h after fertilization) and wide neural plate formation (T2, 45 h after fertilization)) and one late (T22, 64 day old sturgeon) developmental stages using Illumina Hiseq2000 platform generated 64039846, 64635214 and 75293762 clean paired-end reads for T1, T2 and T22, respectively. After quality control, the sequencing reads were de novo assembled to generate a set of 149,265 unigenes with N50 value of 1277 bp. Functional annotation indicated that a substantial number of these unigenes had significant similarity with proteins in public databases. Differential expression profiling allowed the identification of 2789, 12,819 and 10,824 DEGs from the respective T1 vs. T2, T1 vs. T22 and T2 vs. T22 comparisons. High correlation of DEGs' features was recorded among early stages while significant divergences were observed when comparing the late stage with early stages. GO and KEGG enrichment analyses revealed the biological processes, cellular component, molecular functions and metabolic pathways associated with identified DEGs. The qRT-PCR performed for candidate genes in specimens confirmed the validity of the RNA-seq data. This study presents, for the first time, an extensive overview of RNA-Seq based characterization of the early and post-embryonic developmental transcriptomes of A. baeri and provided 149,265 gene sequences that will be potentially valuable for future molecular and genetic studies in A. baeri.

Developmental-stage-dependent radiosensitivity of neural cells in the ventricular zone of telencephalon in mouse and rat fetuses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoshino, K.; Kameyama, Y.

1988-03-01

Pregnant ICR mice were treated with single whole-body X-radiation at a dose of 0.24 Gy on day 10, 13, or 15 of gestation. Fetuses were obtained from mothers during 1 and 24 hours after irradiation. Pyknotic cells in the ventricular zone of telencephalon were counted in serial histological sections. Incidence of pyknotic cells peaked during 6 and 9 hours after irradiation in each gestation day group. Then, dose-response curves were obtained 6 hours after 0-0.48 Gy of irradiation. All three dose-response curves showed clear linearity in the dose range lower than 0.24 Gy. Ratios of radiosensitivity estimated from the slopesmore » of dose-response curves in day 10, 13, and 15 groups were 1, 1.4, and 0.4, respectively. These demonstrated that ventricular cells in the day 13 fetal telencephalon were the most radiosensitive among the three different age groups. In order to confirm the presence of the highly radiosensitive stage common to mammalian cerebral cortical histogenesis, pregnant F344 rats were treated with single whole-body gamma-irradiation at a dose of 0.48 Gy on day 13, 14, 15, 17, or 19 of gestation. The incidence of pyknotic cells in the ventricular zone of telencephalon was examined microscopically during 1 and 24 hours after irradiation. The peak incidence was shown 6 hours after irradiation in all the treated groups, and the highest peak incidence was shown in day-15-treated group. The developmental stage of telencephalon of day 15 rat fetuses was comparable to that of day 13 mouse fetuses. Thus, the highest radiosensitivity in terms of acute cell death was shown in the same developmental stage of brain development, i.e., the beginning phase of cerebral cortical histogenesis, in both mice and rats.« less

Forensic age estimation in anti-piracy trials in Seychelles: Experiences and challenges faced.

PubMed

Gunawardena, S A; Liyanage, U A; Weeratna, J B; Mendis, N D N A; Perera, H J M; Jayasekara, R W; Fernando, R

2017-01-01

Forensic age estimation (FAE) was conducted using a multifactorial method on thirteen Somali detainees claiming juvenile status during the anti-piracy trials of the Seychelles Supreme Court in 2014/2015. A multidisciplinary team, comprising of four of the authors covering specialties in forensic medicine, forensic odontology and radiology, conducted the FAE using a five-stage protocol. Each detainee was interviewed with an interpreter and examined for disorders affecting dental/skeletal development and for assessment of genital development through Tanner staging. Dental maturity was assessed clinically and radiologically. Eruption stage was assessed using Olze et al. and mandibular third-molar maturity was assessed using Demirjian's classification. Skeletal maturity was assessed from hand-wrist X-rays according to Greulich & Pyle and from CT-clavicle according to Kellinghaus et al. and Schultz et al. Interpretation of findings was done using reference population data from similar ethnic and social backgrounds wherever possible. Final age-ranges were calculated by combining dental and clavicle maturity stages using the regression formula developed by Bassed et al. followed by a 10% correction factor. The team later testified on their findings under cross-examination. The protocol adopted by the authors increased the scientific validity of the findings and was useful in addressing cross-examination queries on exclusion of developmental disorders, ethnic/socioeconomic variability and maintaining chain of custody. Unforeseen jurisdictional and practical limitations were experienced but did not affect the outcome. Combining dental and clavicle developmental data provided the court with a much clearer picture on the likelihood of the detainees' juvenile status which emphasizes the importance of conducting more population studies using combinations of different developmental sites. The authors note that available reference data is mostly from affluent populations whereas FAE is mostly required in individuals from less-developed regions. Regional networks that collate and share population-specific data need to be established to overcome these limitations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

An invertebrate model of the developmental neurotoxicity of insecticides: effects of chlorpyrifos and dieldrin in sea urchin embryos and larvae.

PubMed Central

Buznikov, G A; Nikitina, L A; Bezuglov, V V; Lauder, J M; Padilla, S; Slotkin, T A

2001-01-01

Chlorpyrifos targets mammalian brain development through a combination of effects directed at cholinergic receptors and intracellular signaling cascades that are involved in cell differentiation. We used sea urchin embryos as an invertebrate model system to explore the cellular mechanisms underlying the actions of chlorpyrifos and to delineate the critical period of developmental vulnerability. Sea urchin embryos and larvae were exposed to chlorpyrifos at different stages of development ranging from early cell cleavages through the prism stage. Although early cleavages were unaffected even at high chlorpyrifos concentrations, micromolar concentrations added at the mid-blastula stage evoked a prominent change in cell phenotype and overall larval structure, with appearance of pigmented cells followed by their accumulation in an extralarval cap that was extruded from the animal pole. At higher concentrations (20-40 microM), these abnormal cells constituted over 90% of the total cell number. Studies with cholinergic receptor blocking agents and protein kinase C inhibitors indicated two distinct types of effects, one mediated through stimulation of nicotinic cholinergic receptors and the other targeting intracellular signaling. The effects of chlorpyrifos were not mimicked by chlorpyrifos oxon, the active metabolite that inhibits cholinesterase, nor by nonorganophosphate cholinesterase inhibitors. Dieldrin, an organochlorine that targets GABA(A )receptors, was similarly ineffective. The effects of chlorpyrifos and its underlying cholinergic and signaling-related mechanisms parallel prior findings in mammalian embryonic central nervous system. Invertebrate test systems may thus provide both a screening procedure for potential neuroteratogenesis by organophosphate-related compounds, as well as a system with which to uncover novel mechanisms underlying developmental vulnerability. PMID:11485862

Morphological and histomorphological structures of testes and ovaries in early developmental stages of the silkworm, Bombyx mori.

PubMed

Sakai, Hiroki; Kirino, Yohei; Katsuma, Susumu; Aoki, Fugaku; Suzuki, Masataka G

2016-01-01

The gonad develops as a testis in male or an ovary in female. In the silkworm, B. mori , little is known about testis and ovary in the embryonic stages and early larval stages. In this study, we performed morphological and histomorphological observations of ovaries and testes from the late embryonic stage to the 1st instar larval stage. Results obtained with lack of accurate information on sex of examined individuals may be misleading, thus we performed phenotypic observations of gonads by utilizing sex-limited strain that enables us to easily discriminate female embryos from male ones based on those egg colors. In testis, four testicular follicles were clearly observed in the testis at the first instar larval stage, and boundary layers were formed between the testicular follicles. At the late embryonic stage, the testis consisted of four testicular follicles, while the boundary layers were still obscure. In ovary, four ovarioles were easily recognizable in the ovary at the first instar larval stage, and boundary layers were formed between the ovarioles. However, in the late embryonic stage, it was quite difficult to identify four ovarioles. Morphological characteristics were almost similar between testis and ovary in early developmental stages. Our present study demonstrates that the most reliable difference between testis and ovary in early developmental stages is the attaching point of the duct. Formation and development of the duct may be sensitive to the sex-determining signal and display sexual dimorphism in early embryonic stages.

Sublethal effects of atrazine on embryo-larval development of Rhinella arenarum (Anura: Bufonidae).

PubMed

Svartz, Gabriela V; Herkovits, Jorge; Pérez-Coll, Cristina S

2012-05-01

Atrazine (ATR), one of the most widely used herbicides in the world, affects not only target organisms but also the biota in general. Here, the teratogenic and neurotoxic effects of ATR on Rhinella arenarum (South American toad) embryos, and larvae were evaluated by means of standardized bioassays during acute and chronic exposures. The herbicide had a significant incidence of malformations, with a Teratogenic Index (TI) of 3.28. The main effects were delayed development, reduced body size, microcephaly, axial flexures, wavy tail and edema. In addition, delayed development, reduced development of forelimbs, and edema were recorded at metamorphosis stages. Scanning electron microscopy allowed observing different degrees of cellular dissociation and persistent cilliar cells in specific regions like the adhesive structure and tail fin. Results obtained by ATR 24 h pulse exposures at six developmental stages pointed out blastula as the most susceptible developmental stage both for immediate and delayed adverse effects. A noteworthy recovery capacity from acute toxic effects was recorded from the neural plate stage onwards. Regarding neurotoxic effects, abnormal, and erratic swimming and spasmodic contractions were recorded. Both the teratogenic and neurotoxic effects reported in this study demonstrate the importance of evaluating sublethal effects in non-target organisms as they could imply reduced fitness of individuals and eventually a population decline. The Hazard Quotients (HQ) for ATR ranged from 0.14 to 10.80, and the fact that some of these values are above USEPA's level of concern indicate that ATR is likely a risk to R. arenarum.

Mathematical difficulties as decoupling of expectation and developmental trajectories

PubMed Central

McLean, Janet F.; Rusconi, Elena

2014-01-01

Recent years have seen an increase in research articles and reviews exploring mathematical difficulties (MD). Many of these articles have set out to explain the etiology of the problems, the possibility of different subtypes, and potential brain regions that underlie many of the observable behaviors. These articles are very valuable in a research field, which many have noted, falls behind that of reading and language disabilities. Here will provide a perspective on the current understanding of MD from a different angle, by outlining the school curriculum of England and the US and connecting these to the skills needed at different stages of mathematical understanding. We will extend this to explore the cognitive skills which most likely underpin these different stages and whose impairment may thus lead to mathematics difficulties at all stages of mathematics development. To conclude we will briefly explore interventions that are currently available, indicating whether these can be used to aid the different children at different stages of their mathematical development and what their current limitations may be. The principal aim of this review is to establish an explicit connection between the academic discourse, with its research base and concepts, and the developmental trajectory of abstract mathematical skills that is expected (and somewhat dictated) in formal education. This will possibly help to highlight and make sense of the gap between the complexity of the MD range in real life and the state of its academic science. PMID:24567712

Tissue Specificity and Dynamics of Sex-Biased Gene Expression in a Common Frog Population with Differentiated, Yet Homomorphic, Sex Chromosomes.

PubMed

Ma, Wen-Juan; Veltsos, Paris; Toups, Melissa A; Rodrigues, Nicolas; Sermier, Roberto; Jeffries, Daniel L; Perrin, Nicolas

2018-06-12

Sex-biased genes are central to the study of sexual selection, sexual antagonism, and sex chromosome evolution. We describe a comprehensive de novo assembled transcriptome in the common frog Rana temporaria based on five developmental stages and three adult tissues from both sexes, obtained from a population with karyotypically homomorphic but genetically differentiated sex chromosomes. This allows the study of sex-biased gene expression throughout development, and its effect on the rate of gene evolution while accounting for pleiotropic expression, which is known to negatively correlate with the evolutionary rate. Overall, sex-biased genes had little overlap among developmental stages and adult tissues. Late developmental stages and gonad tissues had the highest numbers of stage- or tissue-specific genes. We find that pleiotropic gene expression is a better predictor than sex bias for the evolutionary rate of genes, though it often interacts with sex bias. Although genetically differentiated, the sex chromosomes were not enriched in sex-biased genes, possibly due to a very recent arrest of XY recombination. These results extend our understanding of the developmental dynamics, tissue specificity, and genomic localization of sex-biased genes.

Metabolome analysis of Drosophila melanogaster during embryogenesis.

PubMed

An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

2014-01-01

The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos' metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo.

Metabolome Analysis of Drosophila melanogaster during Embryogenesis

PubMed Central

An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

2014-01-01

The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos’ metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo. PMID:25121768

Influence of Meiotic Stages on Developmental Competence of Goat’ Oocyte After Vitrification

NASA Astrophysics Data System (ADS)

Wahyuningsih, S.; Ihsan, M. N.

2018-02-01

This objective of this research was to investigate effect of goat oocyte meiotic stages on developmental competence after cryopreservation. Ovaries were collected from slaugterhouse and oocytes was aspirated from2-6 mm of follicles. Oocyte with compacted cumulus cells and evenly granulated ooplasm were selected for this experiment. The lenght of in vitro maturation before vitrification was 8 or 22 h in IVM media TCM 199 + FCS 10 % + PMSG 10 IU + hCG 10 IU at 38.5 °C in a humidified atmosphere of 5 % CO2 in air and were vitrified. After vitrification process, GVBD and MII oocyte were matured for 18 or 4 h to fullfill 26 h maturation requirement and then oocytes were subjected to IVF and culture. Cleavage and blastocyst formation rate were to asses their developmental competence. Cleavage rates were obtained for both GVBD ( 56.78 %) and MII (69.64 % ) oocytes (P<0.05). Proportion of cleaved embryos from vitrified MII oocytes develop into blastocysts higher (P<0.05) than those from vitrified GVBD oocytes (10.25% vs 3.54%) repectively. Goat oocytes in different maturation stages response to vitrification differently and MII stages have better developmental competence than GVBD.

Embryonic development of lake whitefish Coregonus clupeaformis: a staging series, analysis of growth and effects of fixation.

PubMed

Sreetharan, S; Thome, C; Mitz, C; Eme, J; Mueller, C A; Hulley, E N; Manzon, R G; Somers, C M; Boreham, D R; Wilson, J Y

2015-09-01

A reference staging series of 18 morphological stages of laboratory reared lake whitefish Coregonus clupeaformis is provided. The developmental processes of blastulation, gastrulation, neurulation as well as development of the eye, circulatory system, chromatophores and mouth are included and accompanied by detailed descriptions and live imaging. Quantitative measurements of embryo size and mass were taken at each developmental stage. Eggs were 3·19 ± 0·16 mm (mean ± s.d.) in diameter at fertilization and embryos reached a total length (LT ) of 14·25 ± 0·41 mm at hatch. Separated yolk and embryo dry mass were 0·25 ± 0·08 mg and 1·39 ± 0·17 mg, respectively, at hatch. The effects of two common preservatives (formalin and ethanol) were examined throughout development and post hatch. Embryo LT significantly decreased following fixation at all points in development. A correction factor to estimate live LT from corresponding fixed LT was determined as live LT = (fixed LT )(1·025) . Eye diameter and yolk area measurements significantly increased in fixed compared with live embryos up to 85-90% development for both measurements. The described developmental stages can be generalized to teleost species, and is particularly relevant for the study of coregonid development due to additionally shared developmental characteristics. The results of this study and staging series are therefore applicable across various research streams encompassing numerous species that require accurate staging of embryos and descriptions of morphological development. © 2015 The Fisheries Society of the British Isles.

A history of normal plates, tables and stages in vertebrate embryology.

PubMed

Hopwood, Nick

2007-01-01

Developmental biology is today unimaginable without the normal stages that define standard divisions of development. This history of normal stages, and the related normal plates and normal tables, shows how these standards have shaped and been shaped by disciplinary change in vertebrate embryology. The article highlights the Normal Plates of the Development of the Vertebrates edited by the German anatomist Franz Keibel (16 volumes, 1897-1938). These were a major response to problems in the relations between ontogeny and phylogeny that amounted in practical terms to a crisis in staging embryos, not just between, but (for some) also within species. Keibel's design adapted a plate by Wilhelm His and tables by Albert Oppel in order to go beyond the already controversial comparative plates of the Darwinist propagandist Ernst Haeckel. The project responded to local pressures, including intense concern with individual variation, but recruited internationally and mapped an embryological empire. Though theoretically inconclusive, the plates became standard laboratory tools and forged a network within which the Institut International d'Embryologie (today the International Society of Developmental Biologists) was founded in 1911. After World War I, experimentalists, led by Ross Harrison and Viktor Hamburger, and human embryologists, especially George Streeter at the Carnegie Department of Embryology, transformed Keibel's complex, bulky tomes to suit their own contrasting demands. In developmental biology after World War II, normal stages-reduced to a few journal pages-helped domesticate model organisms. Staging systems had emerged from discussions that questioned the very possibility of assigning an embryo to a stage. The historical issues resonate today as developmental biologists work to improve and extend stage series, to make results from different laboratories easier to compare and to take individual variation into account.

Influence of Kernel Age on Fumonisin B1 Production in Maize by Fusarium moniliforme

PubMed Central

Warfield, Colleen Y.; Gilchrist, David G.

1999-01-01

Production of fumonisins by Fusarium moniliforme on naturally infected maize ears is an important food safety concern due to the toxic nature of this class of mycotoxins. Assessing the potential risk of fumonisin production in developing maize ears prior to harvest requires an understanding of the regulation of toxin biosynthesis during kernel maturation. We investigated the developmental-stage-dependent relationship between maize kernels and fumonisin B1 production by using kernels collected at the blister (R2), milk (R3), dough (R4), and dent (R5) stages following inoculation in culture at their respective field moisture contents with F. moniliforme. Highly significant differences (P ≤ 0.001) in fumonisin B1 production were found among kernels at the different developmental stages. The highest levels of fumonisin B1 were produced on the dent stage kernels, and the lowest levels were produced on the blister stage kernels. The differences in fumonisin B1 production among kernels at the different developmental stages remained significant (P ≤ 0.001) when the moisture contents of the kernels were adjusted to the same level prior to inoculation. We concluded that toxin production is affected by substrate composition as well as by moisture content. Our study also demonstrated that fumonisin B1 biosynthesis on maize kernels is influenced by factors which vary with the developmental age of the tissue. The risk of fumonisin contamination may begin early in maize ear development and increases as the kernels reach physiological maturity. PMID:10388675

Developmental toxicity of PAH mixtures in fish early life stages. Part II: adverse effects in Japanese medaka.

PubMed

Le Bihanic, Florane; Clérandeau, Christelle; Le Menach, Karyn; Morin, Bénédicte; Budzinski, Hélène; Cousin, Xavier; Cachot, Jérôme

2014-12-01

In aquatic environments, polycyclic aromatic hydrocarbons (PAHs) mostly occur as complex mixtures, for which risk assessment remains problematic. To better understand the effects of PAH mixture toxicity on fish early life stages, this study compared the developmental toxicity of three PAH complex mixtures. These mixtures were extracted from a PAH-contaminated sediment (Seine estuary, France) and two oils (Arabian Light and Erika). For each fraction, artificial sediment was spiked at three different environmental concentrations roughly equivalent to 0.5, 4, and 10 μg total PAH g(-1) dw. Japanese medaka embryos were incubated on these PAH-spiked sediments throughout their development, right up until hatching. Several endpoints were recorded at different developmental stages, including acute endpoints, morphological abnormalities, larvae locomotion, and genotoxicity (comet and micronucleus assays). The three PAH fractions delayed hatching, induced developmental abnormalities, disrupted larvae swimming activity, and damaged DNA at environmental concentrations. Differences in toxicity levels, likely related to differences in PAH proportions, were highlighted between fractions. The Arabian Light and Erika petrogenic fractions, containing a high proportion of alkylated PAHs and low molecular weight PAHs, were more toxic to Japanese medaka early life stages than the pyrolytic fraction. This was not supported by the toxic equivalency approach, which appeared unsuitable for assessing the toxicity of the three PAH fractions to fish early life stages. This study highlights the potential risks posed by environmental mixtures of alkylated and low molecular weight PAHs to early stages of fish development.

Developmentally Appropriate Peace Education Curricula

ERIC Educational Resources Information Center

Lewsader, Joellen; Myers-Walls, Judith A.

2017-01-01

Peace education has been offered to children for decades, but those curricula have been only minimally guided by children's developmental stages and needs. In this article, the authors apply their research on children's developmental understanding of peace along with peace education principles and Vygotsky's sociocultural theory to present…

Does early paternal involvement predict offspring developmental diagnoses?

PubMed

Jackson, Dylan B; Newsome, Jamie; Beaver, Kevin M

2016-12-01

A long line of research has illustrated that fathers play an important role in the development of their children. Few studies, however, have examined the impact of paternal involvement at the earliest stages of life on developmental diagnoses in childhood. The present study extends this line of research by exploring the possibility that paternal involvement prenatally, postnatally, and at the time of birth may influence offspring risk for various diagnoses in childhood. A quasi-experimental, propensity score matching design was used to create treatment and control groups to assess the relationship between paternal involvement at each stage of development and developmental diagnoses. Approximately 6000 children, and a subsample of fathers, who participated in the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B). Activity, attention and learning, speech or language, and other diagnoses in early childhood, and overall number of diagnoses at 4years of age. We find no consistent evidence that low paternal involvement prenatally or postnatally increases the risk of various developmental diagnoses by age 4. However, children whose fathers were absent at the time of their birth were at significantly greater risk of incurring various developmental diagnoses, as well as a significantly greater number of developmental diagnoses. The findings expand our understanding of exactly how early paternal influence begins and the specific dimensions of early father behaviors that are related to the risk of various developmental diagnoses. Ultimately, these results have important implications concerning father involvement during the earliest stages of the life course. Copyright © 2016. Published by Elsevier Ireland Ltd.

K-Cl Cotransporter 2-mediated Cl- Extrusion Determines Developmental Stage-dependent Impact of Propofol Anesthesia on Dendritic Spines.

PubMed

Puskarjov, Martin; Fiumelli, Hubert; Briner, Adrian; Bodogan, Timea; Demeter, Kornel; Lacoh, Claudia-Marvine; Mavrovic, Martina; Blaesse, Peter; Kaila, Kai; Vutskits, Laszlo

2017-05-01

General anesthetics potentiating γ-aminobutyric acid (GABA)-mediated signaling are known to induce a persistent decrement in excitatory synapse number in the cerebral cortex when applied during early postnatal development, while an opposite action is produced at later stages. Here, the authors test the hypothesis that the effect of general anesthetics on synaptogenesis depends upon the efficacy of GABA receptor type A (GABAA)-mediated inhibition controlled by the developmental up-regulation of the potassium-chloride (K-Cl) cotransporter 2 (KCC2). In utero electroporation of KCC2 was used to prematurely increase the efficacy of (GABAA)-mediated inhibition in layer 2/3 pyramidal neurons in the immature rat somatosensory cortex. Parallel experiments with expression of the inward-rectifier potassium channel Kir2.1 were done to reduce intrinsic neuronal excitability. The effects of these genetic manipulations (n = 3 to 4 animals per experimental group) were evaluated using iontophoretic injection of Lucifer Yellow (n = 8 to 12 cells per animal). The total number of spines analyzed per group ranged between 907 and 3,371. The authors found a robust effect of the developmental up-regulation of KCC2-mediated Cl transport on the age-dependent action of propofol on dendritic spines. Premature expression of KCC2, unlike expression of a transport-inactive KCC2 variant, prevented a propofol-induced decrease in spine density. In line with a reduction in neuronal excitability, the above result was qualitatively replicated by overexpression of Kir2.1. The KCC2-dependent developmental increase in the efficacy of GABAA-mediated inhibition is a major determinant of the age-dependent actions of propofol on dendritic spinogenesis.

Ocean acidification has little effect on developmental thermal windows of echinoderms from Antarctica to the tropics.

PubMed

Karelitz, Sam E; Uthicke, Sven; Foo, Shawna A; Barker, Mike F; Byrne, Maria; Pecorino, Danilo; Lamare, Miles D

2017-02-01

As the ocean warms, thermal tolerance of developmental stages may be a key driver of changes in the geographical distributions and abundance of marine invertebrates. Additional stressors such as ocean acidification may influence developmental thermal windows and are therefore important considerations for predicting distributions of species under climate change scenarios. The effects of reduced seawater pH on the thermal windows of fertilization, embryology and larval morphology were examined using five echinoderm species: two polar (Sterechinus neumayeri and Odontaster validus), two temperate (Fellaster zelandiae and Patiriella regularis) and one tropical (Arachnoides placenta). Responses were examined across 12-13 temperatures ranging from -1.1 °C to 5.7 °C (S. neumayeri), -0.5 °C to 10.7 °C (O. validus), 5.8 °C to 27 °C (F. zelandiae), 6.0 °C to 27.1 °C (P. regularis) and 13.9 °C to 34.8 °C (A. placenta) under present-day and near-future (2100+) ocean acidification conditions (-0.3 pH units) and for three important early developmental stages 1) fertilization, 2) embryo (prehatching) and 3) larval development. Thermal windows for fertilization were broad and were not influenced by a pH decrease. Embryological development was less thermotolerant. For O. validus, P. regularis and A. placenta, low pH reduced normal development, albeit with no effect on thermal windows. Larval development in all five species was affected by both temperature and pH; however, thermal tolerance was not reduced by pH. Results of this study suggest that in terms of fertilization and development, temperature will remain as the most important factor influencing species' latitudinal distributions as the ocean continues to warm and decrease in pH, and that there is little evidence of a synergistic effect of temperature and ocean acidification on the thermal control of species ranges. © 2016 John Wiley & Sons Ltd.

Semi-Quantitative Evaluation of Secondary Carbonates via Portable X-ray Fluorescence Spectrometry

NASA Astrophysics Data System (ADS)

Chakraborty, Somsubhra; Weindorf, David; Weindorf, Camille; Duda, Bogdan; Pennington, Sarah; Ortiz, Rebekah

2017-04-01

Secondary calcium carbonate commonly occurs in subsoils of semi-arid soils worldwide. In US Soil Taxonomy, such horizons are frequently described as Bk, Bkk, Bkm, Bkkm, or Ck horizons at variable stages of development. Specifically, the Soil Survey Staff uses a qualitative scale of one through six to indicate differential developmental stages. However, considerable disagreement exists even among experienced soil scientists. Evaluating 75 soil samples from across four US states, a portable X-ray fluorescence (PXRF) spectrometer was used to quantify the total soil Ca content and compare it to average developmental stage scores as determined by a panel of Soil Survey Staff personnel. Samples were evaluated both as intact aggregates as well as ground (<2 mm), homogenized powders. PXRF readings of total soil Ca concentration steadily increased under both conditions as developmental stage progressed. However, minimal difference was observed between stage five and six carbonate accumulation. Stage three showed the widest variability in total soil Ca. Given than PXRF cannot distinguish between primary and secondary CaCO3 in soils, interpretation by the analyst remains essential. Nonetheless, PXRF provides an important tool for assessing carbonate laden subsoils providing elemental differentiation beyond that perceived by the human eye.

Morphological characteristics of developmental stages of Acanthamoeba and Naegleria species before and after staining by various techniques.

PubMed

Ithoi, Init; Ahmad, Arine-Fadzlun; Mak, J W; Nissapatorn, Veeranoot; Lau, Yee-Ling; Mahmud, Rohela

2011-11-01

Seven stains were studied to determine the best color and contrast for staining the developmental stages of free living pathogenic Acanthamoeba and Naegleria species. The acid-fast bacilli stain (AFB) produced a blue color without contrast; trichrome-eosin and modified Field's showed various color contrasts; Giemsa, iron-hematoxylin, modified AFB and Gram produced only one color which distinguished the nucleus, nucleolus, cytoplasm, food- and water-vacuoles. The motile organs (acanthopodia, pseudopodia, lobopodia and flagella) were also clearly differentiated but produced a similar color as the cytoplasm. These motile organelles were first induced by incubating at 37 degrees C for at least 15 minutes and then fixing with methanol in order to preserve the protruding morphology prior to staining. The trichrome-eosin and iron-hematoxylin stains showed good color contrast for detecting all three stages, the trophozoite, cyst and flagellate; Giemsa and Gram stained the trophozoite and flagellate stages; the modified Field's and modified AFB stains stained only the trophozoite stage. Depending on the purpose, all these stains (except the AFB stain) can be used to identify the developmental stages of Acanthamoeba and Naegleria for clinical, epidemiological or public health use.

Parental Involvement and the Developmental Stages of Writing: Knowledge and Skills to Assist Children and Parent Perceptions on Their Experience

ERIC Educational Resources Information Center

Fernandez-Kaltenbach, Elena

2009-01-01

A kindergarten parent workshop series on the developmental stages of writing was created and assessed. The intended outcome was to empower parents with writing knowledge and writing skills so that they could apply this knowledge and skills at home with their child. The researcher developed the workshops from parent involvement research,…

Validity of the Fine Motor Area of the 12-Month Ages and Stages Questionnaire in Infants Following Major Surgery

ERIC Educational Resources Information Center

Smith, Cally; Wallen, Margaret; Walker, Karen; Bundy, Anita; Rolinson, Rachel; Badawi, Nadia

2012-01-01

The Ages and Stages Questionnaires (ASQ) are parent-report screening tools to identify infants at risk of developmental difficulties. The purpose of this study was to examine validity and internal reliability of the fine motor developmental area of the ASQ, 2nd edition (ASQ2-FM) for screening 12-month-old infants following major surgery. The…

De novo sequencing and comparative transcriptome analysis of the male and hermaphroditic flowers provide insights into the regulation of flower formation in andromonoecious taihangia rupestris.

PubMed

Li, Weiguo; Zhang, Lihui; Ding, Zhan; Wang, Guodong; Zhang, Yandi; Gong, Hongmei; Chang, Tianjun; Zhang, Yanwen

2017-02-28

Taihangia rupestris, an andromonoecious plant species, bears both male and hermaphroditic flowers within the same individual. However, the establishment and development of male and hermaphroditic flowers in andromonoecious Taihangia remain poorly understood, due to the limited genetic and sequence information. To investigate the potential molecular mechanism in the regulation of Taihangia flower formation, we used de novo RNA sequencing to compare the transcriptome profiles of male and hermaphroditic flowers at early and late developmental stages. Four cDNA libraries, including male floral bud, hermaphroditic floral bud, male flower, and hermaphroditic flower, were constructed and sequenced by using the Illumina RNA-Seq method. Totally, 84,596,426 qualified Illumina reads were obtained and then assembled into 59,064 unigenes, of which 24,753 unigenes were annotated in the NCBI non-redundant protein database. In addition, 12,214, 7,153, and 8,115 unigenes were assigned into 53 Gene Ontology (GO) functional groups, 25 Clusters of Orthologous Group (COG) categories, and 126 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. By pairwise comparison of unigene abundance between the samples, we identified 1,668 differential expressed genes (DEGs), including 176 transcription factors (TFs) between the male and hermaphroditic flowers. At the early developmental stage, we found 263 up-regulated genes and 436 down-regulated genes expressed in hermaphroditic floral buds, while 844 up-regulated genes and 314 down-regulated genes were detected in hermaphroditic flowers at the late developmental stage. GO and KEGG enrichment analyses showed that a large number of DEGs were associated with a wide range of functions, including cell cycle, epigenetic processes, flower development, and biosynthesis of unsaturated fatty acid pathway. Finally, real-time quantitative PCR was conducted to validate the DEGs identified in the present study. In this study, transcriptome data of this rare andromonoecious Taihangia were reported for the first time. Comparative transcriptome analysis revealed the significant differences in gene expression profiles between male and hermaphroditic flowers at early and late developmental stages. The transcriptome data of Taihangia would be helpful to improve the understanding of the underlying molecular mechanisms in regulation of flower formation and unisexual flower establishment in andromonoecious plants.

The mid-developmental transition and the evolution of animal body plans

PubMed Central

Cole, Alison G.; Winter, Eitan; Mostov, Natalia; Khair, Sally; Senderovich, Naftalie; Kovalev, Ekaterina; Silver, David H.; Feder, Martin; Fernandez-Valverde, Selene L.; Nakanishi, Nagayasu; Simmons, David; Simakov, Oleg; Larsson, Tomas; Liu, Shang-Yun; Jerafi-Vider, Ayelet; Yaniv, Karina; Ryan, Joseph F.; Martindale, Mark Q.; Rink, Jochen C.; Arendt, Detlev; Degnan, Sandie M.; Degnan, Bernard M.; Hashimshony, Tamar; Yanai, Itai

2016-01-01

Animals are grouped into ~35 ‘phyla’ based upon the notion of distinct body plans1–4. Morphological and molecular analyses have revealed that a stage in the middle of development—known as the phylotypic period—is conserved among species within some phyla5–9. Although these analyses provide evidence for their existence, phyla have also been criticized as lacking an objective definition, and consequently based on arbitrary groupings of animals10. Here we compare the developmental transcriptomes of ten species, each annotated to a different phylum, with a wide range of life histories and embryonic forms. We find that in all ten species, development comprises the coupling of early and late phases of conserved gene expression. These phases are linked by a divergent ‘mid-developmental transition’ that uses species-specific suites of signalling pathways and transcription factors. This mid-developmental transition overlaps with the phylotypic period that has been defined previously for three of the ten phyla, suggesting that transcriptional circuits and signalling mechanisms active during this transition are crucial for defining the phyletic body plan and that the mid-developmental transition may be used to define phylotypic periods in other phyla. Placing these observations alongside the reported conservation of mid-development within phyla, we propose that a phylum may be defined as a collection of species whose gene expression at the mid-developmental transition is both highly conserved among them, yet divergent relative to other species. PMID:26886793

Endo-β-mannanase and β-tubulin gene expression during the final phases of coffee seed maturation.

PubMed

Santos, F C; Clemente, A C S; Caixeta, F; Rosa, S D V F

2015-10-02

Coffee seeds begin to develop shortly after fertilization and can take 6 to 8 months to complete their formation, a period during which all the characteristics of the mature seed are determined, directly influencing physiological quality. However, little is known about the molecular mechanisms that act during coffee seed maturation. The objective of the current study was to analyze expression of the β-tubulin (TUB) and endo-β-mannanase (MAN) genes during different phases at the end of development and in different tissues of Coffea arabica seeds. The transcription levels of the TUB and MAN genes were quantified in a relative manner using qRT-PCR in whole seeds, and dissected into embryos and endosperms at different developmental stages. Greater expression of MAN was observed in whole seeds and in endosperms during the green stage, and in the embryo during the over-ripe stage. High TUB gene expression was observed in whole seeds during the green stage and, in the embryos, there were peaks in expression during the over-ripe stage. In endosperms, the peak of expression occurred in both the green stage and in the cherry stage. These results suggest participation of endo-β-mannanase during the initial seed developmental stages, and in the stages of physiological maturity in the embryo tissues. TUB gene expression varied depending on the developmental stage and section of seed analyzed, indicating the participation of β-tubulin during organogenesis and coffee seed maturation.

A Developmental Model Applied to Problems of Deafness.

ERIC Educational Resources Information Center

Schlesinger, Hilde S.

2000-01-01

This "classic" article (1972) in the field of deaf studies includes some interpretive notes for current readers. The article examines the effect of deafness on basic developmental tasks at each of the eight developmental stages of Erik Erikson's theory of psychosocial development and explains the more successful passage through these…

Analysis of global gene expression profiles to identify differentially expressed genes critical for embryo development in Brassica rapa.

PubMed

Zhang, Yu; Peng, Lifang; Wu, Ya; Shen, Yanyue; Wu, Xiaoming; Wang, Jianbo

2014-11-01

Embryo development represents a crucial developmental period in the life cycle of flowering plants. To gain insights into the genetic programs that control embryo development in Brassica rapa L., RNA sequencing technology was used to perform transcriptome profiling analysis of B. rapa developing embryos. The results generated 42,906,229 sequence reads aligned with 32,941 genes. In total, 27,760, 28,871, 28,384, and 25,653 genes were identified from embryos at globular, heart, early cotyledon, and mature developmental stages, respectively, and analysis between stages revealed a subset of stage-specific genes. We next investigated 9,884 differentially expressed genes with more than fivefold changes in expression and false discovery rate ≤ 0.001 from three adjacent-stage comparisons; 1,514, 3,831, and 6,633 genes were detected between globular and heart stage embryo libraries, heart stage and early cotyledon stage, and early cotyledon and mature stage, respectively. Large numbers of genes related to cellular process, metabolism process, response to stimulus, and biological process were expressed during the early and middle stages of embryo development. Fatty acid biosynthesis, biosynthesis of secondary metabolites, and photosynthesis-related genes were expressed predominantly in embryos at the middle stage. Genes for lipid metabolism and storage proteins were highly expressed in the middle and late stages of embryo development. We also identified 911 transcription factor genes that show differential expression across embryo developmental stages. These results increase our understanding of the complex molecular and cellular events during embryo development in B. rapa and provide a foundation for future studies on other oilseed crops.

Developmental constraints shape the evolution of the nematode mid-developmental transition.

PubMed

Zalts, Harel; Yanai, Itai

2017-03-27

Evolutionary theory assumes that genetic variation is uniform and gradual in nature, yet morphological and gene expression studies have revealed that different life-stages exhibit distinct levels of cross-species conservation. In particular, a stage in mid-embryogenesis is highly conserved across species of the same phylum, suggesting that this stage is subject to developmental constraints, either by increased purifying selection or by a strong mutational bias. An alternative explanation, however, holds that the same 'hourglass' pattern of variation may result from increased positive selection at the earlier and later stages of development. To distinguish between these scenarios, we examined gene expression variation in a population of the nematode Caenorhabditis elegans using an experimental design that eliminated the influence of positive selection. By measuring gene expression for all genes throughout development in 20 strains, we found that variations were highly uneven throughout development, with a significant depletion during mid-embryogenesis. In particular, the family of homeodomain transcription factors, whose expression generally coincides with mid-embryogenesis, evolved under high constraint. Our data further show that genes responsible for the integration of germ layers during morphogenesis are the most constrained class of genes. Together, these results provide strong evidence for developmental constraints as the mechanism underlying the hourglass model of animal evolution. Understanding the pattern and mechanism of developmental constraints provides a framework to understand how evolutionary processes have interacted with embryogenesis and led to the diversity of animal life on Earth.

Molecular characterization of BrMYB28 and BrMYB29 paralogous transcription factors involved in the regulation of aliphatic glucosinolate profiles in Brassica rapa ssp. pekinensis.

PubMed

Baskar, Venkidasamy; Park, Se Won

2015-07-01

Glucosinolates (GSL) are one of the major secondary metabolites of the Brassicaceae family. In the present study, we aim at characterizing the multiple paralogs of aliphatic GSL regulators, such as BrMYB28 and BrMYB29 genes in Brassica rapa ssp. pekinensis, by quantitative real-time PCR (qRT-PCR) analysis in different tissues and at various developmental stages. An overlapping gene expression pattern between the BrMYBs as well as their downstream genes (DSGs) was found at different developmental stages. Among the BrMYB28 and BrMYB29 paralogous genes, the BrMYB28.3 and BrMYB29.1 genes were dominantly expressed in most of the developmental stages, compared to the other paralogs of the BrMYB genes. Furthermore, the differential expression pattern of the BrMYBs was observed under various stress treatments. Interestingly, BrMYB28.2 showed the least expression in most developmental stages, while its expression was remarkably high in different stress conditions. More specifically, the BrMYB28.2, BrMYB28.3, and BrMYB29.1 genes were highly responsive to various abiotic and biotic stresses, further indicating their possible role in stress tolerance. Moreover, the in silico cis motif analysis in the upstream regulatory regions of BrMYBs showed the presence of various putative stress-specific motifs, which further indicated their responsiveness to biotic and abiotic stresses. These observations suggest that the dominantly expressed BrMYBs, both in different developmental stages and under various stress treatments (BrMYB28.3 and BrMYB29.1), may be potential candidate genes for altering the GSL level through genetic modification studies in B. rapa ssp. pekinensis. Copyright © 2015. Published by Elsevier SAS.

[The effect of betain on biology and morphology of developmental stages of Eimeria acervulina in broiler chicks experimentally infected].

PubMed

Teixeira, Marcel; Niang, Tania Marcia S; Gomes, Augusto V da C; Lopes, Carlos Wilson G

2006-01-01

Purposing to investigate the betaine effect on biology and morphology of developmental stages of Eimeria acervulina, 420 broiler chicks Cobb were experimentally inoculated with 2 x 10(5) sporulated oocysts and housed in battery cages in a block design with five treatments and six replicates each, including a positive control, a group treated with salinomycin and growth promoter plus three levels of betaine as additive in the feed at 0.05, 0.10 and 0.15%. Measurements of oocysts, sporocysts and endogenous stages were performed as morphological parameters, while pre patent and patent periods and sporulation time were taken as biological parameters. Morphology was also associated with the mathematical constant Phi (1.618) to evaluate possible relationship. Betaine was able to cause modifications in both biology and morphology of oocysts and sporocysts, whereas it was weakly able to affect developmental stages based on trophozoites and macrogamonts measurements. According to the measures of sporocysts E. acervulina development was closely related to Phi.

Fecundity of Uca uruguayensis and Chasmagnathus granulatus (Decapoda, Brachyura) from the "Refugio de Vida Silvestre" Bahía Samborombón, Argentina.

PubMed

César, I I; Armendáriz, L C; Becerra, R V

2007-11-01

The aim of the present work conducted at the Refugio de Vida Silvestre Bahía Samborombón is to analyse the most relevant aspects of the fecundity of Chasmagnathus granulatus and Uca uruguayensis. Samplings were carried out from March 2001 to February 2003. Ovigerous females of U. uruguayensis (N = 13) and C. granulatus (N = 25) were found during spring and summer, their sizes (CW) varied from 9.1 to 11.7 microm for the former species and from 22.8 to 32.4 mm for the latter. The egg diameter in U. uruguayensis ranged from 245 to 260 microm for embryos in the early stage of development and from 250 to 345 microm for those in mid-developmental stage, while in C. granulatus from 250 to 345 microm and from 260 to 365 microm respectively. Fecundity varied from 1126 to 6745 eggs/brood in U. uruguayensis and 15688-57418 eggs/brood in C. granulatus. For those females with broods in mid-developmental stage, several relationships were made. For U. uruguayensis the best correlation coefficients were obtained for the relationships: female weight vs. egg mass weight and carapace width vs. egg mass weight; for C. granulatus the best association was obtained between female size and the egg number and the egg mass weight.

Temporal and spatial variations on accumulation of nomilin and limonin in the pummelos.

PubMed

Wang, Fusheng; Yu, Xiaohan; Liu, Xiaona; Shen, Wanxia; Zhu, Shiping; Zhao, Xiaochun

2016-09-01

Limonoids are the important secondary metabolites in the citrus. In this study, the accumulation of limonoids at different fruit developmental stages and distribution among different genotypes, tissues and developmental stages were investigated in 12 pummelo varieties. The large variations on limonoids concentration were found among different varieties, which ranged from 233.78 mg/kg FW to 4090.41 mg/kg FW in the seeds at full color stage of the fruit. Classification of pummelos based on the limonoids content divided 12 varieties into three groups. It was matched well with the geographic origination of the pummelo varieties, suggesting that the accumulation of limonoids was mainly determined by the genotype of the pummelo. Accumulation of the limonoids in different tissues was highly variable, and in a tissue specific fashion. The trend of the change on the levels of nomilin and limonin in the seeds and segment membrane were corresponded to the physiological development of the fruit. The rapid accumulation of nomilin and limonoids was observed from the physiological ripening of the seeds. It suggested that physiological maturation of the seeds is a key point that the seeds accelerate the accumulation of nomilin and limonin. In most of pummelo varieties, 10% color break of the fruit was a phenotypic landmark associated with the maximum level of nomilin accumulated in the seeds. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A history of normal plates, tables and stages in vertebrate embryology

PubMed Central

HOPWOOD, NICK

2006-01-01

Developmental biology is today unimaginable without the normal stages that define standard divisions of development. This history of normal stages, and the related normal plates and normal tables, shows how these standards have shaped and been shaped by disciplinary change in vertebrate embryology. The article highlights the Normal Plates of the Development of the Vertebrates edited by the German anatomist Franz Keibel (16 volumes, 1897–1938). These were a major response to problems in the relations between ontogeny and phylogeny that amounted in practical terms to a crisis in staging embryos, not just between, but (for some) also within species. Keibel’s design adapted a plate by Wilhelm His and tables by Albert Oppel in order to go beyond the already controversial comparative plates of the Darwinist propagandist Ernst Haeckel. The project responded to local pressures, including intense concern with individual variation, but recruited internationally and mapped an embryological empire. Though theoretically inconclusive, the plates became standard laboratory tools and forged a network within which the Institut International d’Embryologie (today the International Society of Developmental Biologists) was founded in 1911. After World War I, experimentalists, led by Ross Harrison and Viktor Hamburger, and human embryologists, especially George Streeter at the Carnegie Department of Embryology, transformed Keibel’s complex, bulky tomes to suit their own contrasting demands. In developmental biology after World War II, normal stages—reduced to a few journal pages—helped domesticate model organisms. Staging systems had emerged from discussions that questioned the very possibility of assigning an embryo to a stage. The historical issues resonate today as developmental biologists work to improve and extend stage series, to make results from different laboratories easier to compare and to take individual variation into account. PMID:17183461

Developmental Stage of Parasites Influences the Structure of Fish-Parasite Networks

PubMed Central

Bellay, Sybelle; de Oliveira, Edson Fontes; Almeida-Neto, Mário; Lima Junior, Dilermando Pereira; Takemoto, Ricardo Massato; Luque, José Luis

2013-01-01

Specialized interactions tend to be more common in systems that require strong reciprocal adaptation between species, such as those observed between parasites and hosts. Parasites exhibit a high diversity of species and life history strategies, presenting host specificity which increases the complexity of these antagonistic systems. However, most studies are limited to the description of interactions between a few parasite and host species, which restricts our understanding of these systems as a whole. We investigated the effect of the developmental stage of the parasite on the structure of 30 metazoan fish-parasite networks, with an emphasis on the specificity of the interactions, connectance and modularity. We assessed the functional role of each species in modular networks and its interactions within and among the modules according to the developmental stage (larval and adult) and taxonomic group of the parasites. We observed that most parasite and host species perform a few interactions but that parasites at the larval stage tended to be generalists, increasing the network connectivity within and among modules. The parasite groups did not differ among each other in the number of interactions within and among the modules when considering only species at the larval stage. However, the same groups of adult individuals differed from each other in their interaction patterns, which were related to variations in the degree of host specificity at this stage. Our results show that the interaction pattern of fishes with parasites, such as acanthocephalans, cestodes, digeneans and nematodes, is more closely associated with their developmental stage than their phylogenetic history. This finding corroborates the hypothesis that the life history of parasites results in adaptations that cross phylogenetic boundaries. PMID:24124506

Developmental stage of parasites influences the structure of fish-parasite networks.

PubMed

Bellay, Sybelle; de Oliveira, Edson Fontes; Almeida-Neto, Mário; Lima Junior, Dilermando Pereira; Takemoto, Ricardo Massato; Luque, José Luis

2013-01-01

Specialized interactions tend to be more common in systems that require strong reciprocal adaptation between species, such as those observed between parasites and hosts. Parasites exhibit a high diversity of species and life history strategies, presenting host specificity which increases the complexity of these antagonistic systems. However, most studies are limited to the description of interactions between a few parasite and host species, which restricts our understanding of these systems as a whole. We investigated the effect of the developmental stage of the parasite on the structure of 30 metazoan fish-parasite networks, with an emphasis on the specificity of the interactions, connectance and modularity. We assessed the functional role of each species in modular networks and its interactions within and among the modules according to the developmental stage (larval and adult) and taxonomic group of the parasites. We observed that most parasite and host species perform a few interactions but that parasites at the larval stage tended to be generalists, increasing the network connectivity within and among modules. The parasite groups did not differ among each other in the number of interactions within and among the modules when considering only species at the larval stage. However, the same groups of adult individuals differed from each other in their interaction patterns, which were related to variations in the degree of host specificity at this stage. Our results show that the interaction pattern of fishes with parasites, such as acanthocephalans, cestodes, digeneans and nematodes, is more closely associated with their developmental stage than their phylogenetic history. This finding corroborates the hypothesis that the life history of parasites results in adaptations that cross phylogenetic boundaries.

Characteristics of child maltreatment and their relation to dissociation, posttraumatic stress symptoms, and depression in adult psychiatric patients.

PubMed

Mueller-Pfeiffer, Christoph; Moergeli, Hanspeter; Schumacher, Sonja; Martin-Soelch, Chantal; Wirtz, Gustav; Fuhrhans, Christoph; Hindermann, Esther; Rufer, Michael

2013-06-01

Little is known about the influence of particular characteristics of childhood maltreatment, such as developmental stage, relationship to the perpetrator, and nature of the trauma, on adult psychopathology. The effects of childhood maltreatment were assessed in adult psychiatric patients (N = 287) using self-rating scales and diagnostic checklists. Maltreatment was strongly associated with dissociation. This relationship was observed for all childhood developmental stages and was strongest when the perpetrator was outside the family. Dissociation was more strongly correlated with childhood emotional abuse and sexual harassment than with sexual or physical abuse. Childhood sexual abuse was found to be associated with symptoms of posttraumatic stress. The findings suggest that dissociation is a relatively specific consequence of childhood maltreatment that is largely independent of the familial relationship to the perpetrator or the child's developmental stage.

Streptomyces exploration is triggered by fungal interactions and volatile signals.

PubMed

Jones, Stephanie E; Ho, Louis; Rees, Christiaan A; Hill, Jane E; Nodwell, Justin R; Elliot, Marie A

2017-01-03

It has long been thought that the life cycle of Streptomyces bacteria encompasses three developmental stages: vegetative hyphae, aerial hyphae and spores. Here, we show interactions between Streptomyces and fungi trigger a previously unobserved mode of Streptomyces development. We term these Streptomyces cells 'explorers', for their ability to adopt a non-branching vegetative hyphal conformation and rapidly transverse solid surfaces. Fungi trigger Streptomyces exploratory growth in part by altering the composition of the growth medium, and Streptomyces explorer cells can communicate this exploratory behaviour to other physically separated streptomycetes using an airborne volatile organic compound (VOC). These results reveal that interkingdom interactions can trigger novel developmental behaviours in bacteria, here, causing Streptomyces to deviate from its classically-defined life cycle. Furthermore, this work provides evidence that VOCs can act as long-range communication signals capable of propagating microbial morphological switches.

Genome-Wide Association Mapping of Fertility Reduction upon Heat Stress Reveals Developmental Stage-Specific QTLs in Arabidopsis thaliana.

PubMed

Bac-Molenaar, Johanna A; Fradin, Emilie F; Becker, Frank F M; Rienstra, Juriaan A; van der Schoot, J; Vreugdenhil, Dick; Keurentjes, Joost J B

2015-07-01

For crops that are grown for their fruits or seeds, elevated temperatures that occur during flowering and seed or fruit set have a stronger effect on yield than high temperatures during the vegetative stage. Even short-term exposure to heat can have a large impact on yield. In this study, we used Arabidopsis thaliana to study the effect of short-term heat exposure on flower and seed development. The impact of a single hot day (35°C) was determined in more than 250 natural accessions by measuring the lengths of the siliques along the main inflorescence. Two sensitive developmental stages were identified, one before anthesis, during male and female meiosis, and one after anthesis, during fertilization and early embryo development. In addition, we observed a correlation between flowering time and heat tolerance. Genome-wide association mapping revealed four quantitative trait loci (QTLs) strongly associated with the heat response. These QTLs were developmental stage specific, as different QTLs were detected before and after anthesis. For a number of QTLs, T-DNA insertion knockout lines could validate assigned candidate genes. Our findings show that the regulation of complex traits can be highly dependent on the developmental timing. © 2015 American Society of Plant Biologists. All rights reserved.

Genome-Wide Association Mapping of Fertility Reduction upon Heat Stress Reveals Developmental Stage-Specific QTLs in Arabidopsis thaliana

PubMed Central

Bac-Molenaar, Johanna A.; Fradin, Emilie F.; Becker, Frank F.M.; Rienstra, Juriaan A.; van der Schoot, J.; Vreugdenhil, Dick; Keurentjes, Joost J.B.

2015-01-01

For crops that are grown for their fruits or seeds, elevated temperatures that occur during flowering and seed or fruit set have a stronger effect on yield than high temperatures during the vegetative stage. Even short-term exposure to heat can have a large impact on yield. In this study, we used Arabidopsis thaliana to study the effect of short-term heat exposure on flower and seed development. The impact of a single hot day (35°C) was determined in more than 250 natural accessions by measuring the lengths of the siliques along the main inflorescence. Two sensitive developmental stages were identified, one before anthesis, during male and female meiosis, and one after anthesis, during fertilization and early embryo development. In addition, we observed a correlation between flowering time and heat tolerance. Genome-wide association mapping revealed four quantitative trait loci (QTLs) strongly associated with the heat response. These QTLs were developmental stage specific, as different QTLs were detected before and after anthesis. For a number of QTLs, T-DNA insertion knockout lines could validate assigned candidate genes. Our findings show that the regulation of complex traits can be highly dependent on the developmental timing. PMID:26163573

Developmental transitions in C. elegans larval stages.

PubMed

Rougvie, Ann E; Moss, Eric G

2013-01-01

Molecular mechanisms control the timing, sequence, and synchrony of developmental events in multicellular organisms. In Caenorhabditis elegans, these mechanisms are revealed through the analysis of mutants with "heterochronic" defects: cell division or differentiation patterns that occur in the correct lineage, but simply at the wrong time. Subsets of cells in these mutants thus express temporal identities normally restricted to a different life stage. A seminal finding arising from studies of the heterochronic genes was the discovery of miRNAs; these tiny miRNAs are now a defining feature of the pathway. A series of sequentially expressed miRNAs guide larval transitions through stage-specific repression of key effector molecules. The wild-type lineage patterns are executed as discrete modules programmed between temporal borders imposed by the molting cycles. How these successive events are synchronized with the oscillatory molting cycle is just beginning to come to light. Progression through larval stages can be specifically, yet reversibly, halted in response to environmental cues, including nutrient availability. Here too, heterochronic genes and miRNAs play key roles. Remarkably, developmental arrest can, in some cases, either mask or reveal timing defects associated with mutations. In this chapter, we provide an overview of how the C. elegans heterochronic gene pathway guides developmental transitions during continuous and interrupted larval development. © 2013 Elsevier Inc. All rights reserved.

Selection of reliable reference genes for normalization of quantitative RT-PCR from different developmental stages and tissues in amphioxus

PubMed Central

Zhang, Qi-Lin; Zhu, Qian-Hua; Liao, Xin; Wang, Xiu-Qiang; Chen, Tao; Xu, Han-Ting; Wang, Juan; Yuan, Ming-Long; Chen, Jun-Yuan

2016-01-01

Amphioxus is a closest living proxy to the ancestor of cephalochordates with vertebrates, and key animal for novel understanding in the evolutionary origin of vertebrate body plan, genome, tissues and immune system. Reliable analyses using quantitative real-time PCR (qRT-PCR) for answering these scientific questions is heavily dependent on reliable reference genes (RGs). In this study, we evaluated stability of thirteen candidate RGs in qRT-PCR for different developmental stages and tissues of amphioxus by four independent (geNorm, NormFinder, BestKeeper and deltaCt) and one comparative algorithms (RefFinder). The results showed that the top two stable RGs were the following: (1) S20 and 18 S in thirteen developmental stages, (2) EF1A and ACT in seven normal tissues, (3) S20 and L13 in both intestine and hepatic caecum challenged with lipopolysaccharide (LPS), and (4) S20 and EF1A in gill challenged with LPS. The expression profiles of two target genes (EYA and HHEX) in thirteen developmental stages were used to confirm the reliability of chosen RGs. This study identified optimal RGs that can be used to accurately measure gene expression under these conditions, which will benefit evolutionary and functional genomics studies in amphioxus. PMID:27869224

Developmental variation, homology, and the pharyngula stage.

PubMed

Collazo, A

2000-03-01

Understanding how development varies both inter- and intraspecifically can be important for systematic and evolutionary studies. This review will explore three different ways such understanding can be applied to evolutionary analyses. First, developmental data can be useful for homology determination. Interspecific variation in development has been thought to make developmental data poor candidates for determining homology. However, an updated developmental criterion that is more broadly comparative and mechanistic augments the available criteria used in homology determination. Second, modern cell and molecular biology are providing a better understanding of the many developmental processes involved in a structure's formation and will augment the number of characters available for phylogenetic analyses. Recent work has revealed that what had been thought to be a highly conserved developmental stage, the pharyngula (the phylotypic and zootypic stage of craniates) is highly variable. This variation can be seen in the development of such tissues as neural crest and placodes. These tissues are particularly interesting from a phylogenetic standpoint because they and the structures they form contribute to key synapomorphies of craniates. Finally, understanding developmental processes and how they form the variety of morphologies seen in nature will help in constructing the transformations that occurred during evolution. One such example involves descriptions of how lateral line development is affected in different mutant lines of zebrafish. The many species of teleost fishes express great variation in the patterns of their lateral lines, and this is often an important systematic character. Understanding the genetic basis of lateral line development would help not only in hypothesizing possible transformational series but also in determining how many genes may have been required for these transformations.

Automatic stage identification of Drosophila egg chamber based on DAPI images

PubMed Central

Jia, Dongyu; Xu, Qiuping; Xie, Qian; Mio, Washington; Deng, Wu-Min

2016-01-01

The Drosophila egg chamber, whose development is divided into 14 stages, is a well-established model for developmental biology. However, visual stage determination can be a tedious, subjective and time-consuming task prone to errors. Our study presents an objective, reliable and repeatable automated method for quantifying cell features and classifying egg chamber stages based on DAPI images. The proposed approach is composed of two steps: 1) a feature extraction step and 2) a statistical modeling step. The egg chamber features used are egg chamber size, oocyte size, egg chamber ratio and distribution of follicle cells. Methods for determining the on-site of the polytene stage and centripetal migration are also discussed. The statistical model uses linear and ordinal regression to explore the stage-feature relationships and classify egg chamber stages. Combined with machine learning, our method has great potential to enable discovery of hidden developmental mechanisms. PMID:26732176

The development of oocytes in the ovary of a parthenogenetic tick, Haemaphysalis longicornis.

PubMed

Mihara, Ryo; Umemiya-Shirafuji, Rika; Abe, Yasuyuki; Matsuo, Tomohide; Horiuchi, Noriyuki; Kawano, Suguru; Fujisaki, Kozo; Suzuki, Hiroshi

2018-04-17

Haemaphysalis longicornis is an important vector of various pathogens in domestic animals and humans. The tick is a unique species with bisexual and parthenogenetic races. Although mating induces oocyte development, it is possible in the parthenogenetic race to complete oogenesis without copulation. Here we examined the developmental process of oocytes from unfed to the oviposition period in parthenogenetic H. longicornis. We classified the developmental stages of oocytes into five stages: stage I, germinal vesicle occupies more than half of the cytoplasm; stage II, germinal vesicle occupies less than half of the cytoplasm; stage III, germinal vesicle migrates from the center in the oocyte to the vicinity of the pedicel cells; stage IV, the cytoplasm is filled with yolk granules of various sizes; stage V, the cytoplasm is occupied by large yolk granules. Oocytes at the unfed period were undeveloped and classified as stage I. Stage I and II oocytes were observed at the rapid feeding period, indicating that oocyte development began after the initiation of blood feeding. All developmental stages of oocytes were observed at the pre-oviposition period. At 10 days after the beginning of the oviposition period, the ratios of stage I and II oocytes were higher than those of the previous period, suggesting that the ovarian development and activity may be continuing. Based on these findings, we propose classification criteria for the oocyte development in the parthenogenetic H. longicornis. The criteria will be useful for understanding the mechanisms of tick reproduction and transovarial transmission of pathogens. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparative Developmental Staging of Female and Male Water Fleas Daphnia pulex and Daphnia magna During Embryogenesis.

PubMed

Toyota, Kenji; Hiruta, Chizue; Ogino, Yukiko; Miyagawa, Shinichi; Okamura, Tetsuro; Onishi, Yuta; Tatarazako, Norihisa; Iguchi, Taisen

2016-02-01

The freshwater crustacean genus Daphnia has been used extensively in ecological, developmental and ecotoxicological studies. Daphnids produce only female offspring by parthenogenesis under favorable conditions, but in response to various unfavorable conditions and external stimuli, they produce male offspring. Although we reported that exogenous exposure to juvenile hormones and their analogs can induce male offspring even under female-producing conditions, we recently established a male induction system in the Daphnia pulex WTN6 strain simply by changing day-length. This male and female induction system is suitable for understanding the innate mechanisms of sexual dimorphic development in daphnids. Embryogenesis has been described as a normal plate (developmental staging) in various daphnid species; however, all studies have mainly focused on female development. Here, we describe the developmental staging of both sexes during embryogenesis in two representative daphnids, D. pulex and D. magna, based on microscopic time-course observations. Our findings provide the first detailed insights into male embryogenesis in both species, and contribute to the elucidation of the mechanisms underlying sexual differentiation in daphnids.

Carbohydrate Content and Enzyme Metabolism in Developing Canola Siliques.

PubMed

King, S. P.; Lunn, J. E.; Furbank, R. T.

1997-05-01

Little biochemical information is available on carbohydrate metabolism in developing canola (Brassica napus L.) silique (pod) wall and seed tissues. This research examines the carbohydrate contents and sucrose (Suc) metabolic enzyme activities in different aged silique wall and seed tissues during oil filling. The silique wall partitioned photosynthate into Suc over starch and predominantly accumulated hexose. The silique wall hexose content and soluble acid invertase activity rapidly fell as embryos progressed from the early- to late-cotyledon developmental stages. A similar trend was not evident for alkaline invertase, Suc synthase (SuSy), and Suc-phosphate synthase. Silique wall SuSy activities were much higher than source leaves at all times and may serve to supply the substrate for secondary cell wall thickening. In young seeds starch was the predominant accumulated carbohydrate over the sampled developmental range. Seed hexose levels dropped as embryos developed from the early- to midcotyledon stage. Hexose and starch were localized to the testa or liquid endosperm, whereas Suc was evenly distributed among seed components. With the switch to oil accumulation, seed SuSy activity increased by 3.6-fold and soluble acid invertase activity decreased by 76%. These data provide valuable baseline knowledge for the genetic manipulation of canola seed carbon partitioning.

[Studies upon behaviour of snails in anthropogenically changed water environment. 1. Locomotor activity of Lymnaea stagnalis (L.), with regard to subpopulations infected with developmental stages of digeneans].

PubMed

Pokora, Zbigniew

2002-01-01

The aim of the paper was to analyse the locomotor activity of snails, Lymnaea stagnalis, with regard to physico-chemical properties of water in an inhabited reservoir and parasitic infection. The material was collected in selected anthropogenic water environments situated in the Upper Silesian Industrial Region (sinkhole ponds, sand- and clay-excavations). The locomotor activity of each snail was analysed in laboratory conditions by designation of number of penetrated segments, marked in tanks filled with water originating from a given reservoir, during 15', with intervals of 1'. It was observed the significant relationship between locomotor activity of examined snails and the water carbonaceous hardness (r = -0,812, at range of the independent variable 173.0-863.5 mg CaCO3/dm3). Correlation coefficients with other physico-chemical parameters of water were close to zero. Locomotion of snails infected with developmental stages of digenetic trematodes was significantly lower comparing to non-infected individuals. Locomotor activity of these former ones was dependend more on degree of the digestive gland damage by the parasite than on the infection agent.

Developmental Changes for the Hemolymph Metabolome of Silkworm (Bombyx moriL.)

PubMed Central

Zhou, Lihong; Li, Huihui; Hao, Fuhua; Li, Ning; Liu, Xin; Wang, Guoliang; Wang, Yulan; Tang, Huiru

2015-01-01

Silkworm (Bombyx mori) is a lepidopteran-holometabolic model organism. To understand its developmental biochemistry, we characterized the larval hemolymph metabonome from the third instar to prepupa stage using 1H NMR spectroscopy whilst hemolymph fatty acid composition using GC-FID/MS. We unambiguously assigned more than 60 metabolites, among which tyrosine-o-β-glucuronide, mesaconate, homocarnosine, and picolinate were reported for the first time from the silkworm hemolymph. Phosphorylcholine was the most abundant metabolite in all developmental stages with exception for the periods before the third and fourth molting. We also found obvious developmental dependence for the hemolymph metabonome involving multiple pathways including protein biosyntheses, glycolysis, TCA cycle, the metabolisms of choline amino acids, fatty acids, purines, and pyrimidines. Most hemolymph amino acids had two elevations during the feeding period of the fourth instar and prepupa stage. Trehalose was the major blood sugar before day 8 of the fifth instar, whereas glucose became the major blood sugar after spinning. C16:0, C18:0 and its unsaturated forms were dominant fatty acids in hemolymph. The developmental changes of hemolymph metabonome were associated with dietary nutrient intakes, biosyntheses of cell membrane, pigments, proteins, and energy metabolism. These findings offered essential biochemistry information in terms of the dynamic metabolic changes during silkworm development. PMID:25825269

Embryonic and larval development and early behavior in grass carp, Ctenopharyngodon idella: implications for recruitment in rivers

USGS Publications Warehouse

George, Amy E.; Chapman, Duane C.

2015-01-01

With recent findings of grass carp Ctenopharyngodon idella in tributaries of the Great Lakes, information on developmental rate and larval behavior is critical to efforts to assess the potential for establishment within the tributaries of that region. In laboratory experiments, grass carp were spawned and eggs and larvae reared at two temperature treatments, one "cold" and one "warm", and tracked for developmental rate, egg size, and behavior. Developmental rate was quantified using Yi's (1988) developmental stages and the cumulative thermal units method. Grass carp had a thermal minimum of 13.5°C for embryonic stages and 13.3°C for larval stages. Egg size was related to temperature and maternal size, with the largest eggs coming from the largest females, and eggs were generally larger in warmer treatments. Young grass carp larvae exhibited upward and downward swimming interspersed with long periods of lying on the bottom. Swimming capacity increased with ontogeny, and larvae were capable of horizontal swimming and position holding with gas bladder emergence. Developmental rates, behavior, and egg attributes can be used in combination with physical parameters of a river to assess the risk that grass carp are capable of reproduction and recruitment in rivers.

Developmental Changes for the Hemolymph Metabolome of Silkworm (Bombyx mori L.).

PubMed

Zhou, Lihong; Li, Huihui; Hao, Fuhua; Li, Ning; Liu, Xin; Wang, Guoliang; Wang, Yulan; Tang, Huiru

2015-05-01

Silkworm (Bombyx mori) is a lepidopteran-holometabolic model organism. To understand its developmental biochemistry, we characterized the larval hemolymph metabonome from the third instar to prepupa stage using (1)H NMR spectroscopy whilst hemolymph fatty acid composition using GC-FID/MS. We unambiguously assigned more than 60 metabolites, among which tyrosine-o-β-glucuronide, mesaconate, homocarnosine, and picolinate were reported for the first time from the silkworm hemolymph. Phosphorylcholine was the most abundant metabolite in all developmental stages with exception for the periods before the third and fourth molting. We also found obvious developmental dependence for the hemolymph metabonome involving multiple pathways including protein biosyntheses, glycolysis, TCA cycle, the metabolisms of choline amino acids, fatty acids, purines, and pyrimidines. Most hemolymph amino acids had two elevations during the feeding period of the fourth instar and prepupa stage. Trehalose was the major blood sugar before day 8 of the fifth instar, whereas glucose became the major blood sugar after spinning. C16:0, C18:0 and its unsaturated forms were dominant fatty acids in hemolymph. The developmental changes of hemolymph metabonome were associated with dietary nutrient intakes, biosyntheses of cell membrane, pigments, proteins, and energy metabolism. These findings offered essential biochemistry information in terms of the dynamic metabolic changes during silkworm development.

Beneath the floor: re-analysis of neurodevelopmental outcomes in untreated Hurler syndrome.

PubMed

Shapiro, Elsa G; Whitley, Chester B; Eisengart, Julie B

2018-05-11

Hurler syndrome (MPS IH), the severe, neurodegenerative form of type one mucopolysaccharidosis, is associated with rapid neurocognitive decline during toddlerhood and multi-system dysfunction. It is now standardly treated with hematopoietic cell transplantation (HCT), which halts accumulating disease pathology and prevents early death. While norm-based data on developmental functioning in untreated children have previously demonstrated neurocognitive decline, advances in methodology for understanding the cognitive functioning of children with neurodegenerative diseases have highlighted that the previous choice of scores to report results was not ideal. Specifically, the lowest possible norm-based score is 50, which obscures the complete range of cognitive functioning at more advanced stages of neurodeterioration. To a set of cognitive data collected on a sample of untreated children, we applied a modern method of score analysis, calculating a developmental quotient based on age equivalent scores, to reveal the full range of cognitive functioning beneath this cutoff of 50, uncovering new information about the rapidity of decline and the profound impairment in these children. Among 39 observations for 32 patients with untreated Hurler syndrome, the full array of cognitive functioning below 50 includes many children in the severely to profoundly impaired range. The loss of skills per time unit was 14 points between age 1 and 2. There was a very large range of developmental quotients corresponding to the norm-based cutoff of 50. This report enables clarification of functioning at levels that extend beneath the floor of 50 in previous work. At the dawn of newborn screening and amidst a proliferation of new therapies for MPS I, these data can provide crucial benchmark information for developing treatments, particularly for areas of the world where transplant may not be available.

Congenital hypoplasia of the cerebellum: developmental causes and behavioral consequences

PubMed Central

Basson, M. Albert; Wingate, Richard J.

2013-01-01

Over the last 60 years, the spotlight of research has periodically returned to the cerebellum as new techniques and insights have emerged. Because of its simple homogeneous structure, limited diversity of cell types and characteristic behavioral pathologies, the cerebellum is a natural home for studies of cell specification, patterning, and neuronal migration. However, recent evidence has extended the traditional range of perceived cerebellar function to include modulation of cognitive processes and implicated cerebellar hypoplasia and Purkinje neuron hypo-cellularity with autistic spectrum disorder. In the light of this emerging frontier, we review the key stages and genetic mechanisms behind cerebellum development. In particular, we discuss the role of the midbrain hindbrain isthmic organizer in the development of the cerebellar vermis and the specification and differentiation of Purkinje cells and granule neurons. These developmental processes are then considered in relation to recent insights into selected human developmental cerebellar defects: Joubert syndrome, Dandy–Walker malformation, and pontocerebellar hypoplasia. Finally, we review current research that opens up the possibility of using the mouse as a genetic model to study the role of the cerebellum in cognitive function. PMID:24027500

Dynamic Cytology and Transcriptional Regulation of Rice Lamina Joint Development1[OPEN

PubMed Central

2017-01-01

Rice (Oryza sativa) leaf angle is determined by lamina joint and is an important agricultural trait determining leaf erectness and, hence, the photosynthesis efficiency and grain yield. Genetic studies reveal a complex regulatory network of lamina joint development; however, the morphological changes, cytological transitions, and underlying transcriptional programming remain to be elucidated. A systemic morphological and cytological study reveals a dynamic developmental process and suggests a common but distinct regulation of the lamina joint. Successive and sequential cell division and expansion, cell wall thickening, and programmed cell death at the adaxial or abaxial sides form the cytological basis of the lamina joint, and the increased leaf angle results from the asymmetric cell proliferation and elongation. Analysis of the gene expression profiles at four distinct developmental stages ranging from initiation to senescence showed that genes related to cell division and growth, hormone synthesis and signaling, transcription (transcription factors), and protein phosphorylation (protein kinases) exhibit distinct spatiotemporal patterns during lamina joint development. Phytohormones play crucial roles by promoting cell differentiation and growth at early stages or regulating the maturation and senescence at later stages, which is consistent with the quantitative analysis of hormones at different stages. Further comparison with the gene expression profile of leaf inclination1, a mutant with decreased auxin and increased leaf angle, indicates the coordinated effects of hormones in regulating lamina joint. These results reveal a dynamic cytology of rice lamina joint that is fine-regulated by multiple factors, providing informative clues for illustrating the regulatory mechanisms of leaf angle and plant architecture. PMID:28500269

Dynamic Cytology and Transcriptional Regulation of Rice Lamina Joint Development.

PubMed

Zhou, Li-Juan; Xiao, Lang-Tao; Xue, Hong-Wei

2017-07-01

Rice ( Oryza sativa ) leaf angle is determined by lamina joint and is an important agricultural trait determining leaf erectness and, hence, the photosynthesis efficiency and grain yield. Genetic studies reveal a complex regulatory network of lamina joint development; however, the morphological changes, cytological transitions, and underlying transcriptional programming remain to be elucidated. A systemic morphological and cytological study reveals a dynamic developmental process and suggests a common but distinct regulation of the lamina joint. Successive and sequential cell division and expansion, cell wall thickening, and programmed cell death at the adaxial or abaxial sides form the cytological basis of the lamina joint, and the increased leaf angle results from the asymmetric cell proliferation and elongation. Analysis of the gene expression profiles at four distinct developmental stages ranging from initiation to senescence showed that genes related to cell division and growth, hormone synthesis and signaling, transcription (transcription factors), and protein phosphorylation (protein kinases) exhibit distinct spatiotemporal patterns during lamina joint development. Phytohormones play crucial roles by promoting cell differentiation and growth at early stages or regulating the maturation and senescence at later stages, which is consistent with the quantitative analysis of hormones at different stages. Further comparison with the gene expression profile of leaf inclination1 , a mutant with decreased auxin and increased leaf angle, indicates the coordinated effects of hormones in regulating lamina joint. These results reveal a dynamic cytology of rice lamina joint that is fine-regulated by multiple factors, providing informative clues for illustrating the regulatory mechanisms of leaf angle and plant architecture. © 2017 American Society of Plant Biologists. All Rights Reserved.

Are there intergenerational and population-specific effects of oxidative stress in sockeye salmon (Oncorhynchus nerka)?

PubMed

Taylor, Jessica J; Wilson, Samantha M; Sopinka, Natalie M; Hinch, Scott G; Patterson, David A; Cooke, Steven J; Willmore, William G

2015-06-01

Intergenerational effects of stress have been reported in a wide range of taxa; however, few researchers have examined the intergenerational consequences of oxidative stress. Oxidative stress occurs in living organisms when reactive oxygen species remain unquenched by antioxidant defense systems and become detrimental to cells. In fish, it is unknown how maternal oxidative stress and antioxidant capacity influence offspring quality. The semelparous, migratory life history of Pacific salmon (Oncorhynchus spp.) provides a unique opportunity to explore intergenerational effects of oxidative stress. This study examined the effects of population origin on maternal and developing offspring oxidative stress and antioxidant capacity, and elucidated intergenerational relationships among populations of sockeye salmon (Oncorhynchus nerka) with varying migration effort. For three geographically distinct populations of Fraser River sockeye salmon (British Columbia, Canada), antioxidant capacity and oxidative stress were measured in adult female plasma, heart, brain, and liver, as well as in developing offspring until time of emergence. Maternal and offspring oxidative stress and antioxidant capacity varied among populations but patterns were not consistent across tissue/developmental stage. Furthermore, maternal oxidative stress and antioxidant capacity did not affect offspring oxidative stress and antioxidant capacity across any of the developmental stages or populations sampled. Our results revealed that offspring develop their endogenous antioxidant systems at varying rates across populations; however, this variability is overcome by the time of emergence. While offspring may be relying on maternally derived antioxidants in the initial stages of development, they rapidly develop their own antioxidant systems (mainly glutathione) during later stages of development. Copyright © 2015 Elsevier Inc. All rights reserved.

RNA-sequencing analysis reveals abundant developmental stage-specific and immunity-related genes in the pollen beetle Meligethes aeneus.

PubMed

Vogel, H; Badapanda, C; Knorr, E; Vilcinskas, A

2014-02-01

The pollen beetle (Meligethes aeneus) is a major pest of oilseed rape (Brassica napus) and other cruciferous crops in Europe. Pesticide-resistant pollen beetle populations are emerging, increasing the economic impact of this species. We isolated total RNA from the larval and adult stages, the latter either naïve or immunized by injection with bacteria and yeast. High-throughput RNA sequencing (RNA-Seq) was carried out to establish a comprehensive transcriptome catalogue and to screen for developmental stage-specific and immunity-related transcripts. We assembled the transcriptome de novo by combining sequence tags from all developmental stages and treatments. Gene expression data based on normalized read counts revealed several functional gene categories that were differentially expressed between larvae and adults, particularly genes associated with digestion and detoxification that were induced in larvae, and genes associated with reproduction and environmental signalling that were induced in adults. We also identified many genes associated with microbe recognition, immunity-related signalling and defence effectors, such as antimicrobial peptides (AMPs) and lysozymes. Digital gene expression analysis revealed significant differences in the profile of AMPs expressed in larvae, naïve adults and immune-challenged adults, providing insight into the steady-state differences between developmental stages and the complex transcriptional remodelling that occurs following the induction of immunity. Our data provide insight into the adaptive mechanisms used by phytophagous insects and could lead to the development of more effective control strategies for insect pests. © 2013 The Royal Entomological Society.

HUPO BPP pilot study: a proteomics analysis of the mouse brain of different developmental stages.

PubMed

Wang, Jing; Gu, Yong; Wang, Lihong; Hang, Xingyi; Gao, Yan; Wang, Hangyan; Zhang, Chenggang

2007-11-01

This study is a part of the HUPO Brain Proteome Project (BPP) pilot study, which aims at obtaining a reliable database of mouse brain proteome, at the comparison of techniques, laboratories, and approaches as well as at preparing subsequent proteome studies of neurologic diseases. The C57/Bl6 mouse brains of three developmental stages at embryonic day 16 (E16), postnatal day 7 (P7), and 8 wk (P56) (n = 5 in each group) were provided by the HUPO BPP executive committee. The whole brain proteins of each animal were individually prepared using 2-DE coupled with PDQuest software analysis. The protein spots representing developmentally related or stably expressed proteins were then prepared with in-gel digestion followed with MALDI-TOF/TOF MS/MS and analyzed using the MASCOT search engines to search the Swiss-Prot or NCBInr database. The 2-DE gel maps of the mouse brains of all of the developmental stages were obtained and submitted to the Data Collection Centre (DCC). The proteins alpha-enolase, stathmin, actin, C14orf166 homolog, 28,000 kDa heat- and acid-stable phosphoprotein, 3-mercaptopyruvate sulfurtransferase and 40 S ribosomal protein S3a were successfully identified. A further Western blotting analysis demonstrated that enolase is a protein up-regulated in the mouse brain from embryonic stage to adult stage. These data are helpful for understanding the proteome changes in the development of the mouse brain.

Biogenic volatile organic compound emissions from senescent maize leaves and a comparison with other leaf developmental stages

NASA Astrophysics Data System (ADS)

Mozaffar, A.; Schoon, N.; Bachy, A.; Digrado, A.; Heinesch, B.; Aubinet, M.; Fauconnier, M.-L.; Delaplace, P.; du Jardin, P.; Amelynck, C.

2018-03-01

Plants are the major source of Biogenic Volatile Organic Compounds (BVOCs) which have a large influence on atmospheric chemistry and the climate system. Therefore, understanding of BVOC emissions from all abundant plant species at all developmental stages is very important. Nevertheless, investigations on BVOC emissions from even the most widespread agricultural crop species are rare and mainly confined to the healthy green leaves. Senescent leaves of grain crop species could be an important source of BVOCs as almost all the leaves senesce on the field before being harvested. For these reasons, BVOC emission measurements have been performed on maize (Zea mays L.), one of the most cultivated crop species in the world, at all the leaf developmental stages. The measurements were performed in controlled environmental conditions using dynamic enclosures and proton transfer reaction mass spectrometry (PTR-MS). The main compounds emitted by senescent maize leaves were methanol (31% of the total cumulative BVOC emission on a mass of compound basis) and acetic acid (30%), followed by acetaldehyde (11%), hexenals (9%) and m/z 59 compounds (acetone/propanal) (7%). Important differences were observed in the temporal emission profiles of the compounds, and both yellow leaves during chlorosis and dry brown leaves after chlorosis were identified as important senescence-related BVOC sources. Total cumulative BVOC emissions from senescent maize leaves were found to be among the highest for senescent Poaceae plant species. BVOC emission rates varied strongly among the different leaf developmental stages, and senescent leaves showed a larger diversity of emitted compounds than leaves at earlier stages. Methanol was the compound with the highest emissions for all the leaf developmental stages and the contribution from the young-growing, mature, and senescent stages to the total methanol emission by a typical maize leaf was 61, 13, and 26%, respectively. This study shows that BVOC emissions from senescent maize leaves cannot be neglected and further investigations in field conditions are recommended to further constrain the BVOC emissions from this important C4 crop species.

Carbon dioxide exchange in compact and semi-open sorghum inflorescences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eastin, J.D.; Sullivan, C.Y.

Carbon dioxide exchange rates were monitored in light and dark in compact and semi-open heads of sorghum (Sorghum bicolor (L.) Moench). Developmental stages ranged from bottom to hard dough in the grain. Highest CO/sub 2/ uptake in both head types occurred at the bloom stage when net uptake rates for semi-open and compact type heads were 3.9 and 1.2 mg CO/sub 2/ g dry wt/sup -1/ hr/sup -1/, respectively. Beginning at the milk stage, a net CO/sub 2/ evolution on the order of 1 to 1.4 mg g dry wt/sup -1/ hr/sup -1/ occurred in compact heads in the light.more » The semi-open head type continued a small net CO/sub 2/ uptake in the light through the milk and soft dough stages. Both head types evolved CO/sub 2/ at hard dough stage. Dark respiration was similar in both head types and decreased from about 4 to 1 mg CO/sub 2/ g dry wt/sup -1/ hr/sup -1/ from bloom to hard dough. 16 references, 1 figure.« less

Development and Disease: How Susceptibility to an Emerging Pathogen Changes through Anuran Development

PubMed Central

Haislip, Nathan A.; Gray, Matthew J.; Hoverman, Jason T.; Miller, Debra L.

2011-01-01

Ranaviruses have caused die-offs of amphibians across the globe. In North America, these pathogens cause more amphibian mortality events than any other pathogen. Field observations suggest that ranavirus epizootics in amphibian communities are common during metamorphosis, presumably due to changes in immune function. However, few controlled studies have compared the relative susceptibility of amphibians to ranaviruses across life stages. Our objectives were to measure differences in mortality and infection prevalence following exposure to ranavirus at four developmental stages and determine whether the differences were consistent among seven anuran species. Based on previous studies, we hypothesized that susceptibility to ranavirus would be greatest at metamorphosis. Our results did not support this hypothesis, as four of the species were most susceptible to ranavirus during the larval or hatchling stages. The embryo stage had the lowest susceptibility among species probably due to the protective membranous layers of the egg. Our results indicate that generalizations should be made cautiously about patterns of susceptibility to ranaviruses among amphibian developmental stages and species. Further, if early developmental stages of amphibians are susceptible to ranaviruses, the impact of ranavirus epizootic events may be greater than realized due to the greater difficulty of detecting morbid hatchlings and larvae compared to metamorphs. PMID:21799820

Safe-Site Effects on Rhizosphere Bacterial Communities in a High-Altitude Alpine Environment

PubMed Central

Zerbe, Stefan

2014-01-01

The rhizosphere effect on bacterial communities associated with three floristic communities (RW, FI, and M sites) which differed for the developmental stages was studied in a high-altitude alpine ecosystem. RW site was an early developmental stage, FI was an intermediate stage, M was a later more matured stage. The N and C contents in the soils confirmed a different developmental stage with a kind of gradient from the unvegetated bare soil (BS) site through RW, FI up to M site. The floristic communities were composed of 21 pioneer plants belonging to 14 species. Automated ribosomal intergenic spacer analysis showed different bacterial genetic structures per each floristic consortium which differed also from the BS site. When plants of the same species occurred within the same site, almost all their bacterial communities clustered together exhibiting a plant species effect. Unifrac significance value (P < 0.05) on 16S rRNA gene diversity revealed significant differences (P < 0.05) between BS site and the vegetated sites with a weak similarity to the RW site. The intermediate plant colonization stage FI did not differ significantly from the RW and the M vegetated sites. These results pointed out the effect of different floristic communities rhizospheres on their soil bacterial communities. PMID:24995302

Estrogenic exposure affects metamorphosis and alters sex ratios in the northern leopard frog (Rana pipiens): identifying critically vulnerable periods of development.

PubMed

Hogan, Natacha S; Duarte, Paula; Wade, Michael G; Lean, David R S; Trudeau, Vance L

2008-05-01

During the transformation from larval tadpole to juvenile frog, there are critical periods of metamorphic development and sex differentiation that may be particularly sensitive to endocrine disruption. The aim of the present study was to identify sensitive developmental periods for estrogenic endocrine disruption in the northern leopard frog (Rana pipiens) using short, targeted exposures to the synthetic estrogen, ethinylestradiol (EE2). Post-hatch tadpoles (Gosner stage 27) were exposed over five distinct periods of metamorphosis: early (stage 27-30), mid (stage 30-36), early and mid (stage 27-36), late (stage 36-42), and the entire metamorphic period (chronic; stage 27-42). For each period, animals were sampled immediately following the EE2 exposure and at metamorphic climax (stage 42). The effects of EE2 on metamorphic development and sex differentiation were assessed through measures of length, weight, developmental stage, days to metamorphosis, sex ratios and incidence of gonadal intersex. Our results show that tadpoles exposed to EE2 during mid-metamorphosis were developmentally delayed immediately following exposure and took 2 weeks longer to reach metamorphic climax. In the unexposed groups, there was low proportion (0.15) of intersex tadpoles at stage 30 and gonads appeared to be morphologically distinct (male and female) in all individuals by stage 36. Tadpoles exposed early in development displayed a strong female-biased sex ratio compared to the controls. Moreover, these effects were also seen at metamorphic climax, approximately 2-3 months after the exposure period, demonstrating that transient early life-stage exposure to estrogen can induce effects on the reproductive organs that persist into the beginning of adult life-stages.

Description and Codification of Miscanthus × giganteus Growth Stages for Phenological Assessment

PubMed Central

Tejera, Mauricio D.; Heaton, Emily A.

2017-01-01

Triploid Miscanthus × giganteus (Greef et Deu. ex Hodkinson et Renvoize) is a sterile, perennial grass used for biomass production in temperate environments. While M. × giganteus has been intensively researched, a scale standardizing description of M. × giganteus morphological stages has not been developed. Here we provide such a scale by adapting the widely-used Biologische Bundesanstalt, Bundessortenamt, CHemische Industrie (BBCH) scale and its corresponding numerical code to describe stages of morphological development in M. × giganteus using observations of the “Freedom” and “Illinois” clone in Iowa, USA. Descriptive keys with images are also presented. Because M. × giganteus plants overlap in the field, the scale was first applied to individual stems and then scaled up to assess plants or communities. Of the 10 principal growth stages in the BBCH system, eight were observed in M. × giganteus. Each principal stage was subdivided into secondary stages to enable a detailed description of developmental progression. While M. × giganteus does not have seed development stages, descriptions of those stages are provided to extend the scale to other Miscanthus genotypes. We present methods to use morphological development data to assess phenology by calculating the onset, duration, and abundance of each developmental stage. This scale has potential to harmonize previously described study-specific scales and standardize results across studies. Use of the precise staging presented here should more tightly constrain estimates of developmental parameters in crop models and increase the efficacy of timing-sensitive crop management practices like pest control and harvest. PMID:29062320

Maternal-Newborn and Surgical Nurses’ Perceptions of Professional Autonomy During the Development of Shared Governance

DTIC Science & Technology

1993-01-01

women in general (Schutzenhofer, 1988b). Pinch (1981) and Gilligan (1979) noted that most developmental theorists have studied male development and...previous developmental stages . Men find identity through their work, while a woman’s identity is defined by relationships (Gilligan, 1977), since, until...was only .54, while the realistic behavior subscale produced an alpha of .70. Nunnally (1978) recommends that tools in early stages of development

Convergent adaptive radiations in Madagascan and Asian ranid frogs reveal covariation between larval and adult traits

PubMed Central

Bossuyt, Franky; Milinkovitch, Michel C.

2000-01-01

Recent studies have reported that independent adaptive radiations can lead to identical ecomorphs. Our phylogenetic analyses of nuclear and mitochondrial DNA sequences here indicate that a major radiation of ranid frogs on Madagascar produced morphological, physiological, and developmental characters that are remarkably similar to those that independently evolved on the Indian subcontinent. We demonstrate further that, in several cases, adult and larval stages each evolved sets of characters which are not only convergent between independent lineages, but also allowed both developmental stages to invade the same adaptive zone. It is likely that such covariations are produced by similar selective pressures on independent larval and adult characters rather than by genetic or functional linkage. We briefly discuss why larval/adult covariations might constitute an important evolutionary phenomenon in species for which more than one developmental stage potentially has access to multiple environmental conditions. PMID:10841558

Generalized additive models and Lucilia sericata growth: assessing confidence intervals and error rates in forensic entomology.

PubMed

Tarone, Aaron M; Foran, David R

2008-07-01

Forensic entomologists use blow fly development to estimate a postmortem interval. Although accurate, fly age estimates can be imprecise for older developmental stages and no standard means of assigning confidence intervals exists. Presented here is a method for modeling growth of the forensically important blow fly Lucilia sericata, using generalized additive models (GAMs). Eighteen GAMs were created to predict the extent of juvenile fly development, encompassing developmental stage, length, weight, strain, and temperature data, collected from 2559 individuals. All measures were informative, explaining up to 92.6% of the deviance in the data, though strain and temperature exerted negligible influences. Predictions made with an independent data set allowed for a subsequent examination of error. Estimates using length and developmental stage were within 5% of true development percent during the feeding portion of the larval life cycle, while predictions for postfeeding third instars were less precise, but within expected error.

Chemical Composition, Antioxidant, and Antimicrobial Activities on Laserpitium carduchorum Hedge & Lamond Essential Oil and Extracts During Various Growing Stages.

PubMed

Dastan, Dara; Salehi, Peyman; Maroofi, Hossein

2016-10-01

Laserpitium carduchorum is frequently used as a spice, and in Bane folk medicine, the aerial parts of this are used to treat urinary infections. Variation in the quantity and quality of the essential oil of Iranian L. carduchorum at different developmental growth stages including vegetative, flowering, and seed ripening is reported. In total, 33 compounds were identified and quantified in the oils of vegetative, flowering, and seed ripening stages, representing 97.8%, 98.8%, and 98.7% of the oils, respectively. α-Pinene (45.1, 61.4, and 46.4%), sabinene (16.5, 10.3, and 17.5%), and limonene (6.4, 8.5, and 20.4%) were the main compounds in all samples. The antioxidant activities of different extracts of L. carduchorum at different developmental growth stages were examined by employing various established in vitro experiments including DPPH, FRAP, and TEAC assays. The amounts of total phenolics were also determined spectrophotometerically. Antimicrobial activities of different extracts and essential oils of L. carduchorum at different developmental growth stages were examined against five Gram-positive and four Gram-negative bacteria, as well as two fungi. The results showed that maximum antioxidant and antimicrobial activity of extracts were at the flowering stage of the plant. Maximum antimicrobial activity of essential oils was at seed ripening stage. © 2016 Wiley-VHCA AG, Zürich.

The Development of Altruism with Special Reference to Human Relationships: A 10-Stage Theory.

PubMed

Ma, Hing Keung

2017-01-01

All human relationships involve some form of cost and benefit and altruism forms the foundation upon which human relationships are built. In this paper, a taxonomy of human relationships in terms of altruism was constructed. In the proposed taxonomy, human relationships are categorized into three major groups: primary group, secondary group, and tertiary group. The primary group consists of members that are very closely related to each other either by genetic relatedness (e.g., parents, siblings, and cousins) or social relatedness (e.g., mate and close friends) or both. The secondary group consists of members that are socially related but also less closely related with each other (e.g., people of the same political or religious group, teachers, mentors, acquaintances, neighbors, working colleagues, and strangers). Lastly, the tertiary group consists of members of other species. A 10-stage theory of altruism with special reference to human relationships is proposed. The affective, cognitive, and relationship aspects of each stage are delineated in details. There are two developmental principles of altruism. The first principle states that the development of altruism follows the 10-stage theory and moves from Stage 1: Egoism toward the higher stages of altruism slowly. The second developmental principle states that the taxonomy of human relationships is valid at any stage of altruism development. In other words, people at any stage of altruism are more altruistic toward their kin and mate, and then close friends, extended family members, and so on. They are least altruistic toward enemies and members of non-human species. In summary, the proposed developmental principle of altruism and human relationships is logical and robust. It is formulated based on the major developmental and social psychological theories. The theory has the potential in providing a useful framework for future studies on the development and evolution of human relationships.

The Development of Altruism with Special Reference to Human Relationships: A 10-Stage Theory

PubMed Central

Ma, Hing Keung

2017-01-01

All human relationships involve some form of cost and benefit and altruism forms the foundation upon which human relationships are built. In this paper, a taxonomy of human relationships in terms of altruism was constructed. In the proposed taxonomy, human relationships are categorized into three major groups: primary group, secondary group, and tertiary group. The primary group consists of members that are very closely related to each other either by genetic relatedness (e.g., parents, siblings, and cousins) or social relatedness (e.g., mate and close friends) or both. The secondary group consists of members that are socially related but also less closely related with each other (e.g., people of the same political or religious group, teachers, mentors, acquaintances, neighbors, working colleagues, and strangers). Lastly, the tertiary group consists of members of other species. A 10-stage theory of altruism with special reference to human relationships is proposed. The affective, cognitive, and relationship aspects of each stage are delineated in details. There are two developmental principles of altruism. The first principle states that the development of altruism follows the 10-stage theory and moves from Stage 1: Egoism toward the higher stages of altruism slowly. The second developmental principle states that the taxonomy of human relationships is valid at any stage of altruism development. In other words, people at any stage of altruism are more altruistic toward their kin and mate, and then close friends, extended family members, and so on. They are least altruistic toward enemies and members of non-human species. In summary, the proposed developmental principle of altruism and human relationships is logical and robust. It is formulated based on the major developmental and social psychological theories. The theory has the potential in providing a useful framework for future studies on the development and evolution of human relationships. PMID:29085818

Life cycle stage and water depth affect flooding-induced adventitious root formation in the terrestrial species Solanum dulcamara

PubMed Central

Zhang, Qian; Visser, Eric J. W.; de Kroon, Hans; Huber, Heidrun

2015-01-01

Background and Aims Flooding can occur at any stage of the life cycle of a plant, but often adaptive responses of plants are only studied at a single developmental stage. It may be anticipated that juvenile plants may respond differently from mature plants, as the amount of stored resources may differ and morphological changes can be constrained. Moreover, different water depths may require different strategies to cope with the flooding stress, the expression of which may also depend on developmental stage. This study investigated whether flooding-induced adventitious root formation and plant growth were affected by flooding depth in Solanum dulcamara plants at different developmental stages. Methods Juvenile plants without pre-formed adventitious root primordia and mature plants with primordia were subjected to shallow flooding or deep flooding for 5 weeks. Plant growth and the timing of adventitious root formation were monitored during the flooding treatments. Key Results Adventitious root formation in response to shallow flooding was significantly constrained in juvenile S. dulcamara plants compared with mature plants, and was delayed by deep flooding compared with shallow flooding. Complete submergence suppressed adventitious root formation until up to 2 weeks after shoots restored contact with the atmosphere. Independent of developmental stage, a strong positive correlation was found between adventitious root formation and total biomass accumulation during shallow flooding. Conclusions The potential to deploy an escape strategy (i.e. adventitious root formation) may change throughout a plant’s life cycle, and is largely dependent on flooding depth. Adaptive responses at a given stage of the life cycle thus do not necessarily predict how the plant responds to flooding in another growth stage. As variation in adventitious root formation also correlates with finally attained biomass, this variation may form the basis for variation in resistance to shallow flooding among plants. PMID:26105188

Life cycle stage and water depth affect flooding-induced adventitious root formation in the terrestrial species Solanum dulcamara.

PubMed

Zhang, Qian; Visser, Eric J W; de Kroon, Hans; Huber, Heidrun

2015-08-01

Flooding can occur at any stage of the life cycle of a plant, but often adaptive responses of plants are only studied at a single developmental stage. It may be anticipated that juvenile plants may respond differently from mature plants, as the amount of stored resources may differ and morphological changes can be constrained. Moreover, different water depths may require different strategies to cope with the flooding stress, the expression of which may also depend on developmental stage. This study investigated whether flooding-induced adventitious root formation and plant growth were affected by flooding depth in Solanum dulcamara plants at different developmental stages. Juvenile plants without pre-formed adventitious root primordia and mature plants with primordia were subjected to shallow flooding or deep flooding for 5 weeks. Plant growth and the timing of adventitious root formation were monitored during the flooding treatments. Adventitious root formation in response to shallow flooding was significantly constrained in juvenile S. dulcamara plants compared with mature plants, and was delayed by deep flooding compared with shallow flooding. Complete submergence suppressed adventitious root formation until up to 2 weeks after shoots restored contact with the atmosphere. Independent of developmental stage, a strong positive correlation was found between adventitious root formation and total biomass accumulation during shallow flooding. The potential to deploy an escape strategy (i.e. adventitious root formation) may change throughout a plant's life cycle, and is largely dependent on flooding depth. Adaptive responses at a given stage of the life cycle thus do not necessarily predict how the plant responds to flooding in another growth stage. As variation in adventitious root formation also correlates with finally attained biomass, this variation may form the basis for variation in resistance to shallow flooding among plants. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Aspects of embryonic and larval development in bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix

USGS Publications Warehouse

George, Amy E.; Chapman, Duane C.

2013-01-01

As bighead carp Hypophthalmichthys nobilis and silver carp H. molitrix (the bigheaded carps) are poised to enter the Laurentian Great Lakes and potentially damage the region’s economically important fishery, information on developmental rates and behaviors of carps is critical to assessing their ability to establish sustainable populations within the Great Lakes basin. In laboratory experiments, the embryonic and larval developmental rates, size, and behaviors of bigheaded carp were tracked at two temperature treatments, one “cold” and one “warm”. Developmental rates were computed using previously described stages of development and the cumulative thermal unit method. Both species have similar thermal requirements, with a minimum developmental temperature for embryonic stages of 12.1° C for silver carp and 12.9° C for bighead carp, and 13.3° C for silver carp larval stages and 13.4° C for bighead carp larval stages. Egg size differed among species and temperature treatments, as egg size was larger in bighead carp, and “warm" temperature treatments. The larvae started robust upwards vertical swimming immediately after hatching, interspersed with intervals of sinking. Vertical swimming tubes were used to measure water column distribution, and ascent and descent rates of vertically swimming fish. Water column distribution and ascent and descent rates changed with ontogeny. Water column distribution also showed some diel periodicity. Developmental rates, size, and behaviors contribute to the drift distance needed to fulfill the early life history requirements of bigheaded carps and can be used in conjunction with transport information to assess invasibility of a river.

Analyses of outcomes of one-stage operation for treatment of late-diagnosed developmental dislocation of the hip: 864 hips followed for 3.2 to 8.9 years.

PubMed

Ning, Bo; Yuan, Yi; Yao, Jie; Zhang, Sichng; Sun, Jun

2014-11-28

The one-stage procedure for treatment of older developmental dislocation of the hip (DDH) is used widely. However, the best age group for this operation is still unknown. The aims of our study were to evaluate middle-term outcomes of one-stage surgical treatment of a large number of patients with late-diagnosed DDH, and to explore the best age group for treatment. We retrospectively reviewed 652 patients with a total of 864 hip joints with DDH, all aged >18 months. All the hip joints were treated with one-stage procedures including open reduction, pelvic osteotomy, and femoral shortening. The patients were divided into three groups according to age at surgery: Group I: 1.5-2.5 years; Group II: 2.5-8 years; and Group III: >8 years. The latest clinical and radiographic outcomes, complications and avascular necrosis (AVN) of the femoral head were evaluated and compared among the three groups. The mean age at surgery was 5.8 years (range: 1.5-13.2 years). The average time of follow-up was 6.2 years (range: 3.2-8.9 years). A total of 79.4% of good or excellent outcomes were obtained for clinical functional evaluation according to the McKay classification. For radiographic outcomes, 732 hips (84.7%) were classified as good or excellent according to the Severin classification. A total of 27.4% of all hips had a poor outcome according to the Kalamchi and MacEwen classification for AVN. The poorest outcomes were observed for clinical, radiographic and AVN results in Group III (p < 0.001). Compared with Group I, the better results for clinical and AVN outcomes were found in Group II (p < 0.001). However, similar clinical outcomes were observed between Groups I and II (p > 0.05). A significantly higher incidence of redislocation and residual acetabular dysplasia was observed in Tonnis grade II and III hip dislocation (p < 0.001). One-stage treatment of late-diagnosed DDH had a good outcome in young and middle group. Younger patients achieved better results than older patients. However, the best age group was 2.5-8 years. Tonnis grade II and III DDH is a risk factor for redislocation and residual acetabular dysplasia after the one-stage operation.

Developmental Spelling and Word Recognition: A Validation of Ehri's Model of Word Recognition Development

ERIC Educational Resources Information Center

Ebert, Ashlee A.

2009-01-01

Ehri's developmental model of word recognition outlines early reading development that spans from the use of logos to advanced knowledge of oral and written language to read words. Henderson's developmental spelling theory presents stages of word knowledge that progress in a similar manner to Ehri's phases. The purpose of this research study was…

Thin-plate spline analysis of mandibular growth.

PubMed

Franchi, L; Baccetti, T; McNamara, J A

2001-04-01

The analysis of mandibular growth changes around the pubertal spurt in humans has several important implications for the diagnosis and orthopedic correction of skeletal disharmonies. The purpose of this study was to evaluate mandibular shape and size growth changes around the pubertal spurt in a longitudinal sample of subjects with normal occlusion by means of an appropriate morphometric technique (thin-plate spline analysis). Ten mandibular landmarks were identified on lateral cephalograms of 29 subjects at 6 different developmental phases. The 6 phases corresponded to 6 different maturational stages in cervical vertebrae during accelerative and decelerative phases of the pubertal growth curve of the mandible. Differences in shape between average mandibular configurations at the 6 developmental stages were visualized by means of thin-plate spline analysis and subjected to permutation test. Centroid size was used as the measure of the geometric size of each mandibular specimen. Differences in size at the 6 developmental phases were tested statistically. The results of graphical analysis indicated a statistically significant change in mandibular shape only for the growth interval from stage 3 to stage 4 in cervical vertebral maturation. Significant increases in centroid size were found at all developmental phases, with evidence of a prepubertal minimum and of a pubertal maximum. The existence of a pubertal peak in human mandibular growth, therefore, is confirmed by thin-plate spline analysis. Significant morphological changes in the mandible during the growth interval from stage 3 to stage 4 in cervical vertebral maturation may be described as an upward-forward direction of condylar growth determining an overall "shrinkage" of the mandibular configuration along the measurement of total mandibular length. This biological mechanism is particularly efficient in compensating for major increments in mandibular size at the adolescent spurt.

Demands for carbohydrates as major energy substrates depend on the preimplantation developmental stage in pig embryos: Differential use of fructose by parthenogenetic diploids before and after the 4-cell stage in the pig

PubMed Central

SHIBUTANI, Mihiro; LEE, Jibak; MIYANO, Takashi; MIYAKE, Masashi

2015-01-01

The embryo culture technique has been improving, but the detailed demands for energy substrates such as glucose, fructose, pyruvate and lactate of preimplantation embryos are still unclear. In the present study, the demands of pig preimplantation embryos at each different developmental stage were investigated by use of parthenogenetic diploids as a model of pig preimplantation embryos. Pig parthenogenetic diploids showed different use of glucose and fructose before and after the 4-cell stage. Although glucose supported the development of pig embryos throughout the preimplantation stages and even maintained the expansion and hatching of blastocysts, it suppressed development to the blastocyst stage when glucose coexisted with pyruvate and lactate from 4 h after activation, but not after 48 h (early 4-cell stage). Since ketohexokinase that metabolizes fructose was not expressed in 2-cell and 4-cell diploids, a medium that included only fructose as a major energy substrate did not support early cleavage of pig diploids beyond the 4-cell stage, and almost no diploids developed to the morula stage just as in a medium without carbohydrates. These results may explain the different suppressive effects on pig preimplantation development between glucose and fructose when pyruvate and lactate were present in a medium. In addition, 4-cell diploids that had been cultured in a medium with pyruvate and lactate developed to the expanded blastocyst stage without any carbohydrates as a major energy substrate. These results show that the demands for carbohydrates are different depending on the developmental stage in pig preimplantation embryos. PMID:25736264

The development of functional network organization in early childhood and early adolescence: A resting-state fNIRS study.

PubMed

Cai, Lin; Dong, Qi; Niu, Haijing

2018-04-01

Early childhood (7-8 years old) and early adolescence (11-12 years old) constitute two landmark developmental stages that comprise considerable changes in neural cognition. However, very limited information from functional neuroimaging studies exists on the functional topological configuration of the human brain during specific developmental periods. In the present study, we utilized continuous resting-state functional near-infrared spectroscopy (rs-fNIRS) imaging data to examine topological changes in network organization during development from early childhood and early adolescence to adulthood. Our results showed that the properties of small-worldness and modularity were not significantly different across development, demonstrating the developmental maturity of important functional brain organization in early childhood. Intriguingly, young children had a significantly lower global efficiency than early adolescents and adults, which revealed that the integration of the distributed networks strengthens across the developmental stages underlying cognitive development. Moreover, local efficiency of young children and adolescents was significantly lower than that of adults, while there was no difference between these two younger groups. This finding demonstrated that functional segregation remained relatively steady from early childhood to early adolescence, and the brain in these developmental periods possesses no optimal network configuration. Furthermore, we found heterogeneous developmental patterns in the regional nodal properties in various brain regions, such as linear increased nodal properties in the frontal cortex, indicating increasing cognitive capacity over development. Collectively, our results demonstrated that significant topological changes in functional network organization occurred during these two critical developmental stages, and provided a novel insight into elucidating subtle changes in brain functional networks across development. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

An approach to finding teaching moments on families and child development in Disney films.

PubMed

Guerrero, Anthony P S

2015-04-01

In the interest of finding "teaching moments in film" for psychiatric education and education on child development, the author describes an approach to analyzing Disney--and potentially other children's films--based on specifically observing family structure at the beginning and ending of the story, developmental stage and gender of the protagonist, the developmental crisis, and the external change agent and/or stressor. The author considered a convenience sample of ten popular Disney films. A wide variety of family structures and developmental stages and challenges were observed in the reviewed films. A matrix approach such as the one illustrated may help psychiatric educators to select effective teaching moments from Disney and other children's films.

Maturation of the growth axis in marsupials occurs gradually during post-natal life and over an equivalent developmental stage relative to eutherian species.

PubMed

Menzies, Brandon R; Shaw, Geoffrey; Fletcher, Terry P; Pask, Andrew J; Renfree, Marilyn B

2012-02-26

The separation of a nutrition-responsive insulin-like growth factor (IGF) system and a growth hormone (GH) responsive IGF system to control pre- and post-natal growth of developing mammals may originate from the constraints imposed by intra-uterine development. In eutherian species that deliver relatively precocial young, maturation of the GH regulatory system is coincident with the time of birth. We measured the hepatic expression of the four key growth axis genes GH-receptor, IGF-1 and -2, and IGFBBP-3, and plasma protein concentrations of IGF-1 from late fetal life through to adult stages of a marsupial, the tammar wallaby. The data clearly show that maturation of GH-regulated growth in marsupials occurs gradually over the course of post-natal life at an equivalent developmental stage to that of precocial eutherian mammals. This suggests that the timing of GH-regulated growth in marsupials is not related to parturition but instead to the relative developmental stage. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Stage selection and restricted oviposition period improves cryopreservation of dipteran embryos.

PubMed

Rajamohan, Arun; Rinehart, Joseph P; Leopold, Roger A

2015-04-01

Embryos of two dipteran species (Musca domestica and Lucilia sericata) were assessed for an effective sampling time that would result in the highest post-cryopreservation hatch rate, with a primary goal to define species-specific egg collection periods and the effects of manual stage selection on post cryopreservation yield. The effects of the time taken to collect eggs on, (a) the proportion of embryos reaching a specific developmental stage between 17 and 20 h of development, and (b) the post-cryopreservation hatch rate were assessed. Permeabilization treatment applied at any stage of embryonic development did not significantly reduce embryo viability. Eggs collected over longer durations significantly reduced the number of embryos available in a specific developmental stage amenable to cryopreservation. Hatch percentage after cryopreservation of the embryos of M. domestica collected over a 60 min period was 10.7 ± 8.7% compared to 31 ± 5% for the eggs collected for just 15 min. Similarly, percent hatch in L. sericata resulted in 17.0 ± 3.9 and <2% for 15 and 60 min samples, respectively. Significantly higher hatching rates were obtained for cryopreservation after manual selection of specific embryonic developmental stages from the dechorionated samples. Post-cryopreservation hatching rate for stage-selected M. domestica embryos was 86.5 ± 5.5% compared to 33.3 ± 4.5% for embryos staged only by an overall visual confirmation. In the case of L. sericata, the hatching percentage was 79.0 ± 11.1 for stage-selected embryos compared to 17.0 ± 3.9% without individual selection. Published by Elsevier Inc.

Pleiotropy in the wild: the dormancy gene DOG1 exerts cascading control on life cycles.

PubMed

Chiang, George C K; Barua, Deepak; Dittmar, Emily; Kramer, Elena M; de Casas, Rafael Rubio; Donohue, Kathleen

2013-03-01

In the wild, organismal life cycles occur within seasonal cycles, so shifts in the timing of developmental transitions can alter the seasonal environment experienced subsequently. Effects of genes that control the timing of prior developmental events can therefore be magnified in the wild because they determine seasonal conditions experienced by subsequent life stages, which can influence subsequent phenotypic expression. We examined such environmentally induced pleiotropy of developmental-timing genes in a field experiment with Arabidopsis thaliana. When studied in the field under natural seasonal variation, an A. thaliana seed-dormancy gene, Delay Of Germination 1 (DOG1), was found to influence not only germination, but also flowering time, overall life history, and fitness. Flowering time of the previous generation, in turn, imposed maternal effects that altered germination, the effects of DOG1 alleles, and the direction of natural selection on these alleles. Thus under natural conditions, germination genes act as flowering genes and potentially vice versa. These results illustrate how seasonal environmental variation can alter pleiotropic effects of developmental-timing genes, such that effects of genes that regulate prior life stages ramify to influence subsequent life stages. In this case, one gene acting at the seed stage impacted the entire life cycle. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Streptomyces exploration is triggered by fungal interactions and volatile signals

PubMed Central

Jones, Stephanie E; Ho, Louis; Rees, Christiaan A; Hill, Jane E; Nodwell, Justin R; Elliot, Marie A

2017-01-01

It has long been thought that the life cycle of Streptomyces bacteria encompasses three developmental stages: vegetative hyphae, aerial hyphae and spores. Here, we show interactions between Streptomyces and fungi trigger a previously unobserved mode of Streptomyces development. We term these Streptomyces cells ‘explorers’, for their ability to adopt a non-branching vegetative hyphal conformation and rapidly transverse solid surfaces. Fungi trigger Streptomyces exploratory growth in part by altering the composition of the growth medium, and Streptomyces explorer cells can communicate this exploratory behaviour to other physically separated streptomycetes using an airborne volatile organic compound (VOC). These results reveal that interkingdom interactions can trigger novel developmental behaviours in bacteria, here, causing Streptomyces to deviate from its classically-defined life cycle. Furthermore, this work provides evidence that VOCs can act as long-range communication signals capable of propagating microbial morphological switches. DOI: http://dx.doi.org/10.7554/eLife.21738.001 PMID:28044982

Adults Can Be Trained to Acquire Synesthetic Experiences

PubMed Central

Bor, Daniel; Rothen, Nicolas; Schwartzman, David J.; Clayton, Stephanie; Seth, Anil K.

2014-01-01

Synesthesia is a condition where presentation of one perceptual class consistently evokes additional experiences in different perceptual categories. Synesthesia is widely considered a congenital condition, although an alternative view is that it is underpinned by repeated exposure to combined perceptual features at key developmental stages. Here we explore the potential for repeated associative learning to shape and engender synesthetic experiences. Non-synesthetic adult participants engaged in an extensive training regime that involved adaptive memory and reading tasks, designed to reinforce 13 specific letter-color associations. Following training, subjects exhibited a range of standard behavioral and physiological markers for grapheme-color synesthesia; crucially, most also described perceiving color experiences for achromatic letters, inside and outside the lab, where such experiences are usually considered the hallmark of genuine synesthetes. Collectively our results are consistent with developmental accounts of synesthesia and illuminate a previously unsuspected potential for new learning to shape perceptual experience, even in adulthood. PMID:25404369

Developmental effects of the protein kinase inhibitor kenpaullone on the sea urchin embryo.

PubMed

Anello, Letizia; Cavalieri, Vincenzo; Di Bernardo, Maria

2018-01-01

The selection and validation of bioactive compounds require multiple approaches, including in-depth analyses of their biological activity in a whole-animal context. We exploited the sea urchin embryo in a rapid, medium-scale range screening to test the effects of the small synthetic kinase inhibitor kenpaullone. We show that sea urchin embryos specifically respond to this molecule depending on both dose and timing of administration. Phenotypic effects of kenpaullone are not immediately visible, since this molecule affects neither the fertilization nor the spatial arrangement of blastomeres at early developmental stages. Nevertheless, kenpaullone exposure from the beginning of embryogenesis profoundly perturbs specification, detachment from the epithelium, and migration of the primary mesenchyme cells, thus affecting the whole embryonic epithelial mesenchymal transition process. Our results reaffirm the sea urchin embryo as an excellent and sensitive in vivo system, which provides straightforward and rapid response to external stimuli. Copyright © 2017 Elsevier Inc. All rights reserved.

Use of drawings in children with pervasive developmental disorder during hospitalization: a developmental perspective.

PubMed

Stefanatou, Athena

2008-12-01

The level and nature of emotional upheaval and relationship to developmental stage was studied in children with pervasive developmental disorder (PDD) hospitalized for head injury. The sample consisted of 25 hospitalized children aged 5-12 years. Children were asked to make the drawing of a ;person in hospital'. The drawings were evaluated by Koppitz's emotional indicators. Punishment and persecution were the main cognitive constructs of children in order to explain hospitalization.

Effects of developmental variability on the dynamics and self-organization of cell populations

NASA Astrophysics Data System (ADS)

Prabhakara, Kaumudi H.; Gholami, Azam; Zykov, Vladimir S.; Bodenschatz, Eberhard

2017-11-01

We report experimental and theoretical results for spatiotemporal pattern formation in cell populations, where the parameters vary in space and time due to mechanisms intrinsic to the system, namely Dictyostelium discoideum (D.d.) in the starvation phase. We find that different patterns are formed when the populations are initialized at different developmental stages, or when populations at different initial developmental stages are mixed. The experimentally observed patterns can be understood with a modified Kessler-Levine model that takes into account the initial spatial heterogeneity of the cell populations and a developmental path introduced by us, i.e. the time dependence of the various biochemical parameters. The dynamics of the parameters agree with known biochemical studies. Most importantly, the modified model reproduces not only our results, but also the observations of an independent experiment published earlier. This shows that pattern formation can be used to understand and quantify the temporal evolution of the system parameters.

Caste- and development-associated gene expression in a lower termite

PubMed Central

Scharf, Michael E; Wu-Scharf, Dancia; Pittendrigh, Barry R; Bennett, Gary W

2003-01-01

Background Social insects such as termites express dramatic polyphenism (the occurrence of multiple forms in a species on the basis of differential gene expression) both in association with caste differentiation and between castes after differentiation. We have used cDNA macroarrays to compare gene expression between polyphenic castes and intermediary developmental stages of the termite Reticulitermes flavipes. Results We identified differentially expressed genes from nine ontogenic categories. Quantitative PCR was used to quantify precise differences in gene expression between castes and between intermediary developmental stages. We found worker and nymph-biased expression of transcripts encoding termite and endosymbiont cellulases; presoldier-biased expression of transcripts encoding the storage/hormone-binding protein vitellogenin; and soldier-biased expression of gene transcripts encoding two transcription/translation factors, two signal transduction factors and four cytoskeletal/muscle proteins. The two transcription/translation factors showed significant homology to the bicaudal and bric-a-brac developmental genes of Drosophila. Conclusions Our results show differential expression of regulatory, structural and enzyme-coding genes in association with termite castes and their developmental precursor stages. They also provide the first glimpse into how insect endosymbiont cellulase gene expression can vary in association with the caste of a host. These findings shed light on molecular processes associated with termite biology, polyphenism, caste differentiation and development and highlight potentially interesting variations in developmental themes between termites, other insects, and higher animals. PMID:14519197

Location negative priming effects in children with developmental dyslexia: An event-related potential study.

PubMed

Ma, Yujun; Wang, Enguo; Yuan, Tian; Zhao, Guo Xiang

2016-08-01

As the reading process is inseparable from working memory, inhibition, and other higher cognitive processes, the deep cognitive processing defects that are associated with dyslexia may be due to defective distraction inhibition systems. In this study, we used event-related potential technology to explore the source of negative priming effects in children with developmental dyslexia and in a group of healthy children for comparison. We found that the changes in the average response times in the negative priming and control conditions were consistent across the two groups, while the negative priming effects differed significantly between the groups. The magnitude of the negative priming effect was significantly different between the two groups, with the magnitude being significantly higher in the control group than it was in the developmental dyslexia group. These results indicate that there are deficits in distraction inhibition in children with developmental dyslexia. In terms of the time course of processing, inhibition deficits in the dyslexia group appeared during early-stage cognition selection and lasted through the response selection phase. Regarding the cerebral cortex locations, early-stage cognition selection was mainly located in the parietal region, while late-stage response selection was mainly located in the frontal and central regions. The results of our study may help further our understanding of the intrinsic causes of developmental dyslexia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tao Rising: Sexism and Feminist/Transpersonal Therapy.

ERIC Educational Resources Information Center

Sawyer, Llewlee L.

This report presents a dialectical model of identity development which is based on observations of how the self evolves within the context of feminist/transpersonal therapy. Developmental stages which are identified include fusion (Stage I), differentiation (Stage II), and integration (Stage III) of the Child (asserting) and Parent (nurturing)…

Developmental Stages in School Computer Use: Neither Marx Nor Piaget.

ERIC Educational Resources Information Center

Lengel, James G.

Karl Marx's theory of stages can be applied to computer use in the schools. The first stage, the P Stage, comprises the entry of the computer into the school. Computer use at this stage is personal and tends to center around one personality. Social studies teachers are seldom among this select few. The second stage of computer use, the D Stage, is…

Nbn and atm cooperate in a tissue and developmental stage-specific manner to prevent double strand breaks and apoptosis in developing brain and eye.

PubMed

Rodrigues, Paulo M G; Grigaravicius, Paulius; Remus, Martina; Cavalheiro, Gabriel R; Gomes, Anielle L; Rocha-Martins, Maurício; Martins, Mauricio R; Frappart, Lucien; Reuss, David; McKinnon, Peter J; von Deimling, Andreas; Martins, Rodrigo A P; Frappart, Pierre-Olivier

2013-01-01

Nibrin (NBN or NBS1) and ATM are key factors for DNA Double Strand Break (DSB) signaling and repair. Mutations in NBN or ATM result in Nijmegen Breakage Syndrome and Ataxia telangiectasia. These syndromes share common features such as radiosensitivity, neurological developmental defects and cancer predisposition. However, the functional synergy of Nbn and Atm in different tissues and developmental stages is not yet understood. Here, we show in vivo consequences of conditional inactivation of both genes in neural stem/progenitor cells using Nestin-Cre mice. Genetic inactivation of Atm in the central nervous system of Nbn-deficient mice led to reduced life span and increased DSBs, resulting in increased apoptosis during neural development. Surprisingly, the increase of DSBs and apoptosis was found only in few tissues including cerebellum, ganglionic eminences and lens. In sharp contrast, we showed that apoptosis associated with Nbn deletion was prevented by simultaneous inactivation of Atm in developing retina. Therefore, we propose that Nbn and Atm collaborate to prevent DSB accumulation and apoptosis during development in a tissue- and developmental stage-specific manner.

Reproductive and developmental costs of deltamethrin resistance in the Chagas disease vector Triatoma infestans.

PubMed

Germano, Mónica Daniela; Inés Picollo, María

2015-06-01

Effective chemical control relies on reducing vector population size. However, insecticide selection pressure is often associated with the development of resistant populations that reduce control success. In treated areas, these resistant individuals present an adaptive advantage due to enhanced survival. Resistance can also lead to negative effects when the insecticide pressure ceases. In this study, the biological effects of deltamethrin resistance were assessed in the Chagas disease vector Triatoma infestans. The length of each developmental stage and complete life cycle, mating rate, and fecundity were evaluated. Susceptible and resistant insects presented similar mating rates. A reproductive cost of resistance was expressed as a lower fecundity in the resistant colony. Developmental costs in the resistant colony were in the form of a shortening of the second and third nymph stage duration and an extension of the fifth stage. A maternal effect of deltamethrin resistance is suggested as these effects were identified in resistant females and their progeny independently of the mated male's deltamethrin response. Our results suggest the presence of pleiotropic effects of deltamethrin resistance. Possible associations of these characters to other traits such as developmental delays and behavioral resistance are discussed. © 2015 The Society for Vector Ecology.

Calcium promotes activity and confers heat stability on plant peroxidases

PubMed Central

Plieth, Christoph; Vollbehr, Sonja

2012-01-01

In this paper we demonstrate how peroxidase (PO) activities and their heat stability correlate with the availability of free Ca2+ ions. Calcium ions work as a molecular switch for PO activity and exert a protective function, rendering POs heat stable. The concentration ranges of these two activities differ markedly. POs are activated by µM Ca2+ concentration ranges, whereas heat stabilization is observed in the nM range. This suggests the existence of different Ca2+ binding sites. The heat stability of POs depends on the source plant species. Terrestrial plants have POs that exhibit higher temperature stability than those POs from limnic and marine plants. Different POs from a single species can differ in terms of heat stability. The abundance of different POs within a plant is dependent on age and developmental stage. The heat stability of a PO does not necessarily correlate with the maximum temperature the source species is usually exposed to in its natural habitat. This raises questions on the role of POs in the heat tolerance of plants. Consequently, detailed investigations are needed to identify and characterize individual POs, with regard to their genetic origin, subcellular expression, tissue abundance, developmental emergence and their functions in innate and acquired heat tolerance. PMID:22580695

Embracing the Potential of Play for Children on the Autism Spectrum: Facilitating the Earliest Stages of Developmental Integration

ERIC Educational Resources Information Center

Gerber, Sima

2017-01-01

In this article, the breadth and depth of play as an integrating process for children with developmental challenges are explored. The fact that play is a source of developmental growth suggests that its role in intervention with children with language and communication disorders cannot be overstated. Several contemporary play-based intervention…

Impact of hot events at different developmental stages of a moth: the closer to adult stage, the less reproductive output

PubMed Central

Zhang, Wei; Chang, Xiang-Qian; Hoffmann, AryA.; Zhang, Shu; Ma, Chun-Sen

2015-01-01

Hot days in summer (involving a few hours at particularly high temperatures) are expected to become more common under climate change. How such events at different life stages affect survival and reproduction remains unclear in most organisms. Here, we investigated how an exposure to 40 °C at different life stages in the global insect pest, Plutella xylostella, affects immediate survival, subsequent survival and reproductive output. First-instar larvae showed the lowest survival under heat stress, whereas 3rd-instar larvae were relatively heat resistant. Heat exposure at the 1st-instar or egg stage did not influence subsequent maturation success, while exposure at the 3rd-instar larval stage did have an effect. We found that heat stress at developmental stages closer to adult stage caused greater detrimental effects on reproduction than heat stress experienced at earlier life stages. The effects of hot events on insect populations can therefore depend critically on the timing of the event relative to an organism’s life-cycle. PMID:26000790

Effect of timing of development on total cell number and expression profile of HSP-70.1 and GLUT-1 in buffalo (Bubalus bubalis) oocytes and preimplantation embryos produced in vitro.

PubMed

Rajhans, Rajib; Kumar, G Sai; Dubey, Pawan K; Sharma, G Taru

2010-03-29

The present study was designed to compare the expression profile of two developmentally important genes (HSP-70.1 and GLUT-1) and TCN (total cell number) count in fast (group A) and slow (group B) cleaved buffalo embryos to access their in vitro developmental competence. Buffalo COCs (cumulus oocyte complexes) were collected from local abattoir ovaries and subjected to in vitro maturation in: TCM-199 supplemented with 10% FBS (fetal bovine serum), BSA (3 mg/ml), sodium pyruvate (0.25 mM) and 20 ng/ml EGF (epidermal growth factor) at 38.5 degrees C under 5% CO2. In vitro derived embryos were collected at 4-8, 8-16 cell, morula and blastocyst stages at specific time points for gene expression analysis and total cell count. A semiquantitative RT-PCR (reverse transcriptase-PCR) assay was used to determine the HSP-70.1 and GLUT-1 transcripts. Results showed that developmental competence and TCN count in fast (group A)-cleaving embryos was significantly (P<0.05) higher than in the slow group (group B). The gene transcript of HSP-70.1 and GLUT-1 was expressed in oocytes (immature and mature) and throughout the embryonic developmental stages in the fast group (group A), while in the slow (group B) cleaving embryos, the expression of HSP-70.1 was absent in all the embryonic developmental stages, and expression of GLUT-1 was absent after 8-16 cell stage. In conclusion, TCN count and expression profile of HSP-70.1 and GLUT-1 genes in buffalo embryos are different taking into account the cleavage rate. Quality of such embryos for research purposes, TCN and expression profiling of developmentally important genes should be employed to optimize the in vitro culture system to produce superior quality of embryos.

A Standard System to Study Vertebrate Embryos

PubMed Central

Werneburg, Ingmar

2009-01-01

Staged embryonic series are important as reference for different kinds of biological studies. I summarise problems that occur when using ‘staging tables’ of ‘model organisms’. Investigations of developmental processes in a broad scope of taxa are becoming commonplace. Beginning in the 1990s, methods were developed to quantify and analyse developmental events in a phylogenetic framework. The algorithms associated with these methods are still under development, mainly due to difficulties of using non-independent characters. Nevertheless, the principle of comparing clearly defined newly occurring morphological features in development (events) in quantifying analyses was a key innovation for comparative embryonic research. Up to date no standard was set for how to define such events in a comparative approach. As a case study I compared the external development of 23 land vertebrate species with a focus on turtles, mainly based on reference staging tables. I excluded all the characters that are only identical for a particular species or general features that were only analysed in a few species. Based on these comparisons I defined 104 developmental characters that are common either for all vertebrates (61 characters), gnathostomes (26), tetrapods (3), amniotes (7), or only for sauropsids (7). Characters concern the neural tube, somite, ear, eye, limb, maxillary and mandibular process, pharyngeal arch, eyelid or carapace development. I present an illustrated guide listing all the defined events. This guide can be used for describing developmental series of any vertebrate species or for documenting specimen variability of a particular species. The guide incorporates drawings and photographs as well as consideration of species identifying developmental features such as colouration. The simple character-code of the guide is extendable to further characters pertaining to external and internal morphological, physiological, genetic or molecular development, and also for other vertebrate groups not examined here, such as Chondrichthyes or Actinopterygii. An online database to type in developmental events for different stages and species could be a basis for further studies in comparative embryology. By documenting developmental events with the standard code, sequence heterochrony studies (i.e. Parsimov) and studies on variability can use this broad comparative data set. PMID:19521537

Transcriptome dynamics through alternative polyadenylation in developmental and environmental responses in plants revealed by deep sequencing

PubMed Central

Shen, Yingjia; Venu, R.C.; Nobuta, Kan; Wu, Xiaohui; Notibala, Varun; Demirci, Caghan; Meyers, Blake C.; Wang, Guo-Liang; Ji, Guoli; Li, Qingshun Q.

2011-01-01

Polyadenylation sites mark the ends of mRNA transcripts. Alternative polyadenylation (APA) may alter sequence elements and/or the coding capacity of transcripts, a mechanism that has been demonstrated to regulate gene expression and transcriptome diversity. To study the role of APA in transcriptome dynamics, we analyzed a large-scale data set of RNA “tags” that signify poly(A) sites and expression levels of mRNA. These tags were derived from a wide range of tissues and developmental stages that were mutated or exposed to environmental treatments, and generated using digital gene expression (DGE)–based protocols of the massively parallel signature sequencing (MPSS-DGE) and the Illumina sequencing-by-synthesis (SBS-DGE) sequencing platforms. The data offer a global view of APA and how it contributes to transcriptome dynamics. Upon analysis of these data, we found that ∼60% of Arabidopsis genes have multiple poly(A) sites. Likewise, ∼47% and 82% of rice genes use APA, supported by MPSS-DGE and SBS-DGE tags, respectively. In both species, ∼49%–66% of APA events were mapped upstream of annotated stop codons. Interestingly, 10% of the transcriptomes are made up of APA transcripts that are differentially distributed among developmental stages and in tissues responding to environmental stresses, providing an additional level of transcriptome dynamics. Examples of pollen-specific APA switching and salicylic acid treatment-specific APA clearly demonstrated such dynamics. The significance of these APAs is more evident in the 3034 genes that have conserved APA events between rice and Arabidopsis. PMID:21813626

Developmental Toxicity of the Organic Fraction from Hydraulic Fracturing Flowback and Produced Waters to Early Life Stages of Zebrafish ( Danio rerio).

PubMed

He, Yuhe; Sun, Chenxing; Zhang, Yifeng; Folkerts, Erik J; Martin, Jonathan W; Goss, Greg G

2018-03-20

Hydraulic fracturing (HF) has emerged as a major recovery method of unconventional oil and gas reservoirs and concerns have been raised regarding the environmental impact of releases of Flowback and Produced Water (FPW) to aquatic ecosystems. To investigate potential effects of HF-FPW on fish embryo development, HF-FPW samples were collected from two different wells and the organic fractions were isolated from both aqueous and particle phases to eliminate the confounding effects of high salinity. Each organic extract was characterized by non-target analysis with HPLC-Orbitrap-MS, with targeted analysis for polycyclic aromatic hydrocarbons provided as markers of petroleum-affected water. The organic profiles differed between samples, including PAHs and alkyl PAHs, and major substances identified by non-target analysis included polyethylene glycols, alkyl ethoxylates, octylphenol ethoxylates, and other high molecular weight (C 49-79 ) ethylene oxide polymeric material. Zebrafish embryos were exposed to various concentrations of FPW organic extracts to investigate acute (7-day) and developmental toxicity in early life stages. The acute toxicity (LD 50 ) of the extracted FPW fractions ranged from 2.8× to 26× the original organic content. Each extracted FPW fraction significantly increased spinal malformation, pericardial edema, and delayed hatch in exposed embryos and altered the expression of a suite of target genes related to biotransformation, oxidative stress, and endocrine-mediation in developing zebrafish embryos. These results provide novel information on the variation of organic profiles and developmental toxicity among different sources and fractions of HF-FPWs.

Lethal fighting in nematodes is dependent on developmental pathway: male-male fighting in the entomopathogenic nematode Steinernema longicaudum.

PubMed

Zenner, Annemie N R L; O'Callaghan, Kathryn M; Griffin, Christine T

2014-01-01

Aggressive encounters occur between competitors (particularly males) throughout the animal kingdom, and in some species can result in severe injury and death. Here we describe for the first time lethal interactions between male nematodes and provide evidence that the expression of this behaviour is developmentally controlled. Males of the entomopathogenic nematode Steinernema longicaudum coil around each other, resulting in injuries, paralysis and frequently death. The probability of death occurring between pairs of males was affected by the developmental pathway followed, being much greater among males that had passed through the infective juvenile (IJ, or dauer) stage than among males that had not. Post-IJ males are found only in newly colonised hosts, typically with few competing males present. Killing those few competitors may secure valuable resources (both females and a host cadaver for nourishment of offspring). Non-IJ males develop in subsequent generations within a host cadaver, where the presence of many closely related male competitors increases the risk:benefit ratio of fighting. Thus, passage through the IJ stage primes males for enhanced aggression in circumstances where this is more likely to result in increased reproductive success. Fighting occurred between males developing in mixed-sex social groups, indicating that it is an evolved trait and not an abnormal response to absence of females. This is supported by finding high mortality of males, but not of females, across a range of population densities in insect cadavers. We propose that these nematodes, with their relatively simple organization, may be a useful model for studies of aggression.

Chronic Stress Modulates Regional Cerebral Glucose Transporter Expression in an Age-Specific and Sexually-Dimorphic Manner

PubMed Central

Kelly, Sean D.; Harrell, Constance S.; Neigh, Gretchen N.

2014-01-01

Facilitative glucose transporters (GLUT) mediate glucose uptake across the blood-brain-barrier into neurons and glia. Deficits in specific cerebral GLUT isoforms are linked to developmental and neurological dysfunction, but less is known about the range of variation in cerebral GLUT expression in normal conditions and the effects of environmental influences on cerebral GLUT expression. Knowing that puberty is a time of increased cerebral plasticity, metabolic demand, and shifts in hormonal balance for males and females, we first assessed gene expression of five GLUT subtypes in four brain regions in male and female adolescent and adult Wistar rats. The data indicated that sex differences in GLUT expression were most profound in the hypothalamus, and the transition from adolescence to adulthood had the most profound effect on GLUT expression in the hippocampus. Next, given the substantial energetic demands during adolescence and prior demonstrations of the adverse effects of adolescent stress, we determined the extent to which chronic stress altered GLUT expression in males and females in both adolescence and adulthood. Chronic stress significantly altered cerebral GLUT expression in males and females throughout both developmental stages but in a sexually dimorphic and brain region-specific manner. Collectively, our data demonstrate that cerebral GLUTs are expressed differentially based on brain region, sex, age, and stress exposure. These results suggest that developmental and environmental factors influence GLUT expression in multiple brain regions. Given the importance of appropriate metabolic balance within the brain, further assessment of the functional implications of life stage and environmentally-induced changes in GLUTs are warranted. PMID:24382486

Lamellar pro-inflammatory cytokine expression patterns in laminitis at the developmental stage and at the onset of lameness: innate vs. adaptive immune response.

PubMed

Belknap, J K; Giguère, S; Pettigrew, A; Cochran, A M; Van Eps, A W; Pollitt, C C

2007-01-01

Recent research has indicated that inflammation plays a role in the early stages of laminitis and that, similar to organ failure in human sepsis, early inflammatory mechanisms may lead to downstream events resulting in lamellar failure. Characterisation of the type of immune response (i.e. innate vs. adaptive) is essential in order to develop therapeutic strategies to counteract these deleterious events. To quantitate gene expression of pro-inflammatory cytokines known to be important in the innate and adaptive immune response during the early stages of laminitis, using both the black walnut extract (BWE) and oligofructose (OF) models of laminitis. Real-time qPCR was used to assess lamellar mRNA expression of interleukins-1beta, 2, 4, 6, 8, 10, 12 and 18, and tumour necrosis factor alpha and interferon gamma at the developmental stage and at the onset of lameness. Significantly increased lamellar mRNA expression of cytokines important in the innate immune response were present at the developmental stage of the BWE model, and at the onset of acute lameness in both the BWE model and OF model. Of the cytokines characteristic of the Th1 and Th2 arms of the adaptive immune response, a mixed response was noted at the onset of acute lameness in the BWE model, whereas the response was skewed towards a Th1 response at the onset of lameness in the OF model. Lamellar inflammation is characterised by strong innate immune response in the developmental stages of laminitis; and a mixture of innate and adaptive immune responses at the onset of lameness. These results indicate that anti-inflammatory treatment of early stage laminitis (and the horse at risk of laminitis) should include not only therapeutic drugs that address prostanoid activity, but should also address the marked increases in lamellar cytokine expression.

Identifying Stable Reference Genes for qRT-PCR Normalisation in Gene Expression Studies of Narrow-Leafed Lupin (Lupinus angustifolius L.).

PubMed

Taylor, Candy M; Jost, Ricarda; Erskine, William; Nelson, Matthew N

2016-01-01

Quantitative Reverse Transcription PCR (qRT-PCR) is currently one of the most popular, high-throughput and sensitive technologies available for quantifying gene expression. Its accurate application depends heavily upon normalisation of gene-of-interest data with reference genes that are uniformly expressed under experimental conditions. The aim of this study was to provide the first validation of reference genes for Lupinus angustifolius (narrow-leafed lupin, a significant grain legume crop) using a selection of seven genes previously trialed as reference genes for the model legume, Medicago truncatula. In a preliminary evaluation, the seven candidate reference genes were assessed on the basis of primer specificity for their respective targeted region, PCR amplification efficiency, and ability to discriminate between cDNA and gDNA. Following this assessment, expression of the three most promising candidates [Ubiquitin C (UBC), Helicase (HEL), and Polypyrimidine tract-binding protein (PTB)] was evaluated using the NormFinder and RefFinder statistical algorithms in two narrow-leafed lupin lines, both with and without vernalisation treatment, and across seven organ types (cotyledons, stem, leaves, shoot apical meristem, flowers, pods and roots) encompassing three developmental stages. UBC was consistently identified as the most stable candidate and has sufficiently uniform expression that it may be used as a sole reference gene under the experimental conditions tested here. However, as organ type and developmental stage were associated with greater variability in relative expression, it is recommended using UBC and HEL as a pair to achieve optimal normalisation. These results highlight the importance of rigorously assessing candidate reference genes for each species across a diverse range of organs and developmental stages. With emerging technologies, such as RNAseq, and the completion of valuable transcriptome data sets, it is possible that other potentially more suitable reference genes will be identified for this species in future.

Identifying Stable Reference Genes for qRT-PCR Normalisation in Gene Expression Studies of Narrow-Leafed Lupin (Lupinus angustifolius L.)

PubMed Central

Erskine, William; Nelson, Matthew N.

2016-01-01

Quantitative Reverse Transcription PCR (qRT-PCR) is currently one of the most popular, high-throughput and sensitive technologies available for quantifying gene expression. Its accurate application depends heavily upon normalisation of gene-of-interest data with reference genes that are uniformly expressed under experimental conditions. The aim of this study was to provide the first validation of reference genes for Lupinus angustifolius (narrow-leafed lupin, a significant grain legume crop) using a selection of seven genes previously trialed as reference genes for the model legume, Medicago truncatula. In a preliminary evaluation, the seven candidate reference genes were assessed on the basis of primer specificity for their respective targeted region, PCR amplification efficiency, and ability to discriminate between cDNA and gDNA. Following this assessment, expression of the three most promising candidates [Ubiquitin C (UBC), Helicase (HEL), and Polypyrimidine tract-binding protein (PTB)] was evaluated using the NormFinder and RefFinder statistical algorithms in two narrow-leafed lupin lines, both with and without vernalisation treatment, and across seven organ types (cotyledons, stem, leaves, shoot apical meristem, flowers, pods and roots) encompassing three developmental stages. UBC was consistently identified as the most stable candidate and has sufficiently uniform expression that it may be used as a sole reference gene under the experimental conditions tested here. However, as organ type and developmental stage were associated with greater variability in relative expression, it is recommended using UBC and HEL as a pair to achieve optimal normalisation. These results highlight the importance of rigorously assessing candidate reference genes for each species across a diverse range of organs and developmental stages. With emerging technologies, such as RNAseq, and the completion of valuable transcriptome data sets, it is possible that other potentially more suitable reference genes will be identified for this species in future. PMID:26872362

The Utility of Stage-specific Mid-to-late Drosophila Follicle Isolation

PubMed Central

Spracklen, Andrew J.; Tootle, Tina L.

2013-01-01

Drosophila oogenesis or follicle development has been widely used to advance the understanding of complex developmental and cell biologic processes. This methods paper describes how to isolate mid-to-late stage follicles (Stage 10B-14) and utilize them to provide new insights into the molecular and morphologic events occurring during tight windows of developmental time. Isolated follicles can be used for a variety of experimental techniques, including in vitro development assays, live imaging, mRNA expression analysis and western blot analysis of proteins. Follicles at Stage 10B (S10B) or later will complete development in culture; this allows one to combine genetic or pharmacologic perturbations with in vitro development to define the effects of such manipulations on the processes occurring during specific periods of development. Additionally, because these follicles develop in culture, they are ideally suited for live imaging studies, which often reveal new mechanisms that mediate morphological events. Isolated follicles can also be used for molecular analyses. For example, changes in gene expression that result from genetic perturbations can be defined for specific developmental windows. Additionally, protein level, stability, and/or posttranslational modification state during a particular stage of follicle development can be examined through western blot analyses. Thus, stage-specific isolation of Drosophila follicles provides a rich source of information into widely conserved processes of development and morphogenesis. PMID:24326735

WAFs lead molting retardation of naupliar stages with down-regulated expression profiles of chitin metabolic pathway and related genes in the copepod Tigriopus japonicus.

PubMed

Hwang, Dae-Sik; Lee, Min-Chul; Kyung, Do-Hyun; Kim, Hui-Su; Han, Jeonghoon; Kim, Il-Chan; Puthumana, Jayesh; Lee, Jae-Seong

2017-03-01

Oil pollution is considered being disastrous to marine organisms and ecosystems. As molting is critical in the developmental process of arthropods in general and copepods, in particular, the impact will be adverse if the target of spilled oil is on molting. Thus, we investigated the harmful effects of water accommodated fractions (WAFs) of crude oil with an emphasis on inhibition of chitin metabolic pathways related genes and developmental retardation in the copepod Tigriopus japonicus. Also, we analysed the ontology and domain of chitin metabolic pathway genes and mRNA expression patterns of developmental stage-specific genes. Further, the developmental retardation followed by transcriptional modulations in nuclear receptor genes (NR) and chitin metabolic pathway-related genes were observed in the WAFs-exposed T. japonicus. As a result, the developmental time was found significantly (P<0.05) delayed in response to 40% WAFs in comparison with that of control. Moreover, the NR gene, HR3 and chitinases (CHT9 and CHT10) were up-regulated in N4-5 stages, while chitin synthase genes (CHS-1, CHS-2-1, and CHS-2-2) down-regulated in response to WAFs. In brief, a high concentration of WAFs repressed nuclear receptor genes but elicited activation of some of the transcription factors at low concentration of WAFs, resulting in suppression of chitin synthesis. Thus, we suggest that WAF can lead molting retardation of naupliar stages in T. japonicus through down-regulations of chitin metabolism. These findings will provide a better understanding of the mode of action of chitin biosynthesis associated with molting mechanism in WAF-exposed T. japonicus. Copyright © 2016 Elsevier Inc. All rights reserved.

BDE-47 causes developmental retardation with down-regulated expression profiles of ecdysteroid signaling pathway-involved nuclear receptor (NR) genes in the copepod Tigriopus japonicus.

PubMed

Hwang, Dae-Sik; Han, Jeonghoon; Won, Eun-Ji; Kim, Duck-Hyun; Jeong, Chang-Bum; Hwang, Un-Ki; Zhou, Bingsheng; Choe, Joonho; Lee, Jae-Seong

2016-08-01

2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) is a persistent organic pollutant (POP) in marine environments. Despite its adverse effects (e.g. developmental retardation) in ecdysozoa, the effects of BDE-47 on transcription of ecdysteroid signaling pathway-involved-nuclear receptor (NR) genes and metamorphosis-related genes have not been examined in copepods. To examine the deleterious effect of BDE-47 on copepod molting and metamorphosis, BDE-47 was exposed to the harpacticoid copepod Tigriopus japonicus, followed by monitoring developmental retardation and transcriptional alteration of NR genes. The developmental rate was significantly inhibited (P<0.05) in response to BDE-47 and the agricultural insecticide gamma-hexachlorocyclohexane. Conversely, the ecdysteroid agonist ponasterone A (PoA) led to decreased molting and metamorphosis time (P<0.05) from the nauplius stage to the adult stage. In particular, expression profiles of all NR genes were the highest at naupliar stages 5-6 except for SVP, FTZ-F1, and HR96 genes. Nuclear receptor USP, HR96, and FTZ-F1 genes also showed significant sex differences (P<0.05) in gene expression levels over different developmental stages, indicating that these genes may be involved in vitellogenesis. NR gene expression patterns showed significant decreases (P<0.05) in response to BDE-47 exposure, implying that molting and metamorphosis retardation is likely associated with NR gene expression. In summary, BDE-47 leads to molting and metamorphosis retardation and suppresses transcription of NR genes. This information will be helpful in understanding the molting and metamorphosis delay mechanism in response to BDE-47 exposure. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of transcriptome in the Indian meal moth Plodia interpunctella (Lepidoptera: Pyralidae) and gene expression analysis during developmental stages.

PubMed

Tang, Pei-An; Wu, Hai-Jing; Xue, Hao; Ju, Xing-Rong; Song, Wei; Zhang, Qi-Lin; Yuan, Ming-Long

2017-07-30

The Indian meal moth Plodia interpunctella (Lepidoptera: Pyralidae) is a worldwide pest that causes serious damage to stored foods. Although many efforts have been conducted on this species due to its economic importance, the study of genetic basis of development, behavior and insecticide resistance has been greatly hampered due to lack of genomic information. In this study, we used high throughput sequencing platform to perform a de novo transcriptome assembly and tag-based digital gene expression profiling (DGE) analyses across four different developmental stages of P. interpunctella (egg, third-instar larvae, pupae and adult). We obtained approximate 9gigabyte (GB) of clean data and recovered 84,938 unigenes, including 37,602 clusters and 47,336 singletons. These unigenes were annotated using BLAST against the non-redundant protein databases and then functionally classified based on Gene Ontology (GO), Clusters of Orthologous Groups (COG), and Kyoto Encyclopedia of Genes and Genomes databases (KEGG). A large number of differentially expressed genes were identified by pairwise comparisons among different developmental stages. Gene expression profiles dramatically changed between developmental stage transitions. Some of these differentially expressed genes were related to digestion and cuticularization. Quantitative real-time PCR results of six randomly selected genes conformed the findings in the DGEs. Furthermore, we identified over 8000 microsatellite markers and 97,648 single nucleotide polymorphisms which will be useful for population genetics studies of P. interpunctella. This transcriptomic information provided insight into the developmental basis of P. interpunctella and will be helpful for establishing integrated management strategies and developing new targets of insecticides for this serious pest. Copyright © 2017 Elsevier B.V. All rights reserved.

Reproductive biology of the isopod Excirolana braziliensis at the southern edge of its geographical range

NASA Astrophysics Data System (ADS)

Martínez, Gastón; Defeo, Omar

2006-12-01

A full analysis of the reproductive biology of the isopod Excirolana braziliensis Richardson 1912 was conducted in a sandy beach of Uruguay, located at the southernmost edge of its distributional range in the Atlantic Ocean. Reproductive and recruitment periods of E. braziliensis were concentrated in austral summer. Females with oostegites appeared in November, whereas total biomass, individual sizes and fecundity of ovigerous females peaked between December and January. These concurrent traits were responsible for the significant peak of juveniles in January. The size at maturity was 9.88 mm. Four embryonic developmental stages were described and identified: mean length linearly increased from stages I to III, whereas dry weight exponentially decreased from stages I to IV. The high reproductive output (0.41-0.58), reported for the first time in this isopod, exceeds the rates documented for other isopods. Reproduction of E. braziliensis at the southern edge of its range is semelparous: females produce one brood during the reproductive season, exhaust their energy reserves during incubation, and probably die at the end of the reproductive season. A macroscale comparison suggests that E. braziliensis at the southern edge of its range counteracts its narrow reproductive period by a short incubation period with larger individual mature female and embryo sizes, higher fecundity and a higher percentage of ovigerous females than in subtropical and tropical populations. These extreme reproductive indicators could be attributed to the internal retention of embryos that assures offspring survival, coupled with a high adaptation capability to environmental variations across its range.

Vitrification of mouse embryos using the thin plastic strip method

PubMed Central

Hur, Yong Soo; Ann, Ji Young; Maeng, Ja Young; Park, Miji; Park, Jeong Hyun; Yoon, Jung; Yoon, San Hyun; Hur, Chang Young; Lee, Won Don; Lim, Jin Ho

2012-01-01

Objective The aim of this study was to compare vitrification optimization of mouse embryos using electron microscopy (EM) grid, cryotop, and thin plastic strip (TPS) containers by evaluating developmental competence and apoptosis rates. Methods Mouse embryos were obtained from superovulated mice. Mouse cleavage-stage, expanded, hatching-stage, and hatched-stage embryos were cryopreserved in EM grid, cryotop, and TPS containers by vitrification in 15% ethylene glycol, 15% dimethylsulfoxide, 10 µg/mL Ficoll, and 0.65 M sucrose, and 20% serum substitute supplement (SSS) with basal medium, respectively. For the three groups in which the embryos were thawed in the EM grid, cryotop, and TPS containers, the thawing solution consisted of 0.25 M sucrose, 0.125 M sucrose, and 20% SSS with basal medium, respectively. Rates of survival, re-expansion, reaching the hatched stage, and apoptosis after thawing were compared among the three groups. Results Developmental competence after thawing of vitrified expanded and hatching-stage blastocysts using cryotop and TPS methods were significantly higher than survival using the EM grid (p<0.05). Also, apoptosis positive nuclei rates after thawing of vitrified expanded blastocysts using cryotop and TPS were significantly lower than when using the EM grid (p<0.05). Conclusion The TPS vitrification method has the advantages of achieving a high developmental ability and effective preservation. PMID:23346525

The Seven Stages of Man: The Role of Developmental Stage on Medication Adherence in Respiratory Diseases.

PubMed

Costello, Richard W; Foster, Juliet M; Grigg, Jonathan; Eakin, Michelle N; Canonica, Walter; Yunus, Fasail; Ryan, Dermot

2016-01-01

The circumstances and drivers of the decision to initiate, implement, or persist with a medication differ for individuals at each developmental stage. For school-age children with asthma, the social environment of their family's cultural beliefs and the influence of peer networks and school policies are strong determinants of medication adherence. The stage of adolescence can be a particularly challenging time because there is a reduction in parental supervision of asthma management as the young person strives to become more autonomous. To illustrate the importance of such factors, adherence interventions in children and young adults with asthma have used peer-based supports and social supports, particularly social media platforms. In older patients, it is internal rather than external factors and age-related decline that pose challenges to medication adherence. Seniors face the challenges of polypharmacy, reduced social support, increased isolation, and loss of cognitive function. Strategies to promote adherence must be tailored to the developmental stage and respective behavioral determinants of the target group. This review considers the different attitudes toward medication and the different adherence behaviors in young and elderly patients with chronic respiratory conditions, specifically asthma and chronic obstructive pulmonary disease. Opportunities to intervene to optimize adherence are suggested. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

FGF-Dependent, Context-Driven Role for FRS Adapters in the Early Telencephalon

PubMed Central

Gutin, Grigoriy; Blackwood, Christopher A.; Kamatkar, Nachiket G.; Lee, Kyung W.; Fishell, Gordon; Wang, Fen

2017-01-01

FGF signaling, an important component of intercellular communication, is required in many tissues throughout development to promote diverse cellular processes. Whether FGF receptors (FGFRs) accomplish such varied tasks in part by activating different intracellular transducers in different contexts remains unclear. Here, we used the developing mouse telencephalon as an example to study the role of the FRS adapters FRS2 and FRS3 in mediating the functions of FGFRs. Using tissue-specific and germline mutants, we examined the requirement of Frs genes in two FGFR-dependent processes. We found that Frs2 and Frs3 are together required for the differentiation of a subset of medial ganglionic eminence (MGE)-derived neurons, but are dispensable for the survival of early telencephalic precursor cells, in which any one of three FGFRs (FGFR1, FGFR2, or FGFR3) is sufficient for survival. Although FRS adapters are dispensable for ERK-1/2 activation, they are required for AKT activation within the subventricular zone of the developing MGE. Using an FRS2,3-binding site mutant of Fgfr1, we established that FRS adapters are necessary for mediating most or all FGFR1 signaling, not only in MGE differentiation, but also in cell survival, implying that other adapters mediate at least in part the signaling from FGFR2 and FGFR3. Our study provides an example of a contextual role for an intracellular transducer and contributes to our understanding of how FGF signaling plays diverse developmental roles. SIGNIFICANCE STATEMENT FGFs promote a range of developmental processes in many developing tissues and at multiple developmental stages. The mechanisms underlying this multifunctionality remain poorly defined in vivo. Using telencephalon development as an example, we show here that FRS adapters exhibit some selectivity in their requirement for mediating FGF receptor (FGFR) signaling and activating downstream mediators that depend on the developmental process, with a requirement in neuronal differentiation but not cell survival. Differential engagement of FRS and non-FRS intracellular adapters downstream of FGFRs could therefore in principle explain how FGFs play several distinct roles in other developing tissues and developmental stages. PMID:28483978

FGF-Dependent, Context-Driven Role for FRS Adapters in the Early Telencephalon.

PubMed

Nandi, Sayan; Gutin, Grigoriy; Blackwood, Christopher A; Kamatkar, Nachiket G; Lee, Kyung W; Fishell, Gordon; Wang, Fen; Goldfarb, Mitchell; Hébert, Jean M

2017-06-07

FGF signaling, an important component of intercellular communication, is required in many tissues throughout development to promote diverse cellular processes. Whether FGF receptors (FGFRs) accomplish such varied tasks in part by activating different intracellular transducers in different contexts remains unclear. Here, we used the developing mouse telencephalon as an example to study the role of the FRS adapters FRS2 and FRS3 in mediating the functions of FGFRs. Using tissue-specific and germline mutants, we examined the requirement of Frs genes in two FGFR-dependent processes. We found that Frs2 and Frs3 are together required for the differentiation of a subset of medial ganglionic eminence (MGE)-derived neurons, but are dispensable for the survival of early telencephalic precursor cells, in which any one of three FGFRs (FGFR1, FGFR2, or FGFR3) is sufficient for survival. Although FRS adapters are dispensable for ERK-1/2 activation, they are required for AKT activation within the subventricular zone of the developing MGE. Using an FRS2,3-binding site mutant of Fgfr1 , we established that FRS adapters are necessary for mediating most or all FGFR1 signaling, not only in MGE differentiation, but also in cell survival, implying that other adapters mediate at least in part the signaling from FGFR2 and FGFR3. Our study provides an example of a contextual role for an intracellular transducer and contributes to our understanding of how FGF signaling plays diverse developmental roles. SIGNIFICANCE STATEMENT FGFs promote a range of developmental processes in many developing tissues and at multiple developmental stages. The mechanisms underlying this multifunctionality remain poorly defined in vivo Using telencephalon development as an example, we show here that FRS adapters exhibit some selectivity in their requirement for mediating FGF receptor (FGFR) signaling and activating downstream mediators that depend on the developmental process, with a requirement in neuronal differentiation but not cell survival. Differential engagement of FRS and non-FRS intracellular adapters downstream of FGFRs could therefore in principle explain how FGFs play several distinct roles in other developing tissues and developmental stages. Copyright © 2017 the authors 0270-6474/17/375690-09$15.00/0.

Epigenomic Landscape of Human Fetal Brain, Heart, and Liver.

PubMed

Yan, Liying; Guo, Hongshan; Hu, Boqiang; Li, Rong; Yong, Jun; Zhao, Yangyu; Zhi, Xu; Fan, Xiaoying; Guo, Fan; Wang, Xiaoye; Wang, Wei; Wei, Yuan; Wang, Yan; Wen, Lu; Qiao, Jie; Tang, Fuchou

2016-02-26

The epigenetic regulation of spatiotemporal gene expression is crucial for human development. Here, we present whole-genome chromatin immunoprecipitation followed by high throughput DNA sequencing (ChIP-seq) analyses of a wide variety of histone markers in the brain, heart, and liver of early human embryos shortly after their formation. We identified 40,181 active enhancers, with a large portion showing tissue-specific and developmental stage-specific patterns, pointing to their roles in controlling the ordered spatiotemporal expression of the developmental genes in early human embryos. Moreover, using sequential ChIP-seq, we showed that all three organs have hundreds to thousands of bivalent domains that are marked by both H3K4me3 and H3K27me3, probably to keep the progenitor cells in these organs ready for immediate differentiation into diverse cell types during subsequent developmental processes. Our work illustrates the potentially critical roles of tissue-specific and developmental stage-specific epigenomes in regulating the spatiotemporal expression of developmental genes during early human embryonic development. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Effects of multi-well plate incubation on embryo-larval development in the fathead minnow (Pimephales promelas).

PubMed

Marentette, Julie R; Sullivan, Cheryl A; Lavalle, Christine; Shires, Kallie; Parrott, Joanne L

2015-01-01

Fathead minnow embryos and larvae are frequently used in toxicology, including short-term embryo-only tests which often use small volumes of test solution. The effect that such conditions may have on fathead minnow development has yet to be explicitly described. Here we compared rates of embryonic development in fathead minnow embryos reared under standard light and temperature conditions with a range of possible methods. All methods yielded excellent control survival. We demonstrated that fathead minnow embryos incubated in a range of small volumes in multi-well plates (500 μL to 2 mL per embryo) did not substantially vary in developmental rate, but flexed less frequently as embryos, hatched smaller, later and with larger yolk-sacs, and initiated feeding later than embryos reared in an excess of solution (20 mL per embryo) with or without supplemental aeration. Faster hatch and growth were promoted with an orbital shaker, but growth benefits were not sustained into the larval stage. Developmental differences persisted in larvae reared to 20 days post-fertilization when monitoring ceased, but growth differences did not magnify and in some measurements partially resolved. To our knowledge we are the first to report effects of incubation in multi-well plates in any fish taxa. As our data revealed that the eleutheroembryonic stage for fathead minnow may be prolonged in multi-well plates, this may allow the use of longer toxicity tests using fathead minnow embryos without conflicting with existing animal welfare legislation in many countries. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Student Development and Developmental Studies.

ERIC Educational Resources Information Center

Champaigne, John

1982-01-01

Reviews the nine-stage Perry Scheme of Intellectual and Ethical Development, detailing three major student orientations--dualism, multiplicity, and commitments in relativism. Suggests techniques developmental educators can use to communicate with, support, and challenge students to promote intellectual development. Underscores the importance of…

Validating a Measure of Stages of Change in Career Development

ERIC Educational Resources Information Center

Hammond, Marie S.; Michael, Tony; Luke, Charles

2017-01-01

Research on the processes of change in career development has focused on developmental stages rather than processes. This manuscript reports on the development and validation of the stages of change-career development scale, adapted from McConnaughy, Prochaska, & Velicer (1983) measure of stages of change in psychotherapy. Data from 875…

Resolving Ethical Dilemmas: Exploring the Role of Moral Principles

DTIC Science & Technology

2008-08-01

deontological class of moral philosophies. A second major approach is represented by the cognitive - developmental models of moral development ...extent sex, as predictors of individual differences in moral philosophy. 1.3.1 Age The approach of Kohlberg’s (1969) cognitive developmental ...associated with cognitive and developmental gains that can only occur with maturation. For instance, Kohlberg posited the stages 1 and 2 with their

Older Women's Development: A Comparison of Women in Their 60s and 80s on a Measure of Erikson's Developmental Tasks.

ERIC Educational Resources Information Center

Norman, Suzanne M.; McCluskey-Fawcett, Kathleen; Ashcraft, Lisa

2002-01-01

Compares women from two ages groups in order to understand their development across the life span. Measures of Psychosocial Development, which assesses Erikson's developmental stages, were administered to 41 women in 2 cohorts (ages 60-70, ages 80-90). Age group differences in the resolution of Erikson's identity and trust developmental tasks were…

De novo Assembly of the Burying Beetle Nicrophorus orbicollis (Coleoptera: Silphidae) Transcriptome Across Developmental Stages with Identification of Key Immune Transcripts

PubMed Central

Won, Harim I.; Schulze, Thomas T.; Clement, Emalie J.; Watson, Gabrielle F.; Watson, Sean M.; Warner, Rosalie C.; Ramler, Elizabeth A. M.; Witte, Elias J.; Schoenbeck, Mark A.; Rauter, Claudia M.; Davis, Paul H.

2018-01-01

Burying beetles (Nicrophorus spp.) are among the relatively few insects that provide parental care while not belonging to the eusocial insects such as ants or bees. This behavior incurs energy costs as evidenced by immune deficits and shorter life-spans in reproducing beetles. In the absence of an assembled transcriptome, relatively little is known concerning the molecular biology of these beetles. This work details the assembly and analysis of the Nicrophorus orbicollis transcriptome at multiple developmental stages. RNA-Seq reads were obtained by next-generation sequencing and the transcriptome was assembled using the Trinity assembler. Validation of the assembly was performed by functional characterization using Gene Ontology (GO), Eukaryotic Orthologous Groups (KOG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Differential expression analysis highlights developmental stage-specific expression patterns, and immunity-related transcripts are discussed. The data presented provides a valuable molecular resource to aid further investigation into immunocompetence throughout this organism's sexual development. PMID:29707046

A developmental roadmap for learning by imitation in robots.

PubMed

Lopes, Manuel; Santos-Victor, José

2007-04-01

In this paper, we present a strategy whereby a robot acquires the capability to learn by imitation following a developmental pathway consisting on three levels: 1) sensory-motor coordination; 2) world interaction; and 3) imitation. With these stages, the system is able to learn tasks by imitating human demonstrators. We describe results of the different developmental stages, involving perceptual and motor skills, implemented in our humanoid robot, Baltazar. At each stage, the system's attention is drawn toward different entities: its own body and, later on, objects and people. Our main contributions are the general architecture and the implementation of all the necessary modules until imitation capabilities are eventually acquired by the robot. Also, several other contributions are made at each level: learning of sensory-motor maps for redundant robots, a novel method for learning how to grasp objects, and a framework for learning task description from observation for program-level imitation. Finally, vision is used extensively as the sole sensing modality (sometimes in a simplified setting) avoiding the need for special data-acquisition hardware.

Quantitative Proteomics Analysis of Streptomyces coelicolor Development Demonstrates That Onset of Secondary Metabolism Coincides with Hypha Differentiation*

PubMed Central

Manteca, Angel; Sanchez, Jesus; Jung, Hye R.; Schwämmle, Veit; Jensen, Ole N.

2010-01-01

Streptomyces species produce many clinically important secondary metabolites, including antibiotics and antitumorals. They have a complex developmental cycle, including programmed cell death phenomena, that makes this bacterium a multicellular prokaryotic model. There are two differentiated mycelial stages: an early compartmentalized vegetative mycelium (first mycelium) and a multinucleated reproductive mycelium (second mycelium) arising after programmed cell death processes. In the present study, we made a detailed proteomics analysis of the distinct developmental stages of solid confluent Streptomyces coelicolor cultures using iTRAQ (isobaric tags for relative and absolute quantitation) labeling and LC-MS/MS. A new experimental approach was developed to obtain homogeneous samples at each developmental stage (temporal protein analysis) and also to obtain membrane and cytosolic protein fractions (spatial protein analysis). A total of 345 proteins were quantified in two biological replicates. Comparative bioinformatics analyses revealed the switch from primary to secondary metabolism between the initial compartmentalized mycelium and the multinucleated hyphae. PMID:20224110

Small RNA profiling in two Brassica napus cultivars identifies microRNAs with oil production- and development-correlated expression and new small RNA classes.

PubMed

Zhao, Ying-Tao; Wang, Meng; Fu, San-Xiong; Yang, Wei-Cai; Qi, Cun-Kou; Wang, Xiu-Jie

2012-02-01

MicroRNAs (miRNAs) and small interfering RNAs are important regulators of plant development and seed formation, yet their population and abundance in the oil crop Brassica napus are still not well understood, especially at different developmental stages and among cultivars with varied seed oil contents. Here, we systematically analyzed the small RNA expression profiles of Brassica napus seeds at early embryonic developmental stages in high-oil-content and low-oil-content B. napus cultivars, both cultured in two environments. A total of 50 conserved miRNAs and 9 new miRNAs were identified, together with some new miRNA targets. Expression analysis revealed some miRNAs with varied expression levels in different seed oil content cultivars or at different embryonic developmental stages. A large number of 23-nucleotide small RNAs with specific nucleotide composition preferences were also identified, which may present new classes of functional small RNAs.

Biometric studies on premetamorphic eel larvae of Anguilla anguilla (Anguilliformes: Anguillidae) in comparison with younger developmental stages of the species

NASA Astrophysics Data System (ADS)

Strehlow, B.

1996-09-01

387 premetamorphic leptocephali of the family Anguillidae caught off the west coast of Europe were examined taxonomically and compared with the youngest developmental stages of larvae of Anguilla anguilla caught in the Sargasso Sea 1979 (Schoth, 1982). The total number of myomeres and the number of myomeres up to the third, opistonephritic blood vessel present features of this species which are significantly different from those of the larvae of Anguilla rostrata and do not change during the whole larval phase. A combination of these two biometric features enables an infallible species identification of the Atlantic Anguilla larvae at all developmental stages. The number of predorsal and preanal myomeres, the preanal length and features of the head cannot be used for a distinction of Anguilla larvae. One larva, 68.7 mm long, with 107 myomeres, and 44 myomeres to the opistonephritic blood vessel represents the hitherto southernmost record of an A. rostrata larva in the eastern North Atlantic.

Carbohydrate Content and Enzyme Metabolism in Developing Canola Siliques.

PubMed Central

King, S. P.; Lunn, J. E.; Furbank, R. T.

1997-01-01

Little biochemical information is available on carbohydrate metabolism in developing canola (Brassica napus L.) silique (pod) wall and seed tissues. This research examines the carbohydrate contents and sucrose (Suc) metabolic enzyme activities in different aged silique wall and seed tissues during oil filling. The silique wall partitioned photosynthate into Suc over starch and predominantly accumulated hexose. The silique wall hexose content and soluble acid invertase activity rapidly fell as embryos progressed from the early- to late-cotyledon developmental stages. A similar trend was not evident for alkaline invertase, Suc synthase (SuSy), and Suc-phosphate synthase. Silique wall SuSy activities were much higher than source leaves at all times and may serve to supply the substrate for secondary cell wall thickening. In young seeds starch was the predominant accumulated carbohydrate over the sampled developmental range. Seed hexose levels dropped as embryos developed from the early- to midcotyledon stage. Hexose and starch were localized to the testa or liquid endosperm, whereas Suc was evenly distributed among seed components. With the switch to oil accumulation, seed SuSy activity increased by 3.6-fold and soluble acid invertase activity decreased by 76%. These data provide valuable baseline knowledge for the genetic manipulation of canola seed carbon partitioning. PMID:12223695

Assessing Aromatic-Hydrocarbon Toxicity to Fish Early Life Stages Using Passive-Dosing Methods and Target-Lipid and Chemical-Activity Models.

PubMed

Butler, Josh D; Parkerton, Thomas F; Redman, Aaron D; Letinski, Daniel J; Cooper, Keith R

2016-08-02

Aromatic hydrocarbons (AH) are known to impair fish early life stages (ELS). However, poorly defined exposures often confound ELS-test interpretation. Passive dosing (PD) overcomes these challenges by delivering consistent, controlled exposures. The objectives of this study were to apply PD to obtain 5 d acute embryo lethality and developmental data and 30 d chronic embryo-larval survival and growth-effects data using zebrafish with different AHs; to analyze study and literature toxicity data using target-lipid (TLM) and chemical-activity (CA) models; and to extend PD to a mixture and test the assumption of AH additivity. PD maintained targeted exposures over a concentration range of 6 orders of magnitude. AH toxicity increased with log Kow up to pyrene (5.2). Pericardial edema was the most sensitive sublethal effect that often preceded embryo mortality, although some AHs did not produce developmental effects at concentrations causing mortality. Cumulative embryo-larval mortality was more sensitive than larval growth, with acute-to-chronic ratios of <10. More-hydrophobic AHs did not exhibit toxicity at aqueous saturation. The relationship and utility of the TLM-CA models for characterizing fish ELS toxicity is discussed. Application of these models indicated that concentration addition provided a conservative basis for predicting ELS effects for the mixture investigated.

The genome and developmental transcriptome of the strongylid nematode Haemonchus contortus

PubMed Central

2013-01-01

Background The barber's pole worm, Haemonchus contortus, is one of the most economically important parasites of small ruminants worldwide. Although this parasite can be controlled using anthelmintic drugs, resistance against most drugs in common use has become a widespread problem. We provide a draft of the genome and the transcriptomes of all key developmental stages of H. contortus to support biological and biotechnological research areas of this and related parasites. Results The draft genome of H. contortus is 320 Mb in size and encodes 23,610 protein-coding genes. On a fundamental level, we elucidate transcriptional alterations taking place throughout the life cycle, characterize the parasite's gene silencing machinery, and explore molecules involved in development, reproduction, host-parasite interactions, immunity, and disease. The secretome of H. contortus is particularly rich in peptidases linked to blood-feeding activity and interactions with host tissues, and a diverse array of molecules is involved in complex immune responses. On an applied level, we predict drug targets and identify vaccine molecules. Conclusions The draft genome and developmental transcriptome of H. contortus provide a major resource to the scientific community for a wide range of genomic, genetic, proteomic, metabolomic, evolutionary, biological, ecological, and epidemiological investigations, and a solid foundation for biotechnological outcomes, including new anthelmintics, vaccines and diagnostic tests. This first draft genome of any strongylid nematode paves the way for a rapid acceleration in our understanding of a wide range of socioeconomically important parasites of one of the largest nematode orders. PMID:23985341

Evaluation of third molar development and its relation to chronological age: a panoramic radiographic study.

PubMed

Zandi, Mohammad; Shokri, Abbas; Malekzadeh, Hamid; Amini, Payam; Shafiey, Parastu

2015-06-01

Third molar development, in comparison to other teeth in the dentition, has the greatest variation in morphology, anatomical position, and time of development and eruption, and its reliability for chronological age estimation is controversial. The aim of the present study was to evaluate third molar development and its relation to chronological age using panoramic radiography. A total of 2536 digital panoramic radiographs of individuals aged between 5 and 26 years were selected. The developmental status of the third molars was assessed using eight-stage developmental scoring proposed by Demirjian et al., with one modification: a stage 0 was added. The collected data were entered into a checklist and subjected to statistical analyses. The mean ages of the first appearance of third molar bud, complete crown formation, and root apex closure were around 9, 14, and 22 years, respectively. In both jaws, third molar development occurred symmetrically, and sexual dimorphism was observed at some developmental stages. Finally, two formulas were presented to estimate age of the juveniles and adolescents based on their gender and developmental stages of the third molars, and validated on a second sample consisting of 523 individuals aged between 8 and 22. Assessment of third molar development was found to be a reliable method for age estimation of individuals between 11 and 22 years. Because of possible ethnic and geographic differences in third molar development, population specific researches were recommended.

Developmental Issues in Counseling With Couples.

ERIC Educational Resources Information Center

Seligman, Linda; Deutsch, Marjorie B.

Marriages, just like the individuals in them, go through stages of development. Understanding these relatively predictable stages can be helpful to couples, by allaying apprehension, promoting preparation for change, and putting fluctuations into perspective. Research on marital stages and experiences in counseling couples suggest that marriages…

A developmental screening tool for toddlers with multiple domains based on Rasch analysis.

PubMed

Hwang, Ai-Wen; Chou, Yeh-Tai; Hsieh, Ching-Lin; Hsieh, Wu-Shiun; Liao, Hua-Fang; Wong, Alice May-Kuen

2015-01-01

Using multidomain developmental screening tools is a feasible method for pediatric health care professionals to identify children at risk of developmental problems in multiple domains simultaneously. The purpose of this study was to develop a Rasch-based tool for Multidimensional Screening in Child Development (MuSiC) for children aged 0-3 years. The MuSic was developed by constructing items bank based on three commonly used screening tools, validating with developmental status (at risk for delay or not) on five developmental domains. Parents of a convenient sample of 632 children (aged 3-35.5 months) with and without developmental delays responded to items from the three screening tools funded by health authorities in Taiwan. Item bank was determined by item fit of Rasch analysis for each of the five developmental domains (cognitive skills, language skills, gross motor skills, fine motor skills, and socioadaptive skills). Children's performance scores in logits derived in Rasch analysis were validated with developmental status for each domain using the area under receiver operating characteristic curves. MuSiC, a 75-item developmental screening tool for five domains, was derived. The diagnostic validity of all five domains was acceptable for all stages of development, except for the infant stage (≤11 months and 15 days). MuSiC can be applied simultaneously to well-child care visits as a universal screening tool for children aged 1-3 years on multiple domains. Items with sound validity for infants need to be further developed. Copyright © 2014. Published by Elsevier B.V.

Comparative differential gene expression analysis of nucleus-encoded proteins for Rafflesia cantleyi against Arabidopsis thaliana

NASA Astrophysics Data System (ADS)

Ng, Siuk-Mun; Lee, Xin-Wei; Wan, Kiew-Lian; Firdaus-Raih, Mohd

2015-09-01

Regulation of functional nucleus-encoded proteins targeting the plastidial functions was comparatively studied for a plant parasite, Rafflesia cantleyi versus a photosynthetic plant, Arabidopsis thaliana. This study involved two species of different feeding modes and different developmental stages. A total of 30 nucleus-encoded proteins were found to be differentially-regulated during two stages in the parasite; whereas 17 nucleus-encoded proteins were differentially-expressed during two developmental stages in Arabidopsis thaliana. One notable finding observed for the two plants was the identification of genes involved in the regulation of photosynthesis-related processes where these processes, as expected, seem to be present only in the autotroph.

Stagewise cognitive development: an application of catastrophe theory.

PubMed

van der Maas, H L; Molenaar, P C

1992-07-01

In this article an overview is given of traditional methodological approaches to stagewise cognitive developmental research. These approaches are evaluated and integrated on the basis of catastrophe theory. In particular, catastrophe theory specifies a set of common criteria for testing the discontinuity hypothesis proposed by Piaget. Separate criteria correspond to distinct methods used in cognitive developmental research. Such criteria are, for instance, the detection of spurts in development, bimodality of test scores, and increased variability of responses during transitional periods. When a genuine stage transition is present, these criteria are expected to be satisfied. A revised catastrophe model accommodating these criteria is proposed for the stage transition in cognitive development from the preoperational to the concrete operational stage.

"Intermetamorphic" developmental stages in 150 million-year-old achelatan lobsters--The case of the species tenera Oppel, 1862.

PubMed

Haug, Joachim T; Haug, Carolin

2016-03-01

We re-investigated the fossil species tenera Oppel, 1862, an achelatan lobster (traditionally named Palinurina tenera) found in 150 million years old limestones of southern Germany. All known specimens attributed to this species show a mixture of characters, which in modern forms occur either in larvae or post-larval juveniles. Hence these specimens provide insight into a phase in ontogeny that is no longer present in the developmental sequence of any modern achelatan lobster, as the latter ones skip this phase and replace it by a drastic metamorphosis. Comparable cases have been described earlier, yet did only comprise single stages or two successive ones at most. In the here described case four developmental stages are preserved. The reconstructed ontogeny of tenera therefore represents the currently best known sequence of an early achelatan lobster that covers this specific intermediate phase. The largest known stage most likely still represents an immature of a yet undiscovered adult. These findings support the interpretation that early achelatan lobsters developed in a more gradual ontogenetic sequence than modern forms. It furthermore demonstrates that it was even more gradual than anticipated previously. Copyright © 2015 Elsevier Ltd. All rights reserved.

Kohlberg's theory of moral development: insights into rights reasoning.

PubMed

Peens, B J; Louw, D A

2000-01-01

Kohlberg's theory of moral development was based on extensive research done on the reactions of people of all ages to specific moral situational dilemmas. Kohlberg was specifically interested in reasoning processes involved in decision-making. The way in which children perceive their rights is also based on reasoning processes that are inextricably linked to their level of development and more specifically to their level of moral development since the area of human rights can be considered essentially moral. Since Kohlberg's theory is primarily concerned with development, a great deal of insight can be gained into the developmental shift that occurs in children's reasoning about the rights to which they feel they should be entitled. This article focuses on Kohlberg's six-stage theory, specifically as it pertains to reasoning processes similar to those that would be used in rights reasoning. At each stage the authors propose a potential view of how children at each developmental stage might perceive their rights based on the description Kohlberg gives of the developmental trends associated with each stage. A critical assessment of Kohlberg's work is also given in order to highlight certain considerations about the limitations of this theory that need to be considered for future research.

Ambient temperature and genotype differentially affect developmental and phenotypic plasticity in Arabidopsis thaliana.

PubMed

Ibañez, Carla; Poeschl, Yvonne; Peterson, Tom; Bellstädt, Julia; Denk, Kathrin; Gogol-Döring, Andreas; Quint, Marcel; Delker, Carolin

2017-07-06

Global increase in ambient temperatures constitute a significant challenge to wild and cultivated plant species. Forward genetic analyses of individual temperature-responsive traits have resulted in the identification of several signaling and response components. However, a comprehensive knowledge about temperature sensitivity of different developmental stages and the contribution of natural variation is still scarce and fragmented at best. Here, we systematically analyze thermomorphogenesis throughout a complete life cycle in ten natural Arabidopsis thaliana accessions grown under long day conditions in four different temperatures ranging from 16 to 28 °C. We used Q 10 , GxE, phenotypic divergence and correlation analyses to assess temperature sensitivity and genotype effects of more than 30 morphometric and developmental traits representing five phenotype classes. We found that genotype and temperature differentially affected plant growth and development with variing strengths. Furthermore, overall correlations among phenotypic temperature responses was relatively low which seems to be caused by differential capacities for temperature adaptations of individual accessions. Genotype-specific temperature responses may be attractive targets for future forward genetic approaches and accession-specific thermomorphogenesis maps may aid the assessment of functional relevance of known and novel regulatory components.

Genome-wide identification and characterization of auxin response factor (ARF) family genes related to flower and fruit development in papaya (Carica papaya L.).

PubMed

Liu, Kaidong; Yuan, Changchun; Li, Haili; Lin, Wanhuang; Yang, Yanjun; Shen, Chenjia; Zheng, Xiaolin

2015-11-05

Auxin and auxin signaling are involved in a series of developmental processes in plants. Auxin Response Factors (ARFs) is reported to modulate the expression of target genes by binding to auxin response elements (AuxREs) and influence the transcriptional activation of down-stream target genes. However, how ARF genes function in flower development and fruit ripening of papaya (Carica papaya L.) is largely unknown. In this study, a comprehensive characterization and expression profiling analysis of 11 C. papaya ARF (CpARF) genes was performed using the newly updated papaya reference genome data. We analyzed CpARF expression patterns at different developmental stages. CpARF1, CpARF2, CpARF4, CpARF5, and CpARF10 showed the highest expression at the initial stage of flower development, but decreased during the following developmental stages. CpARF6 expression increased during the developmental process and reached its peak level at the final stage of flower development. The expression of CpARF1 increased significantly during the fruit ripening stages. Many AuxREs were included in the promoters of two ethylene signaling genes (CpETR1 and CpETR2) and three ethylene-synthesis-related genes (CpACS1, CpACS2, and CpACO1), suggesting that CpARFs might be involved in fruit ripening via the regulation of ethylene signaling. Our study provided comprehensive information on ARF family in papaya, including gene structures, chromosome locations, phylogenetic relationships, and expression patterns. The involvement of CpARF gene expression changes in flower and fruit development allowed us to understand the role of ARF-mediated auxin signaling in the maturation of reproductive organs in papaya.

Development-related expression patterns of protein-coding and miRNA genes involved in porcine muscle growth.

PubMed

Wang, F J; Jin, L; Guo, Y Q; Liu, R; He, M N; Li, M Z; Li, X W

2014-11-27

Muscle growth and development is associated with remarkable changes in protein-coding and microRNA (miRNA) gene expression. To determine the expression patterns of genes and miRNAs related to muscle growth and development, we measured the expression levels of 25 protein-coding and 16 miRNA genes in skeletal and cardiac muscles throughout 5 developmental stages by quantitative reverse transcription-polymerase chain reaction. The Short Time-Series Expression Miner (STEM) software clustering results showed that growth-related genes were downregulated at all developmental stages in both the psoas major and longissimus dorsi muscles, indicating their involvement in early developmental stages. Furthermore, genes related to muscle atrophy, such as forkhead box 1 and muscle ring finger, showed unregulated expression with increasing age, suggesting a decrease in protein synthesis during the later stages of skeletal muscle development. We found that development of the cardiac muscle was a complex process in which growth-related genes were highly expressed during embryonic development, but they did not show uniform postnatal expression patterns. Moreover, the expression level of miR-499, which enhances the expression of the β-myosin heavy chain, was significantly different in the psoas major and longissimus dorsi muscles, suggesting the involvement of miR-499 in the determination of skeletal muscle fiber types. We also performed correlation analyses of messenger RNA and miRNA expression. We found negative relationships between miR-486 and forkhead box 1, and miR-133a and serum response factor at all developmental stages, suggesting that forkhead box 1 and serum response factor are potential targets of miR-486 and miR-133a, respectively.

Developmental effects of simulated microgravity on zebrafish, (Danio rerio)

NASA Astrophysics Data System (ADS)

Stoyek, Matthew; Edsall, Sara; Franz-Odendaal, Tamara; Smith, Frank; Croll, Roger

Zebrafish are widely used model vertebrates in research and recently this species has been used to study the effects of microgravity on fundamental biological processes. In this study we used a NASA-designed rotating wall vessel (RWV) to investigate the effects of simulated microgravity (SMG) on zebrafish development up to 14 days post fertilization (dpf). At developmental stages beyond the 3-4 somite stage we found SMG-exposed embryos reached key developmental stag-ing points more rapidly than fish raised within a non-rotating vessel. By the 21 somite stage, both groups were again synchronized in their developmental staging. However, SMG-exposed embryos eventually exhibited a delay in hatching time compared to controls. Otolith and to-tal body size were observed to be greater in larvae raised in SMG. In addition, pigmentation patterns in SMG exposed fish differed, with larger and differentially aggregated melanocytes . Heart development was slowed in SMG exposed fish, but no change in nervous system de-velopment was detected. Ongoing research will focus on differences in heart and respiration rates. Finally, by developing a method to extend the duration of SMG exposure, we found the swimming behaviour of SMG-exposed animals was altered with time in the RWV. Initially SMG-exposed animals swam in the direction of RWV rotation (5-9dpf) but older (9+dpf) fish swam against rotation and demonstrated righting behaviour with each rotation. These results suggest that vestibular reflexes may develop normally and be maintained in animals exposed to SMG. Together, our data provide insights into how zebrafish may develop when flown in space, permitting better formulation of experiments to test mechanisms by which microgravity may affect ontogeny of this model organism. Keywords: microgravity, zebrafish, growth, development

Temporal and spatial complexity of maternal thermoregulation in tropical pythons.

PubMed

Stahlschmidt, Zachary Ross; Shine, Richard; Denardo, Dale F

2012-01-01

Parental care is a widespread adaptation that evolved independently in a broad range of taxa. Although the dynamics by which two parents meet the developmental needs of offspring are well studied in birds, we lack understanding about the temporal and spatial complexity of parental care in taxa exhibiting female-only care, the predominant mode of parental care. Thus, we examined the behavioral and physiological mechanisms by which female water pythons Liasis fuscus meet a widespread developmental need (thermoregulation) in a natural setting. Although female L. fuscus were not facultatively thermogenic, they did use behaviors on multiple spatial scales (e.g., shifts in egg-brooding postures and surface activity patterns) to balance the thermal needs of their offspring throughout reproduction (gravidity and egg brooding). Maternal behaviors in L. fuscus varied by stage within reproduction and were mediated by interindividual variation in body size and fecundity. Female pythons with relatively larger clutch sizes were cooler during egg brooding, suggesting a trade-off between reproductive quantity (size of clutch) and quality (developmental temperature). In nature, caregiving parents of all taxa must navigate both extrinsic factors (temporal and spatial complexity) and intrinsic factors (body size and fecundity) to meet the needs of their offspring. Our study used a comprehensive approach that can be used as a general template for future research examining the dynamics by which parents meet other developmental needs (e.g., predation risk or energy balance).

Genome wide analysis reveals Zic3 interaction with distal regulatory elements of stage specific developmental genes in zebrafish.

PubMed

Winata, Cecilia L; Kondrychyn, Igor; Kumar, Vibhor; Srinivasan, Kandhadayar G; Orlov, Yuriy; Ravishankar, Ashwini; Prabhakar, Shyam; Stanton, Lawrence W; Korzh, Vladimir; Mathavan, Sinnakaruppan

2013-10-01

Zic3 regulates early embryonic patterning in vertebrates. Loss of Zic3 function is known to disrupt gastrulation, left-right patterning, and neurogenesis. However, molecular events downstream of this transcription factor are poorly characterized. Here we use the zebrafish as a model to study the developmental role of Zic3 in vivo, by applying a combination of two powerful genomics approaches--ChIP-seq and microarray. Besides confirming direct regulation of previously implicated Zic3 targets of the Nodal and canonical Wnt pathways, analysis of gastrula stage embryos uncovered a number of novel candidate target genes, among which were members of the non-canonical Wnt pathway and the neural pre-pattern genes. A similar analysis in zic3-expressing cells obtained by FACS at segmentation stage revealed a dramatic shift in Zic3 binding site locations and identified an entirely distinct set of target genes associated with later developmental functions such as neural development. We demonstrate cis-regulation of several of these target genes by Zic3 using in vivo enhancer assay. Analysis of Zic3 binding sites revealed a distribution biased towards distal intergenic regions, indicative of a long distance regulatory mechanism; some of these binding sites are highly conserved during evolution and act as functional enhancers. This demonstrated that Zic3 regulation of developmental genes is achieved predominantly through long distance regulatory mechanism and revealed that developmental transitions could be accompanied by dramatic changes in regulatory landscape.

Application of the Modified Erikson Psychosocial Stage Inventory: 25 Years in Review.

PubMed

Darling-Fisher, Cynthia S

2018-04-01

The Modified Erikson Psychosocial Stage Inventory (MEPSI) is an 80-item, comprehensive measure of psychosocial development based on Erikson's theory with published reliability and validity data. Although designed as a comprehensive measure, some researchers have used individual subscales for specific developmental stages as a measure; however, these subscale reliability scores have not been generally shared. This article reviewed the literature to evaluate the use of the MEPSI: the major research questions, samples/populations studied, and individual subscale and total reliability and validity data. In total, 16 research articles (1990-2011) and 28 Dissertations/Theses (1991-2016) from nursing, social work, psychology, criminal justice, and religious studies met criteria. Results support the MEPSI's global reliability (aggregate scores ranged .89-.99) and validity in terms of consistent patterns of changes observed in the predicted direction. Reliability and validity data for individual subscales were more variable. Limitations of the tool and recommendations for possible revision and future research are addressed.

RNAi pathways contribute to developmental history-dependent phenotypic plasticity in C. elegans

PubMed Central

Hall, Sarah E.; Chirn, Gung-Wei; Lau, Nelson C.; Sengupta, Piali

2013-01-01

Early environmental experiences profoundly influence adult phenotypes through complex mechanisms that are poorly understood. We previously showed that adult Caenorhabditis elegans that transiently passed through the stress-induced dauer larval stage (post-dauer adults) exhibit significant changes in gene expression profiles, chromatin states, and life history traits when compared with adults that bypassed the dauer stage (control adults). These wild-type, isogenic animals of equivalent developmental stages exhibit different signatures of molecular marks that reflect their distinct developmental trajectories. To gain insight into the mechanisms that contribute to these developmental history-dependent phenotypes, we profiled small RNAs from post-dauer and control adults by deep sequencing. RNA interference (RNAi) pathways are known to regulate genome-wide gene expression both at the chromatin and post-transcriptional level. By quantifying changes in endogenous small interfering RNA (endo-siRNA) levels in post-dauer as compared with control animals, our analyses identified a subset of genes that are likely targets of developmental history-dependent reprogramming through a complex RNAi-mediated mechanism. Mutations in specific endo-siRNA pathways affect expected gene expression and chromatin state changes for a subset of genes in post-dauer animals, as well as disrupt their increased brood size phenotype. We also find that both chromatin state and endo-siRNA distribution in dauers are unique, and suggest that remodeling in dauers provides a template for the subsequent establishment of adult post-dauer profiles. Our results indicate a role for endo-siRNA pathways as a contributing mechanism to early experience-dependent phenotypic plasticity in adults, and describe how developmental history can program adult physiology and behavior via epigenetic mechanisms. PMID:23329696

Effects of salinity on the transcriptome of growing maize leaf cells point at cell-age specificity in the involvement of the antioxidative response in cell growth restriction

PubMed Central

2013-01-01

Background Salinity inhibits growth and development of most plants. The response to salinity is complex and varies between plant organs and stages of development. It involves challenges of ion toxicities and deficiencies as well as osmotic and oxidative stresses. The range of functions affected by the stress is reflected in elaborate changes to the transcriptome. The mechanisms involved in the developmental-stage specificity of the inhibitory responses are not fully understood. The present study took advantage of the well characterized developmental progression that exists along the maize leaf, for identification of salinity induced, developmentally-associated changes to the transcriptome. Differential subtraction screening was conducted for cells of two developmental stages: from the center of the growth zone where the expansion rate is highest, and from older cells at a more distal location of the growing zone where the expansion rate is lower and the salinity restrictive effects are more pronounced. Real-Time PCR analysis was used for validation of the expression of selected genes. Results The salinity-induced changes demonstrated an age-related response of the growing tissue, with elevation of salinity-damages with increased age. Growth reduction, similar to the elevation of percentage dry matter (%DM), and Na and Cl concentrations were more pronounced in the older cells. The differential subtraction screening identified genes encoding to proteins involved in antioxidant defense, electron transfer and energy, structural proteins, transcription factors and photosynthesis proteins. Of special interest is the higher induced expression of genes involved in antioxidant protection in the young compared to older cells, which was accompanied by suppressed levels of reactive oxygen species (H2O2 and O2-). This was coupled with heightened expression in the older cells of genes that enhance cell-wall rigidity, which points at reduced potential for cell expansion. Conclusions The results demonstrate a cell-age specificity in the salinity response of growing cells, and point at involvement of the antioxidative response in cell growth restriction. Processes involved in reactive oxygen species (ROS) scavenging are more pronounced in the young cells, while the higher growth sensitivity of older cells is suggested to involve effects on cell-wall rigidity and lower protein protection. PMID:23324477

Developmental milestones among Aboriginal children in Canada

PubMed Central

Findlay, Leanne; Kohen, Dafna; Miller, Anton

2014-01-01

BACKGROUND: Windows of achievement provide age ranges for the attainment of early developmental skills. Group-specific research is warranted given that development may be influenced by social or cultural factors. OBJECTIVES: To examine developmental milestones for Inuit, Métis and off-reserve First Nation children in Canada, based on developmental domains collected from the 2006 Aboriginal Children’s Survey. Sociodemographic and health predictors of risk for developmental delay were also examined. RESULTS: The ranges in which children achieve certain developmental milestones are presented. Gross motor and self-help skills were found to be achieved earlier (across the three Aboriginal groups), whereas language skills were achieved slightly later than in Canadian children in general. Furthermore, health factors (eg, low birth weight, chronic health conditions) were associated with late achievement of developmental outcomes even when sociodemographic characteristics were considered. CONCLUSIONS: Findings suggest that the timing of milestone achievement may differ for Aboriginal children, highlighting the importance of establishing culturally specific norms and standards rather than relying on those derived from general populations. This information may be useful for practitioners and parents interested in identifying the age ranges for development, as well as age ranges indicating potential for developmental risk and opportunities for early intervention among Aboriginal children. PMID:24855426

Differential Immunotoxicity Induced by Two Different Windows of Developmental Trichloroethylene Exposure

PubMed Central

Gilbert, Kathleen M.; Woodruff, William; Blossom, Sarah J.

2014-01-01

Developmental exposure to environmental toxicants may induce immune system alterations that contribute to adult stage autoimmune disease. We have shown that continuous exposure of MRL+/+ mice to trichloroethylene (TCE) from gestational day (GD) 0 to postnatal day (PND) 49 alters several aspects of CD4+ T cell function. This window of exposure corresponds to conception-adolescence/young adulthood in humans. More narrowly defining the window of TCE developmental exposure causes immunotoxicity that would establish the stage at which avoidance and/or intervention would be most effective. The current study divided continuous TCE exposure into two separate windows, namely, gestation only (GD0 to birth (PND0)) and early-life only (PND0-PND49). The mice were examined for specific alterations in CD4+ T cell function at PND49. One potentially long-lasting effect of developmental exposure, alterations in retrotransposon expression indicative of epigenetic alterations, was found in peripheral CD4+ T cells from both sets of developmentally exposed mice. Interestingly, certain other effects, such as alterations in thymus cellularity, were only found in mice exposed to TCE during gestation. In contrast, expansion of memory/activation cell subset of peripheral CD4+ T cells were only found in mice exposed to TCE during early life. Different windows of developmental TCE exposure can have different functional consequences. PMID:24696780

Cooler butterflies lay larger eggs: developmental plasticity versus acclimation.

PubMed Central

Fischer, Klaus; Eenhoorn, Evelien; Bot, Adriane N M; Brakefield, Paul M; Zwaan, Bas J

2003-01-01

We use a full factorial design to investigate the effects of maternal and paternal developmental temperature, as well as female oviposition temperature, on egg size in the butterfly Bicyclus anynana. Butterflies were raised at two different temperatures and mated in four possible sex-by-parental-temperature crosses. The mated females were randomly divided between high and low oviposition temperatures. On the first day after assigning the females to different temperatures, only female developmental temperature affected egg size. Females reared at the lower temperature laid larger eggs than those reared at a higher temperature. When eggs were measured again after an acclimation period of 10 days, egg size was principally determined by the prevailing temperature during oviposition, with females ovipositing at a lower temperature laying larger eggs. In contrast to widely used assumptions, the effects of developmental temperature were largely reversible. Male developmental temperature did not affect egg size in either of the measurements. Overall, developmental plasticity and acclimation in the adult stage resulted in very similar patterns of egg size plasticity. Consequently, we argue that the most important question when testing the significance of acclamatory changes is not at which stage a given plasticity is induced, but rather whether plastic responses to environmental change are adaptive or merely physiological constraints. PMID:14561294

Growth and developmental effects of coal combustion residues on Southern Leopard Frog (Rana sphenocephala) tadpoles exposed throughout metamorphosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, J.D.; Peterson, V.A.; Mendonca, M.T.

2008-09-15

The effects of aquatic deposition of coal combustion residues (CCRs) on amphibian life histories have been the focus of many recent studies. In summer 2005, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate (approximately 1 cm deep within plastic bins) and documented effects of sediment type on oral disc condition, as well as time to, mass at, and total body length at key developmental stages, including metamorphosis (Gosner stages (GS) 37, 42, and 46). We found no significant difference in mortality between the two treatments and mortality was relatively low (eight of 48 inmore » the control group and four of 48 in the CCR group). Ninety percent of exposed tadpoles displayed oral disc abnormalities, while no control individuals displayed abnormalities. Tadpoles raised on CCR-contaminated sediment had decreased developmental rates and weighed significantly less at all developmental stages, on average, when compared to controls. The CCR treatment group was also significantly shorter In length than controls at the completion of metamorphosis (GS 46). Collectively, these findings are the most severe sub-lethal effects noted for any amphibian exposed to CCRs to date. More research is needed to understand how these long term effects may contribute to the dynamics of local amphibian populations.« less

MethBank: a database integrating next-generation sequencing single-base-resolution DNA methylation programming data.

PubMed

Zou, Dong; Sun, Shixiang; Li, Rujiao; Liu, Jiang; Zhang, Jing; Zhang, Zhang

2015-01-01

DNA methylation plays crucial roles during embryonic development. Here we present MethBank (http://dnamethylome.org), a DNA methylome programming database that integrates the genome-wide single-base nucleotide methylomes of gametes and early embryos in different model organisms. Unlike extant relevant databases, MethBank incorporates the whole-genome single-base-resolution methylomes of gametes and early embryos at multiple different developmental stages in zebrafish and mouse. MethBank allows users to retrieve methylation levels, differentially methylated regions, CpG islands, gene expression profiles and genetic polymorphisms for a specific gene or genomic region. Moreover, it offers a methylome browser that is capable of visualizing high-resolution DNA methylation profiles as well as other related data in an interactive manner and thus is of great helpfulness for users to investigate methylation patterns and changes of gametes and early embryos at different developmental stages. Ongoing efforts are focused on incorporation of methylomes and related data from other organisms. Together, MethBank features integration and visualization of high-resolution DNA methylation data as well as other related data, enabling identification of potential DNA methylation signatures in different developmental stages and accordingly providing an important resource for the epigenetic and developmental studies. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Identification and validation of reference genes for qRT-PCR studies of the obligate aphid pathogenic fungus Pandora neoaphidis during different developmental stages.

PubMed

Zhang, Shutao; Chen, Chun; Xie, Tingna; Ye, Sudan

2017-01-01

The selection of stable reference genes is a critical step for the accurate quantification of gene expression. To identify and validate the reference genes in Pandora neoaphidis-an obligate aphid pathogenic fungus-the expression of 13classical candidate reference genes were evaluated by quantitative real-time reverse transcriptase polymerase chain reaction(qPCR) at four developmental stages (conidia, conidia with germ tubes, short hyphae and elongated hyphae). Four statistical algorithms, including geNorm, NormFinder, BestKeeper and Delta Ct method were used to rank putative reference genes according to their expression stability and indicate the best reference gene or combination of reference genes for accurate normalization. The analysis of comprehensive ranking revealed that ACT1and 18Swas the most stably expressed genes throughout the developmental stages. To further validate the suitability of the reference genes identified in this study, the expression of cell division control protein 25 (CDC25) and Chitinase 1(CHI1) genes were used to further confirm the validated candidate reference genes. Our study presented the first systematic study of reference gene(s) selection for P. neoaphidis study and provided guidelines to obtain more accurate qPCR results for future developmental efforts.

Transition from Sensorimotor Stage 5 to Stage 6 by Down Syndrome Children: A Response to Gibson.

ERIC Educational Resources Information Center

Mervis, Carolyn B.; Cardoso-Martins, Claudia

1984-01-01

The study compared longitudinally performance of six Down syndrome and six nonretarded children on Object Permanence and Means-Ends Relations Scales. Results indicated that Down syndrome children progressed from Sensorimotor Stage 5 to Stage 6 at the same rate as nonretarded children, once Down's Ss slower developmental pace was considered.…

Autonomy and integration in complex parasite life cycles.

PubMed

Benesh, Daniel P

2016-12-01

Complex life cycles are common in free-living and parasitic organisms alike. The adaptive decoupling hypothesis postulates that separate life cycle stages have a degree of developmental and genetic autonomy, allowing them to be independently optimized for dissimilar, competing tasks. That is, complex life cycles evolved to facilitate functional specialization. Here, I review the connections between the different stages in parasite life cycles. I first examine evolutionary connections between life stages, such as the genetic coupling of parasite performance in consecutive hosts, the interspecific correlations between traits expressed in different hosts, and the developmental and functional obstacles to stage loss. Then, I evaluate how environmental factors link life stages through carryover effects, where stressful larval conditions impact parasites even after transmission to a new host. There is evidence for both autonomy and integration across stages, so the relevant question becomes how integrated are parasite life cycles and through what mechanisms? By highlighting how genetics, development, selection and the environment can lead to interdependencies among successive life stages, I wish to promote a holistic approach to studying complex life cycle parasites and emphasize that what happens in one stage is potentially highly relevant for later stages.

Developmental tempo in children aged 0-5 years living under unfavourable environmental conditions.

PubMed

Lejarraga, Horacio; Kelmansky, Diana M; Nunes, Fernando

2018-04-01

To describe the dynamics of development along the early years of life among children living under unfavorable socioeconomic conditions. In 5401 children younger than 6 years old living in Florencio Varela and in the Matanza-Riachuelo River Basin (Matanza, Villa 21-24, Wilde, Villa Inflamable and Acuba), areas with a high proportion of families with unmet basic needs, a logistic regression analysis was used to estimate the median age at attainment of 13 psychomotor developmental milestones; differences between these ages and median age at attainment of milestones as per the national reference were plotted on the y-axis, while the median age as per the national reference was plotted on the x-axis. Three stages were observed: the first one between 0 and 270 days with normal development, in which the median age at attainment was similar to that of the national reference; a second one of progressive development delay; and a third one of recovery at 1260 days. Adjusted linear spline slopes were 0.06 (not significant), -0.26 (p < 0.0001) and 0.26 (p < 0.01) for stages 1, 2 and 3, respectively. The three slopes were statistically different from each other. The stage of normal development (stage 1) was attributed to the protective effect of the mother and the family environment; stage 2 of progressive delay, to the unfavorable impact of the environment, and stage 3 of partial recovery was attributed to attending a daycare center. These findings allow the implementation of effective interventions at each stage. Three periods with different developmental tempos were identified. Sociedad Argentina de Pediatría.

Analysis of expressed sequence tags from the four main developmental stages of Trypanosoma congolense

PubMed Central

Helm, Jared R.; Hertz-Fowler, Christiane; Aslett, Martin; Berriman, Matthew; Sanders, Mandy; Quail, Michael A.; Soares, Marcelo B.; Bonaldo, Maria F.; Sakurai, Tatsuya; Inoue, Noboru; Donelson, John E.

2009-01-01

Trypanosoma congolense is one of the most economically important pathogens of livestock in Africa. Culture-derived parasites of each of the three main insect stages of the T. congolense life cycle, i.e., the procyclic, epimastigote and metacyclic stages, and bloodstream stage parasites isolated from infected mice, were used to construct stage-specific cDNA libraries and expressed sequence tags (ESTs or cDNA clones) in each library were sequenced. Thirteen EST clusters encoding different variant surface glycoproteins (VSGs) were detected in the metacyclic library and twenty-six VSG EST clusters were found in the bloodstream library, six of which are shared by the metacyclic library. Rare VSG ESTs are present in the epimastigote library, and none were detected in the procyclic library. ESTs encoding enzymes that catalyze oxidative phosphorylation and amino acid metabolism are about twice as abundant in the procyclic and epimastigote stages as in the metacyclic and bloodstream stages. In contrast, ESTs encoding enzymes involved in glycolysis, the citric acid cycle and nucleotide metabolism are about the same in all four developmental stages. Cysteine proteases, kinases and phosphatases are the most abundant enzyme groups represented by the ESTs. All four libraries contain T. congolense-specific expressed sequences not present in the T. brucei and T. cruzi genomes. Normalized cDNA libraries were constructed from the metacyclic and bloodstream stages, and found to be further enriched for T. congolense-specific ESTs. Given that cultured T. congolense offers an experimental advantage over other African trypanosome species, these ESTs provide a basis for further investigation of the molecular properties of these four developmental stages, especially the epimastigote and metacyclic stages for which it is difficult to obtain large quantities of organisms. The T. congolense EST databases are available at: http://www.sanger.ac.uk/Projects/T_congolense/EST_index.shtml. PMID:19559733

Functional analysis of lysosomes during mouse preimplantation embryo development.

PubMed

Tsukamoto, Satoshi; Hara, Taichi; Yamamoto, Atsushi; Ohta, Yuki; Wada, Ayako; Ishida, Yuka; Kito, Seiji; Nishikawa, Tetsu; Minami, Naojiro; Sato, Ken; Kokubo, Toshiaki

2013-01-01

Lysosomes are acidic and highly dynamic organelles that are essential for macromolecule degradation and many other cellular functions. However, little is known about lysosomal function during early embryogenesis. Here, we found that the number of lysosomes increased after fertilization. Lysosomes were abundant during mouse preimplantation development until the morula stage, but their numbers decreased slightly in blastocysts. Consistently, the protein expression level of mature cathepsins B and D was high from the one-cell to morula stages but low in the blastocyst stage. One-cell embryos injected with siRNAs targeted to both lysosome-associated membrane protein 1 and 2 (LAMP1 and LAMP2) were developmentally arrested at the two-cell stage. Pharmacological inhibition of lysosomes also caused developmental retardation, resulting in accumulation of lipofuscin. Our findings highlight the functional changes in lysosomes in mouse preimplantation embryos.

Effects of heat stress on bovine preimplantation embryos produced in vitro

PubMed Central

SAKATANI, Miki

2017-01-01

Summer heat stress decreases the pregnancy rate in cattle and has been thought to be associated with the early embryonic death caused by the elevation of maternal body temperature. In vitro cultures have been widely used for the evaluation of effects of heat stress on oocytes, fertilization, preimplantation, and embryonic development. Susceptibility to heat stress is present in developmental stages from oocytes to cleavage-stage (before embryonic gene activation, EGA) embryos, leading to a consequent decrease in developmental competence. On the other hand, advanced-stage embryos such as morula or blastocysts have acquired thermotolerance. The mechanism for the developmental stage-dependent change in thermotolerance is considered to be the accumulation of antioxidants in embryos in response to heat-inducible production of reactive oxygen species. The supplementation of antioxidants to the culture media has been known to neutralize the detrimental effects of heat stress. Besides, EGA could be involved in acquisition of thermotolerance in later stages of embryos. Morulae or blastocysts can repair heat-induced unfolded proteins or prevent DNA damage occurring in processes such as apoptosis. Therefore, embryo transfer (ET) that can bypass the heat-sensitive stage could be a good solution to improve the pregnancy rate under heat stress. However, frozen-thawed ET could not improve the pregnancy rate as expected. Frozen-thawed blastocysts were more sensitive to heat stress and showed less proliferation upon heat exposure, compared to fresh blastocysts. Therefore, further research is required to improve the reduction in pregnancy rates due to summer heat stress. PMID:28496018

Effects of heat stress on bovine preimplantation embryos produced in vitro.

PubMed

Sakatani, Miki

2017-08-19

Summer heat stress decreases the pregnancy rate in cattle and has been thought to be associated with the early embryonic death caused by the elevation of maternal body temperature. In vitro cultures have been widely used for the evaluation of effects of heat stress on oocytes, fertilization, preimplantation, and embryonic development. Susceptibility to heat stress is present in developmental stages from oocytes to cleavage-stage (before embryonic gene activation, EGA) embryos, leading to a consequent decrease in developmental competence. On the other hand, advanced-stage embryos such as morula or blastocysts have acquired thermotolerance. The mechanism for the developmental stage-dependent change in thermotolerance is considered to be the accumulation of antioxidants in embryos in response to heat-inducible production of reactive oxygen species. The supplementation of antioxidants to the culture media has been known to neutralize the detrimental effects of heat stress. Besides, EGA could be involved in acquisition of thermotolerance in later stages of embryos. Morulae or blastocysts can repair heat-induced unfolded proteins or prevent DNA damage occurring in processes such as apoptosis. Therefore, embryo transfer (ET) that can bypass the heat-sensitive stage could be a good solution to improve the pregnancy rate under heat stress. However, frozen-thawed ET could not improve the pregnancy rate as expected. Frozen-thawed blastocysts were more sensitive to heat stress and showed less proliferation upon heat exposure, compared to fresh blastocysts. Therefore, further research is required to improve the reduction in pregnancy rates due to summer heat stress.

Use of monoclonal antibodies developed against chicken coccidia (Eimeria) to study invasion and development of Eimeria reichenowi in Florida sandhill cranes (Grus canadensis).

PubMed

Augustine, P; Olsen, G; Danforth, H; Gee, G; Novilla, M

2001-03-01

Eimeria gruis and Eimeria reichenowi are common coccidial parasites of a number of species of cranes. Until recently, little was known about either the site for invasion or the dynamics of early development of the crane coccidia because of the difficulty of identifying sporozoites and early developmental stages of these parasites by conventional staining methods. In the present study, monoclonal antibodies (MAbs) elicited against Eimeria spp. of chickens and turkeys were found to cross-react with sporozoites and developmental stages of E. reichenowi in the tissues of Florida sandhill cranes (Grus canadensis). With these Mabs, E. reichenowi sporozoites were found in specimens taken at 6 hr postinoculation (PI) from just proximal to Meckel's diverticulum in the jejunum to the ileocecal juncture. Fewer were found in the ceca and rectum and none in the duodenal loop. At 24 hr PI, there were markedly fewer sporozoites and their location had shifted to the duodenum. No stages were seen in intestinal cells at 5 days PI (DPI), but trophozoites had developed in the liver and spleen. At 10 DPI, sexual stages were detected in the intestine from the duodenal loop through Meckel's diverticulum but not in other organs. By 14 DPI, numerous developmental stages were detected in the intestine (ceca and jejunum), liver, and lungs but not in the heart, kidney, or brain. The number, location, and maturity of the stages in the ceca differed markedly from those in the jejunum.

Use of monoclonal antibodies developed against chicken coccidia (Eimeria) to study invasion and development of Eimeria reichenowi in Florida sandhill cranes (Grus canadensis)

USGS Publications Warehouse

Augustine, P.C.; Olsen, Glenn H.; Danforth, H.D.; Gee, G.F.; Novilla, M.

2001-01-01

Eimeria gruis and Eimeria reichenowi are common coccidial parasites of a number of species of cranes. Until recently, little was known about either the site for invasion or the dynamics of early development of the crane coccidia because of the difficulty of identifying sporozoites and early developmental stages of these parasites by conventional staining methods. In the present study, monoclonal antibodies (MAbs) elicited against Eimeria spp. of chickens and turkeys were found to cross-react with sporozoites and developmental stages of E. reichenowi in the tissues of Florida sandhill cranes (Grus canadensis). With these Mabs, E. reichenowi sporozoites were found in specimens taken at 6 hr postinoculation (PI) from just proximal to Meckel's diverticulum in the jejunum to the ileocecal juncture. Fewer were found in the ceca and rectum and none in the duodenal loop. At 24 hr PI, there were markedly fewer sporozoites and their location had shifted to the duodenum. No stages were seen in intestinal cells at 5 days PI (DPI), but trophozoites had developed in the liver and spleen. At 10 DPI, sexual stages were detected in the intestine from the duodenal loop through Meckel's diverticulum but not in other organs. By 14 DPI, numerous developmental stages were detected in the intestine (ceca and jejunum), liver, and lungs but not in the heart, kidney, or brain. The number, location, and maturity of the stages in the ceca differed markedly from those in the jejunum.

Simulated developmental and reproductive impacts on amphibian populations and implications for assessing long-term effects

EPA Science Inventory

Fish endpoints measured in early life stage toxicity tests are often used as representative of larval amphibian sensitivity in Ecological Risk Assessment (ERA). This application potentially overlooks the impact of developmental delays on amphibian metamorphosis, and thereby red...

Characterization of Guinea Pig Antibody Responses to Salivary Proteins of Triatoma infestans for the Development of a Triatomine Exposure Marker

PubMed Central

Dorňáková, Veronika; Salazar-Sanchez, Renzo; Borrini-Mayori, Katty; Carrion-Navarro, Oscar; Levy, Michael Z.; Schaub, Günter A.; Schwarz, Alexandra

2014-01-01

Background Salivary proteins of Triatoma infestans elicit humoral immune responses in their vertebrate hosts. These immune responses indicate exposure to triatomines and thus can be a useful epidemiological tool to estimate triatomine infestation. In the present study, we analyzed antibody responses of guinea pigs to salivary antigens of different developmental stages of four T. infestans strains originating from domestic and/or peridomestic habitats in Argentina, Bolivia, Chile and Peru. We aimed to identify developmental stage- and strain-specific salivary antigens as potential markers of T. infestans exposure. Methodology and Principal Findings In SDS-PAGE analysis of salivary proteins of T. infestans the banding pattern differed between developmental stages and strains of triatomines. Phenograms constructed from the salivary profiles separated nymphal instars, especially the 5th instar, from adults. To analyze the influence of stage- and strain-specific differences in T. infestans saliva on the antibody response of guinea pigs, twenty-one guinea pigs were exposed to 5th instar nymphs and/or adults of different T. infestans strains. Western blot analyses using sera of exposed guinea pigs revealed stage- and strain-specific variations in the humoral response of animals. In total, 27 and 17 different salivary proteins reacted with guinea pig sera using IgG and IgM antibodies, respectively. Despite all variations of recognized salivary antigens, an antigen of 35 kDa reacted with sera of almost all challenged guinea pigs. Conclusion Salivary antigens are increasingly considered as an epidemiological tool to measure exposure to hematophagous arthropods, but developmental stage- and strain-specific variations in the saliva composition and the respective differences of immunogenicity are often neglected. Thus, the development of a triatomine exposure marker for surveillance studies after triatomine control campaigns requires detailed investigations. Our study resulted in the identification of a potential antigen as useful marker of T. infestans exposure. PMID:24699441

l-Ergothioneine improves the developmental potential of in vitro sheep embryos without influencing OCTN1-mediated cross-membrane transcript expression.

PubMed

Mishra, A; Reddy, I J; Dhali, A; Javvaji, P K

2018-04-02

SummaryThe objective of the study was to investigate the effect of l-ergothioneine (l-erg) (5 mM or 10 mM) supplementation in maturation medium on the developmental potential and OCTN1-dependant l-erg-mediated (10 mM) change in mRNA abundance of apoptotic (Bcl2, Bax, Casp3 and PCNA) and antioxidant (GPx, SOD1, SOD2 and CAT) genes in sheep oocytes and developmental stages of embryos produced in vitro. Oocytes matured with l-erg (10 mM) reduced their embryo toxicity by decreasing intracellular ROS and increasing intracellular GSH in matured oocytes that in turn improved developmental potential, resulting in significantly (P < 0.05) higher percentages of cleavage (53.72% vs 38.86, 46.56%), morulae (34.36% vs 20.62, 25.84%) and blastocysts (14.83% vs 6.98, 9.26%) compared with other lower concentrations (0 mM and 5 mM) of l-erg without change in maturation rate. l-Erg (10 mM) treatment did not influence the mRNA abundance of the majority of apoptotic and antioxidant genes studied in the matured oocytes and developmental stages of embryo. A gene expression study found that the SLC22A4 gene that encodes OCTN1, an integral membrane protein and specific transporter of l-erg was not expressed in oocytes and developmental stages of embryos. Therefore it was concluded from the study that although there was improvement in the developmental potential of sheep embryos by l-erg supplementation in maturation medium, there was no change in the expression of the majority of the genes studied due to the absence of the SLC22A4 gene in oocytes and embryos that encode OCTN1, which is responsible for transportation of l-erg across the membrane to alter gene expression.

Hydrocephalus and arthrogryposis in an immunocompetent mouse model of ZIKA teratogeny: A developmental study

PubMed Central

Xavier-Neto, Jose; Carvalho, Murilo; Pascoalino, Bruno dos Santos; Cardoso, Alisson Campos; Costa, Ângela Maria Sousa; Pereira, Ana Helena Macedo; Santos, Luana Nunes; Saito, Ângela; Marques, Rafael Elias; Smetana, Juliana Helena Costa; Consonni, Silvio Roberto; Bandeira, Carla; Costa, Vivian Vasconcelos; Bajgelman, Marcio Chaim; de Oliveira, Paulo Sérgio Lopes; Cordeiro, Marli Tenorio; Gonzales Gil, Laura Helena Vega; Pauletti, Bianca Alves; Granato, Daniela Campos; Paes Leme, Adriana Franco; Freitas-Junior, Lucio; Holanda de Freitas, Carolina Borsoi Moraes; Teixeira, Mauro Martins; Bevilacqua, Estela; Franchini, Kleber

2017-01-01

The teratogenic mechanisms triggered by ZIKV are still obscure due to the lack of a suitable animal model. Here we present a mouse model of developmental disruption induced by ZIKV hematogenic infection. The model utilizes immunocompetent animals from wild-type FVB/NJ and C57BL/6J strains, providing a better analogy to the human condition than approaches involving immunodeficient, genetically modified animals, or direct ZIKV injection into the brain. When injected via the jugular vein into the blood of pregnant females harboring conceptuses from early gastrulation to organogenesis stages, akin to the human second and fifth week of pregnancy, ZIKV infects maternal tissues, placentas and embryos/fetuses. Early exposure to ZIKV at developmental day 5 (second week in humans) produced complex manifestations of anterior and posterior dysraphia and hydrocephalus, as well as severe malformations and delayed development in 10.5 days post-coitum (dpc) embryos. Exposure to the virus at 7.5–9.5 dpc induces intra-amniotic hemorrhage, widespread edema, and vascular rarefaction, often prominent in the cephalic region. At these stages, most affected embryos/fetuses displayed gross malformations and/or intrauterine growth restriction (IUGR), rather than isolated microcephaly. Disrupted conceptuses failed to achieve normal developmental landmarks and died in utero. Importantly, this is the only model so far to display dysraphia and hydrocephalus, the harbinger of microcephaly in humans, as well as arthrogryposis, a set of abnormal joint postures observed in the human setting. Late exposure to ZIKV at 12.5 dpc failed to produce noticeable malformations. We have thus characterized a developmental window of opportunity for ZIKV-induced teratogenesis encompassing early gastrulation, neurulation and early organogenesis stages. This should not, however, be interpreted as evidence for any safe developmental windows for ZIKV exposure. Late developmental abnormalities correlated with damage to the placenta, particularly to the labyrinthine layer, suggesting that circulatory changes are integral to the altered phenotypes. PMID:28231241

Psychiatric/mental health nursing.

PubMed

DeSalvo Rankin, E A

1986-09-01

From a historical perspective, psychiatric/mental health nursing as a specialized area of practice is in its early developmental stages. Within the discipline of nursing and on the interdisciplinary scene, the range and scope of actions of the psychiatric/mental health specialists is still being debated. Professional roles and responsibilities are somewhat blurred. But the role is expanding. Contemporary psychiatric nursing practice has moved to a position of collegial support among the disciplines with shared responsibility. The attitudes of society, of the nursing profession, and of the health care providers will continue to influence the maturation process of the psychiatric/mental health nursing specialty.

Sensitivity of hiPSC-derived neural stem cells (NSC) to Pyrroloquinoline quinone depends on their developmental stage.

PubMed

Augustyniak, J; Lenart, J; Zychowicz, M; Lipka, G; Gaj, P; Kolanowska, M; Stepien, P P; Buzanska, L

2017-12-01

Pyrroloquinoline quinone (PQQ) is a factor influencing on the mitochondrial biogenesis. In this study the PQQ effect on viability, total cell number, antioxidant capacity, mitochondrial biogenesis and differentiation potential was investigated in human induced Pluripotent Stem Cells (iPSC) - derived: neural stem cells (NSC), early neural progenitors (eNP) and neural progenitors (NP). Here we demonstrated that sensitivity to PQQ is dependent upon its dose and neural stage of development. Induction of the mitochondrial biogenesis by PQQ at three stages of neural differentiation was evaluated at mtDNA, mRNA and protein level. Changes in NRF1, TFAM and PPARGC1A gene expression were observed at all developmental stages, but only at eNP were correlated with the statistically significant increase in the mtDNA copy numbers and enhancement of SDHA, COX-1 protein level. Thus, the "developmental window" of eNP for PQQ-evoked mitochondrial biogenesis is proposed. This effect was independent of high antioxidant capacity of PQQ, which was confirmed in all tested cell populations, regardless of the stage of hiPSC neural differentiation. Furthermore, a strong induction of GFAP, with down regulation of MAP2 gene expression upon PQQ treatment was observed. This indicates a possibility of shifting the balance of cell differentiation in the favor of astroglia, but more research is needed at this point. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Four Stage Approach to Early Childhood Intervention.

ERIC Educational Resources Information Center

Haber, Julian S.

This paper describes a model for the involvement of primary health care personnel in the identification and treatment of developmental disabilities as a part of early childhood intervention programs. The integrated multidisciplinary model is divided into four stages. During the first stage an assignment of prenatal, perinatal, and postnatal risk…

Developmental Play Stages in Child Identity Construction: An Interactionist Theoretical Contribution.

ERIC Educational Resources Information Center

Berg, Lars-Erik

1999-01-01

Presents a theory of child-development stages that reflects the relationship between children's play and the need to create a personal identity. Considers the relationship between socializing play and individuation, and defines four stages of identity development through play: amorphous, play, games, and generalization and maturity. (JPB)

Kohlberg and Piaget on Stages and Moral Reasoning.

ERIC Educational Resources Information Center

Carpendale, Jeremy I. M.

2000-01-01

Maintains that although Kohlberg emphasized the importance of perspective taking in moral reasoning, his view of developmental stages is inconsistent with this position. Argues that a modification of Kohlberg's conception of stages drawing on Piagetian theory would result in a view of moral reasoning as a process of coordinating all perspectives…

Expressed Sequence Reference Standards for Evaluating Stage-specific Gene Expression in Southern Green Lacewings, Chrysoperla rufilabris

USDA-ARS?s Scientific Manuscript database

Five developmental stages of Chrysoperla rufilabris were tested using nine primer pairs. Three sequences were highly expressed at all life stages and six were differentially expressed. These primer pairs may be used as standards to quantitate functional gene expression associated with physiological ...

Freud's Psychosexual Stage Conception: A Developmental Metaphor for Counselors.

ERIC Educational Resources Information Center

Garcia, John L.

1995-01-01

Conceptualizes the counseling process and its outcome by comparing it metaphorically to Freud's psychosexual stage conception of personality development. Focuses on resemblances between oral, anal, phallic, latency, and genital stages. New meanings can be drawn from these resemblances, leading to fresh insight into the counseling relationship.…

Correlation between chronological age and third molar developmental stages in an Iranian population (Demirjian method)

PubMed Central

Khosronejad, Aria; Navabi, Manijeh; Sakhdari, Shirin; Rakhshan, Vahid

2017-01-01

Background: Third molar development is the only available tool for estimating the age of individuals after puberty. Since this tooth has very high interethnic variability, formulas calculated to estimate the age from its development stages cannot be generalized to other populations and should be adjusted for each region. Therefore, this study was conducted to evaluate this method in a sample of Tehran individuals for the first time, and also to compare the development of third molars across sexes and arches, and to estimate cutoff developmental stages for legal minor/major identification. Materials and Methods: A total of 150 dental patients aged between 15 and 25 years old were prospectively enrolled, and their Demirjian stages were recorded. The associations between chronological age and Demirjian stages were evaluated. Dental formation was compared between sexes and jaws. Cutoff stages were determined to identify legal minor/major cases (above or below 18 years old). Age estimation formula was found for this population. Results: Of the 150 included patients, 56 were males. The difference between the ages of males and females at each given developmental stage was nonsignificant (P > 0.05), except for the H stage. Age difference between same stage teeth of the maxilla and mandible was nonsignificant. Each of the G and H stages was significantly above 18 years old (P < 0.001). Furthermore, E and F stages were below 18 years old (P < 0.001). All the correlations between Demirjian stages and age were above 90% (all P < 0.001). Third molar development was positively affected by the chronological age (P = 0.000) and being maxillary (P = 0.000) but not sex (P = 0.113). Regression formula for age estimation was: age = 6.52+ (0.64 × sex) + (0.32 × arch) + (1.86 × Demirjian stage). Conclusion: Development of third molar might complete after the age 22. Iranian individuals with third molars at the G and H stages are likely above 18 while those at E and F are likely below 18. Pace of molar development differs for jaws, but intergender differences are open to further investigations. PMID:28584539

Correlation between chronological age and third molar developmental stages in an Iranian population (Demirjian method).

PubMed

Khosronejad, Aria; Navabi, Manijeh; Sakhdari, Shirin; Rakhshan, Vahid

2017-01-01

Third molar development is the only available tool for estimating the age of individuals after puberty. Since this tooth has very high interethnic variability, formulas calculated to estimate the age from its development stages cannot be generalized to other populations and should be adjusted for each region. Therefore, this study was conducted to evaluate this method in a sample of Tehran individuals for the first time, and also to compare the development of third molars across sexes and arches, and to estimate cutoff developmental stages for legal minor/major identification. A total of 150 dental patients aged between 15 and 25 years old were prospectively enrolled, and their Demirjian stages were recorded. The associations between chronological age and Demirjian stages were evaluated. Dental formation was compared between sexes and jaws. Cutoff stages were determined to identify legal minor/major cases (above or below 18 years old). Age estimation formula was found for this population. Of the 150 included patients, 56 were males. The difference between the ages of males and females at each given developmental stage was nonsignificant ( P > 0.05), except for the H stage. Age difference between same stage teeth of the maxilla and mandible was nonsignificant. Each of the G and H stages was significantly above 18 years old ( P < 0.001). Furthermore, E and F stages were below 18 years old ( P < 0.001). All the correlations between Demirjian stages and age were above 90% (all P < 0.001). Third molar development was positively affected by the chronological age ( P = 0.000) and being maxillary ( P = 0.000) but not sex ( P = 0.113). Regression formula for age estimation was: age = 6.52+ (0.64 × sex) + (0.32 × arch) + (1.86 × Demirjian stage). Development of third molar might complete after the age 22. Iranian individuals with third molars at the G and H stages are likely above 18 while those at E and F are likely below 18. Pace of molar development differs for jaws, but intergender differences are open to further investigations.

Moral Education and the Perils of Developmentalism.

ERIC Educational Resources Information Center

Carr, David

2002-01-01

Discusses conception of moral formation. Traces progress to moral maturity through well defined stages of cognitive, conative, and/or affective growth. Explains that logical status of developmental theories are not clear. Argues that the accounts are more evaluative than descriptive. Explores the problematic moral educational implications of this…

The Socialization Process of Student Teachers: A Descriptive Study.

ERIC Educational Resources Information Center

Piland, Diane E.

This study used a triangulated methodology involving ethnographic interviews, opinionnaires, and rank ordering of student concerns to discover variables that impacted student teachers as they passed through developmental stages. Data collected from interviews with five elementary student teachers were used to discover a developmental theory of…

Interpersonal Cognitive Distortions and Stress Coping Strategies of Laate Adolescents

ERIC Educational Resources Information Center

Coban, Aysel Esen

2013-01-01

Problem Statement: Adolescence is a stage of major growth and development in terms of significant cognitive, behavioral, psychological, and physiological changes. For adolescents, these developmental changes could be accompanied by stressful situations. Adolescents need to cope with these stressors successfully, yet the developmental period of…

Exposure to suboptimal temperatures during metamorphosis reveals a critical developmental window in the solitary bee, Megachile rotundata

USDA-ARS?s Scientific Manuscript database

Metamorphosis is an important developmental stage for holometabolous insects, during which adult morphology and physiology are established. Proper development relies on optimal body temperatures, and natural ambient temperature (Ta) fluctuations, especially in spring or in northern latitudes, could ...

Early Speech Motor Development: Cognitive and Linguistic Considerations

ERIC Educational Resources Information Center

Nip, Ignatius S. B.; Green, Jordan R.; Marx, David B.

2009-01-01

This longitudinal investigation examines developmental changes in orofacial movements occurring during the early stages of communication development. The goals were to identify developmental trends in early speech motor performance and to determine how these trends differ across orofacial behaviors thought to vary in cognitive and linguistic…

Exposure of a Dengue Vector to Tea and Its Waste: Survival, Developmental Consequences, and Significance for Pest Management.

PubMed

Dieng, Hamady; Tan Yusop, Nur Syafiqah Bt; Kamal, Nurafidah Natasyah Bt; Ahmad, Abu Hassan; Ghani, Idris Abd; Abang, Fatimah; Satho, Tomomitsu; Ahmad, Hamdan; Zuharah, Wan Fatma; Majid, Abdul Hafiz Ab; Morales, Ronald E; Morales, Noppawan P; Hipolito, Cirilo N; Noweg, Gabriel Tonga

2016-05-11

Dengue mosquitoes are evolving into a broader global public health menace, with relentless outbreaks and the rise in number of Zika virus disease cases as reminders of the continued hazard associated with Aedes vectors. The use of chemical insecticides-the principal strategy against mosquito vectors-has been greatly impeded due to the development of insecticide resistance and the shrinking spectrum of effective agents. Therefore, there is a pressing need for new chemistries for vector control. Tea contains hundreds of chemicals, and its waste, which has become a growing global environmental problem, is almost as rich in toxicants as green leaves. This paper presents the toxic and sublethal effects of different crude extracts of tea on Aedes albopictus. The survival rates of larvae exposed to tea extracts, especially fresh tea extract (FTE), were markedly lower than those in the control treatment group. In addition to this immediate toxicity against different developmental stages, the extracts tested caused a broad range of sublethal effects. The developmental time was clearly longer in containers with tea, especially in those with young larvae (YL) and FTE. Among the survivors, pupation success was reduced in containers with tea, which also produced low adult emergence rates with increasing tea concentration. The production of eggs tended to be reduced in females derived from the tea treatment groups. These indirect effects of tea extracts on Ae. albopictus exhibited different patterns according to the exposed larval stage. Taken together, these findings indicate that tea and its waste affect most key components of Ae. albopictus vectorial capacity and may be useful for dengue control. Reusing tea waste in vector control could also be a practical solution to the problems associated with its pollution.

Thermotolerance and Heat-Shock Protein Gene Expression Patterns in Bemisia tabaci (Hemiptera: Aleyrodidae) Mediterranean in Relation to Developmental Stage.

PubMed

Jiang, Rui; Qi, Lan-Da; Du, Yu-Zhou; Li, Yuan-Xi

2017-10-01

Temperature plays an important role in the growth, development, and geographic distribution of insects. There is convincing evidence that heat-shock proteins (HSPs) play important roles in helping organisms adapt to thermal stress. To better understand the physiological and ecological influence of thermal stress on the different development stages of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Mediterranean species (MED), nymphs and adults were shocked with temperatures of 35, 38, and 41℃ for 1 and 2 h, respectively, and the survival rate, fecundity, and developmental duration were investigated in the laboratory. The expression levels of the hsp40, hsp70, and hsp90 genes were assessed using real-time PCR. The results indicate that the survival rates of the nymphs and adults decreased with increased temperature. A 2-h heat shock at 41℃ induced a significant reduction in fecundity in adults and an increase in developmental duration in young nymphs. Hsp90 showed higher temperature responses to thermal stress than hsp40 or hsp70. The expression levels of the hsps in the adults were significantly down-regulated by a 2-h heat shock at 41℃ compared with that by a 1-h treatment. A significant decrease in the expression levels of the hsps also occurred in the adults when the temperature increased from 38 to 41℃ for the 2-h treatment, whereas no significant decrease occurred in the nymphs. Compared with previous studies, we provide some evidence indicating that MED has the potential to adapt to a wider temperature range than the Middle East-Asia Minor 1 species. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Amyloid Precursor Protein 96–110 and β-Amyloid 1–42 Elicit Developmental Anomalies in Sea Urchin Embryos and Larvae that are Alleviated by Neurotransmitter Analogs for Acetylcholine, Serotonin and Cannabinoids

PubMed Central

Buznikov, Gennady A.; Nikitina, Lyudmila A.; Seidler, Frederic J.; Slotkin, Theodore A.; Bezuglov, Vladimir V.; Milošević, Ivan; Lazarević, Lidija; Rogač, Ljubica; Ruzdijić, Sabera; Rakić, Ljubiša M.

2008-01-01

Amyloid precursor protein (APP) is overexpressed in the developing brain and portions of its extracellular domain, especially amino acid residues 96–110, play an important role in neurite outgrowth and neural cell differentiation. In the current study, we evaluated the developmental abnormalities caused by administration of exogenous APP96–110 in sea urchin embryos and larvae, which, like the developing mammalian brain, utilize acetylcholine and other neurotransmitters as morphogens; effects were compared to those of β-amyloid 1–42 (Aβ42), the neurotoxic APP fragment contained within neurodegenerative plaques in Alzheimer’s Disease. Although both peptides elicited dysmorphogenesis, Aβ42 was far more potent; in addition, whereas Aβ42 produced abnormalities at developmental stages ranging from early cleavage divisions to the late pluteus, APP96–110 effects were restricted to the intermediate, mid-blastula stage. For both agents, anomalies were prevented or reduced by addition of lipid-permeable analogs of acetylcholine, serotonin or cannabinoids; physostigmine, a carbamate-derived cholinesterase inhibitor, was also effective. In contrast, agents that act on NMDA receptors (memantine) or α-adrenergic receptors (nicergoline), and that are therapeutic in Alzheimer’s Disease, were themselves embryotoxic, as was tacrine, a cholinesterase inhibitor from a different chemical class than physostigmine. Protection was also provided by agents acting downstream from receptor-mediated events: increasing cyclic AMP with caffeine or isobutylmethylxanthine, or administering the antioxidant, α-tocopherol, were all partially effective. Our findings reinforce a role for APP in development and point to specific interactions with neurotransmitter systems that act as morphogens in developing sea urchins as well as in the mammalian brain. PMID:18565728

Effects of temperature on Anoplophora glabripennis (Coleoptera: Cerambycidae) larvae and pupae.

PubMed

Keena, M A; Moore, P M

2010-08-01

Developmental thresholds, degree-days for development, larval weights, and head capsule widths for each larval instar and the pupal stage of Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) were studied at eight constant temperatures (5, 10, 15, 20, 25, 30, 35, and 40°C) for two source populations (Ravenswood, Chicago, IL [IL], and Bayside, Queens, NY [NY]). The estimated lower threshold temperature for development of instars 1-5 and the pupal stage was near 10°C and was near 12°C for the higher instars. Developmental rate was less temperature sensitive for instars 5-9 compared with instars 1-4. Development for all but the first instar was inhibited at constant temperatures >30°C, and all instars failed to develop at 40°C. Although the two source populations had similar responses to temperature, IL larvae were heavier than those from NY. Temperature and its influence on larval weight had profound impacts on whether a larva proceeded to pupation. Based on the temperature effects detailed here, larval development and pupation should be possible in most of the continental United States where suitable hosts are available. These data can be used to develop a degree-day model to estimate beetle phenology; however, at least 2°C should be added to air temperatures to adjust for the mediation of temperature by the wood. These data provide a basis for predicting the potential geographical range of this species and for developing phenological models to predict the timing of immature stages, both of which are important for management programs.

Intraspecific variation in the metabolic scaling exponent in ectotherms: testing the effect of latitudinal cline, ontogeny and transgenerational change in the land snail Cornu aspersum.

PubMed

Gaitán-Espitia, Juan Diego; Bruning, Andrea; Mondaca, Fredy; Nespolo, Roberto F

2013-06-01

The strong dependence of metabolic rates on body mass has attracted the interest of ecological physiologists, as it has important implications to many aspects of biology including species variations in body size, the evolution of life history, and the structure and function of biological communities. The great diversity of observed scaling exponents has led some authors to conclude that there is no single universal scaling exponent, but instead it ranges from 2/3 to 1. Most of the telling evidence against the universality of power scaling exponents comes from ontogenetic changes. Nevertheless, there could be other sources of phenotypic variation that influence this allometric relationship at least at the intraspecific level. In order to explore the general concept of the metabolic scaling in terrestrial molluscs we tested the role of several biological and methodological sources of variation on the empirically estimated scaling exponent. Specifically, we measured a proxy of metabolic rate (CO(2) production) in 421 individuals, during three generations, in three different populations. Additionally, we measured this scaling relationship in 208 individuals at five developmental stages. Our results suggest that the metabolic scaling exponent at the intraspecific level does not have a single stationary value, but instead it shows some degree of variation across geographic distribution, transgenerational change and ontogenetic stages. The major differences in the metabolic scaling exponent that we found were at different developmental stages of snails, because ontogeny involves increases in size at different rates, which in turn, generate differential energy demands. Copyright © 2013 Elsevier Inc. All rights reserved.

Current and emerging screening methods to identify post-head-emergence frost adaptation in wheat and barley.

PubMed

Frederiks, T M; Christopher, J T; Harvey, G L; Sutherland, M W; Borrell, A K

2012-09-01

Cereal crops can suffer substantial damage if frosts occur at heading. Identification of post-head-emergence frost (PHEF) resistance in cereals poses a number of unique and difficult challenges. Many decades of research have failed to identify genotypes with PHEF resistance that could offer economically significant benefit to growers. Research and breeding gains have been limited by the available screening systems. Using traditional frost screening systems, genotypes that escape frost injury in trials due to spatial temperature differences and/or small differences in phenology can be misidentified as resistant. We believe that by improving techniques to minimize frost escapes, such 'false-positive' results can be confidently identified and eliminated. Artificial freezing chambers or manipulated natural frost treatments offer many potential advantages but are not yet at the stage where they can be reliably used for frost screening in breeding programmes. Here we describe the development of a novel photoperiod gradient method (PGM) that facilitates screening of genotypes of different phenology under natural field frosts at matched developmental stages. By identifying frost escapes and increasing the efficiency of field screening, the PGM ensures that research effort can be focused on finding genotypes with improved PHEF resistance. To maximize the likelihood of identifying PHEF resistance, we propose that the PGM form part of an integrated strategy to (i) source germplasm;(ii) facilitate high throughput screening; and (iii) permit detailed validation. PGM may also be useful in other studies where either a range of developmental stages and/or synchronized development are desired.

Young Love: Romantic Concerns and Associated Mental Health Issues among Adolescent Help-Seekers

PubMed Central

Price, Megan; Hides, Leanne; Cockshaw, Wendell; Staneva, Aleksandra A.; Stoyanov, Stoyan R.

2016-01-01

Over 50% of young people have dated by age 15. While romantic relationship concerns are a major reason for adolescent help-seeking from counselling services, we have a limited understanding of what types of relationship issues are most strongly related to mental health issues and suicide risk. This paper used records of 4019 counselling sessions with adolescents (10–18 years) seeking help from a national youth counselling service for a romantic relationship concern to: (i) explore what types and stage (pre, during, post) of romantic concerns adolescents seek help for; (ii) how they are associated with mental health problems, self-harm and suicide risk; and (iii) whether these associations differ by age and gender. In line with developmental-contextual theory, results suggest that concerns about the initiation of relationships are common in early adolescence, while concerns about maintaining and repairing relationships increase with age. Relationship breakups were the most common concern for both male and female adolescents and for all age groups (early, mid, late adolescence). Data relating to a range of mental health issues were available for approximately half of the sample. Post-relationship concerns (including breakups) were also more likely than pre- or during-relationship concerns to be associated with concurrent mental health issues (36.8%), self-harm (22.6%) and suicide (9.9%). Results draw on a staged developmental theory of adolescent romantic relationships to provide a comprehensive assessment of relationship stressors, highlighting post-relationship as a particularly vulnerable time for all stages of adolescence. These findings contribute to the development of targeted intervention and support programs. PMID:27164149

Young Love: Romantic Concerns and Associated Mental Health Issues among Adolescent Help-Seekers.

PubMed

Price, Megan; Hides, Leanne; Cockshaw, Wendell; Staneva, Aleksandra A; Stoyanov, Stoyan R

2016-05-06

Over 50% of young people have dated by age 15. While romantic relationship concerns are a major reason for adolescent help-seeking from counselling services, we have a limited understanding of what types of relationship issues are most strongly related to mental health issues and suicide risk. This paper used records of 4019 counselling sessions with adolescents (10-18 years) seeking help from a national youth counselling service for a romantic relationship concern to: (i) explore what types and stage (pre, during, post) of romantic concerns adolescents seek help for; (ii) how they are associated with mental health problems, self-harm and suicide risk; and (iii) whether these associations differ by age and gender. In line with developmental-contextual theory, results suggest that concerns about the initiation of relationships are common in early adolescence, while concerns about maintaining and repairing relationships increase with age. Relationship breakups were the most common concern for both male and female adolescents and for all age groups (early, mid, late adolescence). Data relating to a range of mental health issues were available for approximately half of the sample. Post-relationship concerns (including breakups) were also more likely than pre- or during-relationship concerns to be associated with concurrent mental health issues (36.8%), self-harm (22.6%) and suicide (9.9%). Results draw on a staged developmental theory of adolescent romantic relationships to provide a comprehensive assessment of relationship stressors, highlighting post-relationship as a particularly vulnerable time for all stages of adolescence. These findings contribute to the development of targeted intervention and support programs.

Parental perceptions of technology and technology-focused parenting: Associations with youth screen time

PubMed Central

Sanders, Wesley; Parent, Justin; Forehand, Rex; Sullivan, Alexandra D.W.; Jones, Deborah J.

2016-01-01

In the present study we propose a model linking parental perceptions of technology to technology-related parenting strategies to youth screen time, and, finally, to internalizing and externalizing problem behaviors. Participants were 615 parents drawn from three community samples of families with children across three developmental stages: young childhood, middle childhood, and adolescence. The model was tested at each stage with the strongest support emerging in the young childhood sample. One component of parental perceptions of technology, perceived efficacy, was related to technology-related parenting strategies across developmental stages. However, the association of these strategies to child screen time and, in turn, problem behaviors, diminished as children increased in age. Implications for intervention are considered. PMID:27795603

Integration of tomato reproductive developmental landmarks and expression profiles, and the effect of SUN on fruit shape

PubMed Central

Xiao, Han; Radovich, Cheryll; Welty, Nicholas; Hsu, Jason; Li, Dongmei; Meulia, Tea; van der Knaap, Esther

2009-01-01

Background Universally accepted landmark stages are necessary to highlight key events in plant reproductive development and to facilitate comparisons among species. Domestication and selection of tomato resulted in many varieties that differ in fruit shape and size. This diversity is useful to unravel underlying molecular and developmental mechanisms that control organ morphology and patterning. The tomato fruit shape gene SUN controls fruit elongation. The most dramatic effect of SUN on fruit shape occurs after pollination and fertilization although a detailed investigation into the timing of the fruit shape change as well as gene expression profiles during critical developmental stages has not been conducted. Results We provide a description of floral and fruit development in a red-fruited closely related wild relative of tomato, Solanum pimpinellifolium accession LA1589. We use established and propose new floral and fruit landmarks to present a framework for tomato developmental studies. In addition, gene expression profiles of three key stages in floral and fruit development are presented, namely floral buds 10 days before anthesis (floral landmark 7), anthesis-stage flowers (floral landmark 10 and fruit landmark 1), and 5 days post anthesis fruit (fruit landmark 3). To demonstrate the utility of the landmarks, we characterize the tomato shape gene SUN in fruit development. SUN controls fruit shape predominantly after fertilization and its effect reaches a maximum at 8 days post-anthesis coinciding with fruit landmark 4 representing the globular embryo stage of seed development. The expression profiles of the NILs that differ at sun show that only 34 genes were differentially expressed and most of them at a less than 2-fold difference. Conclusion The landmarks for flower and fruit development in tomato were outlined and integrated with the effect of SUN on fruit shape. Although we did not identify many genes differentially expressed in the NILs that differ at the sun locus, higher or lower transcript levels for many genes involved in phytohormone biosynthesis or signaling as well as organ identity and patterning of tomato fruit were found between developmental time points. PMID:19422692

Embryonic lethality is not sufficient to explain hourglass-like conservation of vertebrate embryos.

PubMed

Uchida, Yui; Uesaka, Masahiro; Yamamoto, Takayoshi; Takeda, Hiroyuki; Irie, Naoki

2018-01-01

Understanding the general trends in developmental changes during animal evolution, which are often associated with morphological diversification, has long been a central issue in evolutionary developmental biology. Recent comparative transcriptomic studies revealed that gene expression profiles of mid-embryonic period tend to be more evolutionarily conserved than those in earlier or later periods. While the hourglass-like divergence of developmental processes has been demonstrated in a variety of animal groups such as vertebrates, arthropods, and nematodes, the exact mechanism leading to this mid-embryonic conservation remains to be clarified. One possibility is that the mid-embryonic period (pharyngula period in vertebrates) is highly prone to embryonic lethality, and the resulting negative selections lead to evolutionary conservation of this phase. Here, we tested this "mid-embryonic lethality hypothesis" by measuring the rate of lethal phenotypes of three different species of vertebrate embryos subjected to two kinds of perturbations: transient perturbations and genetic mutations. By subjecting zebrafish ( Danio rerio ), African clawed frog ( Xenopus laevis ), and chicken ( Gallus gallus ) embryos to transient perturbations, namely heat shock and inhibitor treatments during three developmental periods [early (represented by blastula and gastrula), pharyngula, and late], we found that the early stages showed the highest rate of lethal phenotypes in all three species. This result was corroborated by perturbation with genetic mutations. By tracking the survival rate of wild-type embryos and embryos with genetic mutations induced by UV irradiation in zebrafish and African clawed frogs, we found that the highest decrease in survival rate was at the early stages particularly around gastrulation in both these species. In opposition to the "mid-embryonic lethality hypothesis," our results consistently showed that the stage with the highest lethality was not around the conserved pharyngula period, but rather around the early period in all the vertebrate species tested. These results suggest that negative selection by embryonic lethality could not explain hourglass-like conservation of animal embryos. This highlights the potential contribution of alternative mechanisms such as the diversifying effect of positive selections against earlier and later stages, and developmental constraints which lead to conservation of mid-embryonic stages.

Functional characterization of three MicroRNAs of the Asian Tiger Mosquito, Aedes albopictus

PubMed Central

2013-01-01

Background Temporal and stage specific expression of microRNAs (miRNAs) in embryos, larvae, pupae and adults of Aedes albopictus showed differential expression levels across the four developmental stages, indicating their potential regulatory roles in mosquito development. The functional characterization of these miRNAs was not known. Accordingly our study evaluated the functional characterization of three miRNAs, which are temporally up-regulated in the various developmental stages of Ae. albopictus mosquitoes. Methods miRNA mimics, inhibitors and negative controls were designed and their knock-in and knock-down efficiency were analyzed by qRT-PCR after transfecting the mosquito cell lines C6/36, and also by injecting in their specific developmental stages. The functional role of each individual miRNA was analyzed with various parameters of development such as, hatching rate and hatching time in embryos, eclosion rate in larvae, longevity and fecundity in the adult mosquitoes. Results The knock-in with the specifically designed miRNA mimics showed increased levels of expression of miRNA compared with their normal controls. We confirmed these findings using qRT-PCR, both by in vitro expression in C6/36 mosquito cell lines after transfection as well as in in vivo expression in developmental stages of mosquitoes by microinjection. The knock-down of expression with the corresponding inhibitors showed a considerable decrease in the expression levels of these miRNAs and obvious functional effects in Ae. albopictus development, detected by a decrease in the hatching rate of embryos and eclosion rate in larvae and a marked reduction in longevity and fecundity in adults. Conclusion This study carried out by knock-in and knock-down of specifically and temporally expressed miRNAs in Ae. albopictus by microinjection is a novel study to delineate the importance of the miRNA expression in regulating mosquito development. The knock-down and loss of function of endogenously expressed miRNAs by the miRNA inhibitors in specific developmental stages had considerable effects on development, but enhancement of their gain of function was not observed on knock-in of these specific miRNAs. Hence, our study indicates that an optimal level of endogenous expression of miRNA is indispensable for the normal development and maintenance of the vectorial population density and pathogen transmissibility of this mosquito vector. PMID:23924583

Correlation Between Mothers' Depression and Developmental Delay in Infants Aged 6-18 Months.

PubMed

Vameghi, Roshanak; Amir Ali Akbari, Sedigheh; Sajjadi, Homeira; Sajedi, Firoozeh; Alavimajd, Hamid

2015-08-23

Regarding the importance of children's developmental status and various factors that delay their development, this study was conducted to examine the correlation between mothers' depression levels and the developmental delay in infants. This descriptive study was performed on 1053 mothers and their infants' age 6 to18 month-old in medical centers affiliated with Shahid Beheshti University of Medical Sciences, Iran, in 2014-2015. The participants were selected through multi-stage random sampling. The following instruments were used in this study: A demographic and obstetric specification questionnaire, infant specification questionnaire, the Beck Depression Inventory, and the Ages and Stages Questionnaire to determine the status of the children's development. The data were analyzed using SPSS19 software, Mann-Whitney; independent T-test and logistic-Regression tests were used. The results showed that 491 mothers (46.7%) suffered mild to extremely severe depression. The delay in infant development was 11.8%. The Mann-Whitney test showed a correlation between mothers' depression levels and developmental delay in infants (P=0.001). Moreover, there was a significant correlation between mothers' depression and developmental delays in gross-motor and problem-solving skills (P<0/05). In logistic model age of infants showed significant correlation with developmental delay (P=0.004 OR=1.07), but unwanted pregnancy, gender of infants, type of delivery and socioeconomic status had no correlation with developmental delay. Given the correlation between mothers' depression and infant development, it is recommended to screen mothers for depression in order to perform early interventions in developmental delay.

Oxygen radical absorbance capacity of different varieties of strawberry and the antioxidant stability in storage.

PubMed

Li, Chunyang; Huang, Wu-Yang; Wang, Xing-Na; Liu, Wen-Xu

2013-01-25

Total antioxidant capacity of different varieties of strawberry (Ningfeng, Ningyu, Zijin 4, Toyonoka, Benihope, Sweet Charlie) in different developmental stages (including green unripe stages, half red stages, and red ripe stages) was investigated by oxygen radical absorbance capacity (ORAC) assay. In addition, effects of the antioxidant properties of strawberry stored at 4 °C or -18 °C for a period of five months were studied. The results showed that antioxidant capacity of strawberry changed based on tested part, developmental stage, variety, and time of collection. Calyces had significantly higher ORAC values compared with fruits. Strawberry fruits had higher ORAC values during the green unripe stages than the half red stages and red ripe stages. Strawberries got higher ORAC values during short-time storage, and then decreased during long-time storage. Samples stored at -18 °C exhibited higher antioxidant capacity than those stored at 4 °C, while vacuum treatment could further increase ORAC values. The results indicated the potential market role of strawberries as a functional food and could provide great value in preventing oxidation reaction in food processing and storage for the dietary industry.

Lettuce facing microcystins-rich irrigation water at different developmental stages: Effects on plant performance and microcystins bioaccumulation.

PubMed

Levizou, Efi; Statiris, George; Papadimitriou, Theodoti; Laspidou, Chrysi S; Kormas, Konstantinos Ar

2017-09-01

This study investigated the microcystins (MCs)-rich irrigation water effect on lettuce of different developmental stages, i.e. during a two months period, covering the whole period from seed germination to harvest at marketable size of the plant. We followed four lettuce plant groups receiving MCs-rich water (1.81μgl -1 of dissolved MCs), originating from the Karla Reservoir, central Greece: 1) from seeds, 2) the cotyledon, 3) two true leaves and 4) four true leaves stages, all of which were compared to control plants that received tap water. Lettuce growth, photosynthetic performance, biochemical and mineral characteristics, as well as MCs accumulation in leaves, roots and soil were measured. The overall performance of lettuce at various developmental stages pointed to increased tolerance since growth showed minor alterations and non-enzymatic antioxidants remained unaffected. Plants receiving MCs-rich water from the seed stage exhibited higher photosynthetic capacity, chlorophylls and leaf nitrogen content. Nevertheless, considerable MCs accumulation in various plant tissues occurred. The earlier in their development lettuce plants started receiving MCs-rich water, the more MCs they accumulated: roots and leaves of plants exposed to MCs-rich water from seeds and cotyledons stage exhibited doubled MCs concentrations compared to respective tissues of the 4 Leaves group. Furthermore, roots accumulated significantly higher MCs amounts than leaves of the same plant group. Concerning human health risk, the Estimated Daily Intake values (EDI) of Seed and Cotyledon groups leaves exceeded Tolerable Daily Intake (TDI) by a factor of 6, while 2 Leaves and 4 Leaves groups exceeded TDI by a factor of 4.4 and 2.4 respectively. Our results indicate that irrigation of lettuce with MCs-rich water may constitute a serious public health risk, especially when contaminated water is received from the very early developmental stages (seed and cotyledon). Finally, results obtained for the tolerant lettuce indicate that MCs bioaccumulation in edible tissues is not necessarily coupled with phytotoxic effects. Copyright © 2017 Elsevier Inc. All rights reserved.

Hierarchical structure of moral stages assessed by a sorting task.

PubMed

Boom, J; Brugman, D; van der Heijden, P G

2001-01-01

Following criticism of Kohlberg's theory of moral judgment, an empirical re-examination of hierarchical stage structure was desirable. Utilizing Piaget's concept of reflective abstraction as a basis, the hierarchical stage structure was investigated using a new method. Study participants (553 Dutch university students and 196 Russian high school students) sorted statements in terms of moral sophistication. These statements were typical for the different stages of moral development as defined in Colby and Kohlberg. The rank ordering performed by participants confirmed the hypotheses. First, despite large individual variation, the ordering of the statements that gave the best fit revealed that each consecutive Kohlbergian stage was perceived to be more morally sophisticated. Second, the lower the stage as represented by the items, the higher the agreement among the participants in their ranking; and the higher the stage as represented by the items, the lower the agreement among the participants in the rankings. Moreover, the pivotal point depended on the developmental characteristics of the sample, which demonstrated a developmental effect: The ordering of statements representative of moral stages below one's own current stage was straightforward, whereas the ordering of statements above one's own stage was difficult. It was concluded that the Piagetian idea of reflective abstraction can be used successfully to operationalize and measure the hierarchical nature of moral development.

MicroRNA-20a is essential for normal embryogenesis by targeting vsx1 mRNA in fish

PubMed Central

Sun, Lei; Li, Heng; Xu, Xiaofeng; Xiao, Guanxiu; Luo, Chen

2015-01-01

MicroRNAs are major post-transcriptional regulators of gene expression and have essential roles in diverse developmental processes. In vertebrates, some regulatory genes play different roles at different developmental stages. These genes are initially transcribed in a wide embryonic region but restricted within distinct cell types at subsequent stages during development. Therefore, post-transcriptional regulation is required for the transition from one developmental stage to the next and the establishment of different cell identities. However, the regulation of many multiple functional genes at post-transcription level during development remains unknown. Here we show that miR-20a can target the mRNA of vsx1, a multiple functional gene, at the 3′-UTR and inhibit protein expression in both goldfish and zebrafish. The expression of miR-20a is initiated ubiquitously at late gastrula stage and exhibits a tissue-specific pattern in the developing retina. Inhibition of vsx1 3′-UTR mediated protein expression occurs when and where miR-20a is expressed. Decoying miR-20a resulted in severely impaired head, eye and trunk formation in association with excessive generation of vsx1 marked neurons in the spinal cord and defects of somites in the mesoderm region. These results demonstrate that miR-20a is essential for normal embryogenesis by restricting Vsx1 expression in goldfish and zebrafish, and that post-transcriptional regulation is an essential mechanism for Vsx1 playing different roles in diverse developmental processes. PMID:25833418

Learning to BREATHE: An Intervention to Foster Mindfulness in Adolescence

ERIC Educational Resources Information Center

Broderick, Patricia C.; Frank, Jennifer L.

2014-01-01

During adolescence, young people are traversing exciting and also challenging stages in their development. Mindfulness, if taught in a developmentally appropriate way, has the potential to be an asset in adolescents' lives. Developmentally appropriate approaches of mindfulness intervention during adolescence need to consider adolescents'…

40 CFR 799.9630 - TSCA developmental neurotoxicity.

Code of Federal Regulations, 2010 CFR

2010-07-01

... exposure of the mother during pregnancy and lactation. (c) Principle of the test method. The test substance... section must be monitored as appropriate for the developmental stage being observed. (C) Any gross signs... motor activity are sound level, size and shape of the test cage, temperature, relative humidity, light...

40 CFR 799.9630 - TSCA developmental neurotoxicity.

Code of Federal Regulations, 2011 CFR

2011-07-01

... exposure of the mother during pregnancy and lactation. (c) Principle of the test method. The test substance... section must be monitored as appropriate for the developmental stage being observed. (C) Any gross signs... motor activity are sound level, size and shape of the test cage, temperature, relative humidity, light...

STAGE- AND SPECIES- SPECIFIC DEVELOPMENTAL TOXICITY OF ALL-TRANS RETINOIC ACID IN FOUR NATIVE NORTH AMERICAN RANIDS AND XENOPUS LAEVIS

EPA Science Inventory

Within the last decade there have been increasing reports of malformed amphibians across North America. Recently, it has been suggested that hindlimb malformations are a consequence of xenobiotic disruption of developmental pathways regulated by retinoids. To assess the validity ...

A Constructive Development Approach to Assessing Variations within a Community College Population

ERIC Educational Resources Information Center

Boyer, Timothy R.

2007-01-01

This study utilized a constructive-developmental approach to accomplish 3 purposes: to create a developmental stage profile for a population of students attending a single community college, to analyze variations within and between subpopulations, and to explore the implications for administrators and planners seeking to provide supportive…

Coaching Techniques and Play Therapy Responses: A New Communication Pattern

ERIC Educational Resources Information Center

Muro, Joel H.; Stulmaker, Hayley; Rose, Katherine Kensinger

2012-01-01

Understanding the developmental stages of children is crucial for coaches. Equally important is the way adults communicate with children. In his seminal work describing the influence of society and social interactions on the psychosocial development of children, Erikson (1950, 1963) described the developmental crises faced by children at each…

Music listening in families and peer groups: benefits for young people's social cohesion and emotional well-being across four cultures

PubMed Central

Boer, Diana; Abubakar, Amina

2014-01-01

Families are central to the social and emotional development of youth, and most families engage in musical activities together, such as listening to music or talking about their favorite songs. However, empirical evidence of the positive effects of musical family rituals on social cohesion and emotional well-being is scarce. Furthermore, the role of culture in the shaping of musical family rituals and their psychological benefits has been neglected entirely. This paper investigates musical rituals in families and in peer groups (as an important secondary socialization context) in two traditional/collectivistic and two secular/individualistic cultures, and across two developmental stages (adolescence vs. young adulthood). Based on cross-sectional data from 760 young people in Kenya, the Philippines, New Zealand, and Germany, our study revealed that across cultures music listening in families and in peer groups contributes to family and peer cohesion, respectively. Furthermore, the direct contribution of music in peer groups on well-being appears across cultural contexts, whereas musical family rituals affect emotional well-being in more traditional/collectivistic contexts. Developmental analyses show that musical family rituals are consistently and strongly related to family cohesion across developmental stages, whereas musical rituals in peer groups appear more dependent on the developmental stage (in interaction with culture). Contributing to developmental as well as cross-cultural psychology, this research elucidated musical rituals and their positive effects on the emotional and social development of young people across cultures. The implications for future research and family interventions are discussed. PMID:24847296

Developmental Progression in the Coral Acropora digitifera Is Controlled by Differential Expression of Distinct Regulatory Gene Networks

PubMed Central

Reyes-Bermudez, Alejandro; Villar-Briones, Alejandro; Ramirez-Portilla, Catalina; Hidaka, Michio; Mikheyev, Alexander S.

2016-01-01

Corals belong to the most basal class of the Phylum Cnidaria, which is considered the sister group of bilaterian animals, and thus have become an emerging model to study the evolution of developmental mechanisms. Although cell renewal, differentiation, and maintenance of pluripotency are cellular events shared by multicellular animals, the cellular basis of these fundamental biological processes are still poorly understood. To understand how changes in gene expression regulate morphogenetic transitions at the base of the eumetazoa, we performed quantitative RNA-seq analysis during Acropora digitifera’s development. We collected embryonic, larval, and adult samples to characterize stage-specific transcription profiles, as well as broad expression patterns. Transcription profiles reconstructed development revealing two main expression clusters. The first cluster grouped blastula and gastrula and the second grouped subsequent developmental time points. Consistently, we observed clear differences in gene expression between early and late developmental transitions, with higher numbers of differentially expressed genes and fold changes around gastrulation. Furthermore, we identified three coexpression clusters that represented discrete gene expression patterns. During early transitions, transcriptional networks seemed to regulate cellular fate and morphogenesis of the larval body. In late transitions, these networks seemed to play important roles preparing planulae for switch in lifestyle and regulation of adult processes. Although developmental progression in A. digitifera is regulated to some extent by differential coexpression of well-defined gene networks, stage-specific transcription profiles appear to be independent entities. While negative regulation of transcription is predominant in early development, cell differentiation was upregulated in larval and adult stages. PMID:26941230

Music listening in families and peer groups: benefits for young people's social cohesion and emotional well-being across four cultures.

PubMed

Boer, Diana; Abubakar, Amina

2014-01-01

Families are central to the social and emotional development of youth, and most families engage in musical activities together, such as listening to music or talking about their favorite songs. However, empirical evidence of the positive effects of musical family rituals on social cohesion and emotional well-being is scarce. Furthermore, the role of culture in the shaping of musical family rituals and their psychological benefits has been neglected entirely. This paper investigates musical rituals in families and in peer groups (as an important secondary socialization context) in two traditional/collectivistic and two secular/individualistic cultures, and across two developmental stages (adolescence vs. young adulthood). Based on cross-sectional data from 760 young people in Kenya, the Philippines, New Zealand, and Germany, our study revealed that across cultures music listening in families and in peer groups contributes to family and peer cohesion, respectively. Furthermore, the direct contribution of music in peer groups on well-being appears across cultural contexts, whereas musical family rituals affect emotional well-being in more traditional/collectivistic contexts. Developmental analyses show that musical family rituals are consistently and strongly related to family cohesion across developmental stages, whereas musical rituals in peer groups appear more dependent on the developmental stage (in interaction with culture). Contributing to developmental as well as cross-cultural psychology, this research elucidated musical rituals and their positive effects on the emotional and social development of young people across cultures. The implications for future research and family interventions are discussed.

Physiological effects and bioconcentration of triclosan on amphibian larvae.

PubMed

Palenske, Nicole M; Nallani, Gopinath C; Dzialowski, Edward M

2010-08-01

We examined the acute effects of triclosan (TCS) exposure, a common antimicrobial found as a contaminant in the field, on survival and physiology of amphibian larvae. LC50 values were determined after 96h for North American larval species: Acris crepitans blanchardii, Bufo woodhousii woodhousii, Rana sphenocephala, and for a developmental model: Xenopus laevis. Amphibian larvae were most sensitive to TCS exposure during early development based upon 96-h LC50 values. Heart rates for X. laevis and North American larvae exposed to TCS were variable throughout development. Metabolic rates of X. laevis and R. sphenocephala larvae exposed to TCS were significantly affected in larvae exposed to [50% LC50] and [LC50]. Tissue uptake and tissue bioconcentration factor (BCF) of TCS were investigated in X. laevis, B. woodhousii woodhousii, and R. sphenocephala. In general, a significant increase was observed as exposure concentration increased. Tissue BCF values were dependent upon stage and species. While TCS concentrations used here are higher than environmental concentrations, exposure to TCS was dependent upon species and developmental stage, with early developmental stages being most sensitive to TCS exposure. Copyright 2010 Elsevier Inc. All rights reserved.

Kid depletion in mouse oocytes associated with multinucleated blastomere formation and inferior embryo development.

PubMed

Egashira, Akiyoshi; Yamauchi, Nobuhiko; Islam, Md Rashedul; Yamagami, Kazuki; Tanaka, Asami; Suyama, Hikaru; El-Sayed, El-Sharawy Mohamed; Tabata, Shoji; Kuramoto, Takashi

2016-08-01

This study investigated the knockdown (KD) of Kid on maturation developmental competence and multinucleation of mouse germinal vesicle (GV) oocytes after parthenogenetic activation. Data revealed that Kid messenger RNA (mRNA) was expressed in GV and MII stage oocyte and 1- and 2-cell embryos. Additionally, Kid mRNA expression in the Kid KD group decreased by nearly 46% compared to the control small interfering RNA (siRNA) groups. The rate of multinucleated embryos in the Kid KD group (52.4%) was significantly higher (P < 0.05) than the control siRNA group (4.7%). Finally, the developmental rates were significantly lower in the Kid siRNA group at > 4-cell stage (28.6% vs. 53.5%) and the blastocyst stage (2.4% vs. 23.3%) compared to the control siRNA groups. Suppression of Kid using siRNA caused multinucleation in early embryos with high frequency and it may increase 2- to 4-cell arrested embryos and reduce the developmental competence to blastocyst. © 2016 Japanese Society of Animal Science.

Developmental Neurotoxicity of Methamidophos in the Embryo-Larval Stages of Zebrafish.

PubMed

He, Xiaowei; Gao, Jiawei; Dong, Tianyu; Chen, Minjian; Zhou, Kun; Chang, Chunxin; Luo, Jia; Wang, Chao; Wang, Shoulin; Chen, Daozhen; Zhou, Zuomin; Tian, Ying; Xia, Yankai; Wang, Xinru

2016-12-28

Methamidophos is a representative organophosphate insecticide. The knowledge of its developmental neurotoxicity is limited, especially for zebrafish in the early stages of their life. Four hour post-fertilization (hpf) zebrafish embryos were exposed to several environmentally relevant concentrations of methamidophos (0, 25, and 500 μg/L) for up to 72 hpf. Locomotor behavior was then studied in the zebrafish larvae at this timepoint. Acridine orange (AO) staining was carried out in the zebrafish larvae, and the mRNA levels of genes associated with neural development ( mbp and syn2a ) were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). The number of escape responders for mechanical stimulation was significantly decreased in exposed groups. AO staining showed noticeable signs of apoptosis mainly in the brain. In addition, the mRNA levels of mbp and syn2a were both significantly down-regulated in exposed groups. Our study provides the first evidence that methamidophos exposure can cause developmental neurotoxicity in the early stages of zebrafish life, which may be caused by the effect of methamidophos on neurodevelopmental genes and the activation of cell apoptosis in the brain.

The role of the parenchyma sheath and PCD during the development of oil cavities in Pterodon pubescens (Leguminosae-Papilionoideae).

PubMed

Rodrigues, Tatiane Maria; Santos, Daniela Carvalho Dos; Machado, Silvia Rodrigues

2011-07-01

Pterodon pubescens cavities are constituted by lumen and uniseriated epithelium surrounded by multiseriate parenchyma sheath. We studied the development of secretory cavities, including the role of parenchyma sheath, using light and transmission electron microscopy. A Tunel assay was performed to verify whether programmed cell death (PCD) occurs during the process. The lumen is formed by schizogeny and lysigeny occur in later developmental stages of the secretory cavities. Ultrastructurally, epithelial cells in later developmental stages become dark and with sinuous walls; the protoplast becomes retracted and the cytoplasm shows low organelle definition. Degenerated cells are released toward the lumen. Our results showed that PCD occurs during later developmental stages of cavities and plays a critical role in functioning of these glands. New cells originated from the parenchyma sheath differentiate into secretory cells and replace those degenerated ones. This fact associated to PCD guarantees epithelium renovation during the secretory cycle and the maintenance of secretory activity of cavities. Copyright © 2011 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Comparison of second molar eruption patterns in patients with skeletal Class II and skeletal Class I malocclusions.

PubMed

Brin, Ilana; Camasuvi, Semin; Dali, Nasser; Aizenbud, Dror

2006-12-01

The eruptive positions of the second molars in Class I and Class II malocclusions were studied. Pretreatment records of 221 patients with a mean age of 11.3 years were evaluated. About 19% of them had skeletal Class I, 31% had skeletal maxillary Class II, and 50% had skeletal mandibular Class II malocclusions. The mean values of the dental and chronologic ages of the subjects were similar. The eruptive positions in relation to a reference line, the developmental stages of the patients' second molars and dental ages were recorded from the panoramic roentgenograms. The distribution of the various developmental stages in each malocclusion group was similar, and no association between skeletal malocclusion and dental developmental stage of the second molars was encountered. The eruptive position of the maxillary second molars was more occlusal only in the oldest maxillary Class II group, above 12 years of age (P = .02). These results support, in part, previous reports suggesting that the maxillary second molars may erupt earlier in patients with skeletal maxillary Class II malocclusions.

Language screening in preschool Chinese children.

PubMed

Wong, V; Lee, P W; Lieh-Mak, F; Yeung, C Y; Leung, P W; Luk, S L; Yiu, E

1992-01-01

The incidence of language delay in Chinese preschool children was studied by a stratified proportional sampling of all 3 year olds in Hong Kong. The Developmental Language Screening Scale (DLSS) devised for use with Cantonese speaking children was used to identify children with language delay. Of 855 children sampled in the stage I screening procedure, 4%, 2.8% and 3.3% were identified as having delay in verbal comprehension, expression or both respectively. The stage II clinical diagnostic study included a randomly selected group of children screened in stage I with or without any associated behavioural problem. Among these, 3.4% were identified as having a language delay using the Reynell Language Developmental Scale (RDLS) with a criterion of language age of less than or equal to two-thirds of the chronological age; 3% had specific language delay using the criteria of language age less than or equal to two-thirds the chronological age and developmental age more than or equal to two-thirds the chronological age. More boys were found to have language delay, although this was not statistically significant.

Thrips developmental stage-specific transcriptome response to tomato spotted wilt virus during the virus infection cycle in Frankliniella occidentalis, the primary vector.

PubMed

Schneweis, Derek J; Whitfield, Anna E; Rotenberg, Dorith

2017-01-01

Tomato spotted wilt virus (TSWV) is transmitted by Frankliniella occidentalis in a circulative-propagative manner. Little is known about thrips vector response to TSWV during the infection process from larval acquisition to adult inoculation of plants. Whole-body transcriptome response to virus infection was determined for first-instar larval, pre-pupal and adult thrips using RNA-Seq. TSWV responsive genes were identified using preliminary sequence of a draft genome of F. occidentalis as a reference and three developmental-stage transcriptomes were assembled. Processes and functions associated with host defense, insect cuticle structure and development, metabolism and transport were perturbed by TSWV infection as inferred by ontologies of responsive genes. The repertoire of genes responsive to TSWV varied between developmental stages, possibly reflecting the link between thrips development and the virus dissemination route in the vector. This study provides the foundation for exploration of tissue-specific expression in response to TSWV and functional analysis of thrips gene function. Copyright © 2016 Elsevier Inc. All rights reserved.

Dynamics of venom composition across a complex life cycle

PubMed Central

Macrander, Jason; Fridrich, Arie; Modepalli, Vengamanaidu; Reitzel, Adam M; Sunagar, Kartik

2018-01-01

Little is known about venom in young developmental stages of animals. The appearance of toxins and stinging cells during early embryonic stages in the sea anemone Nematostella vectensis suggests that venom is already expressed in eggs and larvae of this species. Here, we harness transcriptomic, biochemical and transgenic tools to study venom production dynamics in Nematostella. We find that venom composition and arsenal of toxin-producing cells change dramatically between developmental stages of this species. These findings can be explained by the vastly different interspecific interactions of each life stage, as individuals develop from a miniature non-feeding mobile planula to a larger sessile polyp that predates on other animals and interact differently with predators. Indeed, behavioral assays involving prey, predators and Nematostella are consistent with this hypothesis. Further, the results of this work suggest a much wider and dynamic venom landscape than initially appreciated in animals with a complex life cycle. PMID:29424690

Embryonic staging system for the black mastiff bat, Molossus rufus (Molossidae), correlated with structure-function relationships in the adult

PubMed Central

Nolte, Mark J.; Hockman, Dorit; Cretekos, Chris J.; Behringer, Richard R.; Rasweiler, John J.

2010-01-01

An embryonic staging system for Molossus rufus (also widely known as Molossus ater) was devised using 17 reference specimens obtained during the postimplantation period of pregnancy from wild-caught, captive-bred females. This was done in part by comparing the embryos to a developmental staging system that had been created for another, relatively unrelated bat, Carollia perspicillata (family Phyllostomidae). Particular attention was paid to the development of species-specific features, such as wing and ear morphology, and these are discussed in light of the adaptive significance of these structures in the adult. M. rufus can be maintained and bred in captivity and is relatively abundant in the wild. This embryonic staging system will facilitate further developmental studies of M. rufus, a model species for one of the largest and most successful chiropteran families, the Molossidae. PMID:19089888

Measuring professional identity formation early in medical school.

PubMed

Kalet, Adina; Buckvar-Keltz, Lynn; Harnik, Victoria; Monson, Verna; Hubbard, Steven; Crowe, Ruth; Song, Hyuksoon S; Yingling, Sandra

2017-03-01

To assess the feasibility and utility of measuring baseline professional identity formation (PIF) in a theory-based professionalism curriculum for early medical students. All 132 entering students completed the professional identity essay (PIE) and the defining issues test (DIT2). Students received score reports with individualized narrative feedback and wrote a structured reflection after a large-group session in which the PIF construct was reviewed. Analysis of PIEs resulted in assignment of a full or transitional PIF stage (1-5). The DIT2 score reflects the proportion of the time students used universal ethical principles to justify a response to 6 moral dilemma cases. Students' reflections were content analyzed. PIF scores were distributed across stage 2/3, stage 3, stage 3/4, and stage 4. No student scores were in stages 1, 2, 4/5, or 5. The mean DIT2 score was 53% (range 9.7?76.5%); the correlation between PIF stage and DIT score was ρ =  0.18 (p = 0.03). Students who took an analytic approach to the data and demonstrated both awareness that they are novices and anticipation of continued PIF tended to respond more positively to the feedback. These PIF scores distributed similarly to novice students in other professions. Developmental-theory based PIF and moral reasoning measures are related. Students reflected on these measures in meaningful ways suggesting utility of measuring PIF scores in medical education.

Some like it hot: evolution and ecology of novel endosymbionts in bat flies of cave-roosting bats (hippoboscoidea, nycterophiliinae).

PubMed

Morse, Solon F; Dick, Carl W; Patterson, Bruce D; Dittmar, Katharina

2012-12-01

We investigated previously unknown associations between bacterial endosymbionts and bat flies of the subfamily Nycterophiliinae (Diptera, Streblidae). Molecular analyses revealed a novel clade of Gammaproteobacteria in Nycterophilia bat flies. This clade was not closely related to Arsenophonus-like microbes found in its sister genus Phalconomus and other bat flies. High population infection rates in Nycterophilia across a wide geographic area, the presence of the symbionts in pupae, the general codivergence between hosts and symbionts, and high AT composition bias in symbiont genes together suggest that this host-symbiont association is obligate in nature and ancient in origin. Some Nycterophilia samples (14.8%) also contained Wolbachia supergroup F (Alphaproteobacteria), suggesting a facultative symbiosis. Likelihood-based ancestral character mapping revealed that, initially, obligate symbionts exhibited association with host-specific Nycterophilia bat flies that use a broad temperature range of cave environments for pupal development. As this mutualism evolved, the temperature range of bat flies narrowed to an exclusive use of hot caves, which was followed by a secondary broadening of the bat flies' host associations. These results suggest that the symbiosis has influenced the environmental tolerance of parasite life history stages. Furthermore, the contingent change to an expanded host range of Nycterophilia bat flies upon narrowing the ecological niche of their developmental stages suggests that altered environmental tolerance across life history stages may be a crucial factor in shaping parasite-host relationships.

Some Like It Hot: Evolution and Ecology of Novel Endosymbionts in Bat Flies of Cave-Roosting Bats (Hippoboscoidea, Nycterophiliinae)

PubMed Central

Morse, Solon F.; Dick, Carl W.; Patterson, Bruce D.

2012-01-01

We investigated previously unknown associations between bacterial endosymbionts and bat flies of the subfamily Nycterophiliinae (Diptera, Streblidae). Molecular analyses revealed a novel clade of Gammaproteobacteria in Nycterophilia bat flies. This clade was not closely related to Arsenophonus-like microbes found in its sister genus Phalconomus and other bat flies. High population infection rates in Nycterophilia across a wide geographic area, the presence of the symbionts in pupae, the general codivergence between hosts and symbionts, and high AT composition bias in symbiont genes together suggest that this host-symbiont association is obligate in nature and ancient in origin. Some Nycterophilia samples (14.8%) also contained Wolbachia supergroup F (Alphaproteobacteria), suggesting a facultative symbiosis. Likelihood-based ancestral character mapping revealed that, initially, obligate symbionts exhibited association with host-specific Nycterophilia bat flies that use a broad temperature range of cave environments for pupal development. As this mutualism evolved, the temperature range of bat flies narrowed to an exclusive use of hot caves, which was followed by a secondary broadening of the bat flies' host associations. These results suggest that the symbiosis has influenced the environmental tolerance of parasite life history stages. Furthermore, the contingent change to an expanded host range of Nycterophilia bat flies upon narrowing the ecological niche of their developmental stages suggests that altered environmental tolerance across life history stages may be a crucial factor in shaping parasite-host relationships. PMID:23042170

Enhancer of zeste acts as a major developmental regulator of Ciona intestinalis embryogenesis

PubMed Central

Le Goff, Emilie; Martinand-Mari, Camille; Martin, Marianne; Feuillard, Jérôme; Boublik, Yvan; Godefroy, Nelly; Mangeat, Paul; Baghdiguian, Stephen; Cavalli, Giacomo

2015-01-01

ABSTRACT The paradigm of developmental regulation by Polycomb group (PcG) proteins posits that they maintain silencing outside the spatial expression domains of their target genes, particularly of Hox genes, starting from mid embryogenesis. The Enhancer of zeste [E(z)] PcG protein is the catalytic subunit of the PRC2 complex, which silences its targets via deposition of the H3K27me3 mark. Here, we studied the ascidian Ciona intestinalis counterpart of E(z). Ci-E(z) is detected by immunohistochemistry as soon as the 2- and 4-cell stages as a cytoplasmic form and becomes exclusively nuclear thereafter, whereas the H3K27me3 mark is detected starting from the gastrula stage and later. Morpholino invalidation of Ci-E(z) leads to the total disappearance of both Ci-E(z) protein and its H3K27me3 mark. Ci-E(z) morphants display a severe phenotype. Strikingly, the earliest defects occur at the 4-cell stage with the dysregulation of cell positioning and mitotic impairment. At later stages, Ci-E(z)-deficient embryos are affected by terminal differentiation defects of neural, epidermal and muscle tissues, by the failure to form a notochord and by the absence of caudal nerve. These major phenotypic defects are specifically rescued by injection of a morpholino-resistant Ci-E(z) mRNA, which restores expression of Ci-E(z) protein and re-deposition of the H3K27me3 mark. As observed by qPCR analyses, Ci-E(z) invalidation leads to the early derepression of tissue-specific developmental genes, whereas late-acting developmental genes are generally down-regulated. Altogether, our results suggest that Ci-E(z) plays a major role during embryonic development in Ciona intestinalis by silencing early-acting developmental genes in a Hox-independent manner. PMID:26276097

Construction of a Lotus japonicus late nodulin expressed sequence tag library and identification of novel nodule-specific genes.

PubMed Central

Szczyglowski, K; Hamburger, D; Kapranov, P; de Bruijn, F J

1997-01-01

A range of novel expressed sequence tags (ESTs) associated with late developmental events during nodule organogenesis in the legume Lotus japonicus were identified using mRNA differential display; 110 differentially displayed polymerase chain reaction products were cloned and analyzed. Of 88 unique cDNAs obtained, 22 shared significant homology to DNA/protein sequences in the respective databases. This group comprises, among others, a nodule-specific homolog of protein phosphatase 2C, a peptide transporter protein, and a nodule-specific form of cytochrome P450. RNA gel-blot analysis of 16 differentially displayed ESTs confirmed their nodule-specific expression pattern. The kinetics of mRNA accumulation of the majority of the ESTs analyzed were found to resemble the expression pattern observed for the L. japonicus leghemoglobin gene. These results indicate that the newly isolated molecular markers correspond to genes induced during late developmental stages of L. japonicus nodule organogenesis and provide important, novel tools for the study of nodulation. PMID:9276951

Zebrafish embryo developmental toxicology assay.

PubMed

Panzica-Kelly, Julieta M; Zhang, Cindy X; Augustine-Rauch, Karen

2012-01-01

A promising in vitro zebrafish developmental toxicology assay was generated to test compounds for their teratogenic potential. The assay's predictivity is approximately 87% in AB strain fish (Brannen KC et al., Birth Defects Res B Dev Reprod Toxicol 89:66-77, 2010). The procedure entails exposing dechorionated gastrulation-stage embryos to a range of compound concentrations for 5 days throughout embryonic and larva development. The larvae are evaluated for viability in order to identify an LC25 (the compound concentration in which 25% lethality is observed) and morphological anomalies using a numerical score system to identify the NOAEL (no observed adverse effect level). These values are used to calculate the teratogenic index (LC25/NOAEL ratio) of each compound. If the teratogenic index is equal to or greater than 10 then the compound is classified as a teratogen, and if the ratio is less than 10 then the compound is classified as a nonteratogen (Brannen KC et al., Birth Defects Res B Dev Reprod Toxicol 89:66-77, 2010).

Single-cell transcriptome of early embryos and cultured embryonic stem cells of cynomolgus monkeys

PubMed Central

Nakamura, Tomonori; Yabuta, Yukihiro; Okamoto, Ikuhiro; Sasaki, Kotaro; Iwatani, Chizuru; Tsuchiya, Hideaki; Saitou, Mitinori

2017-01-01

In mammals, the development of pluripotency and specification of primordial germ cells (PGCs) have been studied predominantly using mice as a model organism. However, divergences among mammalian species for such processes have begun to be recognized. Between humans and mice, pre-implantation development appears relatively similar, but the manner and morphology of post-implantation development are significantly different. Nevertheless, the embryogenesis just after implantation in primates, including the specification of PGCs, has been unexplored due to the difficulties in analyzing the embryos at relevant developmental stages. Here, we present a comprehensive single-cell transcriptome dataset of pre- and early post-implantation embryo cells, PGCs and embryonic stem cells (ESCs) of cynomolgus monkeys as a model of higher primates. The identities of each transcriptome were also validated rigorously by other way such as immunofluorescent analysis. The information reported here will serve as a foundation for our understanding of a wide range of processes in the developmental biology of primates, including humans. PMID:28649393

Prevention and anthropology.

PubMed

Jopp, Eilin; Scheffler, Christiane; Hermanussen, Michael

2014-01-01

Screening is an important issue in medicine and is used to early identify unrecognised diseases in persons who are apparently in good health. Screening strongly relies on the concept of "normal values". Normal values are defined as values that are frequently observed in a population and usually range within certain statistical limits. Screening for obesity should start early as the prevalence of obesity consolidates already at early school age. Though widely practiced, measuring BMI is not the ultimate solution for detecting obesity. Children with high BMI may be "robust" in skeletal dimensions. Assessing skeletal robustness and in particularly assessing developmental tempo in adolescents are also important issues in health screening. Yet, in spite of the necessity of screening investigations, appropriate reference values are often missing. Meanwhile, new concepts of growth diagrams have been developed. Stage line diagrams are useful for tracking developmental processes over time. Functional data analyses have efficiently been used for analysing longitudinal growth in height and assessing the tempo of maturation. Convenient low-cost statistics have also been developed for generating synthetic national references.

Is the increase of hypomanic stages during adolescence related to gender and developmental tasks?

PubMed

Brand, Serge; Angst, Jules; Holsboer-Trachsler, Edith

2010-04-01

To detach themselves from their family of origin, adolescents need to develop proactive behaviour which includes increased risk-taking and novelty seeking. These behaviours may be attributable both to developmental issues and to hypomanic-like stages. Since there is a lack of research focusing on hypomania in adolescents, the aim of the study was to compare hypomania scores of adolescents with those of adult outpatients suffering from bipolar II disorders, and to investigate possible gender-related differences. One hundred and seven adolescents (mean age: 18 years) took part in the study; 60 of them indicated that they experienced intense romantic love; 47 were controls. Participants completed the Hypomania Check List, and data were compared with those of adult outpatients suffering from bipolar II disorders. Scores of adolescents in early-stage intense romantic love differed from those of adolescent controls, but not from those of outpatients suffering from a bipolar II disorder. Factor analyses revealed that both groups of adolescents displayed higher scores for the factor "irritable/risk-taking" hypomania. A gender-related pattern was found, with increased scores for female adolescents. Adolescents' developmental tasks surrounding experiences in social, psychosexual and substance use-related engagement may lead to temporary and gender-related hypomanic-like stages.

Flower structure and developmental stages of the capitulum of Smallanthus sonchifolius (Asteraceae): reproductive implications.

PubMed

Ibañez, M S; Mercado, M I; Coll Aráoz, M V; Zannier, M L; Grau, A; Ponessa, G I

2017-03-01

Yacon (Smallanthus sonchifolius, Asteraceae) is an ancient andean crop that has numerous dietary and medicinal properties. Morphological and anatomical features and developmental changes of the capitulum were studied. A ray floret is a pistillate, female flower, while a disc floret is a staminate male flower, and the former opens before the latter, being pseudanthium protogynous. The capitulum presents interesting attributes for pollinators such as flower structure, nectaries and pollenkitt. Gynoecial nectaries were found on undeveloped ovary in the disc floret, but not in the ray floret. Glandular trichomes were observed on the abaxial epidermis of corolla in the ray floret, but not in the disc floret. Capitulum development was divided into eight stages. Stigma receptivity varied with these stages. Pollen viability was low (15%). In accordance with low viability, pollen grains exhibit diverse sizes and shapes, reduction in length of spines, and abnormal protoplasm. Examination of ovary development in the ray floret showed that a mature ovule was formed, but fertilization did not occur. In advanced developmental stages, the capitulum showed proliferation of the endothelium, degeneration of the embryo sac, and all harvested cypselae had aborted seeds. Problems found in pollen viability and aborted cypselae could be the result of a history of vegetative propagation in the domestication process.

Characterization of Adelphocoris suturalis (Hemiptera: Miridae) Transcriptome from Different Developmental Stages

NASA Astrophysics Data System (ADS)

Tian, Caihong; Tek Tay, Wee; Feng, Hongqiang; Wang, Ying; Hu, Yongmin; Li, Guoping

2015-06-01

Adelphocoris suturalis is one of the most serious pest insects of Bt cotton in China, however its molecular genetics, biochemistry and physiology are poorly understood. We used high throughput sequencing platform to perform de novo transcriptome assembly and gene expression analyses across different developmental stages (eggs, 2nd and 5th instar nymphs, female and male adults). We obtained 20 GB of clean data and revealed 88,614 unigenes, including 23,830 clusters and 64,784 singletons. These unigene sequences were annotated and classified by Gene Ontology, Clusters of Orthologous Groups, and Kyoto Encyclopedia of Genes and Genomes databases. A large number of differentially expressed genes were discovered through pairwise comparisons between these developmental stages. Gene expression profiles were dramatically different between life stage transitions, with some of these most differentially expressed genes being associated with sex difference, metabolism and development. Quantitative real-time PCR results confirm deep-sequencing findings based on relative expression levels of nine randomly selected genes. Furthermore, over 791,390 single nucleotide polymorphisms and 2,682 potential simple sequence repeats were identified. Our study provided comprehensive transcriptional gene expression information for A. suturalis that will form the basis to better understanding of development pathways, hormone biosynthesis, sex differences and wing formation in mirid bugs.

Transcriptome analyses reveal genotype- and developmental stage-specific molecular responses to drought and salinity stresses in chickpea

PubMed Central

Garg, Rohini; Shankar, Rama; Thakkar, Bijal; Kudapa, Himabindu; Krishnamurthy, Lakshmanan; Mantri, Nitin; Varshney, Rajeev K.; Bhatia, Sabhyata; Jain, Mukesh

2016-01-01

Drought and salinity are the major factors that limit chickpea production worldwide. We performed whole transcriptome analyses of chickpea genotypes to investigate the molecular basis of drought and salinity stress response/adaptation. Phenotypic analyses confirmed the contrasting responses of the chickpea genotypes to drought or salinity stress. RNA-seq of the roots of drought and salinity related genotypes was carried out under control and stress conditions at vegetative and/or reproductive stages. Comparative analysis of the transcriptomes revealed divergent gene expression in the chickpea genotypes at different developmental stages. We identified a total of 4954 and 5545 genes exclusively regulated in drought-tolerant and salinity-tolerant genotypes, respectively. A significant fraction (~47%) of the transcription factor encoding genes showed differential expression under stress. The key enzymes involved in metabolic pathways, such as carbohydrate metabolism, photosynthesis, lipid metabolism, generation of precursor metabolites/energy, protein modification, redox homeostasis and cell wall component biogenesis, were affected by drought and/or salinity stresses. Interestingly, transcript isoforms showed expression specificity across the chickpea genotypes and/or developmental stages as illustrated by the AP2-EREBP family members. Our findings provide insights into the transcriptome dynamics and components of regulatory network associated with drought and salinity stress responses in chickpea. PMID:26759178

Characterization of Adelphocoris suturalis (Hemiptera: Miridae) Transcriptome from Different Developmental Stages

PubMed Central

Tian, Caihong; Tek Tay, Wee; Feng, Hongqiang; Wang, Ying; Hu, Yongmin; Li, Guoping

2015-01-01

Adelphocoris suturalis is one of the most serious pest insects of Bt cotton in China, however its molecular genetics, biochemistry and physiology are poorly understood. We used high throughput sequencing platform to perform de novo transcriptome assembly and gene expression analyses across different developmental stages (eggs, 2nd and 5th instar nymphs, female and male adults). We obtained 20 GB of clean data and revealed 88,614 unigenes, including 23,830 clusters and 64,784 singletons. These unigene sequences were annotated and classified by Gene Ontology, Clusters of Orthologous Groups, and Kyoto Encyclopedia of Genes and Genomes databases. A large number of differentially expressed genes were discovered through pairwise comparisons between these developmental stages. Gene expression profiles were dramatically different between life stage transitions, with some of these most differentially expressed genes being associated with sex difference, metabolism and development. Quantitative real-time PCR results confirm deep-sequencing findings based on relative expression levels of nine randomly selected genes. Furthermore, over 791,390 single nucleotide polymorphisms and 2,682 potential simple sequence repeats were identified. Our study provided comprehensive transcriptional gene expression information for A. suturalis that will form the basis to better understanding of development pathways, hormone biosynthesis, sex differences and wing formation in mirid bugs. PMID:26047353

Novel Metrics to Characterize Embryonic Elongation of the Nematode Caenorhabditis elegans.

PubMed

Martin, Emmanuel; Rocheleau-Leclair, Olivier; Jenna, Sarah

2016-03-28

Dissecting the signaling pathways that control the alteration of morphogenic processes during embryonic development requires robust and sensitive metrics. Embryonic elongation of the nematode Caenorhabditis elegans is a late developmental stage consisting of the elongation of the embryo along its longitudinal axis. This developmental stage is controlled by intercellular communication between hypodermal cells and underlying body-wall muscles. These signaling mechanisms control the morphology of hypodermal cells by remodeling the cytoskeleton and the cell-cell junctions. Measurement of embryonic lethality and developmental arrest at larval stages as well as alteration of cytoskeleton and cell-cell adhesion structures in hypodermal and muscle cells are classical phenotypes that have been used for more than 25 years to dissect these signaling pathways. Recent studies required the development of novel metrics specifically targeting either early or late elongation and characterizing morphogenic defects along the antero-posterior axis of the embryo. Here, we provide detailed protocols enabling the accurate measurement of the length and the width of the elongating embryos as well as the length of synchronized larvae. These methods constitute useful tools to identify genes controlling elongation, to assess whether these genes control both early and late phases of this stage and are required evenly along the antero-posterior axis of the embryo.

Glycoconjugate distribution in early human notochord and axial mesenchyme.

PubMed

Götz, W; Quondamatteo, F

2001-02-01

Glycosylation patterns of cells and tissues give insights into spatially and temporally regulated developmental processes and can be detected histochemically using plant lectins with specific affinities for sugar moieties. The early development of the vertebral column in man is a process which has never been investigated by lectin histochemistry. Therefore, we studied binding of several lectins (AIA, Con A, GSA II, LFA, LTA, PNA, RCA I, SBA, SNA, WGA) in formaldehyde-fixed sections of the axial mesenchyme of 5 human embryos in Carnegie stages 12-15. During these developmental stages, an unsegmented mesenchyme covers the notochord. Staining patterns did not show striking temporal variations except for SBA which stained the cranial axial mesenchyme only in the early stage 12 embryo and for PNA, of which the staining intensity in the mesenchyme decreased with age. The notochord appeared as a highly glycosylated tissue. Carbohydrates detected may correspond to adhesion molecules or to secreted substances like proteoglycans or proteins which could play an inductive role, for example, for the neural tube. The axial perinotochordal unsegmented mesenchyme showed strong PNA binding. Therefore, its function as a PNA-positive "barrier" tissue is discussed. The endoderm of the primitive gut showed a lectin-binding pattern that was similar to that of the notochord, which may correlate with interactions between these tissues during earlier developmental stages.

Evoecotoxicology: Environmental Changes and Life Features Development during the Evolutionary Process—the Record of the Past at Developmental Stages of Living Organisms

PubMed Central

Herkovits, Jorge

2006-01-01

For most of evolutionary history, scientific understanding of the environment and life forms is extremely limited. In this commentary I discuss the hypothesis that ontogenetic features of living organisms can be considered biomarkers of coevolution between organisms and physicochemical agents during Earth’s history. I provide a new vision of evolution based on correlations between metabolic features and stage-dependent susceptibility of organisms to physicochemical agents with well-known environmental signatures. Thus, developmental features potentially reflect environmental changes during evolution. From this perspective, early multicellular life forms would have flourished in the anoxic Earth more than 2 billion years ago, which is at least 1.2 billion years in advance of available fossil evidence. The remarkable transition to aerobic metabolism in gastrula-stage embryos potentially reflects evolution toward tridermic organisms by 2 billion years ago. Noteworthy changes in embryonic resistance to physicochemical agents at different developmental stages that can be observed in living organisms potentially reflect the influence of environmental stress conditions during different periods of evolutionary history. Evoecotoxicology, as a multidisciplinary and transdisciplinary approach, can enhance our understanding of evolution, including the phylogenetic significance of differences in susceptibility/resistance to physicochemical agents in different organisms. PMID:16882515

Moral motivation based on multiple developmental structures: an exploration of cognitive and emotional dynamics.

PubMed

Kaplan, Ulas; Tivnan, Terrence

2014-01-01

Intrapersonal variability and multiplicity in the complexity of moral motivation were examined from Dynamic Systems and Self-Determination Theory perspectives. L. Kohlberg's (1969) stages of moral development are reconceptualized as soft-assembled and dynamically transformable process structures of motivation that may operate simultaneously within person in different degrees. Moral motivation is conceptualized as the real-time process of self-organization of cognitive and emotional dynamics out of which moral judgment and action emerge. A detailed inquiry into intrapersonal variation in moral motivation is carried out based on the differential operation of multiple motivational structures. A total of 74 high school students and 97 college students participated in the study by completing a new questionnaire, involving 3 different hypothetical moral judgments. As hypothesized, findings revealed significant multiplicity in the within-person operation of developmental stage structures, and intrapersonal variability in the degrees to which stages were used. Developmental patterns were found in terms of different distributions of multiple stages between high school and college samples, as well as the association between age and overall motivation scores. Differential relations of specific emotions to moral motivation revealed and confirmed the value of differentiating multiple emotions. Implications of the present theoretical perspective and the findings for understanding the complexity of moral judgment and motivation are discussed.

Emotional and Motivational Engagement at School Transition: A Qualitative Stage-Environment Fit Study

ERIC Educational Resources Information Center

Symonds, Jennifer; Hargreaves, Linda

2016-01-01

Adolescents typically like school less after making age-graded school transitions. Stage-environment fit theory (Eccles & Midgley, 1989) attributes this to a mismatch between developmental needs and new school environments. Our in vivo study provides a basis for future quantitative designs by uncovering the most prevalent stage-environment…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Preez-Coll, C.S.; Herkovits, J.

Over the last several years, environmental contamination with cadmium has significantly increased because of its extensive use In anthropogenic activities. This heavy metal is a very toxic xenobiotic producing reproductive and developmental impairments in a wide spectrum of organisms. Within the life cycle of organisms, the embryo is the most sensitive period to adverse conditions. Moreover, stage-dependent susceptibilities to toxic agents in amphibian embryos treated with lead, cadmium and aluminium were described. In the case of cadmium, this differential sensitivity could be related to changes in the metal accumulation through development or in the induction of defense mechanisms against cadmiummore » toxicity, such as metallothionein (Mt) synthesis, which seems to be developmentally regulated. In the case of the toad Bufo arenarum, susceptibility to cadmium seems to follow a biphasic pattern during embryonic development. From the two-cell stage to the neurula stage an increase in susceptibility occurs, whereas from the last stage onwards a gradual increase in the resistance against this heavy metal seems to be achieved. This stage reports the uptake profile of cadmium at different post-hatching stages. 20 refs., 3 figs.« less

Effect of Culture Conditions on Viability of Mouse and Rat Embryos Developed in Vitro

PubMed Central

Popova, Elena; Bader, Michael; Krivokharchenko, Alexander

2011-01-01

Currently in vitro culture of mouse preimplantation embryos has become a very important technique to investigate different mechanisms of early embryogenesis. However, there is a big difference in the preimplantation development between mammalian species. Despite close relatedness to mice, in vitro cultivation of rat preimplantation embryos is still delicate and needs further investigation and optimizations. In this study we have compared the in vitro developmental potential of mouse and rat embryos cultured at different culture conditions in parallel experiments. Interestingly, mouse zygotes developed in vitro until blastocyst stage even in inadequate medium without any phosphates and with low osmolarity which was formulated especially for cultivation of rat embryos. Rat parthenotes and zygotes developed in M16 medium formulated for mouse embryos only till 2-cell stage and further development is blocked completely at this stage. Moreover, developmental ability of rat embryos in vitro was significantly lower in comparison with mouse even in special rat mR1ECM medium. Mouse and rat embryos at 2-cell stage obtained in vivo developed until blastocyst stages significantly more efficiently compared to zygotes. Culture of mouse zygotes in glass capillaries resulted in a significantly higher rate of morula and blastocyst development compared with dishes. The Well-of-the-Well system resulted in a significant improvement when compared with dishes for the culture of rat zygotes only until morula stage. Reduced oxygen tension increased the developmental rate of rat but not mouse zygotes until blastocyst stage. This study demonstrates that development of early preimplantation embryos is altered by different culture conditions and show strong differences even between two related species such as mice and rats. Therefore, for understanding the fundamental mechanisms of early mammalian development it is very important to use embryos of various species. PMID:24710194

Naturally occurring mastitis disrupts developmental competence of bovine oocytes.

PubMed

Roth, Z; Dvir, A; Kalo, D; Lavon, Y; Krifucks, O; Wolfenson, D; Leitner, G

2013-10-01

We examined the effects of naturally occurring mastitis on bovine oocyte developmental competence in vitro. Specifically, we investigated the effects of intramammary infection on the ovarian pool of oocytes (i.e., follicle-enclosed oocytes) and their ability to undergo in vitro maturation, fertilization, and further development to the blastocyst stage. Culled Holstein cows (n=50) from 9 commercial dairy farms in Israel were allotted to 3 groups according to somatic cell count (SCC) records of the last 3 monthly milk tests as well as of quarter samples collected before slaughter: (1) low SCC (n=7), (2) medium SCC (n=16), or (3) high SCC (n=27). Means of SCC values differed among low-, medium-, and high-SCC groups: 148,000, 311,000 and 1,813,000 cell/mL milk, respectively. Milk yield and days in milk did not differ among the 3 groups. Bacterial isolates included coagulase-negative staphylococci, Escherichia coli, Streptococcus dysgalactiae, or no bacteria found. Ovaries were collected at the abattoir and brought to the laboratory. Cumulus oocyte complexes were recovered separately from each cow and subjected individually to in vitro maturation and fertilization, followed by 8d in culture. The number of aspirated oocytes did not differ among groups, with a range of 17 to 21 oocytes per cow. The proportion of oocytes that cleaved into 2- to 4-cell-stage embryos (86.1 ± 3.4%) did not differ among groups. In contrast, mean percentages of embryos developed to the blastocyst stage on d 7 and 8 after fertilization were less in both medium- and-high SCC groups than in the low-SCC group (5.6 ± 2.3 and 4.1 ± 1.8 vs. 18.1 ± 4.6%, respectively). Additional analysis indicated that cleavage and blastocyst-formation rates did not differ among the bacterial types in the low-, medium-, and high-SCC groups. These are the first results to demonstrate that naturally occurring mastitis disrupts the developmental competence of the ovarian pool of oocytes, (i.e., oocytes at the germinal vesicle stage). The disruption was associated with elevation of SCC rather than bacterial type. The results may provide a partial explanation for the low fertility of cows that have contracted mastitic pathogens before insemination. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

High-Performance Liquid Chromatography Studies to Estimate Ergosterol Content at Different Developmental Stages of the Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes).

PubMed

Goyal, Anna; Kalia, Anu; Sodhi, Harpreet Singh

2016-01-01

Ganoderma lucidum has been widely used as a source of potent nutraceutical products. This study was planned to identify and characterize the role of ergosterol in the developmental process of G. lucidum. Four strains of G. lucidum (GL-I-IV) showed a gradual increase in biomass (from 25.52 to 31.72 g) after 3 weeks of growth in mushroom complete medium broth, with maximum biomass observed for strain GL-III. Upon cultivation of G. lucidum strains on wheat straw supplemented with 5% wheat bran, maximum biological efficiency was recorded for the GL-I strain (31.23%), followed by GL-II (26.73%); the number of fruiting bodies were 927 and 693, each weighing 33.7 and 38.6 g, respectively. The amount of ergosterol in the Ganoderma test strains varied among the strains and at different developmental stages, namely, the vegetative mycelium, spawn run, pinhead, and fruiting body phases. The maximum ergosterol content was produced by the GL-I strain during the vegetative mycelium (4601 p.g/g) and reproductive fruiting body (7009 p.g/g) stages. However, strain GL-IV followed by strain GL-II exhibited maximum ergosterol content in the spawn run stage. The ergosterol content was better for GL-II at the pinhead stage. This report indicates that ergosterol content varies among the test strains. Moreover, it increases with each stage of the cultivation process, that is, from spawn run to pinhead to and fruiting body formation.

Impact of sociodemographic factors on cognitive function in school-aged HIV-infected Nigerian children.

PubMed

Boyede, Gbemisola O; Lesi, Foluso Ea; Ezeaka, Veronica C; Umeh, Charles S

2013-01-01

In this study, we sought to evaluate the influence of sociodemographic factors, ie, age, sex, socioeconomic status, maternal education, and human immunodeficiency virus (HIV) status, on cognitive performance in school-aged HIV-infected Nigerian children. Sixty-nine HIV-positive children aged 6-15 years were matched with 69 HIV-negative control children for age and sex. The children were subdivided for the purpose of analysis into two cognitive developmental stages using Piaget's staging, ie, the concrete operational stage (6-11 years) and the formal operational stage (12-15 years). All participants underwent cognitive assessment using Raven's Standard Progressive Matrices (RPM). Sociodemographic data for the study participants, ie, age, sex, socioeconomic status, and level of maternal education, were obtained using a study proforma. Logistic regression analyses were used to determine associations of HIV status and sociodemographic characteristics with RPM cognitive scores. The overall mean RPM score for the HIV-positive children was 18.2 ± 9.8 (range 8.0-47.0) which was significantly lower than the score of 27.2 ± 13.8 (range 8.0-52.0) for the HIV-negative children (P < 0.001). On RPM grading, 56.5% of the HIV-positive children had cognitive performance at below average to intellectually defective range. Below average RPM scores were found to be significantly associated with younger age (6-11 years), positive HIV status, lower socioeconomic status, and low level of maternal education. Younger age, poor socioeconomic status, and low level of maternal education were factors apart from HIV infection that were significantly associated with low cognitive function in school-aged HIV-infected Nigerian children.

Standardised classification of pre-release development in male-brooding pipefish, seahorses, and seadragons (Family Syngnathidae)

PubMed Central

2012-01-01

Background Members of the family Syngnathidae share a unique reproductive mode termed male pregnancy. Males carry eggs in specialised brooding structures for several weeks and release free-swimming offspring. Here we describe a systematic investigation of pre-release development in syngnathid fishes, reviewing available data for 17 species distributed across the family. This work is complemented by in-depth examinations of the straight-nosed pipefish Nerophis ophidion, the black-striped pipefish Syngnathus abaster, and the potbellied seahorse Hippocampus abdominalis. Results We propose a standardised classification of early syngnathid development that extends from the activation of the egg to the release of newborn. The classification consists of four developmental periods – early embryogenesis, eye development, snout formation, and juvenile – which are further divided into 11 stages. Stages are characterised by morphological traits that are easily visible in live and preserved specimens using incident-light microscopy. Conclusions Our classification is derived from examinations of species representing the full range of brooding-structure complexity found in the Syngnathidae, including tail-brooding as well as trunk-brooding species, which represent independent evolutionary lineages. We chose conspicuous common traits as diagnostic features of stages to allow for rapid and consistent staging of embryos and larvae across the entire family. In view of the growing interest in the biology of the Syngnathidae, we believe that the classification proposed here will prove useful for a wide range of studies on the unique reproductive biology of these male-brooding fish. PMID:23273265

Standardised classification of pre-release development in male-brooding pipefish, seahorses, and seadragons (Family Syngnathidae).

PubMed

Sommer, Stefan; Whittington, Camilla M; Wilson, Anthony B

2012-12-29

Members of the family Syngnathidae share a unique reproductive mode termed male pregnancy. Males carry eggs in specialised brooding structures for several weeks and release free-swimming offspring. Here we describe a systematic investigation of pre-release development in syngnathid fishes, reviewing available data for 17 species distributed across the family. This work is complemented by in-depth examinations of the straight-nosed pipefish Nerophis ophidion, the black-striped pipefish Syngnathus abaster, and the potbellied seahorse Hippocampus abdominalis. We propose a standardised classification of early syngnathid development that extends from the activation of the egg to the release of newborn. The classification consists of four developmental periods - early embryogenesis, eye development, snout formation, and juvenile - which are further divided into 11 stages. Stages are characterised by morphological traits that are easily visible in live and preserved specimens using incident-light microscopy. Our classification is derived from examinations of species representing the full range of brooding-structure complexity found in the Syngnathidae, including tail-brooding as well as trunk-brooding species, which represent independent evolutionary lineages. We chose conspicuous common traits as diagnostic features of stages to allow for rapid and consistent staging of embryos and larvae across the entire family. In view of the growing interest in the biology of the Syngnathidae, we believe that the classification proposed here will prove useful for a wide range of studies on the unique reproductive biology of these male-brooding fish.

Silver nanoparticles induce developmental stage-specific embryonic phenotypes in zebrafish.

PubMed

Lee, Kerry J; Browning, Lauren M; Nallathamby, Prakash D; Osgood, Christopher J; Xu, Xiao-Hong Nancy

2013-12-07

Much is anticipated from the development and deployment of nanomaterials in biological organisms, but concerns remain regarding their biocompatibility and target specificity. Here we report our study of the transport, biocompatibility and toxicity of purified and stable silver nanoparticles (Ag NPs, 13.1 ± 2.5 nm in diameter) upon the specific developmental stages of zebrafish embryos using single NP plasmonic spectroscopy. We find that single Ag NPs passively diffuse into five different developmental stages of embryos (cleavage, early-gastrula, early-segmentation, late-segmentation, and hatching stages), showing stage-independent diffusion modes and diffusion coefficients. Notably, the Ag NPs induce distinctive stage and dose-dependent phenotypes and nanotoxicity, upon their acute exposure to the Ag NPs (0-0.7 nM) for only 2 h. The late-segmentation embryos are most sensitive to the NPs with the lowest critical concentration (CNP,c < 0.02 nM) and highest percentages of cardiac abnormalities, followed by early-segmentation embryos (CNP,c < 0.02 nM), suggesting that disruption of cell differentiation by the NPs causes the most toxic effects on embryonic development. The cleavage-stage embryos treated with the NPs develop into a wide variety of phenotypes (abnormal finfold, tail/spinal cord flexure, cardiac malformation/edema, yolk sac edema, and acephaly). These organ structures are not yet developed in cleavage-stage embryos, suggesting that the earliest determinative events to create these structures are ongoing, and disrupted by NPs, which leads to the downstream effects. In contrast, the hatching embryos are most resistant to the Ag NPs, and majority of embryos (94%) develop normally, and none of them develop abnormally. Interestingly, early-gastrula embryos are less sensitive to the NPs than cleavage and segmentation stage embryos, and do not develop abnormally. These important findings suggest that the Ag NPs are not simple poisons, and they can target specific pathways in development, and potentially enable target specific study and therapy for early embryonic development.

From Scribbles to Stories: Supporting Writing Development.

ERIC Educational Resources Information Center

Diffily, Deborah

2001-01-01

Describes how caregivers can support young children's writing development. Outlines stages of writing: scribbling, drawing, invented letters, random letters, copying words, developmental spelling, and conventional spelling. Provides tips on what to say to children in each stage of writing. (KB)

Towards microfluidic technology-based MALDI-MS platforms for drug discovery: a review.

PubMed

Winkle, Richard F; Nagy, Judit M; Cass, Anthony Eg; Sharma, Sanjiv

2008-11-01

Microfluidic methods have found applications in various disciplines. It has been predicted that the microfluidic technology would be useful in performing routine steps in drug discovery ranging from target identification to lead optimisation in which the number of compounds evaluated in this regard determines the success of combinatorial screening. The sheer size of the parameter space that can be explored often poses an enormous challenge. We set out to find how close we are towards the use of integrated matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) microfluidic systems for drug discovery. In this article we review the latest applications of microfluidic technology in the area of MALDI-MS and drug discovery. Our literature survey revealed microfluidic technologies-based approaches for various stages of drug discovery; however, they are in still in developmental stages. Furthermore, we speculate on how these technologies could be used in the future.

Exploring cytoplasmic dynamics in zebrafish yolk cells by single particle tracking of fluorescent nanodiamonds

NASA Astrophysics Data System (ADS)

Chang, Cheng-Chun; Zhang, Bailin; Li, Che-Yu; Hsieh, Chih-Chien; Duclos, Guillaume; Treussart, François; Chang, Huan-Cheng

2012-02-01

Fluorescent nanodiamonds (FNDs) have recently developed into an exciting new tool for bioimaging applications. The material possesses several unique features including high biocompatibility, easy bioconjugation, and perfect photostability, making it a promising optical nanoprobe in vitro as well as in vivo. This work explores the potential application of this novel nanomaterial as a photostable, nontoxic tracer in vivo using zebrafish as a model organism. We introduced FNDs into the yolk of a zebrafish embryo by microinjection at the 1-cell stage. Movements of the injected particles were investigated by using single particle tracking techniques. We observed unidirectional and stop-and-go traffic as part of the intricate cytoplasmic movements in the yolk cell. We determined a velocity in the range of 0.19 - 0.40 μm/s for 40 particles moving along with the axial streaming in the early developmental stage (1 to 2 hours post fertilization) of the zebrafish embryos.

Chronic Effects of Fluoride Exposure on Growth, Metamorphosis, and Skeleton Development in Bufo gargarizans Larvae.

PubMed

Chai, Lihong; Wang, Hongyuan; Zhao, Hongfeng; Dong, Suiming

2017-04-01

Bufo gargarizans tadpoles were chronically exposed to waterborne fluoride at measured concentrations ranging from 0.4 to 61.2 mg F - /L for 70 days from Gosner stage 26 to completion of metamorphosis. The chronic exposure caused a concentration-dependent mortality in all tested fluoride concentrations. Total length, snout-to-vent length (SVL), body mass, and developmental stage of tadpoles were significantly inhibited at 42.6 mg F - /L. In addition, significant metamorphic delay and increase in size at completion of metamorphosis occurred after exposure to 19.8 mg F - /L. Moreover, 19.8 mg F - /L suppressed the bone mineralization of larvae at completion of metamorphosis. However, the bone mineralization could be enhanced by 4.1 mg F - /L. In conclusion, our results suggested that the presence of high concentrations of fluoride could increase mortality risk, delay metamorphosis, and suppress skeletal ossification in B. gargarizans larvae.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poudel, Saroj; Aryal, Niranjan; Lu, Chaofu

Camelina sativa is an annual oilseed crop that is under intensive development for renewable resources of biofuels and industrial oils. MicroRNAs, or miRNAs, are endogenously encoded small RNAs that play key roles in diverse plant biological processes. Here, we conducted deep sequencing on small RNA libraries prepared from camelina leaves, flower buds and two stages of developing seeds corresponding to initial and peak storage products accumulation. Computational analyses identified 207 known miRNAs belonging to 63 families, as well as 5 novel miRNAs. These miRNAs, especially members of the miRNA families, varied greatly in different tissues and developmental stages. The predictedmore » miRNA target genes are involved in a broad range of physiological functions including lipid metabolism. This report is the first step toward elucidating roles of miRNAs in C. sativa and will provide additional tools to improve this oilseed crop for biofuels and biomaterials.« less

Earth-to-orbit reusable launch vehicles: A comparative assessment

NASA Technical Reports Server (NTRS)

Chase, R. L.

1978-01-01

A representative set of space systems, functions, and missions for NASA and DoD from which launch vehicle requirements and characteristics was established as well as a set of air-breathing launch vehicles based on graduated technology capabilities corresponding to increasingly higher staging Mach numbers. The utility of the air-breathing launch vehicle candidates based on lift-off weight, performance, technology needs, and risk was assessed and costs were compared to alternative concepts. The results indicate that a fully reusable launch vehicle, whether two stage or one stage, could potentially reduce the cost per flight 60-80% compared to that for a partially reusable vehicle but would require advances in thermal protection system technology. A two-stage-to-orbit, parallel-lift vehicle with an air-breathing booster would cost approximately the same as a single-stage-to-orbit vehicle, but the former would have greater flexibility and a significantly reduced developmental risk. A twin-booster, subsonic-staged, parallel-lift vehicle represents the lowest system cost and developmental risk. However, if a large supersonic turbojet engine in the 350,000-N thrust class were available, supersonic staging would be preferred, and the investment in development would be returned in reduced program cost.

Variability of Bacterial Communities in the Moth Heliothis virescens Indicates Transient Association with the Host

PubMed Central

Staudacher, Heike; Kaltenpoth, Martin; Breeuwer, Johannes A. J.; Menken, Steph B. J.; Heckel, David G.; Groot, Astrid T.

2016-01-01

Microbes associated with insects can confer a wide range of ecologically relevant benefits to their hosts. Since insect-associated bacteria often increase the nutritive value of their hosts' diets, the study of bacterial communities is especially interesting in species that are important agricultural pests. We investigated the composition of bacterial communities in the noctuid moth Heliothis virescens and its variability in relation to developmental stage, diet and population (field and laboratory), using bacterial tag-encoded FLX pyrosequencing of 16S rRNA amplicons. In larvae, bacterial communities differed depending on the food plant on which they had been reared, although the within-group variation between biological replicates was high as well. Moreover, larvae originating from a field or laboratory population did not share any OTUs. Interestingly, Enterococcus sp. was found to be the dominant taxon in laboratory-reared larvae, but was completely absent from field larvae, indicating dramatic shifts in microbial community profiles upon cultivation of the moths in the laboratory. Furthermore, microbiota composition varied strongly across developmental stages in individuals of the field population, and we found no evidence for vertical transmission of bacteria from mothers to offspring. Since sample sizes in our study were small due to pooling of samples for sequencing, we cautiously conclude that the high variability in bacterial communities suggests a loose and temporary association of the identified bacteria with H. virescens. PMID:27139886

Altus aircraft on runway

NASA Technical Reports Server (NTRS)

1996-01-01

The remotely piloted Altus aircraft flew several developmental test flights from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif., in 1996. The Altus--the word is Latin for 'high'--is a variant of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. It is designed for high-altitude, long-duration scientific sampling missions, and is powered by a turbocharged four-cylinder piston engine. The first Altus was developed under NASA's Environmental Research Aircraft and Sensor Technology program, while a second Altus was built for a Naval Postgraduate School/Department of Energy program. A pilot in a control station on the ground flew the craft by radio signals, using visual cues from a video camera in the nose of the Altus and information from the craft's air data system. Equipped with a single-stage turbocharger during the 1996 test flights, the first Altus reached altitudes in the 37,000-foot range, while the similarly-equipped second Altus reached 43,500 feet during developmental flights at Dryden in the summer of 1997. The NASA Altus also set an endurance record of more than 26 hours while flying a science mission in late 1996 and still had an estimated 10 hours of fuel remaining when it landed. Now equipped with a two-stage turbocharger, the NASA Altus maintained an altitude of 55,000 feet for four hours during flight tests in 1999.

Effect of temperature on the development and survival of immature stages of the carambola fruit fly, Bactrocera carambolae, and the Asian papaya fruit fly, Bactrocera papayae, reared on guava diet

PubMed Central

Danjuma, Solomon; Thaochan, Narit; Permkam, Surakrai; Satasook, Chutamas

2014-01-01

Abstract Members of the Bactrocera dorsalis Hendel (Diptera: Tephritidae) complex constitute well-recognized destructive pests of fruits in peninsular Thailand. The development and survival of immature stages of the carambola fruit fly, Bactrocera carambolae Drew & Hancock, and the Asian papaya fruit fly, Bactrocera papayae Drew & Hancock , were compared at six constant temperatures of 15, 20, 25, 27, 30, and 35°C, 70 ± 5% relative humidity, and a photoperiod of 12:12 (L:D). The objectives were to determine the effect of temperature on the developmental stages for optimizing rearing and to understand the geographical pattern of occurrence of these fruit fly species. A strong and positive linear relationship was observed between temperature and developmental rate of immature stages of B. carambolae. Similarly, a strong and positive linear relationship was observed between temperature and developmental rate of B. papayae. A temperature summation model was used to estimate the lower threshold temperature and the thermal constant. Bactrocera papayae was significantly faster in development and higher in survival and appeared to be better adapted to low temperatures than B. carambolae, as it exhibited the lowest threshold temperatures at all immature stages. The observed differences in response to various temperatures revealed to some extent the impact of temperature on these species’ distribution in peninsular Thailand and other parts of the world. PMID:25368070

Post-Larval Developmental Trajectory of Zebrafish Fry is Altered by Exposure to T3 or T4 Analogues

EPA Science Inventory

The thyroid axis plays a key role in development. While the impacts of perturbing thyroid axis development and/or function are documented in embryonic and larval zebrafish, the effects on developmental milestones at later life stages are not well-delineated. To assess potential l...

Scientific and Policy Statements on Environmental Agents Associated with Neurodevelopmental Disorders

ERIC Educational Resources Information Center

Gilbert, Steven G.; Miller, Elise; Martin, Joyce; Abulafia, Laura

2010-01-01

Damage to the brain or nervous system at an early developmental stage creates lifelong challenges for the individual. To examine one source of harm to the developing nervous system, the Collaborative on Health and the Environment's (CHE) Learning and Developmental Disabilities Initiative (LDDI) (Collaborative on Health and the Environment, 2009)…

Developmental Arrest at the Logographic Stage: Impaired Literacy Functions in Klinefelter's XXXY Syndrome.

ERIC Educational Resources Information Center

Seymour, Philip H. K.; Evans, Henryka M.

1988-01-01

Reports a case study of the reading and spelling processes of a developmentally disabled child indicating that there was almost a complete lack of alphabetic functions, that reading appeared to be based on a "logographic lexicon," and that spelling was based on a letter sequence generator. (RS)

Toxicity Screening of the ToxCast Phase II Chemical Library Using a Zebrafish Developmental Assay (SOT)

EPA Science Inventory

As part of the chemical screening and prioritization research program of the US EPA, the ToxCast Phase II chemicals were assessed using a vertebrate screen for developmental toxicity. Zebrafish embryos (Danio rerio) were exposed in 96-well plates from late-blastula stage (6hr pos...

The Developmental Process of Clinical Supervisors in Training: An Investigation of the Supervisor Complexity Model.

ERIC Educational Resources Information Center

Baker, Stanley B.; Exum, Herbert A.; Tyler, Richard E.

2002-01-01

Investigates the supervisor complexity model (SCM) using the Psychotherapy Supervisor Development Scale (PSDS) to ascertain development over a 15-week supervision practicum for 12 doctoral students. A set of retrospective interview questions produced responses used to investigate the viability of the 4 proposed discrete developmental stages in the…

The Effects of Television on Children. Foundation for Child and Youth Studies Selected Papers Number 47.

ERIC Educational Resources Information Center

Tregoning, Julia

This paper begins with an introduction which covers viewing time; television as a significant developmental experience; Piagetian stages of cognitive development; and changing developmental tastes in television viewing. The paper then focuses on television in relation to learning; television and violence; advertising; and parents' ability to…

The Implications of Cognitive-Developmental Theory for Law Related Curriculum in the Elementary School.

ERIC Educational Resources Information Center

Cole, Peggy

Law-related education programs for elementary school should be based on children's perceptions of reality. Psychologist Jean Piaget's studies of cognitive development indicate that children constantly reconstruct reality as they undergo new experiences. Children at early developmental stages may not be capable of understanding the origin and…

Verbal Communication in Museum Programs for Young Children: Perspectives from Greece and the U.K.

ERIC Educational Resources Information Center

Synodi, Evanthia

2014-01-01

This comparative study explores the verbal communication between museum educators and young children, based on principles of developmental psychology. In early developmental stages, when student learning is greatly dependent on verbal communications from the teacher, observation skills may be developed through purposeful instruction. Through the…

Validating an Online Assessment of Developmental Spelling in Grades Five through Eight

ERIC Educational Resources Information Center

Gehsmann, Kristin; Spichtig, Alexandra; Tousley, Elias

2017-01-01

Assessments of developmental spelling, also called spelling inventories, are commonly used to understand students' orthographic knowledge (i.e., knowledge of how written words work) and to determine their stages of spelling and reading development. The information generated by these assessments is used to inform teachers' grouping practices and…

The Juvenile Transition: A Developmental Switch Point in Human Life History

ERIC Educational Resources Information Center

Del Giudice, Marco; Angeleri, Romina; Manera, Valeria

2009-01-01

This paper presents a new perspective on the transition from early to middle childhood (i.e., human juvenility), investigated in an integrative evolutionary framework. Juvenility is a crucial life history stage, when social learning and interaction with peers become central developmental functions; here it is argued that the "juvenile transition"…

Phenylpropanoid biosynthesis in leaves and glandular trichomes of basil (Ocimum basilicum L.).

PubMed

Deschamps, Cícero; Simon, James E

2010-01-01

Basil (Ocimum basilicum L.) essential oil phenylpropenes are synthesized and accumulate in peltate glandular trichomes and their content and composition depend on plant developmental stage. Studies on gene expression and enzymatic activity indicate that the phenylpropene biosynthetic genes are developmentally regulated. In this study, the methylchavicol accumulation in basil leaves and the enzyme activities and gene expression of both chavicol O-methyltransferase (CVOMT) and eugenol O-methyltransferase (EOMT) were investigated in all leaves at four plant developmental stages. Methylchavicol accumulation decreased over time as leaves matured. There was a significant correlation between methylchavicol accumulation and CVOMT (r(2) = 0.88) enzyme activity, suggesting that the levels of biosynthetic enzymes control the essential oil content. CVOMT and EOMT transcript expression levels, which decreased with leaf age, followed the same pattern in both whole leaves and isolated glandular trichomes, providing evidence that CVOMT transcript levels are developmentally regulated in basil glandular trichomes themselves and that differences in CVOMT expression observed in whole leaves are not solely the result of differences in glandular trichome density.

Effects of temperature on the development and survival of eggs of four coastal California fishes

USGS Publications Warehouse

Gadomski, D.M.; Caddell, S.M.

1996-01-01

Laboratory experiments were conducted to determine the effects of temperature on egg development and survival of four fish species found off southern California. Our objectives were to further understanding ofnatural spawning patterns and to aid in identifying and ageing field-collected specimens. An egg-staging procedure was devised and eggs were observed every two hours during development at a range of temperatures (8-28°Cl. Barred sand bass, Parolabrax nebulifer, eggs survived to hatching and produced viable embryos at the highest temperature range (l6-28°C), reflecting this species'summerspawning season. Fantail sole, Xystreurys liolepis, eggs also hatched at a higher temperature range (l6-24°C). This species spawns primarily from summer through fall. Eggs of the two species with winter-spring spawning peaks, white croaker, Genyonemuslineatus, and California halibut, Paralichthys californicus, had lower temperature-tolerance ranges (12- 2O"C). Developmental rate at a specific temperature did not significantly differ between species, whereas within tolerance limits, temperature strongly affected rate of development for all species. Time to hatching for all species was inversely related to temperature, and the relationship was approximately exponential. Species-specific differences in egg-stage sequence were observed; embryonic organogenesisin relation to germ-ring migration and blastopore closure was faster for barred sand bass and fantail sole than for white croaker and California halibut.

In Situ Imaging of Tissue Remodeling with Collagen Hybridizing Peptides

PubMed Central

2017-01-01

Collagen, the major structural component of nearly all mammalian tissues, undergoes extensive proteolytic remodeling during developmental states and a variety of life-threatening diseases such as cancer, myocardial infarction, and fibrosis. While degraded collagen could be an important marker of tissue damage, it is difficult to detect and target using conventional tools. Here, we show that a designed peptide (collagen hybridizing peptide: CHP), which specifically hybridizes to the degraded, unfolded collagen chains, can be used to image degraded collagen and inform tissue remodeling activity in various tissues: labeled with 5-carboxyfluorescein and biotin, CHPs enabled direct localization and quantification of collagen degradation in isolated tissues within pathologic states ranging from osteoarthritis and myocardial infarction to glomerulonephritis and pulmonary fibrosis, as well as in normal tissues during developmental programs associated with embryonic bone formation and skin aging. The results indicate the general correlation between the level of collagen remodeling and the amount of denatured collagen in tissue and show that the CHP probes can be used across species and collagen types, providing a versatile tool for not only pathology and developmental biology research but also histology-based disease diagnosis, staging, and therapeutic screening. This study lays the foundation for further testing CHP as a targeting moiety for theranostic delivery in various animal models. PMID:28877431

Meeting report on the 3rd International Congress on Developmental Origins of Health and Disease (DOHaD).

PubMed

Gillman, Matthew W; Barker, David; Bier, Dennis; Cagampang, Felino; Challis, John; Fall, Caroline; Godfrey, Keith; Gluckman, Peter; Hanson, Mark; Kuh, Diana; Nathanielsz, Peter; Nestel, Penelope; Thornburg, Kent L

2007-05-01

Developmental origins of health and disease (DOHaD) focuses on the earliest stages of human development, and provides a novel paradigm to complement other strategies for lifelong prevention of common chronic health conditions. The 3 International Congress on DOHaD, held in 2005, retained the most popular features from the first two biannual Congresses, while adding a number of innovations, including increased emphasis on implications of DOHaD for the developing world; programs for trainees and young investigators; and new perspectives, including developmental plasticity, influences of social hierarchies, effects of prematurity, and populations in transition. Emerging areas of science included, first, the controversial role of infant weight gain in predicting adult obesity, diabetes, and cardiovascular disease. Second, in the era of epidemic obesity, paying attention to the over-nourished fetus is as important as investigating the growth retarded one. Third, environmental toxins appear to have abroad range of long-lasting effects on the developing human. Fourth, epigenetic mechanisms could unite several strands of human and animal observations, and explain how genetically identical individuals raised in similar postnatal environments can nonetheless develop widely differing phenotypes. Improving the environment to which an individual is exposed during development may be as important as any other public health effort to enhance population health world wide.

Why are children overconfident? Developmental differences in the implementation of accessibility cues when judging concept learning.

PubMed

van Loon, Mariëtte; de Bruin, Anique; Leppink, Jimmie; Roebers, Claudia

2017-06-01

Children are often overconfident when monitoring their learning, which is harmful for effective control and learning. The current study investigated children's (N=167, age range 7-12years) judgments of learning (JOLs) when studying difficult concepts. The main aims were (a) to investigate how JOL accuracy is affected by accessibility cues and (b) to investigate developmental changes in implementing accessibility cues in JOLs. After studying different concepts, children were asked to generate novel sentences and then to make JOLs, select concepts for restudy, and take a final test. Overconfidence for incorrect and incomplete test responses was reduced for older children in comparison with younger children. For older age groups, generating a sentence led to greater overconfidence compared with not being able to generate a sentence, which indicates that older children relied more on accessibility cues when making JOLs. This pattern differed in the youngest age group; younger children were generally overconfident regardless of whether they had generated sentences or not. Overconfidence was disadvantageous for effective control of learning for all age groups. These findings imply that instructions to encourage children to avoid metacognitive illusions need to be adapted to children's developmental stage. Copyright © 2017 Elsevier Inc. All rights reserved.

High Throughput Determination of Plant Height, Ground Cover, and Above-Ground Biomass in Wheat with LiDAR

PubMed Central

Jimenez-Berni, Jose A.; Deery, David M.; Rozas-Larraondo, Pablo; Condon, Anthony (Tony) G.; Rebetzke, Greg J.; James, Richard A.; Bovill, William D.; Furbank, Robert T.; Sirault, Xavier R. R.

2018-01-01

Crop improvement efforts are targeting increased above-ground biomass and radiation-use efficiency as drivers for greater yield. Early ground cover and canopy height contribute to biomass production, but manual measurements of these traits, and in particular above-ground biomass, are slow and labor-intensive, more so when made at multiple developmental stages. These constraints limit the ability to capture these data in a temporal fashion, hampering insights that could be gained from multi-dimensional data. Here we demonstrate the capacity of Light Detection and Ranging (LiDAR), mounted on a lightweight, mobile, ground-based platform, for rapid multi-temporal and non-destructive estimation of canopy height, ground cover and above-ground biomass. Field validation of LiDAR measurements is presented. For canopy height, strong relationships with LiDAR (r2 of 0.99 and root mean square error of 0.017 m) were obtained. Ground cover was estimated from LiDAR using two methodologies: red reflectance image and canopy height. In contrast to NDVI, LiDAR was not affected by saturation at high ground cover, and the comparison of both LiDAR methodologies showed strong association (r2 = 0.92 and slope = 1.02) at ground cover above 0.8. For above-ground biomass, a dedicated field experiment was performed with destructive biomass sampled eight times across different developmental stages. Two methodologies are presented for the estimation of biomass from LiDAR: 3D voxel index (3DVI) and 3D profile index (3DPI). The parameters involved in the calculation of 3DVI and 3DPI were optimized for each sample event from tillering to maturity, as well as generalized for any developmental stage. Individual sample point predictions were strong while predictions across all eight sample events, provided the strongest association with biomass (r2 = 0.93 and r2 = 0.92) for 3DPI and 3DVI, respectively. Given these results, we believe that application of this system will provide new opportunities to deliver improved genotypes and agronomic interventions via more efficient and reliable phenotyping of these important traits in large experiments. PMID:29535749

High Throughput Determination of Plant Height, Ground Cover, and Above-Ground Biomass in Wheat with LiDAR.

PubMed

Jimenez-Berni, Jose A; Deery, David M; Rozas-Larraondo, Pablo; Condon, Anthony Tony G; Rebetzke, Greg J; James, Richard A; Bovill, William D; Furbank, Robert T; Sirault, Xavier R R

2018-01-01

Crop improvement efforts are targeting increased above-ground biomass and radiation-use efficiency as drivers for greater yield. Early ground cover and canopy height contribute to biomass production, but manual measurements of these traits, and in particular above-ground biomass, are slow and labor-intensive, more so when made at multiple developmental stages. These constraints limit the ability to capture these data in a temporal fashion, hampering insights that could be gained from multi-dimensional data. Here we demonstrate the capacity of Light Detection and Ranging (LiDAR), mounted on a lightweight, mobile, ground-based platform, for rapid multi-temporal and non-destructive estimation of canopy height, ground cover and above-ground biomass. Field validation of LiDAR measurements is presented. For canopy height, strong relationships with LiDAR ( r 2 of 0.99 and root mean square error of 0.017 m) were obtained. Ground cover was estimated from LiDAR using two methodologies: red reflectance image and canopy height. In contrast to NDVI, LiDAR was not affected by saturation at high ground cover, and the comparison of both LiDAR methodologies showed strong association ( r 2 = 0.92 and slope = 1.02) at ground cover above 0.8. For above-ground biomass, a dedicated field experiment was performed with destructive biomass sampled eight times across different developmental stages. Two methodologies are presented for the estimation of biomass from LiDAR: 3D voxel index (3DVI) and 3D profile index (3DPI). The parameters involved in the calculation of 3DVI and 3DPI were optimized for each sample event from tillering to maturity, as well as generalized for any developmental stage. Individual sample point predictions were strong while predictions across all eight sample events, provided the strongest association with biomass ( r 2 = 0.93 and r 2 = 0.92) for 3DPI and 3DVI, respectively. Given these results, we believe that application of this system will provide new opportunities to deliver improved genotypes and agronomic interventions via more efficient and reliable phenotyping of these important traits in large experiments.

On the number of genes controlling the grass stage in longleaf pine

Treesearch

C. Dana Nelson; C. Weng; Thomas L. Kubisiak; M. Stine; C.L. Brown

2003-01-01

The grass stage is an inherent and distinctive developmental trait of longleaf pine (Pinus palustris), in which height growth in the first few years after germination is suppressed. In operational forestry practice the grass stage extends for nvo to several years and often plays a role in planting failures and decisions to plant alternative species....

PXD101 significantly improves nuclear reprogramming and the in vitro developmental competence of porcine SCNT embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Jun-Xue; Kang, Jin-Dan; Li, Suo

2015-01-02

Highlights: • First explored that the effects of PXD101 on the development of SCNT embryos in vitro. • 0.5 μM PXD101 treated for 24 h improved the development of porcine SCNT embryos. • Level of AcH3K9 was significantly higher than control group at early stages. - Abstract: In this study, we investigated the effects of the histone deacetylase inhibitor PXD101 (belinostat) on the preimplantation development of porcine somatic cell nuclear transfer (SCNT) embryos and their expression of the epigenetic markers histone H3 acetylated at lysine 9 (AcH3K9). We compared the in vitro developmental competence of SCNT embryos treated with variousmore » concentrations of PXD101 for 24 h. Treatment with 0.5 μM PXD101 significantly increased the proportion of SCNT embryos that reached the blastocyst stage, in comparison to the control group (23.3% vs. 11.5%, P < 0.05). We tested the in vitro developmental competence of SCNT embryos treated with 0.5 μM PXD101 for various amounts of times following activation. Treatment for 24 h significantly improved the development of porcine SCNT embryos, with a significantly higher proportion of embryos reaching the blastocyst stage in comparison to the control group (25.7% vs. 10.6%, P < 0.05). PXD101-treated SCNT embryos were transferred into two surrogate sows, one of whom became pregnant and four fetuses developed. PXD101 treatment significantly increased the fluorescence intensity of immunostaining for AcH3K9 in embryos at the pseudo-pronuclear and 2-cell stages. At these stages, the fluorescence intensities of immunostaining for AcH3K9 were significantly higher in PXD101-treated embryos than in control untreated embryos. In conclusion, this study demonstrates that PXD101 can significantly improve the in vitro and in vivo developmental competence of porcine SCNT embryos and can enhance their nuclear reprogramming.« less

Silver nanoparticles induce developmental stage-specific embryonic phenotypes in zebrafish

NASA Astrophysics Data System (ADS)

Lee, Kerry J.; Browning, Lauren M.; Nallathamby, Prakash D.; Osgood, Christopher J.; Xu, Xiao-Hong Nancy

2013-11-01

Much is anticipated from the development and deployment of nanomaterials in biological organisms, but concerns remain regarding their biocompatibility and target specificity. Here we report our study of the transport, biocompatibility and toxicity of purified and stable silver nanoparticles (Ag NPs, 13.1 +/- 2.5 nm in diameter) upon the specific developmental stages of zebrafish embryos using single NP plasmonic spectroscopy. We find that single Ag NPs passively diffuse into five different developmental stages of embryos (cleavage, early-gastrula, early-segmentation, late-segmentation, and hatching stages), showing stage-independent diffusion modes and diffusion coefficients. Notably, the Ag NPs induce distinctive stage and dose-dependent phenotypes and nanotoxicity, upon their acute exposure to the Ag NPs (0-0.7 nM) for only 2 h. The late-segmentation embryos are most sensitive to the NPs with the lowest critical concentration (CNP,c << 0.02 nM) and highest percentages of cardiac abnormalities, followed by early-segmentation embryos (CNP,c < 0.02 nM), suggesting that disruption of cell differentiation by the NPs causes the most toxic effects on embryonic development. The cleavage-stage embryos treated with the NPs develop into a wide variety of phenotypes (abnormal finfold, tail/spinal cord flexure, cardiac malformation/edema, yolk sac edema, and acephaly). These organ structures are not yet developed in cleavage-stage embryos, suggesting that the earliest determinative events to create these structures are ongoing, and disrupted by NPs, which leads to the downstream effects. In contrast, the hatching embryos are most resistant to the Ag NPs, and majority of embryos (94%) develop normally, and none of them develop abnormally. Interestingly, early-gastrula embryos are less sensitive to the NPs than cleavage and segmentation stage embryos, and do not develop abnormally. These important findings suggest that the Ag NPs are not simple poisons, and they can target specific pathways in development, and potentially enable target specific study and therapy for early embryonic development.Much is anticipated from the development and deployment of nanomaterials in biological organisms, but concerns remain regarding their biocompatibility and target specificity. Here we report our study of the transport, biocompatibility and toxicity of purified and stable silver nanoparticles (Ag NPs, 13.1 +/- 2.5 nm in diameter) upon the specific developmental stages of zebrafish embryos using single NP plasmonic spectroscopy. We find that single Ag NPs passively diffuse into five different developmental stages of embryos (cleavage, early-gastrula, early-segmentation, late-segmentation, and hatching stages), showing stage-independent diffusion modes and diffusion coefficients. Notably, the Ag NPs induce distinctive stage and dose-dependent phenotypes and nanotoxicity, upon their acute exposure to the Ag NPs (0-0.7 nM) for only 2 h. The late-segmentation embryos are most sensitive to the NPs with the lowest critical concentration (CNP,c << 0.02 nM) and highest percentages of cardiac abnormalities, followed by early-segmentation embryos (CNP,c < 0.02 nM), suggesting that disruption of cell differentiation by the NPs causes the most toxic effects on embryonic development. The cleavage-stage embryos treated with the NPs develop into a wide variety of phenotypes (abnormal finfold, tail/spinal cord flexure, cardiac malformation/edema, yolk sac edema, and acephaly). These organ structures are not yet developed in cleavage-stage embryos, suggesting that the earliest determinative events to create these structures are ongoing, and disrupted by NPs, which leads to the downstream effects. In contrast, the hatching embryos are most resistant to the Ag NPs, and majority of embryos (94%) develop normally, and none of them develop abnormally. Interestingly, early-gastrula embryos are less sensitive to the NPs than cleavage and segmentation stage embryos, and do not develop abnormally. These important findings suggest that the Ag NPs are not simple poisons, and they can target specific pathways in development, and potentially enable target specific study and therapy for early embryonic development. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03210h

Dynamic Proteomic Characteristics and Network Integration Revealing Key Proteins for Two Kernel Tissue Developments in Popcorn.

PubMed

Dong, Yongbin; Wang, Qilei; Zhang, Long; Du, Chunguang; Xiong, Wenwei; Chen, Xinjian; Deng, Fei; Ma, Zhiyan; Qiao, Dahe; Hu, Chunhui; Ren, Yangliu; Li, Yuling

2015-01-01

The formation and development of maize kernel is a complex dynamic physiological and biochemical process that involves the temporal and spatial expression of many proteins and the regulation of metabolic pathways. In this study, the protein profiles of the endosperm and pericarp at three important developmental stages were analyzed by isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with LC-MS/MS in popcorn inbred N04. Comparative quantitative proteomic analyses among developmental stages and between tissues were performed, and the protein networks were integrated. A total of 6,876 proteins were identified, of which 1,396 were nonredundant. Specific proteins and different expression patterns were observed across developmental stages and tissues. The functional annotation of the identified proteins revealed the importance of metabolic and cellular processes, and binding and catalytic activities for the development of the tissues. The whole, endosperm-specific and pericarp-specific protein networks integrated 125, 9 and 77 proteins, respectively, which were involved in 54 KEGG pathways and reflected their complex metabolic interactions. Confirmation for the iTRAQ endosperm proteins by two-dimensional gel electrophoresis showed that 44.44% proteins were commonly found. However, the concordance between mRNA level and the protein abundance varied across different proteins, stages, tissues and inbred lines, according to the gene cloning and expression analyses of four relevant proteins with important functions and different expression levels. But the result by western blot showed their same expression tendency for the four proteins as by iTRAQ. These results could provide new insights into the developmental mechanisms of endosperm and pericarp, and grain formation in maize.

Dynamic Proteomic Characteristics and Network Integration Revealing Key Proteins for Two Kernel Tissue Developments in Popcorn

PubMed Central

Du, Chunguang; Xiong, Wenwei; Chen, Xinjian; Deng, Fei; Ma, Zhiyan; Qiao, Dahe; Hu, Chunhui; Ren, Yangliu; Li, Yuling

2015-01-01

The formation and development of maize kernel is a complex dynamic physiological and biochemical process that involves the temporal and spatial expression of many proteins and the regulation of metabolic pathways. In this study, the protein profiles of the endosperm and pericarp at three important developmental stages were analyzed by isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with LC-MS/MS in popcorn inbred N04. Comparative quantitative proteomic analyses among developmental stages and between tissues were performed, and the protein networks were integrated. A total of 6,876 proteins were identified, of which 1,396 were nonredundant. Specific proteins and different expression patterns were observed across developmental stages and tissues. The functional annotation of the identified proteins revealed the importance of metabolic and cellular processes, and binding and catalytic activities for the development of the tissues. The whole, endosperm-specific and pericarp-specific protein networks integrated 125, 9 and 77 proteins, respectively, which were involved in 54 KEGG pathways and reflected their complex metabolic interactions. Confirmation for the iTRAQ endosperm proteins by two-dimensional gel electrophoresis showed that 44.44% proteins were commonly found. However, the concordance between mRNA level and the protein abundance varied across different proteins, stages, tissues and inbred lines, according to the gene cloning and expression analyses of four relevant proteins with important functions and different expression levels. But the result by western blot showed their same expression tendency for the four proteins as by iTRAQ. These results could provide new insights into the developmental mechanisms of endosperm and pericarp, and grain formation in maize. PMID:26587848

Transgenic C. elegans dauer larvae expressing hookworm phospho null DAF-16/FoxO exit dauer.

PubMed

Gelmedin, Verena; Brodigan, Thomas; Gao, Xin; Krause, Michael; Wang, Zhu; Hawdon, John M

2011-01-01

Parasitic hookworms and the free-living model nematode Caenorhabtidis elegans share a developmental arrested stage, called the dauer stage in C. elegans and the infective third-stage larva (L3) in hookworms. One of the key transcription factors that regulate entrance to and exit from developmental arrest is the forkhead transcription factor DAF-16/FoxO. During the dauer stage, DAF-16 is activated and localized in the nucleus. DAF-16 is negatively regulated by phosphorylation by the upstream kinase AKT, which causes DAF-16 to localize out of the nucleus and the worm to exit from dauer. DAF-16 is conserved in hookworms, and hypothesized to control recovery from L3 arrest during infection. Lacking reverse genetic techniques for use in hookworms, we used C. elegans complementation assays to investigate the function of Ancylostoma caninum DAF-16 during entrance and exit from L3 developmental arrest. We performed dauer switching assays and observed the restoration of the dauer phenotype when Ac-DAF-16 was expressed in temperature-sensitive dauer defective C. elegans daf-2(e1370);daf-16(mu86) mutants. AKT phosphorylation site mutants of Ac-DAF-16 were also able to restore the dauer phenotype, but surprisingly allowed dauer exit when temperatures were lowered. We used fluorescence microscopy to localize DAF-16 during dauer and exit from dauer in C. elegans DAF-16 mutant worms expressing Ac-DAF-16, and found that Ac-DAF-16 exited the nucleus during dauer exit. Surprisingly, Ac-DAF-16 with mutated AKT phosphorylation sites also exited the nucleus during dauer exit. Our results suggest that another mechanism may be involved in the regulation DAF-16 nuclear localization during recovery from developmental arrest.

Identification of chemicals inducing cardiomyocyte proliferation in developmental stage-specific manner with pluripotent stem cells.

PubMed

Uosaki, Hideki; Magadum, Ajit; Seo, Kinya; Fukushima, Hiroyuki; Takeuchi, Ayako; Nakagawa, Yasuaki; Moyes, Kara White; Narazaki, Genta; Kuwahara, Koichiro; Laflamme, Michael; Matsuoka, Satoshi; Nakatsuji, Norio; Nakao, Kazuwa; Kwon, Chulan; Kass, David A; Engel, Felix B; Yamashita, Jun K

2013-12-01

The proliferation of cardiomyocytes is highly restricted after postnatal maturation, limiting heart regeneration. Elucidation of the regulatory machineries for the proliferation and growth arrest of cardiomyocytes is imperative. Chemical biology is efficient to dissect molecular mechanisms of various cellular events and often provides therapeutic potentials. We have been investigating cardiovascular differentiation with pluripotent stem cells. The combination of stem cell and chemical biology can provide novel approaches to investigate the molecular mechanisms and manipulation of cardiomyocyte proliferation. To identify chemicals that regulate cardiomyocyte proliferation, we performed a screening of a defined chemical library based on proliferation of mouse pluripotent stem cell-derived cardiomyocytes and identified 4 chemical compound groups: inhibitors of glycogen synthase kinase-3, p38 mitogen-activated protein kinase, and Ca(2+)/calmodulin-dependent protein kinase II, and activators of extracellular signal-regulated kinase. Several appropriate combinations of chemicals synergistically enhanced proliferation of cardiomyocytes derived from both mouse and human pluripotent stem cells, notably up to a 14-fold increase in mouse cardiomyocytes. We also examined the effects of identified chemicals on cardiomyocytes in various developmental stages and species. Whereas extracellular signal-regulated kinase activators and Ca(2+)/calmodulin-dependent protein kinase II inhibitors showed proliferative effects only on cardiomyocytes in early developmental stages, glycogen synthase kinase-3 and p38 mitogen-activated protein kinase inhibitors substantially and synergistically induced re-entry and progression of cell cycle in neonatal but also as well as adult cardiomyocytes. Our approach successfully uncovered novel molecular targets and mechanisms controlling cardiomyocyte proliferation in distinct developmental stages and offered pluripotent stem cell-derived cardiomyocytes as a potent tool to explore chemical-based cardiac regenerative strategies.

Reactivation of larval keratin gene (krt62.L) in blastema epithelium during Xenopus froglet limb regeneration.

PubMed

Satoh, Akira; Mitogawa, Kazumasa; Saito, Nanami; Suzuki, Miyuki; Suzuki, Ken-Ichi T; Ochi, Haruki; Makanae, Aki

2017-12-15

Limb regeneration is considered a form of limb redevelopment because of the molecular and morphological similarities. Forming a regeneration blastema is, in essence, creating a developing limb bud in an adult body. This reactivation of a developmental process in a mature body is worth studying. Xenopus laevis has a biphasic life cycle that involves distinct larval and adult stages. These distinct developmental stages are useful for investigating the reactivation of developmental processes in post-metamorphic frogs (froglets). In this study, we focused on the re-expression of a larval gene (krt62.L) during Xenopus froglet limb regeneration. Recently renamed krt62.L, this gene was known as the larval keratin (xlk) gene, which is specific to larval-tadpole stages. During limb regeneration in a froglet, krt62.L was re-expressed in a basal layer of blastema epithelium, where adult-specific keratin (Krt12.6.S) expression was also observable. Nerves produce important regulatory factors for amphibian limb regeneration, and also play a role in blastema formation and maintenance. The effect of nerve function on krt62.L expression could be seen in the maintenance of krt62.L expression, but not in its induction. When an epidermis-stripped limb bud was grafted in a froglet blastema, the grafted limb bud could reach the digit-forming stage. This suggests that krt62.L-positive froglet blastema epithelium is able to support the limb development process. These findings imply that the developmental process is locally reactivated in an postmetamorphic body during limb regeneration. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Identification of Chemicals Inducing Cardiomyocyte Proliferation in Developmental Stage-Specific Manner with Pluripotent Stem Cells

PubMed Central

Uosaki, Hideki; Magadum, Ajit; Seo, Kinya; Fukushima, Hiroyuki; Takeuchi, Ayako; Nakagawa, Yasuaki; Moyes, Kara White; Narazaki, Genta; Kuwahara, Koichiro; Laflamme, Michael; Matsuoka, Satoshi; Nakatsuji, Norio; Nakao, Kazuwa; Kwon, Chulan; Kass, David A.; Engel, Felix B.; Yamashita, Jun K.

2013-01-01

Background The proliferation of cardiomyocytes is highly restricted after postnatal maturation, limiting heart regeneration. Elucidation of the regulatory machineries for the proliferation and growth arrest of cardiomyocytes is imperative. Chemical biology is efficient to dissect molecular mechanisms of various cellular events and often provide therapeutic potentials. We have been investigating cardiovascular differentiation with pluripotent stem cells (PSCs). The combination of stem cell and chemical biology can provide novel approaches to investigate the molecular mechanisms and manipulation of cardiomyocyte proliferation. Methods and Results To identify chemicals that regulate cardiomyocyte proliferation, we performed a screening of a defined chemical library based on proliferation of mouse PSC-derived cardiomyocytes and identified 4 chemical compound groups - inhibitors of glycogen synthase kinase-3 (GSK3), p38 mitogen-activated protein kinase (MAPK) and Ca2+/calmodulin-dependent protein kinase II (CaMKII), and activators of extracellular signal-regulated kinase (ERK). Several appropriate combinations of chemicals synergistically enhanced proliferation of cardiomyocytes derived from both mouse and human PSCs, notably up to a 14-fold increase in mouse cardiomyocytes. We also examined the effects of identified chemicals on cardiomyocytes in various developmental stages and species. Whereas ERK activators and CaMKII inhibitors showed proliferative effects only on cardiomyocytes in early developmental stages, GSK3 and p38 MAPK inhibitors substantially and synergistically induced reentry and progression of cell cycle in not only neonatal but also adult cardiomyocytes. Conclusions Our approach successfully uncovered novel molecular targets and mechanisms controlling cardiomyocyte proliferation in distinct developmental stages and offered PSC-derived cardiomyocytes as a potent tool to explore chemical-based cardiac regenerative strategies. PMID:24141057

A co-expression gene network associated with developmental regulation of apple fruit acidity.

PubMed

Bai, Yang; Dougherty, Laura; Cheng, Lailiang; Xu, Kenong

2015-08-01

Apple fruit acidity, which affects the fruit's overall taste and flavor to a large extent, is primarily determined by the concentration of malic acid. Previous studies demonstrated that the major QTL malic acid (Ma) on chromosome 16 is largely responsible for fruit acidity variations in apple. Recent advances suggested that a natural mutation that gives rise to a premature stop codon in one of the two aluminum-activated malate transporter (ALMT)-like genes (called Ma1) is the genetic causal element underlying Ma. However, the natural mutation does not explain the developmental changes of fruit malate levels in a given genotype. Using RNA-seq data from the fruit of 'Golden Delicious' taken at 14 developmental stages from 1 week after full-bloom (WAF01) to harvest (WAF20), we characterized their transcriptomes in groups of high (12.2 ± 1.6 mg/g fw, WAF03-WAF08), mid (7.4 ± 0.5 mg/g fw, WAF01-WAF02 and WAF10-WAF14) and low (5.4 ± 0.4 mg/g fw, WAF16-WAF20) malate concentrations. Detailed analyses showed that a set of 3,066 genes (including Ma1) were expressed not only differentially (P FDR < 0.05) between the high and low malate groups (or between the early and late developmental stages) but also in significant (P < 0.05) correlation with malate concentrations. The 3,066 genes fell in 648 MapMan (sub-) bins or functional classes, and 19 of them were significantly (P FDR < 0.05) co-enriched or co-suppressed in a malate dependent manner. Network inferring using the 363 genes encompassed in the 19 (sub-) bins, identified a major co-expression network of 239 genes. Since the 239 genes were also differentially expressed between the early (WAF03-WAF08) and late (WAF16-WAF20) developmental stages, the major network was considered to be associated with developmental regulation of apple fruit acidity in 'Golden Delicious'.

Effects of gamma radiation on the early developmental stages of Zebrafish (Danio rerio).

PubMed

Praveen Kumar, M K; Shyama, S K; Kashif, Shamim; Dubey, S K; Avelyno, D'costa; Sonaye, B H; Kadam Samit, B; Chaubey, R C

2017-08-01

The zebrafish is gaining importance as a popular vertebrate model organism and is widely employed in ecotoxicological studies, especially for the biomonitoring of pollution in water bodies. There is limited data on the genetic mechanisms governing the adverse health effects in regards to an early developmental exposure to gamma radiation. In the present study zebrafish (Danio rerio) embryos were exposed to 1, 2.5, 5, 7.5 and 10Gy of gamma radiation at 3h post fertilization (hpf). Different developmental toxicity endpoints were investigated. Further, expression of genes associated with the development and DNA damage i.e. (sox2 sox19a and p53) were evaluated using Quantitative PCR (qPCR). The significant changes in the expression of sox2 sox19a and p53 genes were observed. This data was supported the developmental defects observed in the zebrafish embryo exposed to gamma radiation such as i.e. increased DNA damage, decreased hatching rate, increase in median hatching time, decreased body length, increased mortality rate, increased morphological deformities. Further, study shows that the potential ecotoxicological threat of gamma radiation on the early developmental stages of zebrafish. Further, it revealed that the above parameters can be used as predictive biomarkers of gamma radiation exposure. Copyright © 2017. Published by Elsevier Inc.

Problematic gaming behaviour and health-related outcomes: A systematic review and meta-analysis.

PubMed

Männikkö, Niko; Ruotsalainen, Heidi; Miettunen, Jouko; Pontes, Halley M; Kääriäinen, Maria

2017-11-01

This systematic review and meta-analysis aimed to investigate the interplay between problematic gaming behaviour and health-related outcomes at different developmental stages. A total of 50 empirical studies met the specified inclusion criteria, and a meta-analysis using correlation coefficients was used for the studies that reported adverse health implications regarding the impact of problematic gaming behaviour on depression, anxiety, obsessive-compulsive disorder and somatisation. Overall, the results suggested that problematic gaming behaviour is significantly associated with a wide range of detrimental health-related outcomes. Finally, the limitations of this review alongside its implications were discussed and considered for future research.

A size threshold governs Caenorhabditis elegans developmental progression

PubMed Central

Uppaluri, Sravanti; Brangwynne, Clifford P.

2015-01-01

The growth of organisms from humans to bacteria is affected by environmental conditions. However, mechanisms governing growth and size control are not well understood, particularly in the context of changes in food availability in developing multicellular organisms. Here, we use a novel microfluidic platform to study the impact of diet on the growth and development of the nematode Caenorhabditis elegans. This device allows us to observe individual worms throughout larval development, quantify their growth as well as pinpoint the moulting transitions marking successive developmental stages. Under conditions of low food availability, worms grow very slowly, but do not moult until they have achieved a threshold size. The time spent in larval stages can be extended by over an order of magnitude, in agreement with a simple threshold size model. Thus, a critical worm size appears to trigger developmental progression, and may contribute to prolonged lifespan under dietary restriction. PMID:26290076

Developmental Flight Instrumentation System for the Crew Launch Vehicle

NASA Technical Reports Server (NTRS)

Crawford, Kevin; Thomas, John

2006-01-01

The National Aeronautics and Space Administration is developing a new launch vehicle to replace the Space Shuttle. The Crew Launch Vehicle (CLV) will be a combination of new design hardware and heritage Apollo and Space Shuttle hardware. The current CLV configuration is a 5 segment solid rocket booster first stage and a new upper stage design with a modified Apollo era J-2 engine. The current schedule has two test flights with a first stage and a structurally identical, but without engine, upper stage. Then there will be two more test flights with a full complement of flight hardware. After the completion of the test flights, the first manned flight to the International Space Station is scheduled for late 2012. To verify the CLV's design margins a developmental flight instrumentation (DFI) system is needed. The DFI system will collect environmental and health data from the various CLV subsystem's and either transmit it to the ground or store it onboard for later evaluation on the ground. The CLV consists of 4 major elements: the first stage, the upper stage, the upper stage engine and the integration of the first stage, upper stage and upper stage engine. It is anticipated that each of CLVs elements will have some version of DFI. This paper will discuss a conceptual DFI design for each element and also of an integrated CLV DFI system.

Coping Strategies and Perceived Social Support of Primiparous Adolescent Mothers

DTIC Science & Technology

1988-01-01

stage , which involves the individual’s stage of psychosocial and cognitive development , and their accrued social experiences (Garland & Bush, 1982... developed by D’Zurilla and Goldfried in 1971. The first stage of this five- stage model would involve helping the adolescent mother to recognize that problems...mothers: Developmental , biomedical, and psychosocial issues In J. B. Lancaster & B. A. Hamburg (Eds.), School-age pregnancy and parenthood (pp. 115

Interactions of sex and early life social experiences at two developmental stages shape nonapeptide receptor profiles.

PubMed

Hiura, Lisa C; Ophir, Alexander G

2018-05-31

Early life social experiences are critical to behavioral and cognitive development, and can have a tremendous influence on developing social phenotypes. Most work has focused on outcomes of experiences at a single stage of development (e.g., perinatal, or post-weaning). Few studies have assessed the impact of social experience at multiple developmental stages and across sex. Oxytocin and vasopressin are profoundly important for modulating social behavior and these nonapeptide systems are highly sensitive to developmental social experience, particularly in brain areas important for social behavior. We investigated whether oxytocin receptor (OTR) and vasopressin receptor (V1aR) distributions of prairie voles (Microtus ochrogaster) change as a function of parental composition within the natal nest or social composition after weaning. We raised pups either in the presence or absence of their fathers. At weaning, offspring were housed either individually or with a same-sex sibling. We also examined whether changes in receptor distributions are sexually dimorphic because the impact of the developmental environment on the nonapeptide system could be sex-dependent. We found that differences in nonapeptide receptor expression were region-, sex-, and rearing condition-specific, indicating a high level of complexity in the ways that early life experiences shape the social brain. We found many more differences in V1aR density compared to OTR density, indicating that nonapeptide receptors demonstrate differential levels of neural plasticity and sensitivity to environmental and biological variables. Our data highlight that critical factors including biological sex and multiple experiences across the developmental continuum interact in complex ways to shape the social brain. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Comparative ultrastructure of fruit plastids in three genetically diverse genotypes of apple (Malus × domestica Borkh.) during development.

PubMed

Schaeffer, Scott M; Christian, Ryan; Castro-Velasquez, Nohely; Hyden, Brennan; Lynch-Holm, Valerie; Dhingra, Amit

2017-10-01

Comparative ultrastructural developmental time-course analysis has identified discrete stages at which the fruit plastids undergo structural and consequently functional transitions to facilitate subsequent development-guided understanding of the complex plastid biology. Plastids are the defining organelle for a plant cell and are critical for myriad metabolic functions. The role of leaf plastid, chloroplast, is extensively documented; however, fruit plastids-chromoplasts-are poorly understood, especially in the context of the diverse metabolic processes operating in these diverse plant organs. Recently, in a comparative study of the predicted plastid-targeted proteomes across seven plant species, we reported that each plant species is predicted to harbor a unique set of plastid-targeted proteins. However, the temporal and developmental context of these processes remains unknown. In this study, an ultrastructural analysis approach was used to characterize fruit plastids in the epidermal and collenchymal cell layers at 11 developmental timepoints in three genotypes of apple (Malus × domestica Borkh.): chlorophyll-predominant 'Granny Smith', carotenoid-predominant 'Golden Delicious', and anthocyanin-predominant 'Top Red Delicious'. Plastids transitioned from a proplastid-like plastid to a chromoplast-like plastid in epidermis cells, while in the collenchyma cells, they transitioned from a chloroplast-like plastid to a chloro-chromo-amyloplast plastid. Plastids in the collenchyma cells of the three genotypes demonstrated a diverse array of structures and features. This study enabled the identification of discrete developmental stages during which specific functions are most likely being performed by the plastids as indicated by accumulation of plastoglobuli, starch granules, and other sub-organeller structures. Information regarding the metabolically active developmental stages is expected to facilitate biologically relevant omics studies to unravel the complex biochemistry of plastids in perennial non-model systems.

[The principle of the energy minimum in ontogeny and the channeling of developmental processes].

PubMed

Ozerniuk, N D

1989-01-01

The principle of minimum of energy in ontogenesis has been formulated on the basis of data concerning age changes in energetic metabolism, as well as the influence of ecological factors on this process. According to this principle the smallest expenditures of energy are observed in the zone of the most favorable developmental conditions. The minimal level of energetic metabolism at every developmental stage that corresponds to the most stable state of organism is treated as homeostasis and the developmental stability is treated as homeorrhesis. Regulation mechanisms of energetic metabolism during ontogenesis and under the influence of environmental factors are analyzed.

Regulatory gene networks and the properties of the developmental process

NASA Technical Reports Server (NTRS)

Davidson, Eric H.; McClay, David R.; Hood, Leroy

2003-01-01

Genomic instructions for development are encoded in arrays of regulatory DNA. These specify large networks of interactions among genes producing transcription factors and signaling components. The architecture of such networks both explains and predicts developmental phenomenology. Although network analysis is yet in its early stages, some fundamental commonalities are already emerging. Two such are the use of multigenic feedback loops to ensure the progressivity of developmental regulatory states and the prevalence of repressive regulatory interactions in spatial control processes. Gene regulatory networks make it possible to explain the process of development in causal terms and eventually will enable the redesign of developmental regulatory circuitry to achieve different outcomes.

Parental Legacy in Insects: Variation of Transgenerational Immune Priming during Offspring Development

PubMed Central

Trauer, Ute; Hilker, Monika

2013-01-01

In insects, a parental immune challenge can prepare and enhance offspring immune activity. Previous studies of such transgenerational immune priming (TGIP) mainly focused on a single offspring life stage. However, different developmental stages may be exposed to different risks and show different susceptibility to parental immune priming. Here we addressed the question (i) whether TGIP effects on the immunity of Manduca sexta offspring vary among the different developmental offspring stages. We differentiated between unchallenged and immunochallenged offspring; for the latter type of offspring, we further investigated (ii) whether TGIP has an impact on the time that enhanced immune levels persist after offspring immune challenge. Finally, we determined (iii) whether TGIP effects on offspring performance depend on the offspring stage. Our results show that TGIP effects on phenoloxidase (PO) activity, but not on antibacterial activity, vary among unchallenged offspring stages. In contrast, TGIP effects on PO and antibacterial activity did not vary among immunochallenged offspring stages. The persistence of enhanced immune levels in immunochallenged offspring was dependent on the parental immune state. Antibacterial (but not PO) activity in offspring of immunochallenged parents decreased over five days after pupal immune challenge, whereas no significant change over time was detectable in offspring of control parents. Finally, TGIP effects on the developmental time of unchallenged offspring varied among stages; young larvae of immunochallenged parents developed faster and gained more weight than larvae of control parents. However, offspring females of immunochallenged parents laid fewer eggs than females derived from control parents. These findings suggest that the benefits which the offspring gains from TGIP during juvenile development are paid by the adults with reduced reproductive power. Our study shows that TGIP effects vary among offspring stages and depend on the type of immunity (PO or antibacterial activity) as well as the time past offspring immune challenge. PMID:23700423

Ontogenetic modification in the Tuckerellidae (Acari: Tetranychoidea)

USDA-ARS?s Scientific Manuscript database

The Tuckerellidae is the only a phytophagous family within the Tetranychoidea (Acari) that retains the ancestral prostigmatan condition of three nymphal stages during development; however it is only the female developmental sequence that retains a tritonymphal stage. Adult females develop from a tr...

Developmental and microbiological analysis of the inception of bioluminescent symbiosis in the marine fish Nuchequula nuchalis (Perciformes: Leiognathidae).

PubMed

Dunlap, Paul V; Davis, Kimberly M; Tomiyama, Shinichi; Fujino, Misato; Fukui, Atsushi

2008-12-01

Many marine fish harbor luminous bacteria as bioluminescent symbionts. Despite the diversity, abundance, and ecological importance of these fish and their apparent dependence on luminous bacteria for survival and reproduction, little is known about developmental and microbiological events surrounding the inception of their symbioses. To gain insight on these issues, we examined wild-caught larvae of the leiognathid fish Nuchequula nuchalis, a species that harbors Photobacterium leiognathi as its symbiont, for the presence, developmental state, and microbiological status of the fish's internal, supraesophageal light organ. Nascent light organs were evident in the smallest specimens obtained, flexion larvae of 6.0 to 6.5 mm in notochord length (NL), a developmental stage at which the stomach had not yet differentiated and the nascent gasbladder had not established an interface with the light organ. Light organs of certain of the specimens in this size range apparently lacked bacteria, whereas light organs of other specimens of 6.5 mm in NL and of all larger specimens harbored large populations of bacteria, representatives of which were identified as P. leiognathi. Bacteria identified as Vibrio harveyi were also present in the light organ of one larval specimen. Light organ populations were composed typically of two or three genetically distinct strain types of P. leiognathi, similar to the situation in adult fish, and the same strain type was only rarely found in light organs of different larval, juvenile, or adult specimens. Light organs of larvae carried a smaller proportion of strains merodiploid for the lux-rib operon, 79 of 249 strains, than those of adults (75 of 91 strains). These results indicate that light organs of N. nuchalis flexion and postflexion larvae of 6.0 to 6.7 mm in NL are at an early stage of development and that inception of the symbiosis apparently occurs in flexion larvae of 6.0 to 6.5 mm in NL. Ontogeny of the light organ therefore apparently precedes acquisition of the symbiotic bacteria. Furthermore, bacterial populations in larval light organs near inception of the symbiosis are genetically diverse, like those of adult fish.

Developmental and Microbiological Analysis of the Inception of Bioluminescent Symbiosis in the Marine Fish Nuchequula nuchalis (Perciformes: Leiognathidae)▿

PubMed Central

Dunlap, Paul V.; Davis, Kimberly M.; Tomiyama, Shinichi; Fujino, Misato; Fukui, Atsushi

2008-01-01

Many marine fish harbor luminous bacteria as bioluminescent symbionts. Despite the diversity, abundance, and ecological importance of these fish and their apparent dependence on luminous bacteria for survival and reproduction, little is known about developmental and microbiological events surrounding the inception of their symbioses. To gain insight on these issues, we examined wild-caught larvae of the leiognathid fish Nuchequula nuchalis, a species that harbors Photobacterium leiognathi as its symbiont, for the presence, developmental state, and microbiological status of the fish's internal, supraesophageal light organ. Nascent light organs were evident in the smallest specimens obtained, flexion larvae of 6.0 to 6.5 mm in notochord length (NL), a developmental stage at which the stomach had not yet differentiated and the nascent gasbladder had not established an interface with the light organ. Light organs of certain of the specimens in this size range apparently lacked bacteria, whereas light organs of other specimens of 6.5 mm in NL and of all larger specimens harbored large populations of bacteria, representatives of which were identified as P. leiognathi. Bacteria identified as Vibrio harveyi were also present in the light organ of one larval specimen. Light organ populations were composed typically of two or three genetically distinct strain types of P. leiognathi, similar to the situation in adult fish, and the same strain type was only rarely found in light organs of different larval, juvenile, or adult specimens. Light organs of larvae carried a smaller proportion of strains merodiploid for the lux-rib operon, 79 of 249 strains, than those of adults (75 of 91 strains). These results indicate that light organs of N. nuchalis flexion and postflexion larvae of 6.0 to 6.7 mm in NL are at an early stage of development and that inception of the symbiosis apparently occurs in flexion larvae of 6.0 to 6.5 mm in NL. Ontogeny of the light organ therefore apparently precedes acquisition of the symbiotic bacteria. Furthermore, bacterial populations in larval light organs near inception of the symbiosis are genetically diverse, like those of adult fish. PMID:18978090

Expression of a hindlimb-determining factor Pitx1 in the forelimb of the lizard Pogona vitticeps during morphogenesis.

PubMed

Melville, Jane; Hunjan, Sumitha; McLean, Felicity; Mantziou, Georgia; Boysen, Katja; Parry, Laura J

2016-10-01

With over 9000 species, squamates, which include lizards and snakes, are the largest group of reptiles and second-largest order of vertebrates, spanning a vast array of appendicular skeletal morphology. As such, they provide a promising system for examining developmental and molecular processes underlying limb morphology. Using the central bearded dragon (Pogona vitticeps) as the primary study model, we examined limb morphometry throughout embryonic development and characterized the expression of three known developmental genes (GHR, Pitx1 and Shh) from early embryonic stage through to hatchling stage via reverse transcription quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC). In this study, all genes were found to be transcribed in both the forelimbs and hindlimbs of P. vitticeps. While the highest level of GHR expression occurred at the hatchling stage, Pitx1 and Shh expression was greatest earlier during embryogenesis, which coincides with the onset of the differentiation between forelimb and hindlimb length. We compared our finding of Pitx1 expression-a hindlimb-determining gene-in the forelimbs of P. vitticeps to that in a closely related Australian agamid lizard, Ctenophorus pictus, where we found Pitx1 expression to be more highly expressed in the hindlimb compared with the forelimb during early and late morphogenesis-a result consistent with that found across other tetrapods. Expression of Pitx1 in forelimbs has only rarely been documented, including via in situ hybridization in a chicken and a frog. Our findings from both RT-qPCR and IHC indicate that further research across a wider range of tetrapods is needed to more fully understand evolutionary variation in molecular processes underlying limb morphology. © 2016 The Authors.

Taxonomic and developmental aspects of radiosensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrison, F.L.; Anderson, S.L.

1996-11-01

Considerable information is available on the effects of radioactivity on adult and early life stages of organisms. The preponderance of data is on mortality after a single irradiation with relatively high doses. Unfortunately, because experiments were carried out under different conditions and for different time periods, the validity of comparing the results from different laxonomic groups is questionable. In general, the conclusions are that there is a relationship (1) between radioresistance to high doses of acute radiation and taxonomy of the organism, primitive forms being more radioresistant than complex vertebrates and (2) between radiosensitivity and developmental stage, early life stagesmore » being more sensitive than later stages. The first conclusion may be related to the capability of the organism to repopulate cells and to differentiate and redifferentiate them; the second to the rate of cellular division and to the degree of differentiation. In question, however, is the relevance of the responses from high levels of acute radiation to that of the responses to long-term exposure to low levels of radiation, which are ecologically of more interest. Data from studies of the effects of acute and chronic exposure on development of gametes and zygotes indicate that, for some fishes and invertebrates, responses at the cellular and molecular levels show effect levels comparable to those observed in some mammals. Acute doses between 0,05 and 0.5Cy and dose rates between 0.02 to 0.2mCy/h appear to define critical ranges in which detrimental effects on fertility are first observed in a variety of radiosensitive organisms. To better understand inherent radiosensitivity, we need more information on the ability of cells to repopulate and differentiate and to prevent or repair damage to biological critical molecules, such as DNA, because these factors may alter significantly organisms` responses to radiation.« less

Ecdysone receptor (EcR) and ultraspiracle (USP) genes from the cyclopoid copepod Paracyclopina nana: Identification and expression in response to water accommodated fractions (WAFs).

PubMed

Puthumana, Jayesh; Lee, Min-Chul; Han, Jeonghoon; Kim, Hui-Su; Hwang, Dae-Sik; Lee, Jae-Seong

2017-02-01

Ecdysteroid hormones are pivotal in the development, growth, and molting of arthropods, and the hormone pathway is triggered by binding ecdysteroid to a heterodimer of the two nuclear receptors; ecdysone receptors (EcR) and ultraspiracle (USP). We have characterized EcR and USP genes, and their 5'-untranslated region (5'-UTR) from the copepod Paracyclopina nana, and studied mRNA transcription levels in post-embryonic stages and in response to water accommodated fractions (WAFs) of crude oil. The open reading frames (ORF) of EcR and USP were 1470 and 1287bp that encoded 490 and 429 amino acids with molecular weight of 121.18 and 105.03kDa, respectively. Also, a well conserved DNA-binding domain (DBD) and ligand-binding domain (LBD) were identified which confirmed by phylogenetic analysis. Messenger RNA transcriptional levels of EcR and USP were developmental stage-specific in early post-embryonic stages (N3-4). However, an evoked expression of USP was observed throughout copepodid stage and in adult females. WAFs (40 and 80%) were acted as an ecdysone agonist in P. nana, and elicited the mRNA transcription levels in adults. Developmental stage-specific transcriptional activation of EcR and USP in response to WAFs was observed. USP gene was down-regulated in the nauplius in response to WAF, whereas up-regulation of USP was observed in the adults. This study represents the first data of molecular elucidation of EcR and USP genes and their regulatory elements from P. nana and the developmental stage specific expression in response to WAFs, which can be used as potential biomarkers for environmental stressors with ecotoxicological evaluations in copepods. Copyright © 2016 Elsevier Inc. All rights reserved.

Screening accuracy of the parent-completed Ages and Stages Questionnaires - second edition as a broadband screener for motor problems in preschoolers with autism spectrum disorders.

PubMed

Vanvuchelen, Marleen; Van Schuerbeeck, Lise; Braeken, Marijke Aka

2017-01-01

Children with autism spectrum disorders are at risk for motor problems. However, this area is often overlooked in the developmental evaluation in autism diagnostic clinics. An alternative can be to identify children who should receive intensive motor assessment by using a parent-based screener. The aim of this study was to examine whether the Ages and Stages Questionnaires - second edition may be used to identify gross and fine motor problems in children. High-functioning children with autism spectrum disorder (n = 43, 22-54 m) participated in this study. Sensitivity, specificity, predictive values and areas under the receiver operating characteristic curve were calculated by comparing the Ages and Stages Questionnaires - second edition scores to the developmental evaluation of the Peabody Developmental Motor Scale - second edition. The results revealed that both the Ages and Stages Questionnaires - second edition gross and fine motor domain may be used to identify children without motor problems. In contrast, sensitivity analyses revealed the likelihood of under screening motor problems in this population. The Ages and Stages Questionnaires - second edition met only the criteria of a fair to good accuracy to identify poor gross motor (sensitivity = 100%) and below-average fine motor development (sensitivity = 71%) in this sample. Hence, the capacity of the Ages and Stages Questionnaires - second edition to identify motor problems in preschoolers with autism spectrum disorder appears to be limited. It is recommended to include a formal standardized motor test in the diagnostic procedure for all children with autism spectrum disorder. © The Author(s) 2016.

Embryonic Developmental Stages of African Giant Catfish Heterobranchus longifilis (Valenciennes, 1840) (Teleostei, Clariidae)

NASA Astrophysics Data System (ADS)

Wilfred-Ekprikpo, P. C.

2016-02-01

One of the major challenges confronting the globe is the issue of food insecurity. This problem results from inadequate protein intake by humans especially those people from the third world countries. In order to arrest this ugly situation, there is the need to increase protein production by intensifying aquaculture. In sub-saharan Africa, particularly Nigeria, the major aquaculture species is African mud catfish (Clarias gariepinus) and its production has increase protein output but the protein deficit is still wide. Thus, necessitating the need to develop other aquaculture species endemic to the region. One of these species is Heterobranchus and there successful breeding depending on a good understanding of their biology. The embryonic developmental stages of Heterobranchus longifilis in freshwater tanks were determined. The first cleavage cell division occurred 30 minutes after fertilization of eggs while, the morula stage was observed within 2 hours. The blastula stage occurred between 2 and 8 hours, while the gastrula stage occurred between 12 and 18 hours. Thereafter, neurulation period, and embryonic body formation appeared. The optical vesicle and auditory vesicle formed. Finally muscular contraction, tail formation, heartbeat and hatching occurred. The embryonic developmental stage of H. longifilis started immediately the oocyte (egg) was fertilized and terminated when the embryo hatched from the chorion membranous wall. The young larva emerged from the embryonic membrane at 24.46 hrs with vigorous lashing of the caudal region against the chorion membrane. The average weight and length of the yolk larvae were 0.005g and 0.43 cm respectively. The percentage fertilization and hatchability rates were 82.50 and 65.10% respectively. The experiment revealed that Heterobranchus longifilis could be a good aquaculture species.

The RNA-Seq-based high resolution gene expression atlas of chickpea (Cicer arietinum L.) reveals dynamic spatio-temporal changes associated with growth and development.

PubMed

Kudapa, Himabindu; Garg, Vanika; Chitikineni, Annapurna; Varshney, Rajeev K

2018-04-10

Chickpea is one of the world's largest cultivated food legumes and is an excellent source of high-quality protein to the human diet. Plant growth and development are controlled by programmed expression of a suite of genes at the given time, stage, and tissue. Understanding how the underlying genome sequence translates into specific plant phenotypes at key developmental stages, information on gene expression patterns is crucial. Here, we present a comprehensive Cicer arietinum Gene Expression Atlas (CaGEA) across different plant developmental stages and organs covering the entire life cycle of chickpea. One of the widely used drought tolerant cultivars, ICC 4958 has been used to generate RNA-Seq data from 27 samples at 5 major developmental stages of the plant. A total of 816 million raw reads were generated and of these, 794 million filtered reads after quality control (QC) were subjected to downstream analysis. A total of 15,947 unique number of differentially expressed genes across different pairwise tissue combinations were identified. Significant differences in gene expression patterns contributing in the process of flowering, nodulation, and seed and root development were inferred in this study. Furthermore, differentially expressed candidate genes from "QTL-hotspot" region associated with drought stress response in chickpea were validated. © 2018 The Authors. Plant, Cell & Environment Published by John Wiley & Sons Ltd.

Transcriptome Dynamics during Maize Endosperm Development

PubMed Central

Feng, Jiaojiao; Xu, Shutu; Wang, Lei; Li, Feifei; Li, Yibo; Zhang, Renhe; Zhang, Xinghua; Xue, Jiquan; Guo, Dongwei

2016-01-01

The endosperm is a major organ of the seed that plays vital roles in determining seed weight and quality. However, genome-wide transcriptome patterns throughout maize endosperm development have not been comprehensively investigated to date. Accordingly, we performed a high-throughput RNA sequencing (RNA-seq) analysis of the maize endosperm transcriptome at 5, 10, 15 and 20 days after pollination (DAP). We found that more than 11,000 protein-coding genes underwent alternative splicing (AS) events during the four developmental stages studied. These genes were mainly involved in intracellular protein transport, signal transmission, cellular carbohydrate metabolism, cellular lipid metabolism, lipid biosynthesis, protein modification, histone modification, cellular amino acid metabolism, and DNA repair. Additionally, 7,633 genes, including 473 transcription factors (TFs), were differentially expressed among the four developmental stages. The differentially expressed TFs were from 50 families, including the bZIP, WRKY, GeBP and ARF families. Further analysis of the stage-specific TFs showed that binding, nucleus and ligand-dependent nuclear receptor activities might be important at 5 DAP, that immune responses, signalling, binding and lumen development are involved at 10 DAP, that protein metabolic processes and the cytoplasm might be important at 15 DAP, and that the responses to various stimuli are different at 20 DAP compared with the other developmental stages. This RNA-seq analysis provides novel, comprehensive insights into the transcriptome dynamics during early endosperm development in maize. PMID:27695101

Meeting report on the 3rd International Congress on Developmental Origins of Health and Disease (DOHaD)

USDA-ARS?s Scientific Manuscript database

Developmental Origins of Health and Disease (DOHaD) focuses on the earliest stages of human development, and provides a novel paradigm to complement other strategies for lifelong prevention of common chronic health conditions. The 3rd International Congress on DOHaD, held in 2005, retained the most ...

Evaluating Number Sense in Community College Developmental Math Students

ERIC Educational Resources Information Center

Steinke, Dorothea A.

2017-01-01

Community college developmental math students (N = 657) from three math levels were asked to place five whole numbers on a line that had only endpoints 0 and 20 marked. How the students placed the numbers revealed the same three stages of behavior that Steffe and Cobb (1988) documented in determining young children's number sense. 23% of the…

An Electro-Physiological Temporal Principal Component Analysis of Processing Stages of Number Comparison in Developmental Dyscalculia

ERIC Educational Resources Information Center

Soltesz, Fruzsina; Szucs, Denes

2009-01-01

Developmental dyscalculia (DD) still lacks a generally accepted definition. A major problem is that the cognitive component processes contributing to arithmetic performance are still poorly defined. By a reanalysis of our previous event-related brain potential (ERP) data (Soltesz et al., 2007) here our objective was to identify and compare…

A Study on the Developmental Characteristics of Adverbial Conjuncts by Chinese Non-English Majors

ERIC Educational Resources Information Center

Junmei, Jiang

2015-01-01

Based on the Chinese Learner English Corpus, the present study seeks to investigate the developmental characteristics of the use of adverbial conjuncts. And the results show that at different learning stages Non-English majors use all kinds of adverbial conjuncts, but their occurrence frequencies are quite different, the enumerative adverbials are…

Cross-Cultural Adaptation of a Pre-School Screening Instrument: Comparison of Korean and US Populations

ERIC Educational Resources Information Center

Heo, K. H.; Squires, J.; Yovanoff, P.

2008-01-01

Background: Accurate and efficient developmental screening measures are critical for early identification of developmental problems; however, few reliable and valid tests are available in Korea as well as other countries outside the USA. The Ages and Stages Questionnaires (ASQ) was chosen for study with young children in Korea. Methods: The ASQ…

Rejected by Peers--Attracted to Antisocial Media Content: Rejection-Based Anger Impairs Moral Judgment among Adolescents

ERIC Educational Resources Information Center

Plaisier, Xanthe S.; Konijn, Elly A.

2013-01-01

Adolescence is an important developmental stage during which both peers and the media have a strong influence. Both peer rejection and the use of morally adverse media are associated with negative developmental outcomes. This study examines processes by which peer rejection might drive adolescents to select antisocial media content by tying…

Public School and Community Mental Health Interagency Cooperation for Treatment of the Child with Special Educational Needs.

ERIC Educational Resources Information Center

Barr, William; DelFava, Christine

The paper describes combined public education and community mental health in a preschool educational day treatment program for seriously emotionally disturbed children. The Developmental Therapy model on which the Tacoma, Washington, program is based is described as using five normal developmental stages to facilitate treatment which stresses the…

Child Development and Cultural Diversity.

ERIC Educational Resources Information Center

Caldwell, Bettye M.

1983-01-01

Each child is to some extent like all children, to some extent like some children, and to some extent like no other child. There are at least three sets of universals that characterize children: (1) they have the same needs and rights; (2) they go through the same developmental stages; and (3) they have essentially the same developmental goals,…

Parental effects in ecology and evolution: mechanisms, processes and implications

PubMed Central

Badyaev, Alexander V.; Uller, Tobias

2009-01-01

As is the case with any metaphor, parental effects mean different things to different biologists—from developmental induction of novel phenotypic variation to an evolved adaptation, and from epigenetic transference of essential developmental resources to a stage of inheritance and ecological succession. Such a diversity of perspectives illustrates the composite nature of parental effects that, depending on the stage of their expression and whether they are considered a pattern or a process, combine the elements of developmental induction, homeostasis, natural selection, epigenetic inheritance and historical persistence. Here, we suggest that by emphasizing the complexity of causes and influences in developmental systems and by making explicit the links between development, natural selection and inheritance, the study of parental effects enables deeper understanding of developmental dynamics of life cycles and provides a unique opportunity to explicitly integrate development and evolution. We highlight these perspectives by placing parental effects in a wider evolutionary framework and suggest that far from being only an evolved static outcome of natural selection, a distinct channel of transmission between parents and offspring, or a statistical abstraction, parental effects on development enable evolution by natural selection by reliably transferring developmental resources needed to reconstruct, maintain and modify genetically inherited components of the phenotype. The view of parental effects as an essential and dynamic part of an evolutionary continuum unifies mechanisms behind the origination, modification and historical persistence of organismal form and function, and thus brings us closer to a more realistic understanding of life's complexity and diversity. PMID:19324619

[Circadian rhythm disruption and human development].

PubMed

Kohyama, Jun

2013-12-01

Ontogenetic developments of rest-activity, sleep-wakefulness, temperature and several hormone rhythms in humans were reviewed. The reported effects of environment on these alterations were also summarized. Then, disorders or conditions which often encounter during early stage of life and reveal circadian rhythm disruptions were described. These disorders or conditions included severe brain damage, visual disturbance, developmental disorders(autistic spectrum disorder and attention deficit/hyperactivity disorder), Rett syndrome, Angelman syndrome, Smith-Magenis syndrome, epilepsy, Yonaki, and inadequate sleep hygiene. Finally, it was emphasized that we should pay special attention on the development of youngsters who showed sleep disturbance during early stage of life with special reference to the later occurrence of developmental disorders.

Developmental stages of Trypanosoma (Megatrypanum) freitasi Rego, Magalhães & Siqueira, 1957 in the opossum Didelphis marsupialis (Marsupialia, Didelphidae).

PubMed

Deane, M P; Jansen, A M

1990-01-01

Trypanosoma (Megatrypanum) freitasi, a parasite of marsupials of the genus Didelphis, has been found to undergo in the lumen of the scent (anal) glands of its vertebrate host, a cycle such as usually occurs in the intestinal tract of the insect vectors of trypanosomatids and similar to what has been reported for Trypanosoma (Schizotrypanum) cruzi. The invertebrate host of Trypanosoma freitasi is still unknown. Developmental stages of the trypanosome in its mammalian host, especially the dividing epimastigotes, multinucleate plasmodial forms and rosettes found in the lumen of the scent glands of a naturally infected Didelphis marsupialis are described and illustrated.

Toxic wavelength of blue light changes as insects grow.

PubMed

Shibuya, Kazuki; Onodera, Shun; Hori, Masatoshi

2018-01-01

Short-wavelength visible light (blue light: 400-500 nm) has lethal effects on various insects, such as fruit flies, mosquitoes, and flour beetles. However, the most toxic wavelengths of blue light might differ across developmental stages. Here, we investigate how the toxicity of blue light changes with the developmental stages of an insect by irradiating Drosophila melanogaster with different wavelengths of blue light. Specifically, the lethal effect on eggs increased at shorter light wavelengths (i.e., toward 405 nm). In contrast, wavelengths from 405 to 466 nm had similar lethal effects on larvae. A wavelength of 466 nm had the strongest lethal effect on pupae; however, mortality declined as pupae grew. A wavelength of 417 nm was the most harmful to adults at low photon flux density, while 466 nm was the most harmful to adults at high photon flux density. These findings suggest that, as the morphology of D. melanogaster changes with growth, the most harmful wavelength also changes. In addition, our results indicated that reactive oxygen species influence the lethal effect of blue light. Our findings show that blue light irradiation could be used as an effective pest control method by adjusting the wavelength to target specific developmental stages.

Large Area Crop Inventory Experiment (LACIE). Evaluation of the LACIE transition year crop calendar model. [Wheat growth in the Great Plains Corridor, North America

NASA Technical Reports Server (NTRS)

Cheffin, R. E.; Woolley, S. K. (Principal Investigator)

1979-01-01

The author has identified the following significant results. The estimates of developmental stage dates from the LACIE adjustable crop calendar (ACC) winter wheat model was somewhat more accurate than the historical crop calendar after jointing. The ACC winter wheat model was not so accurate for the Texas Panhandle as it was for the other areas of the USPG-7 because dry soil conditions delayed fall planting in the Panhandle. Since the LACIE ACC winter wheat model does not contain a moisture term and it was started with historical planting dates, lengthy delays in planting mean that the ACC model will probably be started early and will estimate the developmental growth stages to occur too early in the season. The LACIE ACC spring wheat model was also started early in most areas because of late planting due to fields wet from melting snow and rain. The starter model used to estimate spring planting dates was not accurate under these wet soil conditions and tended to predict the developmental stages to occur earlier than the dates observed in the fields.

Comparative Transcriptomic Characterization of the Early Development in Pacific White Shrimp Litopenaeus vannamei

PubMed Central

Wei, Jiankai; Zhang, Xiaojun; Yu, Yang; Huang, Hao; Li, Fuhua; Xiang, Jianhai

2014-01-01

Penaeid shrimp has a distinctive metamorphosis stage during early development. Although morphological and biochemical studies about this ontogeny have been developed for decades, researches on gene expression level are still scarce. In this study, we have investigated the transcriptomes of five continuous developmental stages in Pacific white shrimp (Litopenaeus vannamei) with high throughput Illumina sequencing technology. The reads were assembled and clustered into 66,815 unigenes, of which 32,398 have putative homologues in nr database, 14,981 have been classified into diverse functional categories by Gene Ontology (GO) annotation and 26,257 have been associated with 255 pathways by KEGG pathway mapping. Meanwhile, the differentially expressed genes (DEGs) between adjacent developmental stages were identified and gene expression patterns were clustered. By GO term enrichment analysis, KEGG pathway enrichment analysis and functional gene profiling, the physiological changes during shrimp metamorphosis could be better understood, especially histogenesis, diet transition, muscle development and exoskeleton reconstruction. In conclusion, this is the first study that characterized the integrated transcriptomic profiles during early development of penaeid shrimp, and these findings will serve as significant references for shrimp developmental biology and aquaculture research. PMID:25197823

Characterization and Expression Patterns of microRNAs Involved in Rice Grain Filling

PubMed Central

Du, Yanxiu; Zhang, Jing; Li, Junzhou; Liu, Yanxia; Zhao, Yafan; Zhao, Quanzhi

2013-01-01

MicroRNAs (miRNAs) are upstream gene regulators of plant development and hormone homeostasis through their directed cleavage or translational repression of the target mRNAs, which may play crucial roles in rice grain filling and determining the final grain weight and yield. In this study, high-throughput sequencing was performed to survey the dynamic expressions of miRNAs and their corresponding target genes at five distinct developmental stages of grain filling. In total, 445 known miRNAs and 45 novel miRNAs were detected with most of them expressed in a developmental stage dependent manner, and the majority of known miRNAs, which increased gradually with rice grain filling, showed negatively related to the grain filling rate. Detailed expressional comparisons revealed a clear negative correlation between most miRNAs and their target genes. It was found that specific miRNA cohorts are expressed in a developmental stage dependent manner during grain filling and the known functions of these miRNAs are involved in plant hormone homeostasis and starch accumulation, indicating that the expression dynamics of these miRNAs might play key roles in regulating rice grain filling. PMID:23365650

Non-destructive determination of floral staging in cereals using X-ray micro computed tomography (µCT).

PubMed

Tracy, Saoirse R; Gómez, José Fernández; Sturrock, Craig J; Wilson, Zoe A; Ferguson, Alison C

2017-01-01

Accurate floral staging is required to aid research into pollen and flower development, in particular male development. Pollen development is highly sensitive to stress and is critical for crop yields. Research into male development under environmental change is important to help target increased yields. This is hindered in monocots as the flower develops internally in the pseudostem. Floral staging studies therefore typically rely on destructive analysis, such as removal from the plant, fixation, staining and sectioning. This time-consuming analysis therefore prevents follow up studies and analysis past the point of the floral staging. This study focuses on using X-ray µCT scanning to allow quick and detailed non-destructive internal 3D phenotypic information to allow accurate staging of Arabidopsis thaliana L. and Barley ( Hordeum vulgare L.) flowers. X-ray µCT has previously relied on fixation methods for above ground tissue, therefore two contrast agents (Lugol's iodine and Bismuth) were observed in Arabidopsis and Barley in planta to circumvent this step. 3D models and 2D slices were generated from the X-ray µCT images providing insightful information normally only available through destructive time-consuming processes such as sectioning and microscopy. Barley growth and development was also monitored over three weeks by X-ray µCT to observe flower development in situ. By measuring spike size in the developing tillers accurate non-destructive staging at the flower and anther stages could be performed; this staging was confirmed using traditional destructive microscopic analysis. The use of X-ray micro computed tomography (µCT) scanning of living plant tissue offers immense benefits for plant phenotyping, for successive developmental measurements and for accurate developmental timing for scientific measurements. Nevertheless, X-ray µCT remains underused in plant sciences, especially in above-ground organs, despite its unique potential in delivering detailed non-destructive internal 3D phenotypic information. This work represents a novel application of X-ray µCT that could enhance research undertaken in monocot species to enable effective non-destructive staging and developmental analysis for molecular genetic studies and to determine effects of stresses at particular growth stages.

Distribution of potato spindle tuber viroid in reproductive organs of petunia during its developmental stages.

PubMed

Matsushita, Yosuke; Tsuda, Shinya

2014-09-01

Embryo infection is important for efficient seed transmission of viroids. To identify the major pattern of seed transmission of viroids, we used in situ hybridization to histochemically analyze the distribution of Potato spindle tuber viroid (PSTVd) in each developmental stage of petunia (flowering to mature seed stages). In floral organs, PSTVd was present in the reproductive tissues of infected female × infected male and infected female × healthy male but not of healthy female × infected male before embryogenesis. After pollination, PSTVd was detected in the developed embryo and endosperm in all three crosses. These findings indicate that PSTVd is indirectly delivered to the embryo through ovule or pollen during the development of reproductive tissues before embryogenesis but not directly through maternal tissues as cell-to-cell movement during embryogenesis.

Transcription profile data of phorbol esters biosynthetic genes during developmental stages in Jatropha curcas.

PubMed

Jadid, Nurul; Mardika, Rizal Kharisma; Purwani, Kristanti Indah; Permatasari, Erlyta Vivi; Prasetyowati, Indah; Irawan, Mohammad Isa

2018-06-01

Jatropha curcas is currently known as an alternative source for biodiesel production. Beside its high free fatty acid content, J. curcas also contains typical diterpenoid-toxic compounds of Euphorbiaceae plant namely phorbol esters. This article present the transcription profile data of genes involved in the biosynthesis of phorbol esters at different developmental stages of leaves, fruit, and seed in Jatropha curcas . Transcriptional profiles were analyzed using reverse transcription-polymerase chain reaction (RT-PCR). We used two genes including GGPPS (Geranylgeranyl diphospate synthase), which is responsible for the formation of common diterpenoid precursor (GGPP) and CS (Casbene Synthase), which functions in the synthesis of casbene. Meanwhile, J. curcas Actin ( ACT ) was used as internal standard. We demonstrated dynamic of GGPPS and CS expression among different stage of development of leaves, fruit and seed in Jatropha .

Evaluation of third molar development in the estimation of chronological age.

PubMed

Soares, Caio Belém Rodrigues Barros; Figueiroa, José Natal; Dantas, Renata Moura Xavier; Kurita, Lúcio Mitsuo; Pontual, Andréa dos Anjos; Ramos-Perez, Flávia Maria de Moraes; Perez, Danyel Elias da Cruz; Pontual, Maria Luiza dos Anjos

2015-09-01

The purpose of this study was to evaluate the correlation between chronological age and the degree of third molar mineralization by Demirjian's developmental stages (Demirjian et al., 1973) using panoramic radiography. From a total of 11.396 digital panoramic radiographs of patients from three oral radiology private clinics from the northeast region of Brazil, obtained from January to June 2009, 2097 radiographic images from patients aged between 6 and 22 years were selected. The images were analyzed individually by two obsevers using a 21-inch computer screen and Windows Picture and Fax Viewer. Reliability was achieved by intra- and interobserver evaluation, using the Kappa test. Chronological age, calcification stage, gender and third molar were interrelated using a multiple linear regression model, considering age as a response variable. There was reliability with Demirjian et al.'s developmental stage assesment, displaying a significant relationship between mineralization stages and patients' age (P<0.05). There was no significant difference between the average age and the calcification stage taking gender and localization of the third molar into consideration. It is possible to estimate chronological age based on Demirjian's stage of a third molar, regardless of gender and location. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Youth participation in organized and informal sports activities across childhood and adolescence: exploring the relationships of motivational beliefs, developmental stage and gender.

PubMed

Dawes, Nickki Pearce; Vest, Andrea; Simpkins, Sandra

2014-08-01

Involvement in physically active pursuits, such as sports, contributes to achieving and maintaining good emotional and physical health. The central goal of this article was to examine the longitudinal relationships between participation (i.e., time spent in the activities) in organized and informal sports contexts and motivational beliefs, and factors that might impact these relationships, such as developmental stage and gender. The data for the current study were drawn from the childhood and beyond longitudinal study, which utilized a cohort sequential design with data collected on three cohorts across four waves. The current study sample included 986 European American youth (51 % female), who t were mostly from working- and middle-class families. Self-report questionnaires were used to collect data from the youth about their participation in sports and their motivational beliefs (i.e., value and perceptions of competence) about this activity. Structural equation modeling was used to examine the relationships between participation and motivational beliefs across childhood and adolescence. The results provide some support for a model of reciprocal relationships between participation and motivational beliefs in organized and informal sports activities. These relationships between participation and motivational beliefs did not vary significantly based on developmental stage or by gender. Overall, the findings suggest that participation in organized and informal sports contexts may be fostered by supporting the development of positive motivational beliefs about the activities across developmental periods.

Development of the Forensically Important Beetle Creophilus maxillosus (Coleoptera: Staphylinidae) at Constant Temperatures.

PubMed

Wang, Y; Yang, J B; Wang, J F; Li, L L; Wang, M; Yang, L J; Tao, L Y; Chu, J; Hou, Y D

2017-03-01

Creophilus maxillosus (L., 1758) is a common and widely distributed beetle species found on corpses, and its development duration is far longer than species belonging to the genus Calliphoridae and Sarcophagidae. Therefore, C. maxillosus can be used as a supplementary indicator to estimate minimum postmortem interval (PMImin), and could greatly extend the range of PMImin when the primary colonizers are no longer associated with the corpse or have emerged from pupae. Better descriptions of C. maxillosus development are needed to apply this species for forensic investigations. In this study, the development of C. maxillosus at seven constant temperatures ranging from 17.5-32.5 °C was studied. Through regression analyses, the simulation equations of larval body length variation with time after hatching were obtained. Isomegalen diagrams of the changes of larval body length over time at specific temperatures, and the isomorphen diagrams on the duration of different developmental milestones at specific temperatures were generated. In addition, thermal summation models of different developmental stages and the overall development process of C. maxillosus were generated through regression analysis, by estimating the development threshold temperatures (D0) and the thermal summation constants (K). These results provide important tools for forensic investigations to generate a long-range of PMImin estimation based on the development of C. maxillosus. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Do Students Think as We Do? Progress with Piaget.

ERIC Educational Resources Information Center

Phillips, John L., Jr.

1982-01-01

Piaget's theories of cognitive development are applied to the college student and suggestions are given for helping students at different developmental stages. It is proposed that teachers provide experiences that promote cognitive conflict as a means of moving students into new stages. (MSE)

Influence of phenological stage on swainsonine concentrations and endophyte amounts in Oxytropis sericea

USDA-ARS?s Scientific Manuscript database

Locoweeds are defined as Astragalus and Oxytropis species that cause intoxication from the alkaloid swainsonine. Swainsonine concentrations in Oxytropis sericea are influenced by location, plant part, and the developmental stage of the plant. Swainsonine concentrations follow similar trends at eac...

Factor Structure of the Piagetian Stage of Concrete Operations.

ERIC Educational Resources Information Center

Klausmeier, Herbert J.; Sipple, Thomas S.

1982-01-01

The Piagetian developmental stage of concrete operational thought and the theoretical groupement structures underlying children's performance of 12 concrete operations tasks are discussed. Tasks were shown to develop in five related sets. Three factor structures were found in this longitudinal study. (Author/CM)

Morphological and functional studies on the epidermal cells of amphioxus ( Branchiostoma belcheri tsingtauense) at different developmental stages

NASA Astrophysics Data System (ADS)

Mao, Bing-Yu; Sun, Xiao-Yang; Zhang, Hong-Wei; Zhang, Shi-Cui; Wu, Xian-Han

1997-09-01

Epidermal cells of amphioxus at different developmental stages were investigated by electron microscopy and colloidal carbon tracing experiments. Amphioxus epidermal cells showed different ultrastructural characteristics at larval and adult stages. The epidermal cells at all larval stages studied (24 96 h) had numerous vesicles containing electron dense materials in their apical cytoplasm. In tracing experiments, carbon particles were found in apical vesicles and interoellular spaces. Under scanning electron microscope, many crater-like protrusions were observed on the surface of the cells. These results indicated that amphioxus larval epidermal cells may be capable of endocytosis. The epidermal cells of 3-month and adult amphioxus were obviously secretory ones characterized by well-developed peripheral filaments, a prominent Golgi apparatus and abundant apical secretory vesicles. This study also showed that adult amphioxus body surface mucus contained lectin that could agglutinate human red blood cells. The authors propose that the epidermal cells of amphioxus larva and adult may contribute to the immune defense of the amimal by different means.

Developmental Transcriptome for a Facultatively Eusocial Bee, Megalopta genalis

PubMed Central

Jones, Beryl M.; Wcislo, William T.; Robinson, Gene E.

2015-01-01

Transcriptomes provide excellent foundational resources for mechanistic and evolutionary analyses of complex traits. We present a developmental transcriptome for the facultatively eusocial bee Megalopta genalis, which represents a potential transition point in the evolution of eusociality. A de novo transcriptome assembly of Megalopta genalis was generated using paired-end Illumina sequencing and the Trinity assembler. Males and females of all life stages were aligned to this transcriptome for analysis of gene expression profiles throughout development. Gene Ontology analysis indicates that stage-specific genes are involved in ion transport, cell–cell signaling, and metabolism. A number of distinct biological processes are upregulated in each life stage, and transitions between life stages involve shifts in dominant functional processes, including shifts from transcriptional regulation in embryos to metabolism in larvae, and increased lipid metabolism in adults. We expect that this transcriptome will provide a useful resource for future analyses to better understand the molecular basis of the evolution of eusociality and, more generally, phenotypic plasticity. PMID:26276382

Developmental Transcriptome for a Facultatively Eusocial Bee, Megalopta genalis.

PubMed

Jones, Beryl M; Wcislo, William T; Robinson, Gene E

2015-08-14

Transcriptomes provide excellent foundational resources for mechanistic and evolutionary analyses of complex traits. We present a developmental transcriptome for the facultatively eusocial bee Megalopta genalis, which represents a potential transition point in the evolution of eusociality. A de novo transcriptome assembly of Megalopta genalis was generated using paired-end Illumina sequencing and the Trinity assembler. Males and females of all life stages were aligned to this transcriptome for analysis of gene expression profiles throughout development. Gene Ontology analysis indicates that stage-specific genes are involved in ion transport, cell-cell signaling, and metabolism. A number of distinct biological processes are upregulated in each life stage, and transitions between life stages involve shifts in dominant functional processes, including shifts from transcriptional regulation in embryos to metabolism in larvae, and increased lipid metabolism in adults. We expect that this transcriptome will provide a useful resource for future analyses to better understand the molecular basis of the evolution of eusociality and, more generally, phenotypic plasticity. Copyright © 2015 Jones et al.

Dynamics of vegetative cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana

NASA Technical Reports Server (NTRS)

Kuang, A.; Musgrave, M. E.

1996-01-01

Ultrastructural changes of pollen cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana were studied. The pollen cytoplasm develops a complicated ultrastructure and changes dramatically during these stages. Lipid droplets increase after generative cell formation and their organization and distribution change with the developmental stage. Starch grains in amyloplasts increase in number and size during generative and sperm cell formation and decrease at pollen maturity. The shape and membrane system of mitochondria change only slightly. Dictyosomes become very prominent, and numerous associated vesicles are observed during and after sperm cell formation. Endoplasmic reticulum appears extensively as stacks during sperm cell formation. Free and polyribosomes are abundant in the cytoplasm at all developmental stages although they appear denser at certain stages and in some areas. In mature pollen, all organelles are randomly distributed throughout the vegetative cytoplasm and numerous small particles appear. Organization and distribution of storage substances and appearance of these small particles during generative and sperm cell formation and pollen maturation are discussed.

Acute sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to copper, cadmium, or zinc in water-only laboratory exposures

USGS Publications Warehouse

Calfee, Robin D.; Little, Edward E.; Puglis, Holly J.; Scott, Erinn L.; Brumbaugh, William G.; Mebane, Christopher A.

2014-01-01

The acute toxicity of cadmium, copper, and zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) were determined for 7 developmental life stages in flow-through water-only exposures. Metal toxicity varied by species and by life stage. Rainbow trout were more sensitive to cadmium than white sturgeon across all life stages, with median effect concentrations (hardness-normalized EC50s) ranging from 1.47 µg Cd/L to 2.62 µg Cd/L with sensitivity remaining consistent during later stages of development. Rainbow trout at 46 d posthatch (dph) ranked at the 2nd percentile of a compiled database for Cd species sensitivity distribution with an EC50 of 1.46 µg Cd/L and 72 dph sturgeon ranked at the 19th percentile (EC50 of 3.02 µg Cd/L). White sturgeon were more sensitive to copper than rainbow trout in 5 of the 7 life stages tested with biotic ligand model (BLM)-normalized EC50s ranging from 1.51 µg Cu/L to 21.9 µg Cu/L. In turn, rainbow trout at 74 dph and 95 dph were more sensitive to copper than white sturgeon at 72 dph and 89 dph, indicating sturgeon become more tolerant in older life stages, whereas older trout become more sensitive to copper exposure. White sturgeon at 2 dph, 16 dph, and 30 dph ranked in the lower percentiles of a compiled database for copper species sensitivity distribution, ranking at the 3rd (2 dph), 5th (16 dph), and 10th (30 dph) percentiles. White sturgeon were more sensitive to zinc than rainbow trout for 1 out of 7 life stages tested (2 dph with an biotic ligand model–normalized EC50 of 209 µg Zn/L) and ranked in the 1st percentile of a compiled database for zinc species sensitivity distribution.