[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. DOI:10.1111/j.1095-8339.1969.tb01974.x · 2.53 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. DOI:10.1016/j.jhevol.2005.12.010 · 3.73 Impact Factor
[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.
[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: 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: Detailed excavation and analysis of a brush hut from Ohalo II, Jordan Valley, Israel, provides an extraordinary view of camp construction 19,000 years ago. This report offers an important contribution to studies of Palaeolithic camp sites.
[Show abstract][Hide abstract] ABSTRACT: French and Russian tarragon, Artemisia dracunculus L., leaves have glandular hairs distributed over the whole surface and secretory cavities arranged in files along the major veins in the mesophyll. Chemical composition analysis of leaves, leaf epidermis, and leaf mesophyll by hydrodistillation and solvent extraction indicate quantitative differences in composition between the epidermis and the mesophyll. The main components in the essential oils, methyl chavicol in French tarragon and elemicin and methyl eugenol in the Russian tarragon, were observed to accumulate primarily in the mesophyll.
[Show abstract][Hide abstract] ABSTRACT: The types of glandular hairs and their pattern of distribution on leaves of Ocimum basilicum L. at different stages, were investigated. Their essential oil at the various stages was chemically analysed. The density of the glandular hairs appears to be very high on young meristematic leaves and on meristematic regions of older leaves. When the leaf regions start to expand no new glandular hairs are produced and their density decreases. The essential oil differs in the percentage of some of its components between young and mature leaf regions. Copyright 1993, 1999 Academic Press
Annals of Botany 01/1993; 71(1). DOI:10.1006/anbo.1993.1005 · 3.65 Impact Factor
[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. DOI:10.1016/0033-5894(92)90034-G · 2.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Dormancy of Kosteletzkya virginica (L.) Presl. seeds is primarily due to the impermeability of the seed coat to water. The impermeable structure is assumed to be, in other Malvaceae, the palisade layer of the seed coat. The percentage of seeds capable of imbibition and germination increased with increasing time of storage at low temperatures, but the release from dormancy was not accompanied by decreased seed coat resistance to pressure. Under natural conditions, mechanical damage to the seed coat due to changes in temperature and/or abrasion may render the seeds water permeable. It is not clear what causes water permeability during storage under laboratory conditions. During seed maturation and drying, the inner epidermis of the tegmen partly separates from the rest of the seed coat and an air space, which makes the seed buoyant, is formed around the region of the chalazal cleft. The optimal temperature for germination of K. virginica seeds is between 28 and 30 C in light or darkness.
American Journal of Botany 03/1992; 79(3). DOI:10.2307/2445012 · 2.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The different germination behaviour of the seeds of two irises, Iris lorteti and I. atropurpurea was found to be due to the different mechanical resistance of the integument, at the micropylar end, to radicle protrusion. A pressure of 135 atm was necessary in l. lorteti seeds for radicle protrusion, while in I. atropurpurea 77 atm was sufficient. In contrast Pancratium maritimum required a pressure of only 10 atm. The outer integument of seeds of I. lorteti was found to contain a compound which was toxic to the germinated embryo but did not act as a germination inhibitor. Extracts of the endosperm also had a slight germination inhibiting effect. An interaction between this weak inhibitor and the effect of the testa could not be ruled out completely. A test assay for germination using excised embryos was developed. A method for germination of Iris seeds, by cutting off the outer integument at the micropylar end, was developed and is being exploited commercially.
Annals of Botany 10/1986; 58(4):551-561. DOI:10.1093/annbot/58.4.551 · 3.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Leaves and flowers of four chemotypes of Origanum vulgare L. were examined for the main components of their essential oil and for the types and distribution of their glandular hairs. Two varieties have high phenol content, one thymol and the other carvacrol, in their essential oils; one has a moderate thymol content and the fourth has a low phenol content and a high alcohol content. The percentage of essential oil and the number of peltate hairs were higher in the flowers than in the leaves, the highest being in the flowers of a chemotype with a high phenol (thymol) concentration. While there were no differences in structure of the peltate and two types of capitate hairs between chemotypes, the density of the peltate hairs varied and appeared to be correlated with the total essential oil content.
Annals of Botany 06/1985; 55(6):793-801. · 3.65 Impact Factor