Long-term Effect of Desferrioxamine to rHuEPO Resistant Anemia in Hemodialysis Patients (혈액 투석 환자에서 나타나는 rHuEPO 저항성 빈혈에 대한 Desferrioxamine의 장기 효과)
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- Journal of Yeungnam Medical Science
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- v.14 no.2
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- pp.399-414
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- 1997
There are several factors concerning to anemia in chronic renal failure patients. But when rHuEPO is used, most of these factors can be overcome, and the levels of hemoglobin are increased. However, about 10% of the renal failure patients represent rHuEPO-resistant anemia eventhough high dosage of rHuEPO. For these cases, desferrioxamine can be applied to correct rHuEPO resistnacy, and many mechanism of DFO are arguing. So we are going to know whether DFO can be applied to correct anemia of the such patients, how long its effect can be continued. The seven pateients as experimental group(DFO+EPO) who represent refractoriness to rHuEPO and the other seven patients as control group(EPO) were included. Experimental group had lower than 9 g/dL of hemoglobin levels despite high rHuEPO dosage (more than 4000U/Wk) and showed normocytic normochromic anemia. There were no definitve causes of anemia such as hemorrhage or iron deficiency. Control group patients had similar characteristics in age, mean dialysis duration but showed adequate response to rHuEPO. DFO was administered to experimental group for 8 weeks along with rHuEPO(the rHuEPO individual mean dosage had been determined by mean dosage of the previous 6 months. Total mean dosage; 123.5 U/Kg/Wk). After 8 weeks of DFO administration, the hemoglobin and rHuEPO dosage levels were checked for 15 consecutive months. It should be noted that the patients determined their own rHuEPO dosage levels according to hemoglobin levels and economic status. In conrol group, rHuEPO was administered by the same method used in experimental group without DFO through the same period. Fifteen months of observation period after DFO trial were divided as Time I(7 months after DFO trial) and Time II(8 months after Time I). The results are as follows: Before DFO trial, mean hemoglobin level of experimental group was 7.8 g/dL, which is similar level(p>0.05) to control group(mean Hb; 8.2 g/dL). But in experimental group, significantly(p<0.05) higher dosages of rHuEPO(mean; 123.5 U/Kg/Wk) than control group (mean; 41.6 U/Kg/Wk) had been used. It means resistancy to rHuEPO of experimental group. But after DFO trial, the hemoglobin levels of the experimental group were increased significantly(p<0.05), and these effect were continued to Time II.(Time I; mean 8.6g/dL, Time II; mean 8.6g/dL) The effects of DFO to hemoglobin were continued for 15 months after DFO trial with similar degree through Time I, Time II. Also, rHuEPO dosages used in the experimental group were decreased to similar levels of the control group after DFO trial and these effect were also continued for 15 months(Time I; mean 48.1 U/Kg/Wk. Time II; mean 51.8 U/Kg/Wk). In the same period, hemoglobin levels and rHuEPO dosages used in the control group were not changed significantly. Notibly, hemoglobin increment and rHuEPO usage decrement in experimental group were showed maxilly in the 1st month after DFO trial. That is, after the use of DFO, erythopoiesis was enhanced with a reduced rHuEPO dosage. So we think rHuEPO reisistancy can be overcome by DFO therapy. In conclusion, the DFO can improve the anemia caused by chronic renal failure at least over 1 year, and hence, can reduce the dosage of rHuEPO for anemia correction. Additional studies in order to determine the mechanism of DFO on erythropoiesis and careful attention to potential side effects of DFO will be needed.
The Draft International Code of Conduct for Outer Space Activities officially proposed by the European Union on the occasion of the 55th Session of the United Nations Peaceful Uses of the Outer Space last June 2012 in Vienna, Austria is to fill the lacunae of the relevant norms to be applied to the human activities in the outer space and thus has the merit our attention. The missing elements of the norms span from the prohibition of an arms race, safety and security of the space objects including the measures to reduce the space debris to the exchange of information of space activities among space-faring nations. The EU's initiatives, when implemented, cover or will eventually prepare for the forum to deal with such issues of interests of the international community. The EU's initiatives begun at the end of 2008 included the unofficial contacts with major space powers including in particular the USA of which position is believed to have been reflected in the Draft with the aim to have it adopted in 2013. Although the Code is made up of soft law rather than hard law for the subscribing countries, the USA seems to be afraid of the eventuality whereby its strategic advantages in the outer space will be affected by the prohibiting norms, possibly to be pursued by the Code from its current non-binding character, of placing weapons in the outer space. It is with this trepidation that the USA has been opposing to the adoption of the United Nations Assembly Resolutions on the prevention of an arms race in the outer space (PAROS) and in the same context to the setting-up of a working group on the arms race in the outer space in the frame of the Conference on Disarmament. China and Russia who together put forward a draft Treaty on Prevention of the Placement of Weapons in Outer Space and of the Threat or Use of Force against Outer Space Objects (PPWT) in 2008 would not feel comfortable either because the EU initiatives will steal the lime light. Consequently their reactions are understandably passive towards the Draft Code while the reaction of the USA to the PPWT was a clear cut "No". With the above background, the future of the EU Code is uncertain. Nevertheless, the purpose of the Code to reduce the space debris, to allow exchange of the information on the space activities, and to protect the space objects through safety and security, all to maximize the principle of the peaceful use and exploration of the outer space is the laudable efforts on the part of EU. When the detailed negotiations will be held, some problems including the cost to be incurred by setting up an office for the clerical works could be discussed for both efficient and economic mechanism. For example, the new clerical works envisaged in the Draft Code could be discharged by the current UN OOSA (Office for Outer Space Affairs) with minimal additional resources. The EU's initiatives are another meaningful contribution following one due to it in adopting the Kyoto Protocol of 1997 to the UNFCCC (UN Framework Convention on the Climate Change) and deserve the praise from the thoughtful international community.
In collaborative tagging systems such as Delicious.com and Flickr.com, users assign keywords or tags to their uploaded resources, such as bookmarks and pictures, for their future use or sharing purposes. The collection of resources and tags generated by a user is called a personomy, and the collection of all personomies constitutes the folksonomy. The most significant need of the folksonomy users Is to efficiently find useful resources or experts on specific topics. An excellent ranking algorithm would assign higher ranking to more useful resources or experts. What resources are considered useful In a folksonomic system? Does a standard superior to frequency or freshness exist? The resource recommended by more users with mere expertise should be worthy of attention. This ranking paradigm can be implemented through a graph-based ranking algorithm. Two well-known representatives of such a paradigm are Page Rank by Google and HITS(Hypertext Induced Topic Selection) by Kleinberg. Both Page Rank and HITS assign a higher evaluation score to pages linked to more higher-scored pages. HITS differs from PageRank in that it utilizes two kinds of scores: authority and hub scores. The ranking objects of these pages are limited to Web pages, whereas the ranking objects of a folksonomic system are somewhat heterogeneous(i.e., users, resources, and tags). Therefore, uniform application of the voting notion of PageRank and HITS based on the links to a folksonomy would be unreasonable, In a folksonomic system, each link corresponding to a property can have an opposite direction, depending on whether the property is an active or a passive voice. The current research stems from the Idea that a graph-based ranking algorithm could be applied to the folksonomic system using the concept of mutual Interactions between entitles, rather than the voting notion of PageRank or HITS. The concept of mutual interactions, proposed for ranking the Semantic Web resources, enables the calculation of importance scores of various resources unaffected by link directions. The weights of a property representing the mutual interaction between classes are assigned depending on the relative significance of the property to the resource importance of each class. This class-oriented approach is based on the fact that, in the Semantic Web, there are many heterogeneous classes; thus, applying a different appraisal standard for each class is more reasonable. This is similar to the evaluation method of humans, where different items are assigned specific weights, which are then summed up to determine the weighted average. We can check for missing properties more easily with this approach than with other predicate-oriented approaches. A user of a tagging system usually assigns more than one tags to the same resource, and there can be more than one tags with the same subjectivity and objectivity. In the case that many users assign similar tags to the same resource, grading the users differently depending on the assignment order becomes necessary. This idea comes from the studies in psychology wherein expertise involves the ability to select the most relevant information for achieving a goal. An expert should be someone who not only has a large collection of documents annotated with a particular tag, but also tends to add documents of high quality to his/her collections. Such documents are identified by the number, as well as the expertise, of users who have the same documents in their collections. In other words, there is a relationship of mutual reinforcement between the expertise of a user and the quality of a document. In addition, there is a need to rank entities related more closely to a certain entity. Considering the property of social media that ensures the popularity of a topic is temporary, recent data should have more weight than old data. We propose a comprehensive folksonomy ranking framework in which all these considerations are dealt with and that can be easily customized to each folksonomy site for ranking purposes. To examine the validity of our ranking algorithm and show the mechanism of adjusting property, time, and expertise weights, we first use a dataset designed for analyzing the effect of each ranking factor independently. We then show the ranking results of a real folksonomy site, with the ranking factors combined. Because the ground truth of a given dataset is not known when it comes to ranking, we inject simulated data whose ranking results can be predicted into the real dataset and compare the ranking results of our algorithm with that of a previous HITS-based algorithm. Our semantic ranking algorithm based on the concept of mutual interaction seems to be preferable to the HITS-based algorithm as a flexible folksonomy ranking framework. Some concrete points of difference are as follows. First, with the time concept applied to the property weights, our algorithm shows superior performance in lowering the scores of older data and raising the scores of newer data. Second, applying the time concept to the expertise weights, as well as to the property weights, our algorithm controls the conflicting influence of expertise weights and enhances overall consistency of time-valued ranking. The expertise weights of the previous study can act as an obstacle to the time-valued ranking because the number of followers increases as time goes on. Third, many new properties and classes can be included in our framework. The previous HITS-based algorithm, based on the voting notion, loses ground in the situation where the domain consists of more than two classes, or where other important properties, such as "sent through twitter" or "registered as a friend," are added to the domain. Forth, there is a big difference in the calculation time and memory use between the two kinds of algorithms. While the matrix multiplication of two matrices, has to be executed twice for the previous HITS-based algorithm, this is unnecessary with our algorithm. In our ranking framework, various folksonomy ranking policies can be expressed with the ranking factors combined and our approach can work, even if the folksonomy site is not implemented with Semantic Web languages. Above all, the time weight proposed in this paper will be applicable to various domains, including social media, where time value is considered important.
The research conducted here focuses on the effect of factors that affect the behavior of UCC (User Created Content) website users, other than user's rational recognition of how useful a UCC website can be. Most discussions in the existing literature on information systems have focused on users' evaluation how a UCC website can help to attain the users' own goals. However, there are other factors and this research pays attention to an individual's 'personality,' which is stable and biological in nature. Specifically, I have noted here that 'extroversion' and 'neuroticism,' the two common personality factors presented in Eysenck's most representative 'EPQ Model' and 'Big Five Model,' are the two personality factors that affect a site's 'usefulness,' by this I mean how useful does the user consider the website and its content. How useful a site is considered by the user is the other factor that has been regarded as the antecedent factor that influences the adoption of information systems in the existing MIS (Management Information System) research. Secondly, as using or creating a UCC website does not guarantee the user's or the creator's extrinsic motivation, unlike when using the information system within an organization, there is a greater likelihood that the increase in user's activities in relation to a UCC website is motivated by emotional factors rather than rational factors. Thus, I have decided to include the relationship between an individual's personality and what they find pleasurable in the research model. Thirdly, when based on the S-O-R Paradigm of Mehrabian and Russell, the two cognitive factors and emotional factors are finally affected by stimulus, and thus these factors ultimately have an effect on an individual's respondent behavior. Therefore, this research has presented an assumption that the recognition of how useful the site and content is and what emotional pleasure it provides will finally affect the behavior of the UCC website users. Finally, the relationship between the recognition of how useful a site is and how pleasurable it is to useand UCC usage may differ depending on certain situational conditions. In other words, the relationship between the three factors may vary according to how much users are involved in the creation of the website content. Creation thus emerges as the keyword of UCC. I analyzed the above relationships through the moderating variable of the user's involvement in the creation of the site. The research result shows the following: When it comes to the relationship between an individual's personality and what they find pleasurable it is extroverted users who have a greater likelihood to feel pleasure when using a UCC website, as was expected in this research. This in turn leads to a more active usage of the UCC web site because a person who is an extrovert likes to spend time on activities with other people, is sensitive to new experiences and stimuli and thus actively responds to these. An extroverted person accepts new UCC activities as part of his/her social life, rather than getting away from this new UCC environment. This is represented by the term 'Foxonomy' where the users meet a variety of users from all over the world and contact new types of content created by these users. However, neuroticism creates the opposite situation to that created by extroversion. The representative symptoms of neuroticism are instability, stress, and tension. These dispositions are more closely related to stress caused by a new environment rather than this creatingcuriosity or pleasure. Thus, neurotic persons have an uneasy feeling and will eventually avoid the situation where their own or others' daily lives are frequently exposed to the open web environment, this eventually makes them have a negative attitude towards the web environment. When it comes to an individual's personality and how useful site is, the two personality factors of extroversion and neuroticism both have a positive relationship with the recognition of how useful the site and its content is. The positive, curious, and social dispositions of extroverted persons tend to make them consider the future usefulness and possibilities of a new type of information system, or website, based on their positive attitude, which has a significant influence on the recognition of how useful these UCC sites are. Neuroticism also favorably affects how useful a UCC website can be through a different mechanism from that of extroversion. As the neurotic persons tend to feel uneasy and have much doubt about a new type of information system, they actively explore its usefulness in order to relieve their uncomfortable feelings. In other words, neurotic persons seek out how useful a site can be in order to secure their own stable feelings. Meanwhile, extroverted persons explore how useful a site can be because of their positive attitude and curiosity. As a lot of MIS research has revealed that the recognition of how useful a site can be and how pleasurable it can be to use have been proven to have a significant effect on UCC activity. However, the relationship between these factors reveals different aspects based on the user's involvement in creation. This factor of creationgauges the interest of users in the creation of UCC contents. Involvement is a variable that shows the level of an individual's mental effort in creating UCC contents. When a user is highly involved in the creation process and makes an enormous effort to create UCC content (classed a part of a high-involvement group), their own pleasure and recognition of how useful the site is have a significantly higher effect on the future usage of the UCC contents, more significantly than the users who sit back and just retrieve the UCC content created by others. The cognitive and emotional response of those in the low-involvement group is unlikely to last long,even if they recognize the contents of a UCC website is pleasurable and useful to them. However, the high-involvement group tends to participate in the creation and the usage of UCC more favorably, connecting the experience with their own goals. In this respect, this research presents an answer to the question; why so many people are participating in the usage of UCC, the representative form of the Web 2.0 that has drastically involved more and more people in the creation of UCC, even if they cannot gain any monetary or social compensation. Neither information system nor a website can succeed unless it secures a certain level of user base. Moreover, it cannot be further developed when the reasons, or problems, for people's participation are not suitably explored, even if it has a certain user base. Thus, what is significant in this research is that it has studied users' respondent behavior based on an individual's innate personality, emotion, and cognitive interaction, unlike the existing research that has focused on 'compensation' to explain users' participation with the UCC website. There are also limitations in this research. Firstly, I divided an individual's personality into extroversion and neuroticism; however, there are many other personal factors such as neuro-psychiatricism, which also needs to be analyzed for its influence on UCC activities. Secondly, as a UCC website comes in many types such as multimedia, Wikis, and podcasting, these types need to be included as a sub-category of the UCC websites and their relationship with personality, emotion, cognition, and behavior also needs to be analyzed.