فهرست مطالب

International Journal of Science
Volume:6 Issue: 1, 2005

  • تاریخ انتشار: 1384/10/11
  • تعداد عناوین: 10
  • S. Abbasi, A. Parvaneh Tafreshi, H. Sepehri, F. Sabooni, B. Zeynali Page 15
    Nerve growth factor (NGF) is the first characterized member of the neurotrophin family. It is known for its crucial role in survival, differentiation and maintenance of neurons both in peripheral and central nervous system. In addition to its neurotrophic role, NGF has been also proposed to influence the immune system. Recent studies indicate that in multiple sclerosis and in its animal model (EAE) there is an increased level of NGF in acute phase of the disease (relapses) and conversely decreased level during the remission phase. Increased level of NGF has been also reported in other autoimmune diseases such as lupus erythmatosus. Concomitantly, proinflammatory cytokines are upregulated in the acute phase of autoimmune diseases, known to be as potent inducers of heat shock protein expression. These observations suggest that over production of NGF in CNS may functionally be related to the state of activation of the immune system in autoimmune diseases. In this study, we have investigated whether increased level of NGF in CNS triggers the immune system. NGF was therefore injected intracerebroventricularly at doses 5 and 20??g/mice for four days. Our histological and immunohistochemical results show that there are no signs of immune cell infiltration and no changes in the level of heat shock protein expression in different areas of the brain. We therefore suggest that either NGF alone is unable to trigger the immune system or the NGF regimen used in this study was insufficient to do so.
  • Hossein Gholamalian Page 27
    New investigations on a Late Devonian outcrop near Esfahan (Chahriseh section) revealed new data about the Polygnathus bouckareti, Polygnathus communis group and genus Clydagnathus. The feature differentiation related to the recovered species shows the exigency of a few changes in the age and variety of morphotypes of P. communis group. Some identified species in this paper are: Polygnathus communis communis, P. communis mugodzharicus, P. bouckaerti, P. pomeranicus, P. lanceolus, P. inconcinnus, Icriodus alternatus alternatus and I. cornutus. By considering the conodont associations, changes in the age of P. bouckaerti and P. communis mugodzharicus are the other results. In addition, two morphotypes of P. communis mugodzharicus and more detailed explanation of P. communis group are presented.
  • G.R. Lashkaripour, A. Asghari, Moghaddam, M. Allaf, Najib Page 47
    Marand plain, a part of the Caspian Sea catchment, stretching over an area of about 820 km2, in northwestern part of Iran is considered as a semi-arid zone. It has gained substantial importance because of agricultural prosperity and population density. Almost all water consumption needs are met from groundwater resources. In the last decades, rapid population growth coupled with agricultural expansion has significantly increased demand on groundwater resources. Large increases in water demand with little recharge have strained Marand groundwater resources resulting in declines in water levels and deterioration of groundwater quality in the major parts of the plain. It''s worth mentioning that the paramount cause of sharp drop in the groundwater table in the recent years is conclusively attributed to pumping out of well water which confirmedly exceeds the level of the natural recharge. As a result, the average water level, for instance, has dropped from 1179.9 m to 1168.2 m during the years from 1982 to 2000. The prime objective of this research is to study and examine the groundwater decline and its effect on the quality of groundwater in the Marand aquifer for the said period
  • E. Ghasemi, Nejad, M.R. Kamali, R. Moussavi, Harami, M.P. Khavari, Khorasani Page 61
    The Kopet-Dagh Basin located in NE Iran, southern Turkmenistan and northern Afghanistan. It contains sediments of Mesozoic and Tertiary Eras. The Chaman-Bid Formation (Bajocian-Tithonian) is composed of shale, marl and marly limestone deposited after the Mid-Kimmerian orogeny in a shallow marine and lagoonal environments. In order to study palynostratigraphy, palynofacies and possibility of hydrocarbon generation, 45 samples were collected and processed palynologically. The studied section can be correlated with Tethyan realm and two events have been identified in the middle part of this section. Based on identified events, the age of Middle part of this section is Oxfordian-Kimmeridgian, while the upper part is Tithonian in age. The lower part of studied section, based on dinoflagellate cysts such as Nannoceratopsis gracilis and N. ridingii, is late Bajocian. Palynofacies study has led to recognition of two types of alternation in the sequence indicating a stagnant anaerobic-dysaerobic bottom condition followed by an energetic and oxygenated condition. Twelve samples rich in dinoflagellate cysts were selected for evaluation of Total Organic Carbon (TOC). These indices show that the potential of hydrocarbon bearing is fair to good and the type of production can be a wet and probably sweet gas; however at this stage the Chaman-Bid Formation is overmature in eastern Kopet-Dagh basin.
  • M. Saraj Page 73
    In this paper we have investigated the behavior of two exterior Griffith cracks opened by heated wedge in an infinite and isotropic medium. By using Fourier sine and cosine transformation under plane strain condition we have obtained the closed form expressions for the stress intensity factor and the crack shape for the problem. Two special casesof heat distributions are discussed, when wedge geometry is prescribed.
  • E. Khoshbin, R.B. Davies Page 85
    As Motor Neuron Disease (MND) involves a progressive deterioration in nerve function, it is possible that risk factors for the disease will also accelerate the progression of the disease.
    This paper uses the two stages of age at onset and age at death to measure progression. Conventional parametric survival models are used to identify significant covariate from a large number of variables which have been suggested as risk factors for “MND / Frailty” models are used to characterize more fully the two stage progression process. Results and
    The results suggest the polluted work environments are associated with early onset of MND. Although there is a negative dependence between duration from onset to death and age at onset, this is not necessarily inconsistent with the expected progressive deterioration; there is a tantalizing suggestion from the frailty modeling that this may be the net result of a positive association due to variation in the rate of progression over the population and a negative association due to the direct effect of age (for example, because the elderly are more at risk from infections).
  • H. Salehi Fathabadi Page 107
    In many real systems, it happens that the existing flow network become inconsistent with the new applications or inputs. This means that some of the applicable structural characteristics have been changed so that the flow network has become infeasible or, in other words, obsolete. Therefore, it has to be adjusted to new applications. It is well known how to use a maximum flow algorithm to determine when a flow network is infeasible, but less known is how to adjust the structural data such that the network becomes feasible while the incurred adjustment cost is minimal. This paper considers an infeasible flow network G= (V, A) in which supplies/demands, arc capacities and flow lower bounds are liable to relax. A minimum cost relaxation model for canceling most positive cuts is constructed. Analyzing the model shows that, in order to make the network feasible, it is sufficient to adjust only one component of the structural data. According to this result, a polynomial time algorithm is developed to cancel all positive cuts and convert the infeasible flow network to a feasible one.
  • E. Pasha, M. Kokabi Nezhad, G. R. Mohtashami Page 119