Investigation of the methanogen population structure and activity in a brackish lake sediment

2005 ◽  
Vol 7 (7) ◽  
pp. 947-960 ◽  
Author(s):  
Natasha Banning ◽  
Fiona Brock ◽  
John C. Fry ◽  
R. John Parkes ◽  
Edward R. C. Hornibrook ◽  
...  
Keyword(s):  
Population Structure ◽  
Lake Sediment ◽  
Brackish Lake ◽  
Methanogen Population ◽  
Structure And Activity

Distribution, abundance, population structure and activity of Halobatrachus didactylus in the Tagus estuary (Portugal) and adjacent coastal waters

2011 ◽  
Vol 93 (2) ◽  
pp. 405-412 ◽  
Author(s):  
João Carlos Cotter ◽  
Tadeu José Pereira ◽  
Maria José Costa ◽  
José Lino Costa
Keyword(s):  
Population Structure ◽  
Coastal Waters ◽  
Low Frequency ◽  
Late Summer ◽  
Tagus Estuary ◽  
Water Current ◽  
Western Coast ◽  
Distinct Features ◽  
Discrete Populations ◽  
Structure And Activity

The Lusitanian toadfish Halobatrachus didactylus is a demersal teleost and the only species of the family Batrachoididae that occurs along the continental Portuguese coast. It is a subtropical species that is more abundant in the south of Portugal, whereas along the western coast it is concentrated in discrete populations, located in estuaries and coastal recesses. The distinct features of these estuaries have revealed important changes in the respective Lusitanian toadfish populations, namely particularities in their distribution and population structure, and also in the morphology and breeding behaviour of the specimens. A survey covering 31 stations in the Tagus estuary, Portugal, and adjacent coastal waters sampled these stations over an 18 month period. This study characterized the distribution, abundance, population structure and activity of H. didactylus in this coastal zone. Toadfish showed a preferential distribution in the intermediate and lower estuarine stretches, and was more abundant in the Montijo Bay, a small bay within the Tagus estuary. Three length-groups were identified, with larger specimens more abundant in deeper areas. The specimens also revealed a preference for areas of higher water temperature, low water current and muddy substrates. Female specimens were slightly more abundant than males and type II males had a very low frequency of occurrence (3.2%). Captures of toadfish were high in spring and late summer and very low in winter.

scholarly journals Spatial analysis of bacteria in brackish lake sediment

2020 ◽  
Vol 35 (3) ◽  
pp. 227-236 ◽  
Author(s):  
Jean-Sebastien Beaulne ◽  
Samir R. Mishra ◽  
Mrutyunjay Suar ◽  
Ananta Narayan Panda ◽  
Gurdeep Rastogi ◽  
...  
Keyword(s):  
Spatial Analysis ◽  
Lake Sediment ◽  
Brackish Lake

Correlative transmission and high-resolution scanning electron microscopic studies on pituitary cells

1990 ◽  
Vol 48 (3) ◽  
pp. 20-21
Author(s):  
S. Tai
Keyword(s):  
Cell Types ◽  
Depth Of Field ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Microscopic Studies ◽  
Structure And Activity ◽  
Intracellular Structure

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.

Separation of Heparin into Subtractions by DEAE-Cellulose Chromatography

1979 ◽  
Vol 42 (05) ◽  
pp. 1452-1459 ◽  
Author(s):  
Robert H Yue ◽  
Toby Starr ◽  
Menard M Gertler
Keyword(s):  
High Activity ◽  
Uronic Acid ◽  
Deae Cellulose ◽  
Exchange Chromatography ◽  
Net Charge ◽  
Uronic Acid Content ◽  
Successful Separation ◽  
Salt Gradient ◽  
Structure And Activity ◽  
Low Activity

SummaryCommercial porcine heparin can be separated into three distinct subtractions by using DEAE-cellulose chromatography and a stepped salt gradient. Gram quantities of heparin can be fractionated by this technique. All three heparin subtractions can accelerate the inhibition of thrombin by antithrombin III with different efficiency. The specific activities of the high activity heparin, intermediate activity heparin and low activity heparin are 228 units/mg, 142 units/mg and 95 units/mg, respectively. Both the uronic acid content and the quantity of N-SO4 for all three heparin subfractions have been evaluated. The high activity heparin has the lowest uronic acid and N-SO4 content. The successful separation of commercial heparin into three distinct subfractions by means of ion-exchange chromatography suggests that the net charge on these three heparin components will serve as a model system in the elucidation of the structure and activity relationship to the biological function of heparin.

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