scholarly journals Marine Antibiotics 2020

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 351
Author(s):  
Yannick Fleury

The range of environmental conditions in marine life is tremendous at different physico-chemical criteria (temperature, light, pressure and salinity) [...]

2014 ◽  
Vol 70 (12) ◽  
pp. 2040-2046 ◽  
Author(s):  
L. Chekli ◽  
S. Phuntsho ◽  
L. D. Tijing ◽  
J. L. Zhou ◽  
J.-H. Kim ◽  
...  

Manufactured nanoparticles (MNPs) are increasingly released into the environment and thus research on their fate and behaviour in complex environmental samples is urgently needed. The fate of MNPs in the aquatic environment will mainly depend on the physico-chemical characteristics of the medium. The presence and concentration of natural organic matter (NOM) will play a significant role on the stability of MNPs by either decreasing or exacerbating the aggregation phenomenon. In this study, we firstly investigated the effect of NOM concentration on the aggregation behaviour of manufactured Fe-oxide nanoparticles. Then, the stability of the coated nanoparticles was assessed under relevant environmental conditions. Flow field-flow fractionation, an emerging method which is gaining popularity in the field of nanotechnology, has been employed and results have been compared to another size-measurement technique to provide increased confidence in the outcomes. Results showed enhanced stability when the nanoparticles are coated with NOM, which was due to electrosteric stabilisation. However, the presence of divalent cations, even at low concentration (i.e. less than 1 mM) was found to induce aggregation of NOM-coated nanoparticles via bridging mechanisms between NOM and Ca2+.


Author(s):  
Gökhan Tamer Kayaalp ◽  
Oya Işık ◽  
Benin Toklu Alıçlı

The study was carried out to estimate the temperature, light intensity, salinity, Dissolved O2 (DO), pH values and the biotic parameter chlorophyll- a in the water column related with the depth. Because, the physico-chemical parameters affect greatly both primary and secondary producers in marine life. For this purpose the physico-chemical properties were determined day and night for 40 meter depth during the eight days. The means were compared by using the analysis of variance method and Duncan’s Multiple Comparison Test. Also physico-chemical parameters were estimated by using the analysis of regression and correlation. The effect of temperature and salinity were found significant according to the result of the analysis of variance during the day. Also the similar results were found for the night. While the effect of the depth on the chloropyll-a a was significant in the night, the effect of the depth on the DO was not significant in the day and night. The correlations among the depth and the parameters were defined. It was found the negative correlation between the depth and the temperature and light intensity. Determination coefficient of the model for salinity was also found different for day time. The correlation values among the depth and the temperature, salinity and pH were found different for the night.


Toxins ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 390
Author(s):  
Seung Ho Baek ◽  
Yunji Kim ◽  
Minji Lee ◽  
Chi-Yong Ahn ◽  
Kyung Hwa Cho ◽  
...  

Blooms of the ichthyotoxic dinoflagellate Cochlodinium polykrikoides are responsible for massive fish mortality events in Korean coastal waters (KCW). They have been consistently present in southern KCW over the last two decades, but they were not observed in 2016, unlike in the previous years. Despite extensive studies, the cause of this absence of this dinoflagellate bloom remains largely unknown. Thus, we compared physico-chemical and biological data from along the Tongyeong coast between 2016 and the previous four years (2012–2015). The averages of water temperature and salinity in August, 2016 were significantly (p < 0.001) different from those in the previous years. The amount of Changjiang River discharge, which can affect the environmental conditions in the southern Korean coastal area via ocean currents, was larger than in the previous years, resulting in a reduction in the salinity level in August when blooms of C. polykrikoides usually occurred. Moreover, compared to previous years, in 2016, there was a weak expansion of C. polykrikoides blooms in the Goheung-Oenarodo area where C. polykrikoides blooms were annually initiated in KCW. Lastly, the strong winds from the typhoon Lionrock may also have contributed to the early termination of this dinoflagellate bloom. Together with these findings, the combination of these environmental conditions in 2016, unlike in previous years, may have inhibited the formation of C. polykrikoides blooms along the Tongyeong coast.


2008 ◽  
Vol 55 (2) ◽  
pp. 307-310 ◽  
Author(s):  
Muzzaffar Khan ◽  
Gul Akhtar ◽  
Arshad Saeed ◽  
Najeeb Ullah ◽  
Imtiaz Ahmad

The chemical, physical evaluation and storage stability of cookies was carried out. studies on quality was based on physico-chemical analysis that is weight, diameter, thickness ,spread ratio, moisture, fat, protein, ash, crude fiber, carbohydrate content as well as sensory characteristics which was determined for fresh and stored sample. The characteristics of cookies were influenced by packaging material, environmental conditions and constituents present in flour. Cookies was packed in LDPE bags and stored at room temperature. This study was conducted at the interval of 15 days up to 45days.


Hoehnea ◽  
2020 ◽  
Vol 47 ◽  
Author(s):  
Andréa Sampaio Dias ◽  
Andréa Tucci

ABSTRACT This is the first record of Ceratium furcoides in the Nova Avanhandava reservoir, São Paulo, whose samples were collected in three stations (S1, S2, S3) in March and October of the years 2015 and 2016. Physico-chemical analyzes of the water were performed. The reservoir was classified, according to the TSI, as mesotrophic. The first record of the species occurred in October 2015 at S3 and, the following year, the dispersion for the other stations was verified. The highest density of the species (28 org mL-1) was recorded in October 2016. Similar values were documented in Furnas (MG) and Ilha Solteira (SP). The low density values of C. furcoides and the presence of phytoplankton groups with higher densities (Cyanobacteria and Cryptophyceae) suggest that the colonization of the species is at an early stage. Thus, studies about dispersion, dynamics, and interaction of C. furcoides with phytoplankton and the potential impacts on aquatic communities are essential to understand the responses of this species to environmental conditions.


2021 ◽  
Author(s):  
Eva Mateo-Marti

&lt;p&gt;Even though space missions provide fundamental and unique knowledge for planetary exploration, they are always costly and extremely time-consuming. Due to the obvious technical and economical limitations for &lt;em&gt;in-situ&lt;/em&gt; planetary exploration; laboratory simulations are one of the most feasible research options to make advances both in planetary science and in a consistent description of the origin of life.&amp;#160; Planetary Atmosphere and Surfaces Chamber (PASC) are able to simulated atmosphere and surface temperature for the majority of the planetary objects and they are especially appropriate to study physico-chemical and biological changes induced in a particular sample due to in-situ irradiation in a controlled environment (1). Number of relevant applications in planetary exploration will be described in order to provide an understanding about the potential and flexibility of planetary simulation chambers systems: mainly, stability and presence of certain minerals on Mars surface; photochemistry process on molecules and microorganisms potential habitability under planetary environmental conditions would be studied. Furthermore, UV-photocatalytic process on mineral surfaces has shown species potential fixation (2-6). Therefore, simulation chambers assess several multidisciplinary and challenging planetary and astrobiological studies. Furthermore, will be a promising tools and necessary platform to design future planetary space mission and to validate in-situ measurements from orbital or rover observations.&lt;/p&gt; &lt;p&gt;References:&lt;/p&gt; &lt;p&gt;1.- Mateo-Mart&amp;#237;, E.; Prieto-Ballesteros, O.; Sobrado, J. M.; G&amp;#243;mez-Elvira, J. and Mart&amp;#237;n-Gago, J. A. 2006. &amp;#8220;A chamber for studying planetary environments and its applications to astrobiology&amp;#8221;. &lt;strong&gt;&lt;em&gt;Measurement and Science Technology&lt;/em&gt; &lt;/strong&gt;17, 2274-2280.&lt;/p&gt; &lt;p&gt;2.- E. Mateo-Marti*, S. Galvez-Martinez, C. Gil-Lozano and Mar&amp;#237;a-Paz Zorzano. &amp;#8220;Pyrite-induced uv-photocatalytic abiotic nitrogen fixation: implications for early atmospheres and Life&amp;#8221;.&lt;strong&gt; &lt;/strong&gt;&lt;strong&gt;Scientific reports&lt;/strong&gt;&amp;#160;&amp;#160;9: 15311-1--9 (2019).&lt;/p&gt; &lt;p&gt;3.- E. J. Cueto D&amp;#237;az, S. Galvez-Martinez, M&amp;#170; C.Torquemada Vico, M. P. Valles Gonz&amp;#225;lez and E. Mateo-Marti*. &amp;#8221;2-D organization of silica nanoparticles on gold surfaces: CO&lt;sub&gt;2&lt;/sub&gt; marker detection and storage&amp;#8221;. &lt;strong&gt;RSC Advances&lt;/strong&gt;,&lt;strong&gt; &lt;/strong&gt;10, 31758 (2020).&lt;/p&gt; &lt;p&gt;4.- C. Gil&amp;#8209;Lozano*, A. G. Fair&amp;#233;n*, V.Mu&amp;#241;oz&amp;#8209;Iglesias, M. Fern&amp;#225;ndez&amp;#8209;Sampedro, O. Prieto&amp;#8209;Ballesteros, L. Gago&amp;#8209;Duport, E.Losa&amp;#8209;Adams, D.Carrizo, Janice L. Bishop, T.Fornaro and E. Mateo-Marti&lt;strong&gt; &lt;/strong&gt;&amp;#8220;Constraining the preservation of organic compounds in Mars analog nontronites after exposure to acid and alkaline fluids&amp;#8221;&lt;strong&gt; &lt;/strong&gt;&lt;strong&gt;Scientific reports,&lt;/strong&gt;&amp;#160; 20, 71657-9 (2020).&lt;/p&gt; &lt;p&gt;5.- Zorzano, M. P.; Mateo-Mart&amp;#237;, E.; Prieto-Ballesteros, O.; Osuna, S. and Renno, N. 2009. &amp;#8220;The stability of liquid saline water on present day Mars&amp;#8221;.&lt;em&gt; &lt;strong&gt;Geophys. Res. Lett.&lt;/strong&gt;&lt;/em&gt;&lt;strong&gt;&amp;#160;&lt;/strong&gt; 36, L20201.&lt;/p&gt; &lt;p&gt;6.- Gomez, F., Mateo-Mart&amp;#305;&amp;#180;, E., Prieto-Ballesteros, O., Mart&amp;#305;n-Gago, J.A., Amils, R., 2010. &amp;#8220;Protection of chemolithoautotrophic bacteria exposed to simulated mars environmental conditions&amp;#8221;. &lt;strong&gt;Icarus&lt;/strong&gt; 209, 482&amp;#8211;487.&lt;/p&gt;


1967 ◽  
Vol 45 (8) ◽  
pp. 1285-1295 ◽  
Author(s):  
Humberto F. Dias ◽  
Howard E. Waterworth

Seedlings of Chenopodium amaranticolor and C. quinoa were found to contain a highly infectious, seed-borne virus that may remain latent. Under certain environmental conditions and following abrasion of the leaves with carborundum and water, infected, symptomless young plants develop visible systemic symptoms. The presence and erratic behavior of the virus in these species can lead to erroneous identification of the causal agent of diseases of other crops. The virus is restricted to the Chenopodiaceae and is similar to Chenopodium mosaic virus (= sowbane mosaic virus) in morphology and in physico-chemical properties. It is serologically related to Chenopodium star mottle virus, to a latent virus isolated from apple in the USA and, by inference, to Chenopodium mosaic virus.


2016 ◽  
Vol 13 (1) ◽  
pp. 145-152
Author(s):  
Z Ferdoushi ◽  
RH Chowdhury ◽  
K Fatema ◽  
A Islam

Limnological aspects of the Ramsagar lake, a manmade lake of Dinajpur district was studied from January 2013 to August 2013. In this experiment, five sampling points inside the Ramsagar lake were selected and water quality parameters were analyzed fortnightly. Among different physico-chemical parameters, water temperature, dissolved oxygen, total alkalinity, total hardness, phosphate-phosphorus and concentration of Chlorophyll-a did not differ significantly except the water level and pH. A total of 29 species of plankton were recorded where phytoplankton comprised of 21 species and zooplankton comprised of 8 species. Chlorophyceae was found dominant throughout the study period followed by Bacillariophyceae, Cyanophyceae and Euglenophyceae. The highest plankton cell density was observed in the month of July and lowest plankton density was observed during the month of January. The study revealed that on the basis of physical, chemical, biological and environmental conditions the water of the lake was found to be suitable for survival of aquatic flora and fauna and also suitable for fish culture.J. Bangladesh Agril. Univ. 13(1): 145-152, June 2015


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