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81.
Andrew?J.?FeitzEmail author Sven?Lundie 《The International Journal of Life Cycle Assessment》2002,7(4):244-249
Salinity is an increasing environmental problem in agricultural ecosystems and is not adequately represented in conventional
life cycle assessment (LCA) impact categories. It is often not the total quantity of salts emitted or the proportion of salt
accumulated in the soil profile that is the primary mechanism for deteriorating soil conditions for irrigated salinity, rather
the ratio of major cations in the soil matrix and the potential for colloid dispersion and reduced permeability. A soil salinisation
potential (SP) is proposed as an indicator for irrigated salinity and potential soil degradation from poor irrigation practices.
The indicator uses the threshold electrolyte concentration concept that predicts the adjusted sodium adsorption ratio (SAR)/
Electrical conductivity (EC) ratio that soil will no longer flocculate, but potentially disperse. The SAR is converted to
a threshold EC and compared to the measured EC in order to develop a site-specific irrigation equivalence factor (EF). This
site/region/process specific EF is then used to weight the sodium load to soil and repeated for each stage throughout the
entire life cycle to determine the overall Salinisation Potential (SP). The data required for calculating the SP is generally
readily available either on site or from the water chemistry of the local watercourses. Preliminary calculations simply require
the volume, pH, electrical conductivity (EC), alkalinity and the concentrations of Na, Ca, and Mg of the irrigation water.
The site/process/region specific nature of the indicator ensures a quantitative measure to enable comparisons between different
systems and is useful for identifying stages in the life cycle of a product (particularly food products), where the potential
for soil salinisation and soil degradation is most severe. 相似文献
82.
MARK J. JORDAN J. MARK HIGLEY SEAN M. MATTHEWS OLIN E. RHODES MICHAEL K. SCHWARTZ REGINALD H. BARRETT PER J. PALSB
LL 《Molecular ecology resources》2007,7(5):797-801
We developed 22 new microsatellite loci for the fisher (Martes pennanti), a North American mesocarnivore. The loci were developed with samples from the southern Sierra Nevada Mountains in California, and were screened with samples from this population and four other populations. We observed a range of six to 21 polymorphic loci per population, with the Sierra Nevada population exhibiting markedly lower levels of variation compared to the other four. 相似文献
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Diahann TSL Jansen Hanane el Bannoudi Ramon Arens Kim LL Habets Marjolijn Hameetman Tom WJ Huizinga Jeroen N. Stoop René EM Toes 《Arthritis research & therapy》2015,17(1)
IntroductionAbatacept is a fusion protein of human cytotoxic T-lymphocyte–associated protein (CTLA)-4 and the Fc portion of human immunoglobulin G1 (IgG1). It is believed to be effective in the treatment of rheumatoid arthritis by inhibiting costimulation of T cells via blocking CD28–B7 interactions as CTLA-4 binds to both B7.1 (CD80) and B7.2 (CD86). However, the interaction of CD28 with B7 molecules is crucial for activation of naive cells, whereas it is unclear whether the action of already activated CD4+ T cells, which are readily present in established disease, also depends on this interaction. The aim of this study was to determine whether the mode of action of abatacept depends solely on its ability to halt T cell activation in established disease.MethodsArthritis was induced in thymectomized male DBA/1 mice by immunisation with bovine collagen type II. The mice were subsequently depleted for CD4+ T cells. Abatacept or control treatment was started when 80 % of the mice showed signs of arthritis. Arthritis severity was monitored by clinical scoring of the paws, and anti-collagen antibody levels over time were determined by enzyme-linked immunosorbent assay.ResultsTreatment with abatacept in the absence of CD4+ T cells resulted in lower disease activity. This was associated with decreasing levels of collagen-specific IgG1 and IgG2a antibodies, whereas the antibody levels in control or CD4+ T cell–depleted mice increased over time.ConclusionsThese results show that abatacept decreased disease activity in the absence of CD4+ T cells, indicating that the mode of action of abatacept in established arthritis does not depend entirely on its effects on CD4+ T cell activation. 相似文献
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Ecological and historical factors of the Balearic archipelago (Western Mediterranean Sea) result is some peculiarities to its rotifer fauna. A group of warm-stenothermous species are frequent seasonally in the islands. Among them the occurrence of Keratella procurva (Thorpe, 1912), a pantropical species, is remarkable, and this is found more or less abundantly on each island. We briefly describe the different habitat categories of the archipelago. Clustering the collected species we relate each community type to its habitat; in this sense we distinguish 4 community type in the islands corresponding to different environments. This work also summarizes all the obtainable data on the rotifer fauna of the Balearic archipelago, adding the results of the investigations done in the last survey (spring, 1989); a checklist, including 100 species from the archipelago, is shown (69 Majorca, 72 Minorca, 24 Ibiza, 25 Formentera). Some examples of pantropical distribution are given, and the biotic and abiotic factors which determine the colonization of the islands by these species are discussed. 相似文献
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