Question Essay Example | Topics and Well Written Essays - 500 words - 13

Question - Essay Example Yes water affects mass wasting processes. Water reduces adhesive forces been the soil among other debris materials thereby facilitating mass wasting. Additionally, water often has force large enough to move material including large debris down the stream. The downward movement of loose and unconsolidated materials including soil and sediment is often due to force of gravity. At the point where the soil among other consolidated materials is not moving down the hill, such material are held in place with frictional force. The point at which the gravitational and frictional force balances is referred to angle of repose. This is the maximum angle that a friction force can hold loose material on the surface of the earth not to move downhill. Therefore, angles greater than angle of repose usually lead to mass wasting and at this point the force of gravity is slightly greater than frictional force holding the same materials. Soil creeping is a long term mass wasting process and it combine the movement of small and rocky materials in undirected direction. The movement of such materials are often facilitated by force of gravity. The creep usually do much damage since it leads to collection of materials over time especially behind trees; thus, it may lead to landslides triggered mainly by these tree particularly in cases that they lose root

Present the current status of gene therapy for retinal diseases Research Paper

Present the current status of gene therapy for retinal diseases - Research Paper Example Diseases of the eye which have the potential of being treatable with gene therapy in future are retinitis pigmentosa, proliferative retinopathy, autoimmune uveitis, gyrate atrophy, age-related macular degeneration, retinoblastoma and Leber's congential amaurosis. Thus gene therapy has the potential to treat various inheritable retinal diseases in future. As of now, no product has been approved for clinical use and most of them are in clinical trial stage. Introduction Whenever a particular gene is defective or absent, there is either absence of a particular protein, or there is production of abnormal protein or the amount of protein produced is insufficient. This causes diseased states. Many of these diseases can be either prevented or treated by replacing the abnormal gene, or by introducing the absent gene or by supplementing the defective gene. Using genes thus to prevent or treat a disease is known as gene therapy (HGPI, 2009). This is an experimental technique and is done by ins erting genetic material into the patient’s cells. The genes thus introduced exert their benefits by either compensating for the abnormal genes or by producing beneficial protein or by supplementing the abnormal gene (Hecht, 2004). ... g genetic material into cells that cause cancer cells to revert back to normal cells, delivering genes of bacteria or virus as a form of vaccination, elivering genetic material that either impedes or promotes growth of a new tissue and delivering genetic material that stimulates healing of a damaged tissue (Hecht, 2004). Currently, research is going on for gene therapy by various approaches in different parts of the world for various diseases like combined immuno-deficiencies, hemophilia, Parkinson's disease, cancer and even HIV. Thus, gene therapy has emerged as one of the novel treatment strategies for several untreatable diseases (Singh and Tripathi, 2002). One significant area in which enormous research has been done with regard to gene therapy is retinal diseases. In this article, the current status of gene therapy for retinal diseases will be discussed through review of suitable literature. Why is retina suitable for gene therapy? Several genes which are responsible for various inherited retinal disorders have been identified (Dejneka and Bennett, 2001). Eye, especially retina, is one of the best suitable targets for gene therapy because of easy accessibility and allowance for local application of various therapeutic agents, along with decreased risk for systemic effects. Another major advantage is that the effects of therapy can be monitored through various non-invasive tests. Of the parts in the ocular system, retina is the most suitable candidate for gene therapy. This is because; the amount of virus that needs to be injected into the retina is just 1/1000 of that needed for other systemic diseases (Singh and Tripathi, 2002). The blood ocular barrier that is present in the eye separates eye from other parts of the body and protects retina. This barrier