scholarly journals Photosynthetic Pigments Changes of Three Phenotypes of Picocyanobacteria Synechococcus sp. under Different Light and Temperature Conditions

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2030 ◽  
Author(s):  
Sylwia Śliwińska-Wilczewska ◽  
Zofia Konarzewska ◽  
Kinga Wiśniewska ◽  
Marta Konik

It is estimated that the genus Synechococcus is responsible for about 17% of net primary production in the Global Ocean. Blooms of these organisms are observed in tropical, subtropical and even temperate zones, and they have been recorded recently even beyond the polar circle. The long-term scenarios forecast a growing expansion of Synechococcus sp. and its area of dominance. This is, among others, due to their high physiological plasticity in relation to changing environmental conditions. Three phenotypes of the genus Synechococcus sp. (Type 1, Type 2, and Type 3a) were tested in controlled laboratory conditions in order to identify their response to various irradiance (10, 55, 100 and 145 µmol photons m−2 s−1) and temperature (15, 22.5 and 30 °C) conditions. The highest total pigment content per cell was recorded at 10 μmol photons m−2 s−1 at all temperature variants with the clear dominance of phycobilins among all the pigments. In almost every variant the highest growth rate was recorded for the Type 1. The lowest growth rates were observed, in general, for the Type 3a. However, it was recognized to be less temperature sensitive in comparison to the other two types and rather light-driven with the highest plasticity and adaptation potential. The highest amounts of carotenoids were produced by Type 2 which also showed signs of the cell stress even around 55 μmol photons m−2 s−1 at 15 °C and 22.5 °C. This may imply that the Type 2 is the most susceptible to higher irradiances. Picocyanobacteria Synechococcus sp. require less light intensity to achieve the maximum rate of photosynthesis than larger algae. They also tolerate a wide range of temperatures which combined together make them gain a powerful competitive advantage. Our results will provide key information for the ecohydrodynamical model development. Thus, this work would be an important link in forecasting future changes in the occurrence of these organisms in the context of global warming.

2019 ◽  
Vol 15 (S356) ◽  
pp. 96-96
Author(s):  
Eleonora Sani

AbstractI present a detailed study of ionized outflows in a large sample of 650 hard X-ray detected AGN. Taking advantage of the legacy value of the BAT AGN Spectroscopic Survey (BASS, DR1), we are able to reveal the faintest wings of the [OIII] emission lines associated with outflows. The sample allows us to derive the incidence of outflows covering a wide range of AGN bolometric luminosity and test how the outflow parameters are related with various AGN power tracers, such as black hole mass, Eddington ratio, luminosity. I’ll show how ionized outflows are more frequently found in type 1.9 and type 1 AGN (50% and 40%) with respect to the low fraction in type 2 AGN (20%). Within such a framework, I’ll demonstrate how type 2 AGN outflows are almost evenly balanced between blue- and red-shifted winds. This, in strong contrast with type 1 and type 1.9 AGN outflows which are almost exclusively blue-shifted. Finally, I’ll prove how the outflow occurrence is driven by the accretion rate, whereas the dependence of outflow properties with respect to the other AGN power tracers happens to be quite mild.


2015 ◽  
Vol 73 (6) ◽  
pp. 531-543 ◽  
Author(s):  
Pollyanna Barros Batista ◽  
Eny Maria Goloni Bertollo ◽  
Danielle de Souza Costa ◽  
Lucas Eliam ◽  
Karin Soares Gonçalves Cunha ◽  
...  

Part 1 of this guideline addressed the differential diagnosis of the neurofibromatoses (NF): neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2) and schwannomatosis (SCH). NF shares some features such as the genetic origin of the neural tumors and cutaneous manifestations, and affects nearly 80 thousand Brazilians. Increasing scientific knowledge on NF has allowed better clinical management and reduced rate of complications and morbidity, resulting in higher quality of life for NF patients. Most medical doctors are able to perform NF diagnosis, but the wide range of clinical manifestations and the inability to predict the onset or severity of new features, consequences, or complications make NF management a real clinical challenge, requiring the support of different specialists for proper treatment and genetic counseling, especially in NF2 and SCH. The present text suggests guidelines for the clinical management of NF, with emphasis on NF1.


JMS SKIMS ◽  
2019 ◽  
Vol 22 (1) ◽  
Author(s):  
Shariq R Masoodi

In recent years, vitamin D has received increased attention, as a number of studies have shown its link to the pathogenesis of various diseases. Apart from its benefits on bone health, vitamin D supplementation has been shown beneficial in reducing risk for many chronic diseases including autoimmune diseases, type 2 diabetes, heart disease, many cancers and infectious diseases. Vitamin deficiency has been associated with increased risk of elevated blood pressure, heart attack and stroke in studies. The relationship between vitamin D deficiency and the increased incidence of upper respiratory infections, asthma and eczema, among children, has been observed in several studies. Recent meta-analyzes showed a relationship between vitamin D administration during the early months of life and a lower incidence of type 1 diabetes later in life. Therefore, it is not surprising that Vitamin D supplementation is used to prevent and treat a wide range of diseases, and the use has increased considerably in the last decade.


Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 179 ◽  
Author(s):  
Zofia Konarzewska ◽  
Sylwia Śliwińska-Wilczewska ◽  
Aldo Barreiro Felpeto ◽  
Vitor Vasconcelos ◽  
Adam Latała

Organisms belonging to Synechococcus sp. genera are observed in all freshwater, brackish, and marine waters of the world. They play a relevant role in these ecosystems, since they are one of the main primary producers, especially in open ocean. Eventually, they form mass blooms in coastal areas, which are potentially dangerous for the functioning of marine ecosystems. Allelopathy could be an important factor promoting the proliferation of these organisms. According to the authors’ best knowledge, there is no information on the allelopathic activity and allelopathic compounds exhibited by different Synechococcus sp. phenotypes. Therefore, the research conducted here aimed to study the bioactivity of compounds produced by three phenotypes of Synechococcus sp. by studying their influence on the growth, chlorophyll fluorescence, and photosynthetic pigments of eighteen cyanobacteria and microalgae species. We demonstrated that three different Synechococcus sp. phenotypes, including a phycocyanin (PC)-rich strain (Type 1; green strain) and phycoerythrin (PE)-rich strains containing phycoerythrobilin (PEB) and phycocyanobilin (PCB) (Type 2; red strain and Type 3a; brown strain), had a significant allelopathic effect on the selected species of cyanobacteria, diatoms, and green algae. For all green algae, a decrease in cell abundance under the influence of phenotypes of donor cyanobacteria was shown, whereas, among some target cyanobacteria and diatom species, the cell-free filtrate was observed to have a stimulatory effect. Our estimates of the stress on photosystem II (Fv/Fm) showed a similar pattern, although for some diatoms, there was an effect of stress on photosynthesis, while a stimulatory effect on growth was also displayed. The pigment content was affected by allelopathy in most cases, particularly for chlorophyll a, whilst it was a bit less significant for carotenoids. Our results showed that Synechococcus sp. Type 3a had the strongest effect on target species, while Synechococcus sp. Type 1 had the weakest allelopathic effect. Furthermore, GC-MS analysis produced different biochemical profiles for the Synechococcus strains. For every phenotype, the most abundant compound was different, with oxime-, methoxy-phenyl- being the most abundant substance for Synechococcus Type 1, eicosane for Synechococcus Type 2, and silanediol for Synechococcus Type 3a.


2020 ◽  
Vol 23 (12) ◽  
pp. 2626-2641
Author(s):  
Seyed Hossein Hosseini Lavasani ◽  
Hamed Alizadeh ◽  
Rouzbeh Doroudi ◽  
Peyman Homami

Suspension bridges due to their long span can experience large displacement response under dynamic loading like earthquakes. Unlike other structures, their vertical vibration may make remarkable difficulty that a control strategy seems to be essential. Tuned mass damper is a passive control system that can be changed to active one by adding an external source producing the active control force called active tuned mass damper. Unlike passive systems, active ones need a controller system affecting the performance of them considerably. In this study, the efficiency of tuned mass damper and active tuned mass damper are investigated in the bridges. Two controllers, fuzzy type 2 and fuzzy type 1, are used to estimate control force of active tuned mass damper. Tuned mass damper’s parameters are optimized under wide range of ground motions. Also, fuzzy type 2 and fuzzy type 1’s parameters are optimized under the influence of three different conditions containing far-field and near-field ground motions and also combination of them. In addition, Lion Pride Optimization Algorithm is selected for optimizing section. Numerical analysis indicates that active tuned mass damper is more effective than tuned mass damper, and also active tuned mass damper does not make any instability matter of concern in active control systems. Furthermore, performance of fuzzy type 2 is better than fuzzy type 1.


Author(s):  
Shuji Ohno ◽  
Masanori Ohta ◽  
Shizuo Nakajin

Abstract: Glucocorticoid (GC) concentrations in peripheral tissues are precisely regulated by 11β-hydroxysteroid dehydrogenase (HSD) isozymes. When considering the physiological effects of GC in various tissues, quantitative determination of these isozymes and other components involved in corticosteroid signaling is important and informative. We thus performed comprehensive determination of the expression of these mRNAs in a wide range of human tissues.: An absolute comparison of mRNA expression of human 11β-HSD isozymes, hexose-6-phosphate dehydrogenase (H6PDH), glucose-6-phosphate transporter (G6PT), glucocorticoid receptors (GRs), and mineralocorticoid receptor (MR) was performed by real-time RT-PCR.: Human 11β-HSD type 1 mRNA was strongly expressed in the liver and placenta at comparatively high levels. H6PDH was expressed at low copy number, and comparatively high expression was observed in the kidney, testis, and ovary. G6PT expression was ubiquitous, but marked expression was observed in the liver, kidney, small intestine, and colon. GRα was also ubiquitously expressed at relatively high levels, which were approximately 10-fold higher than those of MR, whereas GRβ levels were below the detection limit in all tissues. 11β-HSD type 2 was predominantly expressed in the kidney, small intestine and colon; however, copy numbers of these transcripts showed a nearly identical pattern to type 1. MR was observed in various tissues examined, but was not fully correlated to the distribution of 11β-HSD type 2.: The present quantitative results were partially consistent with previous studies. This quantification method can thus provide valuable information for understanding the physiological effects and physiological roles of glucocorticoid in humans.


2004 ◽  
Vol 92 (4) ◽  
pp. 2283-2294 ◽  
Author(s):  
T. Tateno ◽  
A. Harsch ◽  
H. P. C. Robinson

Neurons and dynamical models of spike generation display two different types of threshold behavior, with steady current stimulation: type 1 [the firing frequency vs. current ( f– I) relationship is continuous at threshold) and type 2 (discontinuous f– I)]. The dynamics at threshold can have profound effects on the encoding of input as spikes, the sensitivity of spike generation to input noise, and the coherence of population firing. We have examined the f– I and frequency–conductance ( f– g) relationships of cells in layer 2/3 of slices of young (15–21 DIV) rat somatosensory cortex, focusing in detail on the nature of the threshold. Using white-noise stimulation, we also measured firing frequency and interspike interval variability as a function of noise amplitude. Regular-spiking (RS) pyramidal neurons show a type 1 threshold, consistent with their well-known ability to fire regularly at very low frequencies. In fast-spiking (FS) inhibitory interneurons, although regular firing is supported over a wide range of frequencies, there is a clear discontinuity in their f– I relationship at threshold (type 2), which has not previously been highlighted. FS neurons are unable to support maintained periodic firing below a critical frequency fc, in the range of 10 to 30 Hz. Very close to threshold, FS cells switch irregularly between bursts of periodic firing and subthreshold oscillations. These characteristics mean that the dynamics of RS neurons are well suited to encoding inputs into low-frequency firing rates, whereas the dynamics of FS neurons are suited to maintaining and quickly synchronizing to gamma and higher-frequency input.


Author(s):  
Khalid Almohammadi

<p><span style="font-family: Times New Roman; font-size: medium;">Obesity is a critical public health concern affecting a wide range of people globally. The rise in obesity is limited to not only the wealthiest countries but also the poorest. Childhood obesity has grown exponentially in the last few years, and its progression is significant contribution to the increase in mortality rates. Childhood obesity is linked with a wide range of risk factors. These include individual and parental biological factors, sedentary behavior or decreased physical activity, and parent restriction. This paper focuses on reviewing the techniques of artificial intelligence (AI) utilized in the management of obesity in children. The paper will also propose a conceptual framework to use novel type-1 and type-2 fuzzy logic methods capable of predicting risks for developing childhood obesity. The proposed approach will address factors such as family characteristics, unhealthy food choices and lack of exercise, and others related to children and their home environment. The procedure will help in the prevention of childhood obesity, promote public health, and reduce treatment costs for a wide range of obesity-related conditions. The paper will also plan an examination of type-1 and type-2 fuzzy logic systems on approximately one thousand families in Saudi Arabia. The proposed methods can handle the encountered uncertainties to enhance modeling and promote the accuracy of predictions of the risk for childhood obesity. Type-1 and type-2 fuzzy logic systems can also encode extracted rules comprehensively to provide insight into the best childhood obesity prevention behaviors.</span><strong></strong></p>


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