scholarly journals Studies on tail regeneration and homeotic transformation in anuran tadpoles

2020 ◽  
Vol 64 (1-2-3) ◽  
pp. 65-70
Author(s):  
Priyambada Mohanty-Hejmadi ◽  
Pravati Kumari Mahapatra

Anuran tadpoles are excellent models for regeneration studies. The tail, an organ essential for swimming for the aquatic tadpole, regenerates completely following injury or amputation. However, treatment with the morphogen, vitamin A or retinoic acid inhibits normal tail regeneration and induces homeotic transformation of tail to limbs. This phenomenon was discovered for the first time in the Indian marbled balloon frog Uperodon systoma in the Developmental Biology laboratory of Utkal University (Odisha, India) in the year 1992. In this paper, we present the results of morphological, histological, biochemical and molecular (immonohistochemistry) investigations of vitamin A induced homeotic transformation in different anuran species. In addition, we discuss the putative role of fibroblast growth factor 1 during spinal cord regeneration in the tadpoles of the Indian tree frog, Polypedates maculatus, an ideal model for regeneration studies in an Indian context.

2000 ◽  
Vol 59 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Malcolm Maden

Retinoic acid (RA) is the bioactive metabolite of vitamin A (retinol) which acts on cells to establish or change the pattern of gene activity. Retinol is converted to RA by the action of two types of enzyme, retinol dehydrogenases and retinal dehydrogenases. In the nucleus RA acts as a ligand to activate two families of transcription factors, the RA receptors (RAR) and the retinoid X receptors (RXR) which heterodimerize and bind to the upstream sequences of RA-responsive genes. Thus, in addition to the well-established experimental paradigm of depriving animals of vitamin A to determine the role of RA in embryonic and post-embryonic development, molecular biology has provided us with two additional methodologies: knockout the enzymes or the RAR and RXR in the mouse embryo. The distribution of the enzymes and receptors, and recent experiments to determine the endogenous distribution of RA in the embryo are described here, as well as the effects on the embryo of knocking out the enzymes and receptors. In addition, recent studies using the classical vitamin A-deprivation technique are described, as they have provided novel insights into the regions of the embryo which crucially require RA, and the gene pathways involved in their development. Finally, the post-embryonic or regenerating systems in which RA plays a part are described, i.e. the regenerating limb, lung regeneration, hair cell regeneration in the ear and spinal cord regeneration in the adult.


2020 ◽  
Vol 64 (1-2-3) ◽  
pp. 59-64
Author(s):  
Priyambada Mohanty-Hejmadi

The paper deals with the background and the establishment of a Developmental Biology Laboratory in Utkal University in Odisha state. It describes the process from a humble beginning with limited facilities into a leading research centre, initially for amphibians and later for the endangered olive ridley (Lepidochelys olivacea) turtle. Starting from the biology, reproduction and development in many anurans, the laboratory took up research on regeneration, especially on super-regeneration in tadpoles under the influence of morphogens such as vitamin A (retinoids). Treatment with vitamin A after amputation of the tail inhibited tail regeneration but unexpectedly induced homeotic transformation of tails into limbs in many anurans, starting with the marbled balloon frog Uperodon systoma. This was the first observation of homeotic transformation in any vertebrate. The laboratory continues research on histological and molecular aspects of this phenomenon. In addition, taking advantage of the largest rookery of olive ridley sea turtles in Gahirmatha, in the same state the laboratory has contributed significantly to the biology, breeding patterns, development and especially the temperature-dependent sex determination phenomenon (TSD). This research was extended to biochemical and ultrastructural aspects during development for the first time for any sea turtle. The laboratory has contributed significantly to the conservation of olive ridleys as well as the saltwater crocodile (Crocodylus porosus). Recognition and awards for the laboratory have been received from both national and international bodies.


Crisis ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 130-139 ◽  
Author(s):  
Danica W. Y. Liu ◽  
A. Kate Fairweather-Schmidt ◽  
Richard Burns ◽  
Rachel M. Roberts ◽  
Kaarin J. Anstey

Abstract. Background: Little is known about the role of resilience in the likelihood of suicidal ideation (SI) over time. Aims: We examined the association between resilience and SI in a young-adult cohort over 4 years. Our objectives were to determine whether resilience was associated with SI at follow-up or, conversely, whether SI was associated with lowered resilience at follow-up. Method: Participants were selected from the Personality and Total Health (PATH) Through Life Project from Canberra and Queanbeyan, Australia, aged 28–32 years at the first time point and 32–36 at the second. Multinomial, linear, and binary regression analyses explored the association between resilience and SI over two time points. Models were adjusted for suicidality risk factors. Results: While unadjusted analyses identified associations between resilience and SI, these effects were fully explained by the inclusion of other suicidality risk factors. Conclusion: Despite strong cross-sectional associations, resilience and SI appear to be unrelated in a longitudinal context, once risk/resilience factors are controlled for. As independent indicators of psychological well-being, suicidality and resilience are essential if current status is to be captured. However, the addition of other factors (e.g., support, mastery) makes this association tenuous. Consequently, resilience per se may not be protective of SI.


2020 ◽  
pp. 49-57
Author(s):  
S. V. Orlova ◽  
E. A. Nikitina ◽  
L. I. Karushina ◽  
Yu. A. Pigaryova ◽  
O. E. Pronina

Vitamin A (retinol) is one of the key elements for regulating the immune response and controls the division and differentiation of epithelial cells of the mucous membranes of the bronchopulmonary system, gastrointestinal tract, urinary tract, eyes, etc. Its significance in the context of the COVID‑19 pandemic is difficult to overestimate. However, a number of studies conducted in the past have associated the additional intake of vitamin A with an increased risk of developing cancer, as a result of which vitamin A was practically excluded from therapeutic practice in developed countries. Our review highlights the role of vitamin A in maintaining human health and the latest data on its effect on the development mechanisms of somatic pathology.


2018 ◽  
pp. 1060-1068
Author(s):  
Galina A. Dvoenosova ◽  

The article assesses synergetic theory of document as a new development in document science. In information society the social role of document grows, as information involves all members of society in the process of documentation. The transformation of document under the influence of modern information technologies increases its interest to representatives of different sciences. Interdisciplinary nature of document as an object of research leads to an ambiguous interpretation of its nature and social role. The article expresses and contends the author's views on this issue. In her opinion, social role of document is incidental to its being a main social tool regulating the life of civilized society. Thus, the study aims to create a scientific theory of document, explaining its nature and social role as a tool of social (goal-oriented) action and social self-organization. Substantiation of this idea is based on application of synergetics (i.e., universal theory of self-organization) to scientific study of document. In the synergetic paradigm, social and historical development is seen as the change of phases of chaos and order, and document is considered a main tool that regulates social relations. Unlike other theories of document, synergetic theory studies document not as a carrier and means of information transfer, but as a unique social phenomenon and universal social tool. For the first time, the study of document steps out of traditional frameworks of office, archive, and library. The document is placed on the scales with society as a global social system with its functional subsystems of politics, economy, culture, and personality. For the first time, the methods of social sciences and modern sociological theories are applied to scientific study of document. This methodology provided a basis for theoretical vindication of nature and social role of document as a tool of social (goal-oriented) action and social self-organization. The study frames a synergetic theory of document with methodological foundations and basic concepts, synergetic model of document, laws of development and effectiveness of document in the social continuum. At the present stage of development of science, it can be considered the highest form of theoretical knowledge of document and its scientific explanatory theory.


2020 ◽  
Author(s):  
Armand Chatard ◽  
Margaux Renoux ◽  
Jean Monéger ◽  
Leila Selimbegovic

Research indicates that individuals often deal with mortality salience by affirming beliefs in national or cultural superiority (worldview defense). Because worldview defense may be associated with negative consequences (discrimination), it is important to identify alternative means to deal with death-related thoughts. In line with an embodied terror management perspective, we evaluate for the first time the role of physical warmth in reducing defensive reaction to mortality salience. We predicted that, like social affiliation (social warmth), physical warmth could reduce worldview defense when mortality is salient. In this exploratory (preregistered) study, 202 French participants were primed with death-related thoughts, or an aversive control topic, in a heated room or a non-heated room. The main outcome was worldview defense (ethnocentric bias). We found no main effect of mortality salience on worldview defense. However, physical warmth reduced worldview defense when mortality was salient. Implications for an embodied terror management perspective are discussed.


2019 ◽  
Vol 12 (2) ◽  
Author(s):  
Bibi Tahira ◽  
Naveed Saif ◽  
Muhammad Haroon ◽  
Sadaqat Ali

The current study tries to understand the diverse nature of relationship between personality Big Five Model (PBFM) and student's perception of abusive supervision in higher education institutions of Khyber Pakhtoonkhwa Pakistan. Data was collected in dyads i.e. (supervisors were asked to rate their personality attributes while student were asked to rate the supervisor behavior) through adopted construct. For this purpose, data was collected from three government state universities and one Private Sector University. The focus was on MS/M.Phill and PhD student and their supervisors of the mentioned universities. After measuring normality and validity regression analysis was conducted to assess the impact of supervisor personality characteristics that leads to abusive supervision. Findings indicate interestingly that except agreeableness other four attributes of (PBFM) are play their role for abusive supervision. The results are novel in the nature as for the first time Neuroticism, openness to experience, extraversion and conscientiousness are held responsible for the abusive supervision. The study did not explore the demographic characteristics, and moderating role of organizational culture, justice and interpersonal deviances to understand the strength of relationship in more detail way. Keywords: Personality big five model, abusive supervision, HEIs


Author(s):  
Bisma Laeeque

Retinol and Tocopherol are commonly known as fat soluble Vitamin A and D. This research was undertaken with the objective to study Vitamin A and D’s effect in combating smog caused illness among females. This case report highlights diseases caused among young woman of Lahore due to smog. Hypothesis formulated for this study was accepted after testing that intake of daily-recommended amount of Vitamin A and D by females helps them in fighting diseases caused by smog. An intervention based on Food and Nutrition Board’s Recommended Dietary Allowances (RDAs) was planned. After the analysis of data by SPSS and excel, it was indicated that women could fight smog caused diseases better by including Vitamin A and D in their daily diet. It was also found that a strong positive correlation existed between good health condition among females and intake of Vitamin A and D.


2020 ◽  
Vol 19 (2) ◽  
pp. 139-145
Author(s):  
Sheena Chhabra ◽  
Apurva Bakshi ◽  
Ravineet Kaur

Nutraceuticals have been around for quite some time. As the nomenclature suggests, they are placed somewhere between food (nutra-) and medicine (-ceuticals) in terms of their impact on human health. Researches have focused on the impact of various types of nutraceuticals on health, their efficacy in health promotion and disease prevention, and often on suitable uses of certain categories of nutraceuticals for specific health issues. However, we are still far from utilizing the immense potential of nutraceuticals for benefiting human health in a substantial manner. We review the available scholarly literature regarding the role of nutraceuticals in health promotion, their efficacy in disease prevention and the perception of nutraceuticals' health benefits by consumers. Thereafter we analyze the need for regulation of nutraceuticals and various provisions regarding the same.


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