The role of initial cells in maize anther morphogenesis

Development ◽  
1992 ◽  
Vol 116 (4) ◽  
pp. 1077-1085 ◽  
Author(s):  
R.K. Dawe ◽  
M. Freeling
Keyword(s):  
Cell Division ◽  
Small Groups ◽  
Cell Movement ◽  
Basic Structure ◽  
Early Growth ◽  
Structural Template ◽  
Axes Of Symmetry ◽  
The Relationship ◽  
Mature Anther

The near absence of cell movement in plants makes clonal analysis a particularly informative method for reconstructing the early events of organ formation. We traced the patterns of cell division during maize anther development by inducing sector boundaries that preceded the earliest events of anther initiation. In doing this, we were able to estimate the smallest number of cells that are fated to form an anther, characteristic cell division patterns that occur during anther morphogenesis, and the relationship between the pre-existing symmetry of the initial cells and the final symmetry of the mature anther. Four general conclusions are made: (1) anthers are initiated from small groups of 12 or fewer cells in each of two floral meristematic layers; (2) the early growth of the anther is more like a shoot than a glume or leaf; (3) cell ancestry does not dictate basic structure and (4) the orientation of initial cells predicts the orientation of the four pollen-containing microsporangia, which define the axes of symmetry on the mature anther. The final point is discussed with other data, and an explanation involving a ‘structural template’ is invoked. The idea is that the orientation of initial cells within the floral meristem establishes an architectural pattern into which anther cells are recruited without regard to their cellular lineages. The structural template hypothesis may prove to be generally applicable to problems of pattern formation in plants.

Budding in hydra: the role of cell multiplication and cell movement in bud initiation

Development ◽  
1972 ◽  
Vol 27 (2) ◽  
pp. 301-316
Author(s):  
Gerald Webster ◽  
Susan Hamilton
Keyword(s):  
Cell Division ◽  
Mitotic Index ◽  
Cell Population ◽  
Cell Movement ◽  
Growth Zone ◽  
Cell Multiplication ◽  
Rapid Rise ◽  
The Mean ◽  
Bud Initiation

The work described in this paper is concerned with the role of cell multiplication and cell movement in relation to the initiation of buds in hydra. Hydra starved for 6 days do not initiate new buds; in such animals the mean mitotic index is only 10% of that in well-fed animals. When starved animals are re-fed, there is a rapid rise in mitotic index which reaches a maximum 12 h after feeding and thereafter declines. This cell division causes an increase in the cell population of about 30% in the 24 h following the meal. New buds are initiated at 24–72 h, i.e. at some time after the major part of the cell multiplication. Cell division occurs in all parts of the axis to more or less the same extent and there is no sign of a growth zone in the budding region. However, the cell population in the budding zone of re-fed animals shows a significantly greater increase than in other parts of the axis and this can only be accounted for if it is assumed that cells have moved into this region from other parts of the axis. Some cell multiplication is a necessary prerequisite for bud initiation, but grafting experiments with starved animals suggest that division per se is not necessary; the important factor seems to be the increase in size resulting from division. The mechanics and causes of the cell movement which results in bud initiation are briefly discussed. It is suggested that changes in intercellular adhesion may be important.

The Advancement of Children's Verbal Referential Communication Skills: The Role of Metacognitive Guidance

1982 ◽  
Vol 5 (3) ◽  
pp. 329-355 ◽  
Author(s):  
E. J. Robinson ◽  
W. P. Robinson
Keyword(s):  
Communication Skills ◽  
Small Groups ◽  
Referential Communication ◽  
Communication Failure ◽  
Practice Group ◽  
Post Test ◽  
The Relationship ◽  
Listening And Speaking ◽  
Metacognitive Guidance

36 children aged between 4-4 and 5-4 were assessed for both their understanding about the role of message ambiguity as a cause of communication failure, and their level of performance in verbal referential communication tasks. All children then took part in six half-hour sessions during which they practised listening and speaking in small groups, with the experimenter modelling appropriate behaviour on her turns. In addition, half the children received information about when and why listeners understood or failed to understand (metacognitive guidance) during the course of the sessions. Both groups improved in both performance and understanding in the immediate post-test and in a delayed post-test seven weeks later there was no sign of regression in understanding. The guidance group advanced more than the practice group in both performance and understanding (with the exception of those at the highest levels of understanding originally). Performance and understanding measures were significantly related to each other in the pre-test, and the relationship remained unchanged following intervention, with the exception of question-asking, which increased even among children who made no advances in understanding. The results were interpreted as suggesting that we can advance children's verbal communication skills not only by giving them information about communication, but also by treating them as though they understand that messages can be ambiguous and can cause communication failure.

The role of yan in mediating the choice between cell division and differentiation

Development ◽  
1995 ◽  
Vol 121 (12) ◽  
pp. 3947-3958 ◽  
Author(s):  
R. Rogge ◽  
P.J. Green ◽  
J. Urano ◽  
S. Horn-Saban ◽  
M. Mlodzik ◽  
...  
Keyword(s):  
Cell Division ◽  
Growth Factor Receptor ◽  
Developmental Context ◽  
Eye Disc ◽  
A Cell ◽  
Epidermal Growth ◽  
Notch Pathways ◽  
Relationship Of ◽  
The Relationship

An allele of the yan locus was isolated as an enhancer of the Ellipse mutation of the Drosophila epidermal growth factor receptor (Egfr) gene. This yan allele is an embryonic lethal and also fails to complement the lethality of anterior open (aop) mutations. Phenotypic and complementation analysis revealed that aop is allelic to yan and genetically the lethal alleles act as null mutations for the yan gene. Analysis of the lethal alleles in the embryo and in mitotic clones showed that loss of yan function causes cells to overproliferate in the dorsal neuroectoderm of the embryo and in the developing eye disc. Our studies suggest that the role of yan is defined by the developmental context of the cells in which it functions. An important role of this gene is in allowing a cell to choose between cell division and differentiation. The relationship of the Egfr and Notch pathways to this developmental role of yan is discussed.

scholarly journals Propio-cuerpo y persona: experiencias propio-corporales e identidad personal en la fenomenología de H. Schmitz

2020 ◽  
Vol 7 (3, jul.-dez.) ◽  
pp. 323-354
Author(s):  
Martín Mercado-Vásquez
Keyword(s):  
Personal Identity ◽  
Basic Structure ◽  
The Body ◽  
Palabras Clave ◽  
Conception Of Man ◽  
Personal A ◽  
Phenomenological Anthropology ◽  
Relationship Of ◽  
The Relationship

El presente artículo de investigación estudia la relación entre experiencias corporales e identidad personal, a partir de la pregunta sobre si aquellas son fundamento de esta. En la primera parte del artículo se justifica el tema abordado, mediante la revisión del planteamiento del problema de la identidad personal de J. Locke; por lo que se estudia el rol del cuerpo en la idea de hombre y en la identidad personal. Después, se analiza la noción de identidad personal tomando en cuenta las experiencias de dolor y placer. En la segunda parte, se aborda la antropología neo-fenomenológica de Hermann Schmitz, a partir de la tesis de “sin propio-cuerpo no hay persona” y de su descripción del dolor como fundamento propio-corporal de la identidad personal. A continuación, se expone la dinámica entre actitud propio-corporal y equilibrio personal como estructura básica de la situación personal. Finalmente, se ofrece una breve conclusión (3). Palabras clave: Identidad personal, cuerpo, propio-cuerpo, dinámica propio-corporal, situación personal.   Abstract The following research article examines the relationship between felt-bodily experiences and personal identity, and whether the former can be considered the basis for the latter. The first part of the article deals with the relationship of these two concepts within Locke's view of personal identity in order to justify the question. Therefore, the role of the body in the conception of man and in personal identity is revised. Then the idea of personal identity in relation to pain experience is questioned. The second part deals with the neo-phenomenological anthropology of Hermann Schmitz, which is based on the thesis: “without felt-body no person”. Next, the dynamics between attitude and composure as the basic structure of the personal situation identity is revealed, which can be assumed as an answer to the question of personal identity. Finally, a brief conclusion is given. Key words: Personal identity, body, felt-body, felt-body dynamics, personal situation.   Resumo O presente artigo estuda a relação entre experiências corporais e identidade pessoal, tomando como base a indagação se aquelas são fundamentos desta. Na primeira parte do artigo, justifica-se o problema mediante a revisão da abordagem de J. Locke para o problema da identidade pessoal; razão pela qual o papel do corpo na ideia do homem e na identidade pessoal é estudado. Na sequência, estuda-se a noção de identidade pessoal, levando-se em consideração as experiências de dor e de prazer. Na segunda parte, aborda-se a antropologia neo-fenomenológica de Hermann Schmitz, com base na tese de "sem o seu próprio-corpo, não existe pessoa" e sua descrição da dor como fundamento próprio-corporal da identidade pessoal. Em seguida, a dinâmica entre atitude próprio-corporal e equilíbrio pessoal é exposta como estrutura básica da situação pessoal. Por fim, é oferecida uma breve conclusão. Palavras-chave: Identidade pessoal, corpo, próprio-corpo, dinâmica do próprio-corpo, situação pessoal.

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

Staring Down Death

Crisis ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Thomas E. Joiner ◽  
Melanie A. Hom ◽  
Megan L. Rogers ◽  
Carol Chu ◽  
Ian H. Stanley ◽  
...  
Keyword(s):  
Suicide Risk ◽  
Clinical Utility ◽  
Blink Rate ◽  
Specific Task ◽  
Careful Planning ◽  
Eye Blink ◽  
Eye Blinks ◽  
Potential Clinical Utility ◽  
The Relationship

Abstract. Background: Lowered eye blink rate may be a clinically useful indicator of acute, imminent, and severe suicide risk. Diminished eye blink rates are often seen among individuals engaged in heightened concentration on a specific task that requires careful planning and attention. Indeed, overcoming one’s biological instinct for survival through suicide necessitates premeditation and concentration; thus, a diminished eye blink rate may signal imminent suicidality. Aims: This article aims to spur research and clinical inquiry into the role of eye blinks as an indicator of acute suicide risk. Method: Literature relevant to the potential connection between eye blink rate and suicidality was reviewed and synthesized. Results: Anecdotal, cognitive, neurological, and conceptual support for the relationship between decreased blink rate and suicide risk is outlined. Conclusion: Given that eye blinks are a highly observable behavior, the potential clinical utility of using eye blink rate as a marker of suicide risk is immense. Research is warranted to explore the association between eye blink rate and acute suicide risk.

Parenting Behaviors and Anxiety in Young Adults

2015 ◽  
Vol 36 (3) ◽  
pp. 170-176 ◽  
Author(s):  
Erin N. Stevens ◽  
Joseph R. Bardeen ◽  
Kyle W. Murdock
Keyword(s):  
Effortful Control ◽  
Parenting Behaviors ◽  
Protective Role ◽  
Anxiety Symptoms ◽  
Interactive Effects ◽  
Parental Overprotection ◽  
High Control ◽  
Development Of Anxiety ◽  
The Relationship

Parenting behaviors – specifically behaviors characterized by high control, intrusiveness, rejection, and overprotection – and effortful control have each been implicated in the development of anxiety pathology. However, little research has examined the protective role of effortful control in the relation between parenting and anxiety symptoms, specifically among adults. Thus, we sought to explore the unique and interactive effects of parenting and effortful control on anxiety among adults (N = 162). Results suggest that effortful control uniquely contributes to anxiety symptoms above and beyond that of any parenting behavior. Furthermore, effortful control acted as a moderator of the relationship between parental overprotection and anxiety, such that overprotection is associated with anxiety only in individuals with lower levels of effortful control. Implications for potential prevention and intervention efforts which specifically target effortful control are discussed. These findings underscore the importance of considering individual differences in self-regulatory abilities when examining associations between putative early-life risk factors, such as parenting, and anxiety symptoms.

Social Support, Emotional Intelligence, and Posttraumatic Stress Disorder Symptoms

2016 ◽  
Vol 37 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Nicole L. Hofman ◽  
Austin M. Hahn ◽  
Christine K. Tirabassi ◽  
Raluca M. Gaher
Keyword(s):  
Social Support ◽  
Posttraumatic Stress Disorder ◽  
Emotional Intelligence ◽  
Protective Factors ◽  
Posttraumatic Stress ◽  
Stress Disorder ◽  
Traumatic Events ◽  
Ptsd Symptoms ◽  
The Relationship

Abstract. Exposure to traumatic events and the associated risk of developing Posttraumatic stress disorder (PTSD) symptoms is a significant and overlooked concern in the college population. It is important for current research to identify potential protective factors associated with the development and maintenance of PTSD symptoms unique to this population. Emotional intelligence and perceived social support are two identified protective factors that influence the association between exposure to traumatic events and PTSD symptomology. The current study examined the mediating role of social support in the relationship between emotional intelligence and PTSD symptoms. Participants included 443 trauma-exposed university students who completed online questionnaires. The results of this study indicated that social support mediates the relationship between emotional intelligence and reported PTSD symptoms. Thus, emotional intelligence is significantly associated with PTSD symptoms and social support may play an integral role in the relationship between emotional intelligence and PTSD. The current study is the first to investigate the role of social support in the relationship between emotional intelligence and PTSD symptoms. These findings have important treatment and prevention implications with regard to PTSD.

Coping Humor as a Mediator Between Emotional Intelligence and Job Satisfaction

2017 ◽  
Vol 16 (3) ◽  
pp. 155-159 ◽  
Author(s):  
Peizhen Sun ◽  
Jennifer J. Chen ◽  
Hongyan Jiang
Keyword(s):  
Job Satisfaction ◽  
Emotional Intelligence ◽  
Future Research ◽  
Satisfaction Scale ◽  
Primary School Teachers ◽  
Mediating Role ◽  
Regulation Of Emotion ◽  
The Relationship ◽  
Overall Job Satisfaction

Abstract. This study investigated the mediating role of coping humor in the relationship between emotional intelligence (EI) and job satisfaction. Participants were 398 primary school teachers in China, who completed the Wong Law Emotional Intelligence Scale, Coping Humor Scale, and Overall Job Satisfaction Scale. Results showed that coping humor was a significant mediator between EI and job satisfaction. A further examination revealed, however, that coping humor only mediated two sub-dimensions of EI (use of emotion and regulation of emotion) and job satisfaction. Implications for future research and limitations of the study are discussed.

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