Comment on "Early domesticated fig in the Jordan Valley"     

Lev-Yadun S  Ne'eman G  Abbo S  Flaishman MA 《Science (New York, N.Y.)》2006,314(5806):1683; author reply 1683

Kislev et al. (Reports, 2 June 2006, p. 1372) described Neolithic parthenocarpic fig fruits and proposed that they derive from trees propagated only by cuttings and thus represent the first domesticated plant of the Neolithic Revolution. Because parthenocarpic fig trees naturally produce both seeded and seedless fruits and are capable of spontaneous reproduction, we argue that the finds do not necessarily indicate cultivation, nor horticulture predating grain crops.  相似文献   

Surface crystallization in a liquid AuSi alloy     

Shpyrko OG  Streitel R  Balagurusamy VS  Grigoriev AY  Deutsch M  Ocko BM  Meron M  Lin B  Pershan PS 《Science (New York, N.Y.)》2006,313(5783):77-80

X-ray measurements reveal a crystalline monolayer at the surface of the eutectic liquid Au82Si18, at temperatures above the alloy's melting point. Surface-induced atomic layering, the hallmark of liquid metals, is also found below the crystalline monolayer. The layering depth, however, is threefold greater than that of all liquid metals studied to date. The crystallinity of the surface monolayer is notable, considering that AuSi does not form stable bulk crystalline phases at any concentration and temperature and that no crystalline surface phase has been detected thus far in any pure liquid metal or nondilute alloy. These results are discussed in relation to recently suggested models of amorphous alloys.  相似文献   

Coarse and nano emulsions for effective delivery of the natural pest control agent pulegone for stored grain protection          下载免费PDF全文

Gilad Golden  Elazar Quinn  Eli Shaaya  Moshe Kostyukovsky  Elena Poverenov 《Pest management science》2018,74(4):820-827

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Antioxidant activity and inhibition of alpha-glucosidase by trans-resveratrol, piceid, and a novel trans-stilbene from the roots of Israeli Rumex bucephalophorus L     

Kerem Z  Bilkis I  Flaishman MA  Sivan L 《Journal of agricultural and food chemistry》2006,54(4):1243-1247

The roots of Rumex bucephalophorus, collected in Israel, were analyzed for trans-stilbenes. Two stilbene-O-glycosyl derivatives were identified, in addition to 3,5,4'-trihydroxystilbene (1) (resveratrol). The stilbene-O-glycosyl derivatives were 5,4'-dihydroxystilbene-3-O-beta-d-glucopyranoside (2) (piceid) and the new 5,4'-dihydroxystilbene-3-O-alpha-arabinopyranoside (3), which is being named rumexoid. The structure of rumexoid was elucidated by using spectroscopic data. The antioxidant capacities of stilbenoids 1-3 were determined and expressed as trolox equivalent antioxidant capacity (TEAC). TEAC value for trans-resveratrol was highest (2.7) and for rumexoid lowest (1.5). In vitro, trans-resveratrol and rumexoid demonstrated a potent inhibitory effect on alpha-glucosidase activity (IC50 < 0.1 and < 0.5 mM, respectively). The commercial antidiabetic agent acarbose was shown to inhibit only 35% of the enzyme activity at 0.5 mM. The addition of piceid to the reaction mixture did not inhibit alpha-glucosidase in vitro in the range of concentrations used. These findings extend the range of reported beneficial effects of stilbene derivatives, and demonstrate the multifaceted activities that dietary polyphenols may exert in the intestine, where their concentrations are highest in the body.  相似文献   

The presence of Rickettsia is associated with increased susceptibility of Bemisia tabaci (Homoptera: Aleyrodidae) to insecticides     

Kontsedalov S  Zchori-Fein E  Chiel E  Gottlieb Y  Inbar M  Ghanim M 《Pest management science》2008,64(8):789-792

BACKGROUND: The presence of certain symbiotic microorganisms may be associated with insecticide resistance in insects. The authors compared the susceptibility of two isofemale lines, Rickettsia-plus and Rickettsia-free, of the sweet potato whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) to major insecticides from different chemical groups, including imidacloprid, acetamiprid, thiamethoxam, pyriproxyfen, spiromesifen and diafenthiuron. RESULTS: While the Rickettsia-plus and Rickettsia-free lines showed no differences in their susceptibility to imidacloprid and diafenthiuron, higher susceptibility of the Rickettsia-plus line to acetamiprid, thiamethoxam, spiromesifen and especially pyriproxyfen was observed. LC(90) values indicated that the Rickettsia-free line was 15-fold more resistant to pyriproxyfen than the Rickettsia-plus line. CONCLUSION: Findings indicate that the infection status of B. tabaci populations by Rickettsia is an important consideration that should be taken into account when performing resistance monitoring studies, and may help in understanding the dynamics of B. tabaci resistance, symbiont-pest associations in agricultural systems and the biological impact of Rickettsia on whitefly biology.  相似文献   

Extinct plants of Israel     

Amots Dafni  Moshe Agami 《Biological conservation》1976,10(1):49-52

As a result of rapid land development in Israel during the past three decades, some 26 species of higher plants, about one percent of the local flora, have become extinct. In addition to listing such species, this paper deals with the ecological implications of this finding. Recommendations for the prevention of further damage to the local flora, and rare plants in particular, are given.  相似文献   

Abstracts of papers presented at the F.E. Nitzany Workshop on Epidemiology and Diagnosis of Plant Viruses     

B. Raccah  Y. Antignus  A. Gal-On  S. Cohen  Adina Rieger-Stein  R. Aly  B. Levi  S. Marco  M. Bar-Joseph  A. Franck  R. Salomon  A. Rosner  Edna Tanne  Sara Spiegel  G. Loebenstein  A. Gera  T. P. Pirone  A. F. Murant  M. Conti  R. T. Plumb  M. Klein  Svetlana Fishman  Ruth Marcus  H. Talpaz  Y. Spiegel 《Phytoparasitica》1984,12(3-4):207-216

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Identification of a constitutive 45 kDa soluble protein associated with resistance to downy mildew in muskmelon (Cucumis melo L.), line PI 124111 F     

M. Balass  Y. Cohen  M. Bar-Joseph 《Physiological and Molecular Plant Pathology》1992,41(6)

Analysis by sodium dodecylsulphate-polyacrylamide gel electrophoresis of the soluble proteins extracted from muskmelon (Cucumis melo L.), inbred line PI 124111F (PI) with resistance to Pseudoperonospora cubensis (Berk, et Curt.) Rost, and two susceptible cvs, Hemed and AnanasYokneam revealed the presence of a unique 45 kDa protein (P45) in the resistant but not in the susceptible plants. Subcellular fractionation indicated that P45 is a cytoplasmic soluble protein. It was detected in leaves and cotyledons but not in stems or roots. F₁ hybrid plants (Hemed × PI) that displayed only a partial resistance against P. cubensis expressed P45 at an intermediate level, whereas plants of the inbred generations F₅, F₇ and F₁₀ that displayed a high degree of resistance, expressed P45 at a level similar to the parental PI. Back-cross progeny plants [(Hemed × PI) × Hemed] segregate 1:2:1 partially resistant: susceptible: highly susceptible to the disease. The partially resistant plants showed an intermediate level of P45 (similar to F₁) whereas the highly susceptible plants had no P45, thus indicating cosegregation of P45 with resistance. The resistance of PI to P. cubensis was found to decrease at a colonization temperature of 12 °C. ³⁵S-methionine in vivo protein labelling revealed a reduction in the intensity of the P45 band in plants incubated for 11 h at 12 °C. The application of P45 in breeding programs of muskmelon for downy mildew resistance and its possible involvement in resistance to P. cubensis are discussed.  相似文献   

Modeling armed conflicts     

Kress M 《Science (New York, N.Y.)》2012,336(6083):865-869

Armed conflicts have been prevalent throughout history, in some cases having very great consequences. To win, one needs to understand the characteristics of an armed conflict and be prepared with resources and capabilities for responding to its specific challenges. An important tool for understanding these characteristics and challenges is a model--an abstraction of the field of conflict. Models have evolved through the years, addressing different conflict scenarios with varying techniques.  相似文献   

Shmuel Gothilf (1927-1994)     

Ezra Dunkelblum  Moshe Kehat 《Phytoparasitica》1995,23(1):89-91

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