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Irrigation with saline–sodic water imposes sodic conditions on the soil and reduces the soil’s productivity. We hypothesized
that replacing saline–sodic irrigation water with lesser saline–sodic treated waste water (TWW), albeit with higher loads
of organic matter and suspended solids, might help sodic soils regain their structure and hydraulic conductivity. We studied
hydraulic conductivity (HC), aggregate stability and clay swelling of a soil from the Bet She’an Valley, Israel using samples
taken from a non-cultivated field (control), and plots irrigated with TWW, saline–sodic Jordan River (JR) water, and moderately
saline–sodic spring (SP) water. Soil samples were taken at the end of the irrigation season (autumn 2005) and at the end of
the subsequent rainy season (spring 2006). In the HC and the aggregate stability determinations, for both sampling seasons,
the TWW-irrigated samples gave significantly higher values than the SP- and JR-irrigated samples, but lower than the samples
from the control plot. The autumn samples exhibited, generally, higher HC and lower swelling levels compared with the spring
samples. Conversely, aggregate stability of the spring samples was higher than that of the autumn samples. These seasonal
changes in the results of the three tests were associated with seasonal changes in the salinity and sodicity of the soils.
Contributions from the Agricultural Research Organization, The Volcani Center, Bet-Dagan 50250, Israel. No. 601/2007 series. 相似文献
2.
Two oil spills occurred in the Evrona Nature Reserve (southern Israel), in 1975 and 2014. This oil contamination induced highly persistent soil hydrophobicity. The objective of this study was to investigate the decrease in oil-induced soil hydrophobicity under different environmental conditions and to assess the relationship between the hydrophobicity and hydrocarbon content. A laboratory incubation experiment was conducted over 1.5 years to monitor the soil hydrophobicity and total hydrocarbon concentration under different environmental conditions. We hypothesized that the addition of water (20% or 50% saturation), nutrients, and biosurfactants can accelerate the reduction in hydrophobicity and decomposition of hydrocarbons. Water drop penetration time and molarity of ethanol droplet tests were used to assess soil hydrophobicity. In parallel, alkane composition and total petroleum hydrocarbons were evaluated to indicate oil attenuation. The addition of water, nutrients, and biosurfactants resulted in a concomitant reduction in hydrophobicity and hydrocarbon concentration of varying degrees, exhibiting enhanced degradation and hydrophobicity reduction observed in treatments to which nutrients and biosurfactants were added. At the end of the incubation, however, soil hydrophobicity in all treatments remained severe, even though total petroleum hydrocarbon removal was fairly high and reached 40%–80% in the treatments to which water with or without nutrients and/or surfactants was added. 相似文献
3.
A retroviral expression vector (N2) containing the selectable gene, neoR, has been used to determine the optimal conditions for infecting murine hematopoietic progenitor cells at high efficiency. After infected bone marrow cells were introduced into lethally irradiated mice, the presence, stability, and expression of the vector DNA sequences were analyzed either in individual spleen foci 10 days later or in the blood, bone marrow, and spleens of mice 4 months later. When bone marrow cells were cultured in medium containing virus with titers of more than 10(6) colony-forming units per milliliter in the presence of purified murine interleukin-3, more than 85 percent of the resulting foci contained vector DNA. This proviral vector DNA was intact. Efficient expression of the neoR gene was demonstrated in most of the DNA-positive foci examined. The spleens of reconstituted animals (over a long term) contained intact "vector DNA" and the blood and bone marrow expressed the neoR gene in some animals. Thus, a retroviral vector can be used to introduce intact exogenous DNA sequences into hematopoietic stem cells with high efficiency and with substantial expression. 相似文献
4.
An in vivo model of somatic cell gene therapy for human severe combined immunodeficiency. 总被引：9，自引：0，他引：9
G Ferrari S Rossini R Giavazzi D Maggioni N Nobili M Soldati G Ungers F Mavilio E Gilboa C Bordignon 《Science (New York, N.Y.)》1991,251(4999):1363-1366
Deficiency of adenosine deaminase (ADA) results in severe combined immunodeficiency (SCID), a candidate genetic disorder for somatic cell gene therapy. Peripheral blood lymphocytes from patients affected by ADA- SCID were transduced with a retroviral vector for human ADA and injected into immunodeficient mice. Long-term survival of vector-transduced human cells was demonstrated in recipient animals. Expression of vector-derived ADA restored immune functions, as indicated by the presence in reconstituted animals of human immunoglobulin and antigen-specific T cells. Retroviral vector gene transfer, therefore, is necessary and sufficient for development of specific immune functions in vivo and has therapeutic potential to correct this lethal immunodeficiency. 相似文献
5.
Jrg Bachmann Gilboa Arye Markus Deurer Susanne&#x;K. Woche Robert Horton Karl‐Heinz Hartge Yona Chen 《植物养料与土壤学杂志》2006,169(6):745-753
Wettability of soil affects a wide variety of processes in soils like infiltration, percolation, preferential flow, and surface runoff. Even though efforts have been made to determine contact angles and surface tension or energy of smooth surfaces, the determination on granular materials like soil particles remains unsolved. One objective of this study was to test the consistency of contact angles (CA) measured with the newly modified and easy‐to‐apply Wilhelmy plate method by using solid particles and liquids with defined variations of surface tension. A second objective was to derive basic physical surface properties for the irregularly shaped and chemically heterogeneous soil particles. Advancing contact angles were determined by using model soils varying in texture from clay to coarse sand to check the impact of grain size on the CA measurements. Varying the solid‐surface tension with dichlorodimethlylsilane treatments provided for pure‐water wetting stages ranging from wettable to extremely hydrophobic. The surface tensions of the liquids were varied from 72 mN m–1 to 25 mN m–1 by using water or water‐ethanol mixtures. The surface tensions of the model soils were determined with the zero degree–contact angle method following Zisman's critical–surface tension concept. Results show that the measured CA varied continuously with the variations of the surface tension of the liquid and the solid phase, respectively. A general interpretation of the results is possible by using the concept of the Equation of State Approach. 相似文献
6.
David Gidoni Moshe Bar Baruch Leshem Nehama Gilboa Anahit Mett Julia Feiler 《Euphytica》2001,121(2):145-156
FLP site-specific recombination has been shown in transgenic plants to excise DNA sequences between target FRT sites, and thereby activate transgenes in plants. In previous reports, crossing of tobacco plants expressing FLP recombinase
from a CaMV-35s promoter with plants containing the target FRT sites, hybrid plants with deletion sectors were generated, which were infrequently transmitted to progeny. In this report
we evaluate the occurrence of recombination in F1 hybrid seed derived from crosses of different FLP and FRT-reporter target lines and the germinal transmission of recombined loci from these hybrids to F2 progeny. Twenty hybrids were generated from crosses of independent five FLP-active lines and four FRT-reporter target lines. In one hybrid, FLP deletions occurred at an early stage, prior to seed maturation, and the deletions
from this hybrid were more efficiently transmitted to F2 progeny. The demonstration of FLP-mediated recombination activity and germinal inheritance of the recombined FRT loci are supported by both molecular and enzymatic evidence.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
7.
R E Urizar J Cerda W J Dodds S L Raymond J A Largent R Simon N Gilboa 《American journal of veterinary research》1984,45(8):1624-1631
This longitudinal study compared the renal morphologic changes and hemostatic defects of FH/Wjd rats at different ages. A second aim was to determine whether the bleeding tendency becomes intensified in older animals by the concomitant renal disease. Results indicated that reduced capacity for platelet 14C-serotonin release (P less than 0.01) was found for each age group studied in comparison with Wistar controls. The nephropathy of old FH/Wjd male rats was more severe than that in either FH/Wjd females or age-matched Wistars of both sexes. The mesangial lesions showed abundant deposits of factor VIII-related antigen, fibronectin, and immunoglobulins, but not C3, along with tightly packed or loose electron-dense material. Polyethylene glycol precipitation and platelet aggregation tests detected small amounts of circulating immune complex-like material. Old FH/Wjd rats did not develop edema, and the glomerular filtration rate remained normal despite the persistent proteinuria, hematuria, and arterial hypertension characteristic of this strain. Our data indicated that the congenital platelet dysfunction does not become more severe in older animals and that the nephropathy seems unrelated, does not appear to be mediated by immune complexes, and, in contrast to the focal segmental glomerulosclerosis of persons, the lesions progress without a parallel impairment of renal function. 相似文献
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