scholarly journals Epiphytic Diatom Communities on Sub-Fossil Leaves of <i>Posidonia oceanica</i> Delile in the Graeco-Roman Harbor of Neapolis: A Tool to Explore the Past

2014 ◽  
Vol 05 (05) ◽  
pp. 549-553 ◽  
Author(s):  
Paola Cennamo ◽  
Paolo Caputo ◽  
Mario De Stefano ◽  
Elda Russo Ermolli ◽  
Maria Rosaria Barone Lumaga
Keyword(s):  
Posidonia Oceanica ◽  
The Past ◽  
Fossil Leaves ◽  
Diatom Communities

scholarly journals Factors regulating primary producers' assemblages in Posidonia oceanica (L.) Delile ecosystems over the past 1800 years

2020 ◽  
Vol 718 ◽  
pp. 137163 ◽  
Author(s):  
Carmen Leiva-Dueñas ◽  
Peter R. Leavitt ◽  
Teresa Buchaca ◽  
Antonio Martínez Cortizas ◽  
Lourdes López-Merino ◽  
...  
Keyword(s):  
Posidonia Oceanica ◽  
Primary Producers ◽  
The Past

Benthic diatom communities from rivers in close proximity to the Athabasca tar sands (Alberta, Canada)

2011 ◽  
Vol 46 (4) ◽  
pp. 355-365
Author(s):  
Isabelle Lavoie ◽  
Céline Guéguen ◽  
Claude Fortin
Keyword(s):  
Limited Information ◽  
Aquatic Life ◽  
Athabasca River ◽  
Tar Sands ◽  
Future Studies ◽  
The Past ◽  
Close Proximity ◽  
Diatom Communities ◽  
Natural Water Bodies

This project was undertaken to study diatom communities from rivers in close proximity to tar sands development in the Athabasca River watershed, Alberta, Canada. Over the past years, tar sands development in Alberta has been intensified and presents new challenges for environmental management in Alberta. As the predominant technologies for extracting bitumen from the tar sands rely on large amounts of freshwater, concerns on the water quality of natural water bodies and its impacts on aquatic life and human health are increasing. Although limited information on the diatom communities in this region is available from the late 1970s and early 1980s, there are no reference diatom communities with which to compare modern-day samples. In this study, water and diatom samples were collected from nine sites in 2008 and replicate samples were collected from a subset of those sites in 2009. Based on the few samples available, it was not possible to directly link tar sands-related pollution with changes in diatom community structure, although diatoms clearly showed a response to dissolved organic carbon (DOC) and conductivity. However, diatom communities collected represent a benchmark for biomonitoring assessment in the region following expansion of the industry and represent valuable information for future studies.

Observations of the continuum near the galactic centre

1967 ◽  
Vol 31 ◽  
pp. 405
Author(s):  
F. J. Kerr
Keyword(s):  
Galactic Centre ◽  
The Past ◽  
Centre Region ◽  
The Continuum

A continuum survey of the galactic-centre region has been carried out at Parkes at 20 cm wavelength over the areal11= 355° to 5°,b11= -3° to +3° (Kerr and Sinclair 1966, 1967). This is a larger region than has been covered in such surveys in the past. The observations were done as declination scans.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

On The Possibility of an Autonomous History of Modern Southeast Asia

1961 ◽  
Vol 2 (2) ◽  
pp. 73-105 ◽  
Author(s):  
John R. W. Small
Keyword(s):  
Southeast Asia ◽  
Contemporary History ◽  
The Past ◽  
History Of

It is generally accepted that history is an element of culture and the historian a member of society, thus, in Croce's aphorism, that the only true history is contemporary history. It follows from this that when there occur great changes in the contemporary scene, there must also be great changes in historiography, that the vision not merely of the present but also of the past must change.

Stellar Evolution

1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild
Keyword(s):  
Solar System ◽  
Stellar Evolution ◽  
Space Craft ◽  
New Techniques ◽  
Substantial Body ◽  
Individual Stars ◽  
The Past ◽  
Evolution Of Galaxies ◽  
History Of ◽  
Fast Flow

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.

Novae in the Magellanic Clouds

1979 ◽  
Vol 46 ◽  
pp. 96-101
Author(s):  
J.A. Graham
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
University Of Michigan ◽  
The Past ◽  
Spectroscopic Information ◽  
Objective Prism ◽  
The University ◽  
Small Cloud ◽  
Low Dispersion

During the past several years, a systematic search for novae in the Magellanic Clouds has been carried out at Cerro Tololo Inter-American Observatory. The Curtis Schmidt telescope, on loan to CTIO from the University of Michigan is used to obtain plates every two weeks during the observing season. An objective prism is used on the telescope. This provides additional low-dispersion spectroscopic information when a nova is discovered. The plates cover an area of 5°x5°. One plate is sufficient to cover the Small Magellanic Cloud and four are taken of the Large Magellanic Cloud with an overlap so that the central bar is included on each plate. The methods used in the search have been described by Graham and Araya (1971). In the CTIO survey, 8 novae have been discovered in the Large Cloud but none in the Small Cloud. The survey was not carried out in 1974 or 1976. During 1974, one nova was discovered in the Small Cloud by MacConnell and Sanduleak (1974).

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

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