The planet’s largest and most powerful driver of climate changes from one year to the next, the El Niño Southern Oscillation in the tropical Pacific Ocean, was widely thought to have been weaker in ancient times because of a different configuration of the Earth’s orbit. But scientists analyzing 25-foot piles of ancient shells have found that the El Niños 10,000 years ago were as strong and frequent as the ones we experience today. (more…)
Glanz und Glitzer scheinen bereits vor 10.000 Jahren eine große Anziehungskraft gehabt zu haben. Prof. Walter Leitner und sein Team vom Institut für Archäologien der Universität Innsbruck konnten eine prähistorische Abbaustelle für Bergkristall in den Tuxer Alpen nachweisen und ermöglichen Einblicke in das steinzeitliche Leben Tirols.
Die Forschungsarbeit an der mit 2800 Metern höchstgelegenen archäologischen Fundstelle Österreichs ist beschwerlich. Mehrere Stunden Fußmarsch sind nötig, um das so genannte Riepenkar am Südfuß des Berges Olperer zu erreichen. Die instabile Wetterlage in dieser hochalpinen Gegend macht archäologische Sondagen nur an wenigen Tagen des Jahres überhaupt erst möglich. Das aus der Quarzkluft abgetragene Gesteinsmaterial wird in bis zu 25 Kilo schweren Rucksäcken ins Tal getragen. „Die Mühe lohnt sich aber allemal“, freut sich Walter Leitner über seine Entdeckungen. Durch Hinweise des Zillertaler Mineraliensammlers Walter Ungerank wurde der Archäologe auf die Stelle aufmerksam und begann mit Untersuchungen vor Ort. (more…)
The idea of everyone in a community pitching in is so universal that even bacteria have a system to prevent the layabouts of their kind from enjoying the fruit of others’ hard work, Princeton University researchers have discovered.
Groups of the bacteria Vibrio cholerae deny loafers their unjust desserts by keeping the food generated by the community’s productive members away from V. cholerae that attempt to live on others’ leftover nutrients, the researchers report in the journal Current Biology. The researchers found that individual bacteria produce a thick coating around themselves to prevent nutrients from drifting over to the undeserving. Alternatively, the natural flow of fluids over the surface of bacterial communities can wash away excess food before the freeloaders can indulge. (more…)
Ray Callahan discusses his career as historian, author of British military history
A head-on collision with the British Official Secrets Act of 1911 changed the focus of Raymond Callahan’s doctoral dissertation, but also led to a long and distinguished career as a teacher, researcher and author.
Professor emeritus of history at UD, Callahan recounted his personal and professional journey during a “My Intellectual Journey” lecture, sponsored by the UD Association of Retired Faculty on Nov. 7 at the Courtyard Newark-University of Delaware. (more…)
Washington, D.C.— Reconstructing the rise of life during the period of Earth’s history when it first evolved is challenging. Earth’s oldest sedimentary rocks are not only rare, but also almost always altered by hydrothermal and tectonic activity. A new study from a team including Carnegie’s Nora Noffke, a visiting investigator, and Robert Hazen revealed the well-preserved remnants of a complex ecosystem in a nearly 3.5 billion-year-old sedimentary rock sequence in Australia. Their work is published in Astrobiology.
The Pilbara district of Western Australia constitutes one of the famous geological regions that allow insight into the early evolution of life. Mound-like deposits created by ancient photosynthetic bacteria, called stromatolites, and microfossils of bacteria have been described by scientists in detail. However, a phenomenon called microbially induced sedimentary structures, or MISS, had not previously been seen in this region. These structures are formed from mats of microbial material, much like mats seen today on stagnant waters or in coastal flats. (more…)
Book focuses on race relations between Native Americans, African Americans
It’s a rosy picture, to think of Native Americans and African Americans embracing one another over the course of our country’s history.
But that rosy picture has a dark side, one tainted by tense race relations little discussed in the academic literature, pop culture and history textbooks, according to the University of Delaware’s Arica Coleman. (more…)
It was announced on Oct. 10 that Family Equality, which represents the 3 million LGBT parents in America and their 6 million children, will deed to Yale all historical materials related to the organization and its role in the LGBT family equality movement. The agreement ensures the preservation of more than 30 years of materials related to the founding, growth, and expansion of Family Equality, and documents the organization’s ongoing efforts to advance equality for families with LGBT parents. (more…)
New research from the University of Exeter and King’s College London has shown how a population of brown trout can survive in the contaminated waters of the River Hayle in Cornwall where metal concentrations are so high they would be lethal to fish from unpolluted sites.
The team believe this is due to changes in the expression of their genes. The research was funded by NERC and the Salmon and Trout Association.
The researchers compared the trout living in the River Hayle with a population living in a relatively clean site in the River Teign. The results showed that the accumulation of metals in the kidney and liver – where metals are stored and detoxified – were 19 and 34 times higher in the Hayle trout, respectively. In the gill, concentrations averaging 63 times higher were present in the Hayle fish, but there were no differences in metal content in the gut. This accumulation of metals in the Hayle fish highlights their extraordinary tolerance of the extreme metal concentrations in their environment. (more…)
