[Show abstract][Hide abstract] ABSTRACT: The spatial designation of discrete areas for different activities reflects formalized conceptualization of a living space. The results of spatial analyses of a Middle Pleistocene Acheulian archaeological horizon (about 750,000 years ago) at Gesher Benot Ya'aqov, Israel, indicate that hominins differentiated their activities (stone knapping, tool use, floral and faunal processing and consumption) across space. These were organized in two main areas, including multiple activities around a hearth. The diversity of human activities and the distinctive patterning with which they are organized implies advanced organizational skills of the Gesher Benot Ya'aqov hominins.
[Show abstract][Hide abstract] ABSTRACT: The primary resin ducts in the axis of plants of Pinus halepensis Mill, consist of two separate systems the pattern of which is correlated with the vascular systems of the organs in which they appear. These systems are: (1) ducts of the roots and the hypocotyl; (2) ducts of all the branches and juvenile leaves or scaleS. Both systems are produced by the apical meristemS. In the needles there is a third system of primary resin ducts situated in the mesophyll. These ducts are produced only to a small extent by the apical meristem of the needle and mainly by its intercalary meristem. In addition to these primary ducts of the needle, which form a separate system for each needle, at the base of the needle there may be ducts of secondary origin which are situated within the vein. These are continuous with secondary ducts of the brachyblast axis.The secondary ducts constitute one system in the secondary xylem and phloem of the roots, branches and needle bases. They are formed by the cambium. In the xylem there are vertical and radial ducts which together form co-planar radial networkS. Each radial duct starts from a vertical duct. The first location of the stimulus for the formation of the two types of ducts is discussed. In the phloem there are only radial ducts, continuous with the radial ducts of the xylem. The cavities of the radial phloem and xylem ducts are not continuous, as there are no intercellular spaces in the region of the cambium.The innermost vertical ducts of the secondary xylem form a kind of transitional type, in respect of their response to internal and external factors, between the primary resin ducts and the bulk of the secondary resin ducts.
Botanical Journal of the Linnean Society 06/2008; 62(4):379 - 411. · 2.70 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Eight wooden objects were found at Ohalo II, a submerged and well-preserved site in the Sea of Galilee, Israel. The fisher-hunter-gatherers' site has been radiometrically dated to 22,500-23,500 (cal BP) with 45 assays read by four laboratories. The wooden objects were found on brush-hut floors. They include a bark plank with polish and use signs, pencil-shaped specimens with longitudinal shavings, and other types that may have been decorative or symbolic. One incised wooden object is identical in size and incision pattern to a gazelle bone implement found in a grave, behind a human skull. The recovered wooden objects are not directly related to hunting, gathering, or fishing, and frustratingly, there are no remains of bows, arrows, spears, handles, or other such items. Nonetheless, the objects present a wide repertoire in terms of size, shape, and possible function. The new finds add to the growing body of evidence concerning the use of perishable materials during the Upper Paleolithic.
Journal of Human Evolution 07/2006; 50(6):644-62. · 3.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Glandular hairs are spread over the aerial vegetative and reproductive organs of the Lamiaceae. They produce essential oils which apparently protect against herbivores and pathogens. From a functional viewpoint, owing to the mode and timing of secretion, the glandular hairs may be classified into two types: (a) short-term glandular hairs, which start and end secretion rapidly, and which serve for the protection of young organs; and (b) long-term glandular hairs, in which secretory materials accumulate gradually under an elevated cuticle, and which serve for the protection of mature organs. In the flower, protection against herbivores and attraction of pollinators are both apparently achieved by glandular hairs situated on various floral parts.
[Show abstract][Hide abstract] ABSTRACT: The development of traumatic resin ducts, in response to wounding and to hormone [napthalene acetic acid (NAA) and gibberellic acid (GA)] application at various times of the year was studied in the secondary xylem of Cedrus libani Loud. Resin duct formation was associated with enhanced cambial activity. As a result of wounding or of application of NAA or NAA together with GA3, a system of longitudinally oriented ducts developed around the treated area. In most cases the ducts reached their greatest length above the treated area. Application of GA3 alone did not normally cause the formation of ducts. Wounding and auxin application, at the time of highest cambial activity, led to duct formation shortly after treatment. Ducts did not develop during the period of cambial dormancy. When auxin was applied during dormancy, duct systems developed in the following season of cambial activity, but wounding during the same period produced no ducts or only short ones in the following season.
New Phytologist 05/2006; 82(2):537 - 544. · 6.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The presence of burned seeds, wood, and flint at the Acheulian site of Gesher Benot Ya'aqov in Israel is suggestive of the control of fire by humans nearly 790,000 years ago. The distribution of the site's small burned flint fragments suggests that burning occurred in specific spots, possibly indicating hearth locations. Wood of six taxa was burned at the site, at least three of which are edible--live, wild barley, and wild grape.
[Show abstract][Hide abstract] ABSTRACT: The Gesher Benot Ya'aqov archaeological site in the northern Dead Sea Rift of Israel contains Acheulian artifacts and middle Pleistocene fossils. Initial results of a new interdisciplinary study have shown that fluviolacustrine sediments of the Benot Ya'aqov Formation, which contains several archaeological occupations, were deposited in an embayment of the Hula Basin. They were subsequently deformed by tectonic activity associated with the Dead Sea Rift. Biostratigraphy, magnetostratigraphy, and K-Ar dating serve to constrain the age of the Benot Ya'aqov Formation to between 240,000 and 730,000 yr B.P. Archaeological excavation of three areas and two trenches at the new study area have produced abundant basalt, flint, and limestone artifacts, mammalian and avian fossils, and considerable plant material. The lithic materials provide an excellent opportunity to study large assemblages of in situ Acheulian artifacts, a rare phenomenon in the middle Pleistocene Levantine record. In addition, the organic materials will facilitate paleoenvironmental reconstructions from an ecological-floral perspective.
Quaternary Research 07/1992; 38(1):117-128. · 2.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: THE site of resin synthesis in the epithelial and sheath cells of Pinus is not known, although it has been suggested to occur initially in the plastids and later on the endoplasmic reticulum1. We have tried to identify the site of resin synthesis by specifically staining sections and examining them with the optical microscope.
[Show abstract][Hide abstract] ABSTRACT: Unusual low water levels in the Sea of Galilee (Dead Sea Fault, Israel) have caused the recent exposure of sub-merged Late Pleistocene prehistoric sites and lacustrine sediments along the southern shores of the lake. The Ohalo II site is a large fisher–hunter–gatherers camp with in-situ brush hut floors, hearths, and a human grave. The site is radiometrically dated by 25 charcoal dates to 19,430 BP (average, uncalibrated). The archaeological remains include quantities of excellently pre-served organic remains. These would not have been preserved without a rapid rise of lake level immediately after the occupa-tion, covering the remains with silts and sand. Recently a concentration of eight tree trunks were found about 1.5 km south of Ohalo II, of which five trunks were identified as Salix species and dated as a single accumulation at about 16,100 BP. The trunks, too, had to be submerged quickly together to ensure excellent preservation. The camp and the trunks were found at –212/ –213 m, almost 4 m below modern high water levels. We suggest that the finds represent two separate episodes of deposition during low lake levels, almost 3,000 radiocarbon years apart, each followed by an abrupt water rise. It is possible that climatic changes caused the observed fluctuations, though earthquakes (blocking or lowering the Jordan outlet, for example) cannot be ruled out.
[Show abstract][Hide abstract] ABSTRACT: Small drops of a mucilaginous character near the tip of root hairs were seen by light microscopy in several species of Sorghum and the Sorghum hybrid Vidan. Electron microscopy revealed that the drops are formed from at least two distinct substances, both apparently secreted from the endoplasmic reticulum. In addition, a patchy, fibrillar mucilaginous layer, also with at least two components, was found on the cell wall of the root hairs and on the outer wall of ordinary root epidermal cells. Golgi bodies as well as mitochondria take part in its production. As a rule, the mucilaginous patches are colonized by bacteria.