Execution-based retrieval of object-oriented classes: An improved method.

Software reuse has become a topic of much interest in the software community due to its potential benefits, which include increased product quality and productivity and decreased product cost and time. The software reusability can be enhanced by the Object-Oriented approach. The potential problem in software reuse is to find an effective and efficient way to retrieve the candidate components from the library. An improved methodology of retrieval by execution on object-oriented (OO) classes is proposed in this thesis. The system allows users to enter the data on the constructor, observer and modifier in order. The system then organizes them into a test program and executes the classes from the selected library. Finally, the system returns to the user a list of candidates according to the matching number of methods and constructors. The user does not need to take care of the argument order, and the system handles each case. This proposed method is the first retrieval by execution that works on OO classes and discloses the complete class behavior. Characteristics of OO components such as information hiding, inheritance, overloading and overriding are fully considered. Compared with the previous execution-based retrieval method, this method greatly improves the retrieval precision, recall and efficiency. A prototype system, called EBCRS, is developed using HTML, JavaScript, Applet and Servlets. This system could be used to retrieve, browse and save the Java classes from the class library. It also allows the administrator to manage the class library such as adding to and deleting from the class library. This system is Internet and Intranet ready. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2001 .X8. Source: Masters Abstracts International, Volume: 42-01, page: 0270. Adviser: Young G. Park. Thesis (M.Sc.)--University of Windsor (Canada), 2001

Seasonal dynamics of trace elements in sediment and seagrass tissues in the largest Zostera japonica habitat, the Yellow River Estuary, northern China

Trace element accumulation is an anthropogenic threat to seagrass ecosystems, which in turn may affect the health of humans who depend on these ecosystems. Trace element accumulation in seagrass meadows may vary temporally due to, e.g., seasonal patterns in sediment discharge from upstream areas. In addition, when several trace elements are present in sufficiently high concentrations, the risk of seagrass loss due to the cumulative impact of these trace elements is increased. To assess the seasonal variation and cumulative risk of trace element contamination to seagrass meadows, trace element (As, Cd, Cr, Cu, Pb, Hg, Mn and Zn) levels in surface sediment and seagrass tissues were measured in the largest Chinese Zostera japonica habitat, located in the Yellow River Estuary, at three sites and three seasons (fall, spring and summer) in 2014–2015. In all three seasons, trace element accumulation in the sediment exceeded background levels for Cd and Hg. Cumulative risk to Z. japonica habitat in the Yellow River Estuary, from all trace elements together, was assessed as “moderate” in all three seasons examined. Bioaccumulation of trace elements by seagrass tissues was highly variable between seasons and between above-ground and below-ground biomass. The variation in trace element concentration of seagrass tissues was much higher than the variation in trace element concentration of the sediment. In addition, for trace elements which tended to accumulate more in above-ground biomass than below-ground biomass (Cd and Mn), the ratio of above-ground to below-ground trace element concentration peaked at times corresponding to high water discharge and high sediment loads in the Yellow River Estuary. Overall, our results suggest that trace element accumulation in the sediment may not vary between seasons, but bioaccumulation in seagrass tissues is highly variable and may respond directly to trace elements in the water column

Generation of Human Epidermis-Derived Mesenchymal Stem Cell-like Pluripotent Cells and their reprogramming in mouse chimeras

Stem cells can be derived from the embryo (embryonic stem cells, ESCs), from adult tissues (adult stem cells, ASCs), and by induction of fibroblasts (induced pluripotent stem cells, iPSs). Ethical problems, immunological rejection, and difficulties in obtaining human tissues limit the use of ESCs in clinical medicine. Induced pluripotent stem cells are difficult to maintain in vitro and carry a greater risk of tumor formation. Furthermore, the complexity of maintenance and propagation is especially difficult in the clinic. Adult stem cells can be isolated from several adult tissues and present the possibility of self-transplantation for the clinical treatment of a variety of human diseases. Recently, several ASCs have been successfully isolated and cultured in vitro, including hematopoietic stem cells (HSCs) , mesenchymal stem cells (MSCs), epidermis stem cells, neural stem cells (NSCs), adipose-derived stem cells (ADSCs), islet stem cells, and germ line stem cells. Human mesenchymal stem cells originate mainly from bone marrow, cord blood, and placenta, but epidermis-derived MSCs have not yet been isolated. We isolated small spindle-shaped cells with strong proliferative potential during the culture of human epidermis cells and designed a medium to isolate and propagate these cells. They resembled MSCs morphologically and demonstrated pluripotency in vivo; thus, we defined these cells as human epidermis-derived mesenchymal stem cell-like pluripotent cells (hEMSCPCs). These hEMSCPCs present a possible new cell resource for tissue engineering and regenerative medicine

The asparagus genome sheds light on the origin and evolution of a young Y chromosome

Several models have been proposed to explain the emergence of sex chromosomes. Here, through comparative genomics and mutant analysis, Harkess et al. show that linked but separate genes on the Y chromosome are responsible for sex determination in Asparagus, supporting a two-gene model for sex chromosome evolution

The conservation and uniqueness of the caspase family in the basal chordate, amphioxus

<p>Abstract</p> <p>Background</p> <p>The caspase family, which plays a central role in apoptosis in metazoans, has undergone an expansion in amphioxus, increasing to 45 members through domain recombination and shuffling.</p> <p>Results</p> <p>In order to shed light on the conservation and uniqueness of this family in amphioxus, we cloned three representative caspase genes, designated as <it>bbtCaspase-8, bbtCaspase-1/2 </it>and <it>bbtCaspase3</it>-like, from the amphioxus <it>Branchiostoma belcheri tsingtauense</it>. We found that <it>bbtCaspase-8 </it>with conserved protein architecture is involved in the Fas-associated death domain-Caspase-8 mediated pro-apoptotic extrinsic pathway, while <it>bbtCaspase3</it>-like may mediate a nuclear apoptotic pathway in amphioxus. Also, <it>bbtCaspase-1/2 </it>can co-localize with <it>bbtFADD2 </it>in the nucleus, and be recruited to the cytoplasm by amphioxus apoptosis associated speck-like proteins containing a caspase recruitment domain, indicating that <it>bbtCaspase-1/2 </it>may serve as a switch between apoptosis and caspase-dependent innate immune response in invertebrates. Finally, amphioxus extrinsic apoptotic pathway related caspases played important roles in early embryogenesis.</p> <p>Conclusions</p> <p>Our study not only demonstrates the conservation of <it>bbtCaspase-8 </it>in apoptosis, but also reveals the unique features of several amphioxus caspases with novel domain architectures arose some 500 million years ago.</p

Empirical Validation of Test-Driven Pair Programming in Game Development

This paper investigates the effects of some extreme programming practices in game development by conducting a case study with 12 students who were assigned to implement a simple game application either as pairs or as individuals. The pairs used some XP practices, such as pair programming, test-driven and refactoring, while the individuals applied the traditional waterfall-like approach. The results of the case study showed that paired students completed their tasks faster and with higher quality than individuals. The programs written by pairs pass more test cases than those developed by individuals. Paired programmers also wrote cleaner code with higher cohesion by creating more reasonable number of methods. Therefore, some XP practices, such as pair programming, test-driven and refactoring could be used in game development. 1