Byungjeong Lee

Development of bovine oocytes reconstructed with different donor somatic cells with or without serum starvation

We conducted this study to examine whether serum starvation in culture contributes to better development of bovine reconstructed oocytes and to evaluate which serum-starved somatic cell is the most effective for cloned calf production. In Experiment 1, donor cells of four different types (cumulus cells, ear fibroblasts, oviduct cells and uterine cells) were either serum-starved or not before fusion with enucleated oocytes, and reconstructed oocytes were further cultured for 168 h. Regardless of serum starvation, cumulus cells or ear fibroblasts yielded higher (P < 0.05) rates of fusion than other cells (62.6-69.3 versus 33.3-38.7%). In the serum-starved group, the first cleavage after reconstruction was significantly increased in cumulus cells and ear fibroblasts, compared with oviduct cells (93.4-94.3 versus 78.8-86.0%), and oocytes reconstructed with either of these yielded more blastocysts than oocytes reconstructed with oviduct or uterine cells (40.6-43.8 versus 20.3-19.0%). We observed a similar pattern in the non-starved group, but we found a significant increase in blastocyst formation was found only in cumulus cells compared with other donor cells (42.6 versus 15.4-27.7%). Overall comparison showed that serum starvation increased the rates of cleavage and development to the blastocyst stage, but we found a statistical significance only in the cleavage rate (80.0 versus 89.5%). In Experiment 2, we transferred randomly selected 59 blastocysts that were developed from oocytes reconstructed with serum-starved cells to 44 synchronised recipients. Of those recipients, 23 became pregnant on Day 60 after transfer (52.3%) and 12 (27.3%) delivered cloned calves. The mean gestation length and birth weight was 275 +/- 8 days and 39.6 +/- 15.6 kg, respectively. Although there was no significant difference among donor cells, blastocysts that were derived from oocytes reconstructed with ear fibroblasts yielded the highest rates of pregnancy (50.0%) and delivery (27.3%). In conclusion, serum starvation is effective for improving preimplantation development of oocytes reconstructed with cumulus or ear fibroblast cells and it may positively influence on obtaining better pregnancy outcome.

Effect of maturation media and oocytes derived from sows or gilts on the development of cloned pig embryos

In order to develop a culture system and recipient cytoplasm that could improve the developmental competence of somatic cell nuclear transfer (SCNT) embryos for successful cloning of pigs, we evaluated the effect of donor oocytes and in vitro maturation (IVM) media on maturation of oocytes and developmental competence of SCNT embryos. In Experiment 1, oocytes derived from sows or gilts were matured in two IVM media (TCM-199 versus NCSU-23) and maturation of oocytes was evaluated by the status of chromatin configuration, the diameter of matured oocytes, the thickness of the zona pellucida, and the size of the perivitelline space (PVS). Sow oocytes matured in TCM-199 (S-TCM group) and NCSU-23 (S-NCSU group) showed significantly higher (P<0.05) maturation rates (S-TCM and S-NSCU, 86+/-4 and 82+/-4%, respectively) when evaluated by metaphase-II status than the gilt oocytes matured in TCM-199 (G-TCM group, 71+/-3%) and in NCSU-23 (G-NCSU-23 group, 71+/-3%). Oocyte diameter, the thickness of the zona pellucida, and the perivitelline space of sow oocytes (S-TCM and S-NCSU) were larger than those of gilt oocytes (G-TCM and G-NCSU) after IVM (P<0.05). In Experiment 2, SCNT was performed, using in vitro-matured oocytes from each group as recipient cytoplasm and porcine fetal fibroblasts as karyoplasts. The reconstructed embryos were electrically fused and activated, and cleavage and blastocyst formation were monitored under a stereomicroscope. The total cell number of flattened blastocysts stained with 5 microM bisbenzimide on day 7 were counted. In addition, in vitro matured non-enucleated oocytes were also electrically activated (parthenogenetic activation) and pronuclear formation was monitored. No difference in pronuclear formation rate after parthenogenetic activation and fusion rate after SCNT was observed among experimental groups. A significantly higher cleavage rate (P<0.05) was observed in S-TCM (69+/-4%) when compared with only G-NCSU (58+/-4%), but not with G-TCM (60+/-4%) or S-NCSU (68+/-4%). The rate of blastocyst formation was significantly higher (P<0.05) in sow oocytes (24% in S-TCM and S-NCSU), when compared to that observed in G-TCM (15%), and G-NCSU (14%). When the same source of oocytes was used, there was no significant difference in rate of blastocyst formation in the two culture media. Total cell number of blastocysts were not significantly different among experimental groups. In conclusion, the present study clearly demonstrated that sow oocytes have a greater developmental competence than gilt oocytes, regardless of the maturation medium examined.

A unified model for the implementation of both ISO 9001

ISO 9001 is a standard for quality management systems and CMMI is a model for process improvement. If an ISO-certified organization wishes to improve its processes continuously, implementing CMMI would be a good choice, as it provides more detailed practices for process improvement than the ISO standards. However, there are two issues that need to be resolved when an ISO-certified organization implements CMMI. First, it is not easy to identify any reusable parts of the ISO standards, and it would be advantageous to be able to reuse selected portions of the ISO standards during CMMI adoption in order to use existing resources to their best advantage. Second, it is difficult for an ISO-certified organization to implement CMMI in a straightforward, easy manner because of the differences in the language, structure, and details of the two sets of documents. In this paper, we present our unified model for ISO 9001:2000 and CMMI that resolves these two issues. Our model would be an extremely useful tool for ISO-certified organizations that plan to implement CMMI.

An integrated model of ISO 9001:2000 and CMMI for ISO registered organizations

ISO 9001 is a standard for quality management systems while CMMI is a model for process improvement. If an organization that has achieved ISO registration wishes to improve processes continuously, CMMI can be a strong candidate because it provides a more detailed roadmap for process improvement. However, with respect to adopting CMMI in organizations that are familiar with ISO 9001, there are some issues that need to be resolved. For example, ISO 9001 and CMMI have different targets, intent, and quantity of detail. In this paper, we present an integrated model of ISO 9001:2000 and CMMI, which would resolve the above problems. We expect that this model will be a useful tool for ISO registered organizations aim to attain higher CMMI levels.

A reengineering process for migrating from an object-oriented legacy system to a component-based system

Computing environments are evolving from mainframe systems to distributed systems. Stand-alone programs that have been developed using object-oriented technology are not suitable for these new environments. However, programs that have been developed using a component-based technology have proven to be more suitable for the new environments due to their granularity and reusability. In this paper, we present a reengineering process for migrating from an object-oriented legacy system to a component-based system. This process consists of two steps: first, to create basic components with the relationship of their constituent classes, second, to refine components using the metrics we propose.

Towards Semi-automatic Bug Triage and Severity Prediction Based on Topic Model and Multi-feature of Bug Reports

Bug fixing is an essential activity in the software maintenance, because most of the software systems have unavoidable defects. When new bugs are submitted, triagers have to find and assign appropriate developers to fix the bugs. However, if the bugs are at first assigned to inappropriate developers, they may later have to be reassigned to other developers. That increases the time and cost for fixing bugs. Therefore, finding appropriate developers becomes a key to bug resolution. When triagers assign a new bug report, it is necessary to decide how quickly the bug report should be addressed. Thus, the bug severity is an important factor in bug fixing. In this paper, we propose a novel method for the bug triage and bug severity prediction. First, we extract topic(s) from historical bug reports in the bug repository and find bug reports related to each topic. When a new bug report arrives, we decide the topic(s) to which the report belongs. Then we utilize multi-feature to identify corresponding reports that have the same multi-feature (e.g., Component, product, priority and severity) with the new bug report. Thus, given a new bug report, we are able to recommend the most appropriate developer to fix each bug and predict its severity. To evaluate our approach, we not only measured the effectiveness of our study by using about 30,000 golden bug reports extracted from three open source projects (Eclipse, Mozilla, and Net beans), but also compared some related studies. The results show that our approach is likely to effectively recommend the appropriate developer to fix the given bug and predict its severity.

Building Concept Network-Based User Profile for Personalized Web Search

This paper presents a novel way of building the user profile of concept network for personalized search. The user profile is defined as a concept network, in which each concept is approximately represented with the formal concept analysis (FCA) theory. We assume that a concept, called ‘session interest concept’, subsume a user’s query intention during a query session and it can reflect the user’s preference. Whenever a user issues his/her query, a session interest concept is generated. Then, new concepts are merged into the current concept network (i.e., a user profile) in which recent user preferences are accumulated. According to FCA, a session interest concept is defined as a pair of extent and intent where the extent covers a set of documents selected by the user among the search results and the intent covers a set of keyword features extracted from the selected documents. And, in order to make a concept network grow, we need to calculate the similarity between a new concept and existing concepts, and to this end, we use a reference concept hierarchy called Open Directory Project. The user profile of concept network is eventually used to expand a user’s initial query. The empirical results show that our approach improves the accuracy of search results in terms of personal preference.

Evolving Web Service Applications Using UML and OWL-S

Web service provides a way to satisfy time-to-market and quality need by reusing services and building applications. Dynamic evolution offers flexibility so that software can adapt to unforeseen and fluctuating business requirements. OWL-S, based on OWL, is a service ontology language. The semantics provided by OWL-S support automation of service discovery, invocation, and service composition. In this paper we propose a framework to support dynamic evolution of Web applications based on semantic web service. This framework proposes a method to consider Web service features and to derive service description from use- case model. A prototype is implemented to show the validity of this framework.

Automatic Discovery of Web Services Based on Dynamic Black-Box Testing

Most current approaches to Web Service discovery exploit description logic-based matchmaking algorithms. Until now, these Semantic Web Service technologies have not substituted for traditional search methods, because higher modeling costs, such as representing Service Annotation Ontologies and Domain Ontologies, are required. In this paper, we present an automatic testing-based approach to the discovery of Web Services. Through the automatic generation and execution of test cases based on a small amount of semantic information, Web Services are simultaneously evaluated and a decision is made on which Web Services the requestor needs. The experimental results show our technique reduces modeling costs significantly, whilst outperforming existing approaches in terms of precision. Furthermore, reliable QoS attribute values are obtained as by-products.

Influence of Ovulation Status, Seasonality and Embryo Transfer Method on Development of Cloned Porcine Embryos

To improve pig cloning efficiency, the present study evaluated the effect of ovulation status, seasonality and embryo transfer (ET) method on in vivo development of cloned porcine embryos. Cloned embryos were transferred to surrogate mothers on the same day of somatic cell nuclear transfer. In pre-ovulation stage (PO), pregnancy rate (PR) and delivery rate (DR) were 36.3% and 9.4%, respectively. In post-ovulation stage, 22.7% PR and 2.1% DR were recorded (both PR and DR are significantly higher in PO). When ET was performed during winter (December-February), spring (March-May), summer (June-August) and autumn (September-November), the PRs were 13.4%, 37.3%, 24.6% and 51.0%, while DRs were 0%, 12.7%, 4.3% and 7.8%, respectively. The highest PRs were recorded in autumn groups. However, DRs were significantly lower in autumn (7.8%) group compared with spring (12.7%) group. The PR was the lowest and no piglets were born in winter group, which might be because of the effect of low temperature during ET. To overcome the low PR in winter group, 0.25 ml straws were used for ET to minimize exposure time of embryos to ambient temperature. The straw ET group showed significantly higher PR in the winter group (23. 9%) compared with the conventional catheter-loading group (7.7%). We suggest that using PO recipient and ET in spring is the best condition for pig cloning. In addition, alternative method to reduce cold shock during ET in winter is necessary.