In the present study, the effect of swim stress on morphine-induced tolerance was investigated in mice using formalin test. In this respect, intraperitoneal administration of different doses of morphine (3, 6, and 9 mg/kg) induced a dose-dependent antinociception in both acute and chronic phases of the formalin test. In addition, an exposure to swim stress 2 or 3 times for 3 consecutive days was performed in order to induce tolerance. This exercise decreased morphine-induced antinociception. Meanwhile, morphine administration (25 mg/kg) for 3 days in the presence of swim stress (for two to three times) potentiated tolerance induced by morphine in both phases of the formalin test. Administration of a higher dose of morphine (50 mg/kg) for 3 days in the presence of swim stress did not alter morphine-induced tolerance in both phases of the test. On the other hand, administration of the latter dose of morphine for 3 days in the absence of swim stress decreased morphine-induced antinociception in both phases of the formalin test. It can be concluded that there may be a cross interaction between morphineinduced antinociception and swim stress.

Inelastic solution of an axisymmetric boundary value problem is obtained from elastic solution using variable material properties method. The distribution of material properties, which are considered as field parameter is obtained as a part of the solution. This method is applied to process of cold worked fastener holes. The residual stress field induced by the process is determined. The actual material behavior in loading and unloading is utilized, while different hardening models, isotropic and kinematic hardening, are also used. Results are shown to be in good agreement with published results. The process of recoiled work is also studied. It is shown that a recold worked fastener hole may have a more useful residual stress pattern.

In this study, the induced responses of Kabuli and Desi chickpea (Cicer arietinum L. ) genotypes to cold stress physio-biochemical and molecular indices have been assayed. Cold acclimation established more readiness in facing up cold stress in Kabuli genotype compared to Desi one so that the minimum damage indices and the maximum enzyme activities were observed under these conditions. Simultaneous change of antioxidative activities related with damage indices electrolyte leakage index (ELI) and hydrogen peroxide (H2O2) showed that these enzymes accompanied with other defense mechanisms increased cold tolerance in chickpea. Results indicated that there were significant differences in catalase (CAT) and ascorbate peroxidase (APX) genes expression under thermal treatments. A significant increase of genes expression in Kabuli genotype compared to Desi one showed global patterns programmed cell responses along with increases in antioxidative activities, accompanying with a significant decrease particularly in Kabuli genotype. The short-term cold acclimation increased genetic capacity in chickpea genotypes so that the degree of tolerance in Kabuli genotype was higher than that of Desi one. Such defense and damage indices may be used as cold tolerance marker in evaluation of genotypes in a short-term cold stress profitably in a short time and low cost.

Olive (Olea europaea L.) is an evergreen tree traditionally cultivated in the Mediterranean area, relatively tolerant to salinity and drought conditions. However, olive trees are not so resistant to low temperatures. In recent years, because of high demands for olive oil and its fruit, the cultivation of olive trees has been widly spread in Iran. Different cultivars of olives show diverse reactions to cold stress and so, the selection of cold resistant cultivars is the most effective method to avoid frost damages. In order to compare the impact of cold stress on the content of total protein, lipid peroxidation and photosynthetic pigments, one-years old olive cultivars of Sevillana and Frantoio, were exposed to low temperatures of 10, 5, 0, -5, -10, -15, -20 and the control to 20oC for 12 h. The results indicated that both cultivars were resistant to 0oC temperature with no adverse effects. The photosynthetic pigments of Frantoio did not change even at -15oC and malondialdehyde levels were slightly increased compared with the control (20oC). Total protein content in Frantoio showed significant decrease below -10oC, while in Sevillana cultivar there was significant decline of total protein content from -5oC. Therefore, it could be concluded that the Frantoio cultivar was more resistant to cold stress than Sevillana.

In order to determine yield and physiological response of different wheat genotypes to low temperature, many pot and field experiments were conducted in 2007-2008 at the Plant Physiology Laboratory, University of Kurdistan, and Ghamlo Dryland Agricultural Research Station in Kurdistan province. In both experiments, the experimental design was a randomized complete block in a split plot arrangement with three replications. Experiment was carried out in 2007. Corresponding to three field sowing dates, Oct 1th, Oct 16th and Nov 5th, three pot treatments were performed. Pot treatments were conducted at following temperatures: 20 (control), 10 and 5 oC. Temperature treatments were considered in main plot and twelve genotypes of dryland wheat were assigned to the sub-plots. Both in pot and field experiments, leaf chlorophyll and sugar contents, fatty acids, polyamines and leaf water were significantly affected by treatments. When protein, spermine and oleic acid were measured, no differences were evident among genotypes. Cold stress and genotype had significant effects on the lethal temperature 50 (LT50) and electrolyte leakage. Among the genotypes, Ogosta exhibited the highest cold resistance (LT50), and the lowest electrolyte leakage. Also, Sardari and Ogosta had the greatest grain yield (1178-1210 kg.ha-1), chlorophyll a, chlorophyll b, soluble sugars, protein, putrescine, spermine, spermidine, linolenic acid and oleic acid.