Starch: A Flexible, Adaptable Carbon Store Coupled to Plant Growth

2020 ◽  
Vol 71 (1) ◽  
pp. 217-245 ◽  
Author(s):  
Alison M. Smith ◽  
Samuel C. Zeeman
Keyword(s):  
Starch Synthesis ◽  
Control Mechanisms ◽  
Starch Granules ◽  
Level Control ◽  
The Past ◽  
Starch Mobilization ◽  
Controlled Environments ◽  
Carbon Store ◽  
Synthesis And Degradation

Research in the past decade has uncovered new and surprising information about the pathways of starch synthesis and degradation. This includes the discovery of previously unsuspected protein families required both for processes and for the long-sought mechanism of initiation of starch granules. There is also growing recognition of the central role of leaf starch turnover in making carbon available for growth across the day-night cycle. Sophisticated systems-level control mechanisms involving the circadian clock set rates of nighttime starch mobilization that maintain a steady supply of carbon until dawn and modulate partitioning of photosynthate into starch in the light, optimizing the fraction of assimilated carbon that can be used for growth. These discoveries also uncover complexities: Results from experiments with Arabidopsis leaves in conventional controlled environments are not necessarily applicable to other organs or species or to growth in natural, fluctuating environments.

scholarly journals Reforming the Institutions of Eurozone Governance

2021 ◽  
Vol 9 (2) ◽  
pp. 159-162
Author(s):  
Anna-Lena Högenauer ◽  
Moritz Rehm
Keyword(s):  
Domestic Politics ◽  
Governance Structure ◽  
Thematic Issue ◽  
Control Mechanisms ◽  
Member States ◽  
The Past ◽  
Adequate Control ◽  
Legal Control ◽  
Democratic Debate

The Eurozone has faced repeated crises and has experienced profound transformations in the past years. This thematic issue seeks to address the questions arising from the changing governance structure of the Eurozone. First, how have the negotiations, pressures of the crises and reforms impacted the relationships between key actors like EU institutions and Member States? Second, where did national positions come from and what role did domestic politics play in the negotiations? And finally, to what extent has the evolution of Eurozone governance left room for adequate control mechanisms and democratic debate? The articles in this issue highlight the developing role of Member States, domestic politics and democratic and legal control mechanisms.

scholarly journals The role of calcium in the regulation of renin secretion

2010 ◽  
Vol 298 (1) ◽  
pp. F1-F11 ◽  
Author(s):  
William H. Beierwaltes
Keyword(s):  
Intracellular Calcium ◽  
Second Messenger ◽  
Renin Secretion ◽  
Secretory Cells ◽  
The Past ◽  
Calcium Sensing ◽  
Rate Limiting Step ◽  
Rate Limiting ◽  
Synthesis And Degradation

Renin is the enzyme which is the rate-limiting step in the formation of the hormone angiotensin II. Therefore, the regulation of renin secretion is critical in understanding the control of the renin-angiotensin-aldosterone system and its many biological and pathological actions. Renin is synthesized, stored in, and released from the juxtaglomerular (JG) cells of the kidney. While renin secretion is positively regulated by the “second messenger” cAMP, unlike most secretory cells, renin secretion from the JG cell is inversely related to the extracellular and intracellular calcium concentrations. This novel relationship is referred to as the “calcium paradox.” This review will address observations made over the past 30 years regarding calcium and the regulation of renin secretion, and focus on recent observations which address this scientific conundrum. These include 1) receptor-mediated pathways for changing intracellular calcium; 2) the discovery of a calcium-inhibitable isoform of adenylyl cyclase associated with renin in the JG cells; 3) calcium-sensing receptors in the JG cells; 4) calcium-calmodulin-mediated signals; 5) the role of phosphodiesterases; and 6) connexins, gap junctions, calcium waves, and the cortical extracellular calcium environment. While cAMP is the dominant second messenger for renin secretion, calcium appears to modulate the integrated activities of the enzymes, which balance cAMP synthesis and degradation. Thus this review concludes that calcium modifies the amplitude of cAMP-mediated renin-signaling pathways. While calcium does not directly control renin secretion, increased calcium inhibits and decreased calcium amplifies cAMP-stimulated renin secretion.

scholarly journals O vlogi trehaloze v rastlinah

2018 ◽  
Vol 111 (1) ◽  
pp. 219
Author(s):  
Tjaša GORJANC ◽  
Dominik VODNIK
Keyword(s):  
Vascular Plants ◽  
Higher Plants ◽  
Starch Synthesis ◽  
Plant Interactions ◽  
Primary Metabolite ◽  
Abiotic Stressors ◽  
Lower Plants ◽  
Synthesis And Degradation ◽  
Stimulation Of

Trehalose is an important disaccharide which takes a major role of a stress protector in many organisms, including green algae and lower plants. It has long been thought that trehalose functions in higher plants are marginal and that they have been overtaken by sucrose. In the last years it has been discovered that trehalose takes on a lot of important physiological roles in vascular plants metabolism. It is an important signal metabolite of sucrose availability and maintains sucrose concentrations within an appropriate range. It also contributes to starch synthesis and degradation and to synthesis of organic acids. Trehalose-sucrose nexus was found to be very important in plant interactions with pathogenic organisms and herbivorous insects. Furthermore, trehalose is involved in response of plant to abiotic stressors such as drought, cold, salinity and hypoxia. It contributes in regulation of stomatal conductivity where it interacts with abscisic acid. All this makes trehalose an important primary metabolite which significantly influences plant growth and development such as induction of flowering and stimulation of photosynthesis.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

A literature review on firms' internationalisation through e-commerce

2019 ◽  
pp. 121-143
Author(s):  
Riccardo Resciniti ◽  
Federica De Vanna
Keyword(s):  
Systematic Review ◽  
Literature Review ◽  
International Business ◽  
Decision Process ◽  
Foreign Markets ◽  
New Markets ◽  
Integrative Framework ◽  
The Past ◽  
The Relationship

The rise of e-commerce has brought considerable changes to the relationship between firms and consumers, especially within international business. Hence, understanding the use of such means for entering foreign markets has become critical for companies. However, the research on this issue is new and so it is important to evaluate what has been studied in the past. In this study, we conduct a systematic review of e-commerce and internationalisation studies to explicate how firms use e-commerce to enter new markets and to export. The studies are classified by theories and methods used in the literature. Moreover, we draw upon the internationalisation decision process (antecedents-modalities-consequences) to propose an integrative framework for understanding the role of e-commerce in internationalisation

Concealment of Illegally Obtained Assets in Nigeria: Revisiting the Role of the Churches in Money Laundering

2020 ◽  
Vol 28 (1) ◽  
pp. 106-121
Author(s):  
Kato Gogo Kingston
Keyword(s):  
Economic Growth ◽  
Money Laundering ◽  
Financial Crime ◽  
The Past ◽  
Key Drivers ◽  
Nigerian Government

Financial crime in Nigeria – including money laundering – is ravaging Nigeria's economic growth. In the past few years, the Nigerian government has made efforts to tackle money laundering by enacting laws and setting up several agencies to enforce the laws. However, there are substantial loopholes in the regulatory and enforcement regimes. This article seeks to unravel the involvement of the churches as key drivers in money laundering crimes in Nigeria. It concludes that the permissive secrecy which enables churches to conceal the names of their financiers and donors breeds criminality on an unimaginable scale.

Provision of Remedies for Violation of Economic, Social and Cultural Rights: A Comparative Study of the United Nations, Inter-American and African Human Rights Systems

2020 ◽  
Vol 28 (2) ◽  
pp. 298-318
Author(s):  
Roman Girma Teshome
Keyword(s):  
Human Rights ◽  
United Nations ◽  
Comparative Study ◽  
Economic Rights ◽  
Regional Monitoring ◽  
Cultural Rights ◽  
The Past ◽  
The United Nations ◽  
To Receive

The effectiveness of human rights adjudicative procedures partly, if not most importantly, hinges upon the adequacy of the remedies they grant and the implementation of those remedies. This assertion also holds water with regard to the international and regional monitoring bodies established to receive individual complaints related to economic, social and cultural rights (hereinafter ‘ESC rights’ or ‘socio-economic rights’). Remedies can serve two major functions: they are meant, first, to rectify the pecuniary and non-pecuniary damage sustained by the particular victim, and second, to resolve systematic problems existing in the state machinery in order to ensure the non-repetition of the act. Hence, the role of remedies is not confined to correcting the past but also shaping the future by providing reforming measures a state has to undertake. The adequacy of remedies awarded by international and regional human rights bodies is also assessed based on these two benchmarks. The present article examines these issues in relation to individual complaint procedures that deal with the violation of ESC rights, with particular reference to the case laws of the three jurisdictions selected for this work, i.e. the United Nations, Inter-American and African Human Rights Systems.

Receptions of the Past: Commemoration, Racism, Desire

Somatechnics ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 288-303
Author(s):  
Michael Connors Jackman
Keyword(s):  
Critical Point ◽  
Social Relations ◽  
White Privilege ◽  
Body Politic ◽  
The Body ◽  
Race And Racism ◽  
Lesbian And Gay ◽  
The Past ◽  
History Of

This article investigates the ways in which the work of The Body Politic (TBP), the first major lesbian and gay newspaper in Canada, comes to be commemorated in queer publics and how it figures in the memories of those who were involved in producing the paper. In revisiting a critical point in the history of TBP from 1985 when controversy erupted over race and racism within the editorial collective, this discussion considers the role of memory in the reproduction of whiteness and in the rupture of standard narratives about the past. As the controversy continues to haunt contemporary queer activism in Canada, the productive work of memory must be considered an essential aspect of how, when and for what reasons the work of TBP comes to be commemorated. By revisiting the events of 1985 and by sifting through interviews with individuals who contributed to the work of TBP, this article complicates the narrative of TBP as a bluntly racist endeavour whilst questioning the white privilege and racially-charged demands that undergird its commemoration. The work of producing and preserving queer history is a vital means of challenging the intentional and strategic erasure of queer existence, but those who engage in such efforts must remain attentive to the unequal terrain of social relations within which remembering forms its objects.

Vitamin A: dietologist’s position

2020 ◽  
pp. 49-57
Author(s):  
S. V. Orlova ◽  
E. A. Nikitina ◽  
L. I. Karushina ◽  
Yu. A. Pigaryova ◽  
O. E. Pronina
Keyword(s):  
Immune Response ◽  
Urinary Tract ◽  
Gastrointestinal Tract ◽  
Vitamin A ◽  
Developed Countries ◽  
Therapeutic Practice ◽  
The Past ◽  
Increased Risk ◽  
Mucous Membranes

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.

Learning Zulu

2016 ◽  
Author(s):  
Mark Sanders
Keyword(s):  
Language Learning ◽  
Cultural History ◽  
South African ◽  
Press Coverage ◽  
African History ◽  
African Culture ◽  
The Past ◽  
Correct Form ◽  
Linguistic Purism

When this book's author began studying Zulu, he was often questioned why he was learning it. This book places the author's endeavors within a wider context to uncover how, in the past 150 years of South African history, Zulu became a battleground for issues of property, possession, and deprivation. The book combines elements of analysis and memoir to explore a complex cultural history. Perceiving that colonial learners of Zulu saw themselves as repairing harm done to Africans by Europeans, the book reveals deeper motives at work in the development of Zulu-language learning—from the emergence of the pidgin Fanagalo among missionaries and traders in the nineteenth century to widespread efforts, in the twentieth and twenty-first centuries, to teach a correct form of Zulu. The book looks at the white appropriation of Zulu language, music, and dance in South African culture, and at the association of Zulu with a martial masculinity. In exploring how Zulu has come to represent what is most properly and powerfully African, the book examines differences in English- and Zulu-language press coverage of an important trial, as well as the role of linguistic purism in xenophobic violence in South Africa. Through one person's efforts to learn the Zulu language, the book explores how a language's history and politics influence all individuals in a multilingual society.

Sign in / Sign up

Export Citation Format

Share Document