Structure and developmental process of a Quercus mongolica var. grosseserrata forest in the Fagetea crenatae region in Japan

2000 ◽  
Vol 30 (12) ◽  
pp. 1877-1885 ◽  
Author(s):  
Kazumi Fujita ◽  
Junji Sano
Keyword(s):  
Stand Structure ◽  
Developmental Process ◽  
Tree Establishment ◽  
Seedling Regeneration ◽  
Developmental Processes ◽  
Quercus Mongolica ◽  
Large Fluctuations ◽  
Alnus Hirsuta ◽  
Growth Change ◽  
Quercus Forest

Structure and developmental processes were studied in a Quercus mongolica Fisch. var. grosseserrata (Bl.) Rehd. et Wils. forest in the Fagetea crenatae Bl. region in Japan. The Quercus forest was classified into three stand types: stands dominated by Quercus with many species (type Q-MIX), Quercus-Fagus (type Q-F), and Quercus (type Q). In Q-MIX, Alnus hirsuta Turcz. had a bell-shaped DBH-class distribution. Most Quercus trees were single stemmed. The establishment of Quercus trees occurred continuously from the 1900s. The percentage of growth change (%GC) exhibited negative values from the 1940s. In Q-F and Q, Quercus trees had bell-shaped DBH-class distributions, and multiple-stemmed trees showed broad distributions. In Q-F, tree establishment peak was in the 1870s. %GC exhibited large fluctuations. In Q, tree establishment peak was in the 1850s. %GC exhibited negative values for 60 years. In conclusion, type Q-MIX, Q-F, and Q developed mainly by seedling regeneration following major cutting in the 1900s, sprout and seedling regeneration following intermittent cuttings mainly in the 1870s, and sprout and seedling regeneration following successive cuttings mainly in the 1850s, respectively. Cutting disturbance can be a major factor in developmental processes in Quercus forest; the frequency and intensity of cuttings affect the stand structure and the dominance of Quercus in the Fagetea crenatae region.

Editorial: Operationalizing child maltreatment: Developmental processes and outcomes

2001 ◽  
Vol 13 (4) ◽  
pp. 755-757 ◽  
Author(s):  
DANTE CICCHETTI ◽  
JODY TODD MANLY
Keyword(s):  
Child Maltreatment ◽  
Developmental Process ◽  
Psychological Maltreatment ◽  
Special Issue ◽  
Battered Child Syndrome ◽  
Developmental Processes ◽  
Battered Child ◽  
Child Syndrome ◽  
Definition Of

Significant advances have occurred in our knowledge of the effects of maltreatment on the developmental process since the “battered child syndrome” (Kempe, Silverman, Steele, Droegemueller, & Silver, 1962) was first identified. In fact, during the mid-1980s and onward, the quality and methodological sophistication of investigations of the developmental sequelae of child maltreatment increased dramatically (for summaries, see Cicchetti & Lynch, 1995, and Cicchetti & Toth, 2000). However, overall progress has been hampered by a lack of consensus on the operationalization of the construct of child maltreatment (Barnett, Manly, & Cicchetti, 1993; Besharov, 1981; Cicchetti & Rizley, 1981; Giovannoni & Becerra, 1979). In recognition of the complexities accompanying definitional issues in the area of maltreatment, a decade ago a Special Issue of Development and Psychopathology was devoted to defining psychological maltreatment (Cicchetti, 1991). The challenges associated with defining maltreatment were again highlighted in a Special Issue of Development and Psychopathology that addressed advances and challenges in the study of the sequelae of child maltreatment (Cicchetti, 1994a). In the editorial to that issue, Cicchetti (1994b) concluded that “the lack of consensus regarding the definition of maltreatment employed by various investigators [had] made comparability across studies difficult to achieve” (p. 2).

scholarly journals An Improved Protocol for Asymbiotic Seed Germination and Seedling Development of Paphiopedilum tigrinum

Horticulturae ◽  
2021 ◽  
Vol 7 (9) ◽  
pp. 298
Author(s):  
Linling Yao ◽  
Jialin Huang ◽  
Shibao Zhang
Keyword(s):  
Seed Germination ◽  
Developmental Process ◽  
Seedling Development ◽  
Ms Medium ◽  
Seedling Regeneration ◽  
Asymbiotic Seed Germination ◽  
Differentiation Stage ◽  
Optimal Medium ◽  
Germination Stage

Paphiopedilum tigrinum is an endangered orchid with high ornamental value. However, seed germination and seedling regeneration in P. tigrinum is very difficult in vitro. Little is known about why P. tigrinum seedlings are difficult to propagate or how to improve the seed germination and seedling rates of this species. In this study, we investigated the developmental process of P. tigrinum from asymbiotic seed germination to seedling rooting by comparing it with P. appletoniantum, a much easier species for germination and seedling formation. We found that asymbiotic seed germination in P. tigrinum is limited by severe browning of the protocorm at the seed germination stage, and protocorm rooting at the differentiation stage was also proved to be difficult. The optimal medium for seed germination of P. tigrinum was a modified Harvais (mHa) medium supplemented with 0.5 mg·L−1 kinetin (Kin), 0.1 g·L−1 activated charcoal (AC) and 100 mL·L−1 coconut water (CW). At the protocorm differentiation stage, seedlings with 1–2 leaves were obtained on a 1/4 MS medium supplemented with 1.0 mg·L−1 6-benzylaminopurin (BA), 0.3 g·L−1 AC and 50–100 mL·L−1 CW after culturing for 120 day. At the seedling subculture stage, a 1/2 MS medium supplemented with 0.5–1.5 g·L−1 AC and 100 mL·L−1 CW was better for leaf and root growth of P. tigrinum. At the rooting stage, a 1/2 MS medium supplemented with 1.0 g·L−1 AC, 0.5 g·L−1 dolomite flour, 15 g·L−1 potato homogenate and 30 g·L−1 banana homogenate was most suitable for the growth and rooting of seedlings. This study has established an effective protocol for seed germination and seedling regeneration of P. tigrinum.

Statistical Mediation in Lifespan Developmental Analyses

2018 ◽  
Author(s):  
Oscar Gonzalez ◽  
David P. MacKinnon
Keyword(s):  
Repeated Measures ◽  
Developmental Process ◽  
Theory Of Change ◽  
Developmental Pathways ◽  
Developmental Research ◽  
Mediation Model ◽  
Developmental Processes ◽  
Statistical Mediation ◽  
Future Outcomes ◽  
Interindividual Change

Lifespan developmental research studies how individuals change throughout their lifetime and how intraindividual or interindividual change leads to future outcomes. Lifespan researchers are interested in how developmental processes unfold and how specific developmental pathways lead to an outcome. Developmental processes have been previously studied using developmental cascade models, concepts of equifinality and multifinality, and developmental interventions. Statistical mediation analysis also provides a framework for studying developmental processes and developmental pathways by identifying intermediate variables, known as mediators, that transmit the effect between early exposures and future outcomes. The role of statistical mediation in lifespan developmental research is either to explain how the developmental process unfolds, or to identify mediators that researchers can target in interventions so that individuals change developmental pathways. The statistical mediation model is inherently causal, so the relations between the exposures, mediators, and outcomes have to be correctly specified, and ruling out alternative explanations for the relations is of upmost importance. The statistical mediation model can be extended to deal with longitudinal data. For example, the autoregressive mediation model can represent change through time by examining lagged relations in multiwave datasets. On the other hand, the multilevel mediation model can deal with the clustering of repeated measures within individuals to study intraindividual and interindividual change. Finally, the latent growth curve mediation model can represent the variability of linear and nonlinear trajectories for individuals in the variables in the mediation model through time. As a result, developmental researchers have access to a range of models that could describe the theory of change they want to study. Researchers are encouraged to consider mechanisms of change and to formulate mediation hypotheses about lifespan development.

Stand Structure of Long Term Monitoring Sites for Quercus mongolica in Mt. Myeonbong

2018 ◽  
Vol 52 (3) ◽  
pp. 133-144
Author(s):  
Byeong-Joo Park ◽  
◽  
Kwangil Cheon ◽  
Jae-Jin Kim ◽  
Sung-Hyun Joo ◽  
...  
Keyword(s):  
Stand Structure ◽  
Quercus Mongolica ◽  
Long Term Monitoring ◽  
Term Monitoring

scholarly journals The diverse roles of cytokinins in regulating leaf development

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Wenqi Wu ◽  
Kang Du ◽  
Xiangyang Kang ◽  
Hairong Wei
Keyword(s):  
Leaf Development ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Developmental Process ◽  
Chlorophyll Synthesis ◽  
Growth Potential ◽  
Sugar Accumulation ◽  
Developmental Processes ◽  
Leaf Formation ◽  
Underlying Mechanisms

AbstractLeaves provide energy for plants, and consequently for animals, through photosynthesis. Despite their important functions, plant leaf developmental processes and their underlying mechanisms have not been well characterized. Here, we provide a holistic description of leaf developmental processes that is centered on cytokinins and their signaling functions. Cytokinins maintain the growth potential (pluripotency) of shoot apical meristems, which provide stem cells for the generation of leaf primordia during the initial stage of leaf formation; cytokinins and auxins, as well as their interaction, determine the phyllotaxis pattern. The activities of cytokinins in various regions of the leaf, especially at the margins, collectively determine the final leaf morphology (e.g., simple or compound). The area of a leaf is generally determined by the number and size of the cells in the leaf. Cytokinins promote cell division and increase cell expansion during the proliferation and expansion stages of leaf cell development, respectively. During leaf senescence, cytokinins reduce sugar accumulation, increase chlorophyll synthesis, and prolong the leaf photosynthetic period. We also briefly describe the roles of other hormones, including auxin and ethylene, during the whole leaf developmental process. In this study, we review the regulatory roles of cytokinins in various leaf developmental stages, with a focus on cytokinin metabolism and signal transduction processes, in order to shed light on the molecular mechanisms underlying leaf development.

scholarly journals MicroRNA-202 safeguards meiotic progression by preventing premature degradation of REC8 mediated by separase

2021 ◽  
Author(s):  
Jian Chen ◽  
Chenxu Gao ◽  
Chunwei Zheng ◽  
Xiwen Lin ◽  
Yan Ning ◽  
...  
Keyword(s):  
Germ Cells ◽  
Sister Chromatid ◽  
Developmental Process ◽  
Developmental Processes ◽  
Meiotic Progression ◽  
Multiple Processes ◽  
Direct Target ◽  
Meiosis I

AbstractMicroRNAs (miRNAs) are believed to play important roles in mammalian spermatogenesis but the in vivo functions of single miRNAs in this highly complex developmental process remain unclear. Here, we reported that miR-202, a member of the let-7 family, played an important role in mouse spermatogenesis by phenotypic evaluation of miR-202 knockout (KO) mice. In miR-202 KO mice, germ cells underwent apoptosis. Multiple processes in meiosis I including synapsis and crossover formation were disrupted, and inter-sister chromatid synapses were detected. More importantly, we found that upon miR-202 KO, meiotic-specific cohesin protein REC8 was prematurely cleaved by precociously activated separase, whose mRNA was a direct target of miR-202-3p. Our findings identify miR-202 as a novel regulator of meiosis and contribute to the list of miRNAs that play specific and important roles in developmental processes.

Statistical Power for Longitudinal Developmental Trajectories: The (Non-)Impact of Age Matching within Measurement Occasions

2018 ◽  
Author(s):  
Sean Patrick Lane ◽  
Bridgette Tonnsen
Keyword(s):  
Statistical Power ◽  
Developmental Process ◽  
Developmental Trajectories ◽  
Chronological Age ◽  
Interval Scale ◽  
Developmental Processes ◽  
Longitudinal Development ◽  
Sampling Variability ◽  
Development Data ◽  
Present Simulation

Recruiting participants for studies of early-life longitudinal development is challenging, often resulting in practical upper bounds in sample size and missing data due to attrition. These factors pose risks for the statistical power of such studies. One mitigation strategy is to increase measurement precision by conducting assessments of children as close to a fixed chronological age as possible. We present simulation analyses that illustrate how such practices are only sometimes useful. Simulations were conducted using results from two studies of longitudinal development. Data were generated according to both continuous and discrete developmental processes and factorially analyzed treating time on either interval, ordinal, or categorical scales. The power to detect continuously generated developmental processes was robust to, and even benefited from, increased variability around target ages. For discrete processes, power was unaffected when modeled appropriately, but declined steadily if modeled using exact chronological age on an interval scale. Our results suggest that in many circumstances, researchers may be unnecessarily devoting resources toward minimizing age sampling variability in their studies. In fact, when the theoretical developmental process is continuous, increasing the age sampling variability of assessments can be associated with substantial gains, rather than reductions, in power.

Nonlinear Developmental Processes as Sources of Dominance

Genetics ◽  
2001 ◽  
Vol 159 (1) ◽  
pp. 423-432
Author(s):  
Michael A Gilchrist ◽  
H Fredrik Nijhout
Keyword(s):  
Genetic Variation ◽  
Metabolic Pathways ◽  
Developmental Process ◽  
Nonlinear Process ◽  
Nonlinear Relationship ◽  
Developmental Processes ◽  
Developmental Mechanism ◽  
Dominance Relationships ◽  
Threshold Mechanism ◽  
New Mutations

Abstract Phenotypes are the products of developmental processes whose dynamics are controlled by genes. In many developmental processes there is a nonlinear relationship between genetic variation and phenotypic variation. These nonlinear relationships can result in the emergence of dominance among alleles that control the developmental process. We explore the properties of dominance relationships in a simple developmental system consisting of a diffusion-gradient-threshold mechanism commonly deployed in pattern formation. We show that a single nonlinear process (diffusion) within this integrated mechanism leads to the emergence of dominance in all components of the mechanism. Unlike the situation in metabolic pathways, where new mutations are most likely to be recessive, the structure of the nonlinearities in this developmental mechanism is such that in certain circumstances new mutations are equally likely to be dominant or recessive. Although the dominance we observe in this system is the result of a physiological process, we also find that dominance can evolve by microevolutionary mechanisms and thus are able to reconcile the opposing views of Fisher and Wright on dominance.

scholarly journals Threshold Response to Extreme Drought Shifts Inter-Tree Growth Dominance in Pinus sylvestris

2021 ◽  
Vol 4 ◽  
Author(s):  
Thomas S. Ovenden ◽  
Mike P. Perks ◽  
Toni-Kim Clarke ◽  
Maurizio Mencuccini ◽  
Alistair S. Jump
Keyword(s):  
Pinus Sylvestris ◽  
Tree Growth ◽  
Stand Structure ◽  
Mixed Effects ◽  
Extreme Drought ◽  
Tree Level ◽  
Drought Severity ◽  
Drought Impact ◽  
Threshold Response ◽  
Growth Change

Many studies quantify short-term drought impact on tree growth relative to pre-drought growth averages. However, fewer studies examine the extent to which droughts of differing severity differentially impact tree growth or shape stand dynamics. Focusing on three droughts in high and low density stands of Pinus sylvestris in Scotland, we calculated pre-drought growth averages using climatically standardized antecedent growth years to assess tree level drought and post-drought growth performance as percentage growth change (PGC). We then used mixed-effects models to understand how droughts of differing severity impact tree growth and calculated indices of growth dominance (Gd), size inequality (Si), and size asymmetry (Sa) to detect changes in stand structure. Mixed-effects model results indicate that the magnitude and duration of the growth reduction during and following the more extreme drought was significantly larger compared to less severe droughts, for which we found limited evidence of drought impact. While no changes in Si or Sa were noted following any drought, we found evidence of a difference in Gd after the most extreme drought in both stand densities indicative of a threshold response, with smaller trees contributing proportionally more to stand growth relative to their size. Under less severe droughts, inter-tree variability may have partially buffered against stand-level growth change, however, a small increase in drought severity was associated with a significant reduction in average tree growth, an increase in the number of trees growing at >2SD below pre-drought levels and a shift in Gd toward smaller trees, indicating that a drought severity threshold in P. sylvestris may have been exceeded.

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