Marine Synechococcus picocyanobacteria: Light utilization across latitudes

2021 ◽  
Vol 118 (38) ◽  
pp. e2111300118
Author(s):  
Christophe Six ◽  
Morgane Ratin ◽  
Dominique Marie ◽  
Erwan Corre

The most ubiquitous cyanobacteria, Synechococcus, have colonized different marine thermal niches through the evolutionary specialization of lineages adapted to different ranges of temperature seawater. We used the strains of Synechococcus temperature ecotypes to study how light utilization has evolved in the function of temperature. The tropical Synechococcus (clade II) was unable to grow under 16 °C but, at temperatures >25 °C, induced very high growth rates that relied on a strong synthesis of the components of the photosynthetic machinery, leading to a large increase in photosystem cross-section and electron flux. By contrast, the Synechococcus adapted to subpolar habitats (clade I) grew more slowly but was able to cope with temperatures <10 °C. We show that growth at such temperatures was accompanied by a large increase of the photoprotection capacities using the orange carotenoid protein (OCP). Metagenomic analyzes revealed that Synechococcus natural communities show the highest prevalence of the ocp genes in low-temperature niches, whereas most tropical clade II Synechococcus have lost the gene. Moreover, bioinformatic analyzes suggested that the OCP variants of the two cold-adapted Synechococcus clades I and IV have undergone evolutionary convergence through the adaptation of the molecular flexibility. Our study points to an important role of temperature in the evolution of the OCP. We, furthermore, discuss the implications of the different metabolic cost of these physiological strategies on the competitiveness of Synechococcus in a warming ocean. This study can help improve the current hypotheses and models aimed at predicting the changes in ocean carbon fluxes in response to global warming.

Author(s):  
B.K. Cameron

THE PROPERTY to be discussed is a mixed sheep and cropping unit, situated ei ht a miles east of Ashburton and midway between the Ra aia and the Ashburton rivers. Average annual rainfall is 27 in., evenly spread, but there is very high summer evaporation and therefore frequent droughts. On average, the soil is below wilting point for 40 to 50 days each summer. Winters are cold with the soil temperature being below 48°F for about four months each year. The soil is a Lismore stony silt loam averaging 9 in. in depth over gravel.


2020 ◽  
Vol 11 (SPL1) ◽  
pp. 259-261
Author(s):  
Aamir Khan ◽  
Rajni K. Gurmule

Vasavaleha is one of the best medicine given for respiratory diseases. Corona viruses typically affect the respiratory system, causing symptoms such as coughing, fever and shortness of breath. It also affects host immune system of human body. Spreading rate of this disease is very high. Whole world is seeking for the treatment which can uproots this diseases. There in no vaccine available till date against this pandemic disease. Ayurveda mainly focuses on prevention of diseases alongwith its total cure. Rajyakshma Vyadhi is MadhyamMarga Roga as per Ayurveda. It shows many symptoms such as Kasa, Shwasa etc. By overall view of Covid 19, shows its resemblance with Rajyakshma Vyadhi described in Ayurveda. Vasavaleha is a Kalpa which is described in Rogadhikara of Rajyakshma. It shows Kasahara, Shwashara properties. It consists of Vasa, Pipalli, Madhu and Goghrita. These components shows actions like bronchodilation, antitussive effect and many more other actions. Pipalli shows important Rasayana effect. So in present review, we have tried to focus on role of Vasavaleha in the management of Covid 19. This can be used as preventive as well as adjuvant medication in treating Covid 19. There is need of further clinical research to rule of exact action of Vasavaleha against Covid 19.


2019 ◽  
Vol 118 (8) ◽  
pp. 236-240
Author(s):  
Dr.R. Murugesan ◽  
M. Leelavathi ◽  
Dr. K. Ravindran

towards jumping from the category of developing economy to developed economy there is one big factor that stops and poses a hindrance in its path of advancement and that obstacle is termed as Poverty. The Indian economic policy focuses on a high growth rate along with a equal participation of the poor so that they avail the opportunities available in the market economy. And in order to ensure the participation of the poor it has become important for the country to create a platform where the poor can easily access the various financial products. Microfinance is one such strategy for inclusive growth. Microfinance can change the life of the poor though not completely but a reasonable change can be ensured. In different phases of life women play a crucial role despite the discrimination that is faced by them. But equality can be endowed to women by enhancing the entrepreneurial skills in them. This is possible through Self Help Groups (SHGs). In India women produce around 30% of the total food consumed but she gets only 10% of the property or wealth of the country. Development of women is inevitable for the development and growth of any economy. SHGs happen to be a positive step in this direction. Along with these mediums there should be a cheap and easy source of credit for them and Microfinance fulfills the requirement. This study aims to find the role of this strong medium of Microfinance in the advancement of SHGs in India


Author(s):  
Hazel Gray

This chapter explores the role of the political settlement in shaping outcomes of land investments by analysing struggles in key sectors of the economy. Land reform during the socialist period had far-reaching implications for the political settlement. Reforms to land rights under liberalization involved strengthening land markets; however, the state continued to play a significant role. Corruption within formal land management systems became prevalent during the period of high growth. Vietnam experienced a rapid growth in export agriculture but, in contrast with stable property rights for smallholders, Tanzania’s efforts to encourage large land investments were less successful. Industrialization in both countries generated new forms of land struggles that were influenced by the different distributions of power between the state, existing landowners, and investors.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tuomas Huokko ◽  
Tao Ni ◽  
Gregory F. Dykes ◽  
Deborah M. Simpson ◽  
Philip Brownridge ◽  
...  

AbstractHow thylakoid membranes are generated to form a metabolically active membrane network and how thylakoid membranes orchestrate the insertion and localization of protein complexes for efficient electron flux remain elusive. Here, we develop a method to modulate thylakoid biogenesis in the rod-shaped cyanobacterium Synechococcus elongatus PCC 7942 by modulating light intensity during cell growth, and probe the spatial-temporal stepwise biogenesis process of thylakoid membranes in cells. Our results reveal that the plasma membrane and regularly arranged concentric thylakoid layers have no physical connections. The newly synthesized thylakoid membrane fragments emerge between the plasma membrane and pre-existing thylakoids. Photosystem I monomers appear in the thylakoid membranes earlier than other mature photosystem assemblies, followed by generation of Photosystem I trimers and Photosystem II complexes. Redistribution of photosynthetic complexes during thylakoid biogenesis ensures establishment of the spatial organization of the functional thylakoid network. This study provides insights into the dynamic biogenesis process and maturation of the functional photosynthetic machinery.


2020 ◽  
Vol 287 (1939) ◽  
pp. 20202127
Author(s):  
S. Hervías-Parejo ◽  
C. Tur ◽  
R. Heleno ◽  
M. Nogales ◽  
S. Timóteo ◽  
...  

Many vertebrate species act as both plant pollinators and seed-dispersers, thus interconnecting these processes, particularly on islands. Ecological multilayer networks are a powerful tool to explore interdependencies between processes; however, quantifying the links between species engaging in different types of interactions (i.e. inter-layer edges) remains a great challenge. Here, we empirically measured inter-layer edge weights by quantifying the role of individually marked birds as both pollinators and seed-dispersers of Galápagos plant species over an entire year. Although most species (80%) engaged in both functions, we show that only a small proportion of individuals actually linked the two processes, highlighting the need to further consider intra-specific variability in individuals' functional roles. Furthermore, we found a high variation among species in linking both processes, i.e. some species contribute more than others to the modular organization of the multilayer network. Small and abundant species are particularly important for the cohesion of pollinator seed-dispersal networks, demonstrating the interplay between species traits and neutral processes structuring natural communities.


Author(s):  
Sachin A Meshram ◽  
A. M. Rawani

Entrepreneurial ecosystems are a strategy that is designed to nurture economic development by promoting entrepreneurship, small business growth, and innovation. Ecosystems represent a new direction for entrepreneurship research that simultaneously increases knowledge of the complex contextual environments surrounding the entrepreneurship process, while at the same time providing useful contributions to policy debates around the role of high-growth entrepreneurship as a driver of regional economic development. This article reviews the concept evolution; different definitions and factors of entrepreneurial ecosystems. Additionally, it provides approaches of past contributions about entrepreneurial ecosystem. This article contributes to knowledge generation and provides further research directions. This study is an attempt to cover the different articles that exist on the entrepreneurial ecosystems.


2007 ◽  
Vol 22 (3) ◽  
pp. 587-594 ◽  
Author(s):  
V. Bedekar ◽  
S.V. Chavan ◽  
A.K. Tyagi

Highly sinter-active powders of RE2O3 [rare earth (RE) = Gd, Eu, Dy] have been prepared using the corresponding metal nitrates as the oxidants, and glycine and citric acid as the fuels. Two different oxidant-to-fuel ratios, namely stoichiometric ratio and fuel-deficient ratio were used to explore the possibility of preparing different crystallographic modifications. By a careful control of oxidant-to-fuel ratio, nanocrystalline Eu2O3 and Gd2O3 could be prepared in cubic (C-type) as well as monoclinic (B-type) modifications. However, the high-temperature monoclinic modification could not be obtained for Dy2O3 due to a very high C-to-B-type phase transition temperature. The crystallite size, surface area, and sintering behavior were also studied for powders prepared using different oxidant-to-fuel ratios, and the results showed a remarkable correlation between different fuel contents and powder properties. Some of these powders resulted in pellets of nearly theoretical density. The sintered microstructure was studied by scanning electron microscopy.


Sign in / Sign up

Export Citation Format

Share Document