فهرست مطالب

  • No. 3101, 2000
  • A1
  • تاریخ انتشار: 1378/10/11
  • تعداد عناوین: 14
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  • H. Khazali Pages 1-5
    It has been well established that the secretions of thyroid hormones and growth hormone (GH) is under the regulation of different neurotransmitters. The goal of this study was to determine whether substance-P, as a neurotransmitter, regulates the mean plasma concentrations of thyroxin (T4), triiodothyronine (T3), GH, milk amount and constituents in Sanan goats. Nine Sanan goats were randomly divided into 3 groups. Each group received a daily infusion of either 1, 2 or 4 Ug substance-P for 7 days into the third ventricle. Blood samples were collected daily for 11 days, and assayed for plasma T3, T4 and GH concentrations by double-antibody RIA. Milk samples were collected daily for each of the 11 days. Milk samples were assayed for protein, fat and lactose constituents. The daily amount of milk was determined throughout the experiment. Infusions of 1 and 2 Ug substance-P did not change the plasma concentrations of the T3, T4 and GH throughout the experiment. Infusions of 4 Ug substance-P significantly (P<0.01) increased the plasma concentrations of the T3, T4 and GH among all the animals, however, different dosages of substance-P did not change the amount, the protein, fat and lactose constituents of milk among all the animals in the different groups. The result of this experiment indicated that substance-P may increase the mean plasma concentrations of GH, T3, and T4 in Sanan goats.
    Keywords: Substance, P, T3, T4, GH, Sanan goats
  • R. Kasra Kermanshahi A. Ghazifard, A. Tavakoli Pages 7-16
    During this research, bacteria resistant to metals were evaluated in the soil of Isfahan Province. According to the sampling locations the soils are classified as agricultural soils, non-agricultural soils and sediments of the Zayanderood Riverbank. The bacteria resistant to lead (2 mM), copper (5 mM), cadmium (0.5 mM) and arsenic (5 mM) were identified, and then during later stages, the minimum inhibitory concentration (MIC) for the growth of the bacteria resistant to metals were determined. The dry cellular weight and the metal uptake rate were also defined for the bacteria resistant to metals.
    Keywords: Resistant, heavy metals, soils, bacteria, biomass
  • A. Jarrahpour, P. Alvand Pages 17-22
    Synthesis of some new monocyclic β-lactams containing a quaternary carbon center via a [2+2] cycloaddition reaction is described. The reaction of achiral diphenyl ketene with chiral aldimines derived from chiral 2, 3, 4, 6-tetra-O-acetyl-β-D-galactopyranosylamine, 2, 3, 4, 6-tetra-O-acetyl-β-D-glucopyranosylamine and different benzaldehydes resulted in the formation of β-lactams as single diastereomers.
    Keywords: 2, azetidinone, asymmetric synthesis, chiral Schiff bases, sugar, [2+2] cycloaddition
  • N. Abbassi Pages 23-33
    Upper Devonian sediments of the Kuh-e Zard area northwest of Zefreh, Central Iran, are composed mainly of brown and grey limestones with sandstone and shale intercalations. They contain trace fossils such as Chondrites isp., Diplocraterion parallelum, Fustiglyphus annulatus, Lockeia isp., Phycodes isp., and Taenidium barretti. These trace fossils indicate a shallow marine environment.
    Keywords: Trace fossils, Systematic ichnology, Upper Devonian, Central Iran
  • F. Motamedi Sedeh, A. Khorasani, K. Shafaee, M. Salehizadeh, H. Fatolahi, K. Arbabi, S. Daneshvari, M. Abhari Pages 35-41
  • F. Fatemi, S. Kazemnejad, A. Dadkhah, M. Rahmati, A. Allameh Pages 43-52
    Glutathione S-transferase (GST) is a superfamily enzyme which plays a major role in detoxification of xenobiotic compounds by catalyzing the conjugation of xenobiotic to cellular glutathione (GSH). GST-P is an important class of GSTs which is expressed during the early stage of life and during developmental stages. Its activity is relatively high during embryogenesis and immediately after birth and diminished in normal adult rat liver. To investigate the effects of hepatotoxic agents such as acetaminophen (APAP) and aflatoxin B1 (AFB1) on liver GST-P in rats during postnatal age, suckling rats age (14±2 days old) were divided into groups (n=5) and treated with both APAP (250 or 450 mg/kg B.W) and AFB1 (3 mg/kg B.W). Livers were removed at different time intervals (2, 6, 12, 18 and 24 h) and processed for GST and GST-P activity at protein and mRNA levels (RT-PCR). Administration of a single high dose of AFB1 (3 mg/kg BW) and APAP (450 mg/kg BW) to weanling rats caused a significant (P< 0.05) induction in total GST activity in developing rats. Based on the Western blotting technique and GST-P specific mRNA amplification by RT-PCR, the GST-pi protein level and its expression were not affected by APAP or AFB1. Despite the inducible effects of AFB1 and APAP on liver total GST activity, GST-P remained unaffected in response to the drugs at protein and mRNA levels.
    Keywords: Acetaminophen, aflatoxin B1, glutathione S, transferases, expression
  • Sh. Varkouhi Pages 53-61
    Thirteen environmental elements were distinguished in the livers of various species of fish that have been sampled from 15 sites in a restricted area of the KhorramAbad River Basin in Lorestan province (west of Iran). Sites sampled represented agricultural, mining, mixed, and urban/recreation land uses and background conditions. Lithium and silver were not detected at any of the sites. The minimum concentration of trace elements in the fish liver of the above mentioned basin belongs to vanadium and the maximum concentration to iron. Cadmium, selenium, and zinc were selected for a more detailed analysis. Cadmium concentrations in fish liver were highest at mining land use sites, whereas the selenium and zinc concentrations were highest at agricultural land use sites in the KhorramAbad River Basin. A comparison of the study to similar studies in the United States and Iran indicated that the total medium frequency of fish samples for cadmium, selenium and zinc in the KhorramAbad unit was higher than the analyzed fish samples of the Upper Colorado River Basin and Southern beaches of the Caspian Sea study basins.
    Keywords: Biogeochemical evaluation, trace elements, fish liver, KhorramAbad River Basin, background conditions
  • N. Kamalian, H. Hamzehloo, H. Ghasemi Pages 63-71
  • M. A. Rajabzadeh Pages 73-87
  • H. Fathpour, A. Noori, B. Zeinali Pages 89-98
    The German cockroach, Blattella germanica, is one of the most common pest species, and is a carrier of many pathogen and allergen factors in humans. Thus, regarding public health, the control of this insect is quite important. Dietary use of hormone analogues, especially juvenoids which disrupt reproductive organ development, is a relatively new method to control cockroaches. In this study, the effect of dietary juvenoid pyriproxyfen was investigated on these insects. The control groups received a regular diet with no juvenoid and each of the treatment groups received 10, 30, 50, 100, or 300 ppm of pyriproxyfen in their diets, respectively. For each dose, 15 fifth-instar nymphs were used and the experiment was replicated three times. Each of the experimental repeats had a separate control group. The treatment period was 14 days, then the insects were fed with a regular diet until they emerged into an adult. At this stage, the treated adults were kept with an untreated opposite sex until the formation of the first egg capsule. Use of pyriproxyfen was found to be effective in inducing abnormalities in wing formation such as divergent, curly wing and giant nymphs. Furthermore, dietary use of this juvenoid caused the sterility of the insects due to incomplete development of the internal reproductive organs. Various morphologic abnormalities like deformation and degeneration were observed in the ovaries and accessory glands of sterile insects. Histological investigation of testis and ovaries in infertile insects indicated a degeneration of ovarian follicle cells, defective vitellogenesis, hypertrophy of testis walls, spermatogenesis disorder and a decrease in the numbers of spermatocyts and spermatozoa. The external genitalia of the sterile insects in both sexes were not significantly altered compared with the controls.
    Keywords: German cockroach, pyriproxyfen, wing twisting, reproductive organ, sterility
  • RECRACKING OF JOINTED ROCK MASSES IN THE SYDNEY BASIN, NEW SOUTH WALES, AUSTRALIA
    H. Memarian, C. L. Fergusson Pages 99-115
    Fracture mapping of Late Permian-Early Triassic flat-lying sedimentary rocks in the Sydney Basin, New South Wales, Australia, shows that joints developed originally in extension were faulted in subsequent events. Joints with a regional distribution fall into two (early and late) formed groups. Group I joints propagated horizontally and never interfered with each other. These joints were subsequently reworked or recracked. Recracking commenced with jointing and continued with lateral slip. Faulted joints grew horizontally by the linking of recracked segments. En echelon arrays are the result of the vertical propagation of faulted joints into intact rock. Recracking of rock also resulted in the formation of sets of secondary joints (Group II). The sense of movement on conjugate faulted joints and the orientation of the sets of secondary joints are related to three compressional stress fields. The intensity of recracking and the amount of lateral slip is mostly related to the strength of infilling materials, the length and continuity of the parent joint, the angle between the existing fractures and the maximum compression direction, and the number of compressional events imposed on the fracture.
    Keywords: Joint, faulted joint, recracking, secondary joint, Sydney Basin
  • J. Raheb, S. Naghdi, K. P. Flint Pages 117-121
    To survive in natural waters, bacteria must respond to a variety of environmental variables such as starvation. Flexibacter chinensis was grown and multiplied in the starvation medium and its viable count, total count and cell size were investigated under different temperatures. Also, the effects of different nutrient sources were investigated. The survival of the organism under starvation conditions was temperature dependent with the longest survival occurring at 4˚C and the shortest at above 30˚C. Amendments of starvation medium with glucose or urea (as carbon and nitrogen source respectively) delayed the reduction in cell size and increased the survival time of F. chinensis at a number of different temperatures.
    Keywords: Flexibacter chinensis, stress, starvation
  • K. Moradi Harsini, M. Khamehchiyan, N. Hafezi Moghadas, A. Amini Pages 123-129
    Holocene in Southwest Khuzestan is represented by a fluvio-tidal succession termed the Bahmanshir Series which consists of two clayey layers separated by silty sand to silt beds. This paper describes the geotechnical properties of the clayey layers that have wide exposure in the lowlands of the Persian Gulf coast. Studied layers are generally clay sized and consist of a lesser percentage of clay minerals. Most of the clayey layers have intermediate plasticity, and low potential for expansion. The variation of physical and engineering properties of the layers from base to top and along the Bahmanshir River is investigated in this research. The engineering properties of the beds seem to be affected by tidal and river flow currents and totally by their formation sedimentary environments. Links of the geotechnical data with geological features as formation sources in the upstream of the basin, the cementation due to the capillary feature in the floodplain sub-environment and the flocculated texture of clays in the brackish water, have been discussed in this paper. Overall, it is observed that the geotechnical data could be correlated with the geological features of the Bahmanshir Series.
    Keywords: Bahmanshir, series, clay, geotechnical properties, sedimentary environment, Holocene
  • M. R. Vaziri, A. Mahanipour, A. Arab Pages 131-135
    A fauna of 16 species and genera of marine Ostracoda is described and illustrated for the first time from the mid-Cretaceous of the Badamouyeh Mountain in Kerman province. The ostracod assemblage suggests a favorable condition during the deposition of the strata. The ostracods can also be used for the correlation of Cenomanian age formations in many places in the Middle East.
    Keywords: Cretaceous, ostracod, Albian, Cenomanian, paleoenvironment