South American floras are famous for their high species diversity. However, because of the undersampled South American plant-fossil record, remarkably little is known about how long this floral richness has existed. The Patagonian region of Argentina is an ideal place to study the history of South American plant diversity: fifty million years ago, Patagonia had humid subtropical forests with luxuriant vegetation, and today some of these forests are beautifully preserved in desert rock exposures accessible to paleontologists.
For this study, which will appear in the June 2005 issue of The American Naturalist, researchers collected more than 4000 specimens of fossil leaves, fruits, seeds, and flowers at a site with outstanding fossil preservation, Laguna del Hunco. Adjusted for sampling effort, the Laguna del Hunco flora, which has produced 186 species, is more diverse than any comparable deposit known elsewhere in the world. Preliminary collections at a second site, Río Pichileufú, show comparable richness. Precise radioisotopic ages, including the first from the Río Pichileufú flora, show it be almost 5 million years younger (47.46 ± 0.05 myr) than Laguna del Hunco (51.91 ± 0.22 myr). Highly diverse floras were present in a warm area of South America by the Eocene and were long lived and areally extensive.
Carrie Olivia Adams | EurekAlert!
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy