scholarly journals Intensive exploitation of marine crabs and sea urchins during the middle holocene in the eastern Arabian peninsula offers new perspectives on ancient maritime adaptations

Author(s):  
Kevin Lidour ◽  
Philippe Béarez ◽  
Mark Beech ◽  
Vincent Charpentier ◽  
Sophie Méry
Author(s):  
Diego Salazar ◽  
Carola Flores ◽  
César Borie ◽  
Laura Olguín ◽  
Sandra Rebolledo ◽  
...  

Chapter 3 summarizes research on maritime adaptations at Middle Holocene (~7,500 to 4,500 cal BP) occupations of the southern extreme of the Atacama Desert, centered around Taltal on the north Chilean coast. Through this period, the authors see increasing population, complexity, and sedentism, but the social system comes to an abrupt end at 4,500 cal BP. In this hyperarid region, marine resources were always extremely important.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
Frank J. Longo

Measurement of the egg's electrical activity, the fertilization potential or the activation current (in voltage clamped eggs), provides a means of detecting the earliest perceivable response of the egg to the fertilizing sperm. By using the electrical physiological record as a “real time” indicator of the instant of electrical continuity between the gametes, eggs can be inseminated with sperm at lower, more physiological densities, thereby assuring that only one sperm interacts with the egg. Integrating techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy, we are able to identify the fertilizing sperm precisely and correlate the status of gamete organelles with the first indication (fertilization potential/activation current) of the egg's response to the attached sperm. Hence, this integrated system provides improved temporal and spatial resolution of morphological changes at the site of gamete interaction, under a variety of experimental conditions. Using these integrated techniques, we have investigated when sperm-egg plasma membrane fusion occurs in sea urchins with respect to the onset of the egg's change in electrical activity.


Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
S Ivanova ◽  
I Urakova ◽  
O Pozharitskaya ◽  
A Shikov ◽  
V Makarov

1970 ◽  
pp. 56-63
Author(s):  
Tim Walters ◽  
Susan Swan ◽  
Ron Wolfe ◽  
John Whiteoak ◽  
Jack Barwind

The United Arab Emirates is a smallish Arabic/Islamic country about the size of Maine located at the tip of the Arabian Peninsula. Though currently oil dependent, the country is moving rapidly from a petrocarbon to a people-based economy. As that economy modernizes and diversifies, the country’s underlying social ecology is being buffeted. The most significant of the winds of change that are blowing include a compulsory, free K-12 education system; an economy shifting from extractive to knowledge-based resources; and movement from the almost mythic Bedouin-inspired lifestyle to that of a sedentary highly urbanized society. Led by resource-rich Abu Dhabi and Dubai, the federal government has invested heavily in tourism, aviation, re-export commerce, free trade zones, and telecommunications. The Emirate of Dubai, in particular, also has invested billions of dirhams in high technology. The great dream is that educated and trained Emiratis will replace the thousands of foreign professionals now running the newly emerging technology and knowledge-driven economy.


2004 ◽  
pp. 66-76
Author(s):  
E. Hershberg

The influence of globalization on international competitiveness is considered in the article. Two strategies of economic growth are pointed out: the low road, that is producing more at lower cost and lower wages, with increasingly intensive exploitation of labor and environment, and the high road, that is upgrading capabilities in order to produce better basing on knowledge. Restrictions for developing countries trying to reach global competitiveness are formulated. Special attention is paid to the concept of upgrading and opportunities of joining transnational value chains. The importance of learning and forming social and political institutions for successful upgrading of the economy is stressed.


Author(s):  
Ksenya V. Poleshchuk ◽  
Zinaida V. Pushina ◽  
Sergey R. Verkulich

The diatom analysis results of sediment samples from Dunderbukta area (Wedel Jarlsberg Land, West Svalbard) are presented in this paper. The diatom flora consists of four ecological groups, which ratio indicates three ecological zones. These zones show environmental changes of the area in early–middle Holocene that is demonstrating periods of regression and temperature trends.


2015 ◽  
Vol 42 (1) ◽  
pp. 101-112
Author(s):  
I. Friis

In spite of widespread consumption of coffee in Europe at the time of the Royal Danish expedition to Arabia 1761–1767, little was known of the cultivation of coffee in Yemen and of the Arabian coffee export to Europe. Fresh leaves of qat were used as a stimulant on the Arabian Peninsula and in East Africa, but before the Royal Danish expedition to Arabia this plant was known in Europe only from secondary reports. Two members of the expedition, Carsten Niebuhr and Peter Forsskål, pioneered studies of coffee and qat in Yemen and of the Arabian coffee export. Linnaeus' instructions for travellers requested observations on the use of coffee, but otherwise Forsskål and Niebuhr's studies of coffee and qat were made entirely on their own initiative. Now, 250 years after The Royal Danish expedition to Arabia, coffee has become one of the world's most valuable trade commodities and qat has become a widely used and banned drug.


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