Complexity and maintenance : a comparative study of object-oriented and structured methodologies : a thesis presented in partial fulfilment of the requirements for the degree of Master of Business Studies in Information Systems at Massey University

Maintenance has been found to be one of the most expensive phases in the life of an information system. It has been suggested that the use of object-oriented methods instead of traditional structured methods may be one way of reducing the cost of maintenance required for an information system. This thesis is an attempt to determine whether the object-oriented approach does in fact undergo a relatively smaller increase in complexity when subjected to a change in specifications than a similar system that is developed using a "structured methodology", and is therefore easier to maintain. The methodologies used in this study were Yourdon's (1989) Modern Structured Methodology and Booch's (1994) Object-Oriented methodology. The analysis phase of both methodologies were applied to the same case study twice in order to evaluate the effects of a change in the system's specifications. Once the two models for each methodology were complete, various metrics were applied to the structured system and a separate set of metrics were applied to the object-oriented system. The results of the models and the metrics were then analysed and validated in order to determine which system suffered a smaller proportional increase in complexity as a result of the changes to the system. It was found that overall, the object-oriented system proved to undergo a smaller increase in complexity, and it was therefore easier to maintain as a result of the changes than the structured system

Portal Venous Thrombosis Associated with Use of Etonogestrel/ethinyl Estradiol Vaginal Ring

Introduction: Portal venous thrombosis is a life-threatening cause of abdominal pain. In younger patients, heritable thrombophilias, pregnancy, tobacco use, and oral contraceptives are associated.Case Report: A 26-year-old woman prescribed contraceptive vaginal ring presented with abdominal pain and was diagnosed with an extensive portal venous thrombosis. Management included heparin and later an oral anticoagulant with good short-term outcome.Discussion: Women using hormonal contraception are approximately four times more likely to develop thromboembolism. Risk of thromboembolism is similar between users of intravaginal and oral contraceptives.Conclusion: Portal venous thrombosis must be considered in women presenting with abdominal pain who are prescribed hormonal contraceptives, including intravaginal forms

Who visits World Heritage? A comparative analysis of three cultural sites

Heritage tourism is a growing segment of the modern tourism industry, and several studies have been undertaken to identify the individuals who participate in this type of tourism. These have indicated that heritage tourists, generally, are middle class, middle age, and well educated. However, despite their iconic role, there has been relatively little attention paid to profile of visitors to World Heritage Sites. This study aims to better understand the demography of this specific tourism segment through the use of survey-based research at three geographically diverse World Heritage Sites: Independence Hall in the USA, Studenica Monastery in Serbia, and the Archaeological Site of Volubilis in Morocco. Through the use of descriptive statistics, several over-arching trends were noted among the three sites. World Heritage Site visitors were found to be very well educated, but they did not have any similarities in relation to age, income, or residence, which contrasts the “general” heritage tourist typology. However, there were several World Heritage specific trends. While this work is a snapshot of the three sites under study and thus is difficult to generalize, it provides the basis for more comprehensive demographic research on visitors to World Heritage Sites

Feasibility of a resonance-based Planet Nine search

It has been proposed that mean motion resonances (MMRs) between Planet Nine and distant objects of the scattered disk might inform the semimajor axis and instantaneous position of Planet Nine. Within the context of this hypothesis, the specific distribution of occupied MMRs largely determines the available constraints. Here we characterize the behavior of scattered Kuiper Belt objects arising in the presence of an eccentric Planet Nine ($e_9 \in 0.1$, $0.7$), focusing on relative sizes of populations occupying particular commensurabilities. Highlighting the challenge of predicting the exact MMR of a given object, we find that the majority of resonant test particles have period ratios with Planet Nine other than those of the form $P_9/P=N/1$, $N/2$ $(N \in \mathbb{Z}^+)$. Taking into account the updated prior distribution of MMRs outlined in this work, we find that the close spacing of high-order resonances, as well as chaotic transport, preclude resonance-based Planet Nine constraints from current observational data.Comment: 6 pages, 7 figure

Characterization of the PCMBS-dependent modification of KCa3.1 channel gating.

Intermediate conductance, calcium-activated potassium channels are gated by the binding of intracellular Ca(2+) to calmodulin, a Ca(2+)-binding protein that is constitutively associated with the C terminus of the channel. Although previous studies indicated that the pore-lining residues along the C-terminal portion of S6 contribute to the activation mechanism, little is known about whether the nonluminal face of S6 contributes to this process. Here we demonstrate that the sulfhydral reagent, parachloromercuribenze sulfonate (PCMBS), modifies an endogenous cysteine residue predicted to have a nonluminal orientation (Cys(276)) along the sixth transmembrane segment (S6). Modification of Cys(276) manipulates the steady-state and kinetic behavior of the channel by shifting the gating equilibrium toward the open state, resulting in a left shift in apparent Ca(2+) affinity and a slowing in the deactivation process. Using a six-state gating scheme, our analysis shows that PCMBS slows the transition between the open state back to the third closed state. Interpreting this result in the context of the steady-state and kinetic data suggests that PCMBS functions to shift the gating equilibrium toward the open state by disrupting channel closing. In an attempt to understand whether the nonluminal face of S6 participates in the activation mechanism, we conducted a partial tryptophan scan of this region. Substituting a tryptophan for Leu(281) recapitulated the effect on the steady-state and kinetic behavior observed with PCMBS. Considering the predicted nonluminal orientation of Cys(276) and Leu(281), a simple physical interpretation of these results is that the nonluminal face of S6 forms a critical interaction surface mediating the transition into the closed conformation, suggesting the nonluminal C-terminal portion of S6 is allosterically coupled to the activation gate

A limnological assessment of Russell Pond, Woodstock, New Hampshire

A limnological survey was conducted during 17-18 September, 1998 to characterize the trophic state of Russell Pond, a 15.8 Ha natural Lake located in Woodstock, Grafton County, New Hampshire. Physical, biological and chemical parameters were measured to assess the health of the lake and changes from previous studies. Russell Pond is oligotrophic with high Secchi disk depths (13.8 m), low phosphorus levels (3.8 µg L1) and low Chlorophyll a concentration (0.5 µg L-1). Peridinium (Dinophyceae) dominated (64%) the net phytoplankton. Calanoid copepods (Diaptomidae) constituted 87.5% of the crustacean zooplankton. The lake is at risk for acidification because of low acid neutralizing capacity (1.2 mg CaCO3 L-1) and low pH (5.6) in the deep water. Russell Pond has exceptionally high water clarity due to the low phytoplankton density and low water color (6.9 CPU). Water quality of the lake has been stable over the past few years. Compared to data from four other New Hampshire lakes, Russell Pond is the most oligotrophic of the lakes, followed by Pleasant Lake and Stonehouse Pond. Great Pond and Townhouse Pond were the most mesotrophic of the lakes

USING REAL OPTIONS TO EVALUATE PRODUCER INVESTMENT IN NEW GENERATION COOPERATIVES

New Generation Cooperatives have emerged as a contemporary means for farmers to invest in further processing activities. This paper considers real options as the basis for evaluating producer investment in a start-up cooperative that involves technological uncertainty. The investment and risk inherent in producer membership in an NGC is analyzed using real options theory logic. Real options theory has recently been extended to technology positioning projects and how the extent of uncertainty influences the value of a technology "option". Conventional net present value formulas have been shown to be limited when the conditions of the investment require substantial commitment under uncertainty, such as investments in technology. Implications for producers are drawn from the analysis. Producers always have the alternative of not investing in the initial start-up but waiting and buying in at a later time, perhaps when less uncertainty prevails. Results indicate that producers are better able to evaluate investment in a NGC using real options.Agribusiness,

Plant pathogens as biocontrol agents for Cirsium arvense : an answer to Müller and Nentwig

Recently, Müller and Nentwig (2011) reviewed the plant pathogens that have been considered for biological control of the weed Cirsium arvense (L.) Scop. (Canada thistle, Californian thistle, creeping thistle), and concluded that the prospects have been largely overestimated. The premise of their conclusion is that no bioherbicide products have achieved marketability, which they surmise is due to lack of host specificity, effectiveness, and issues with application. While it is true that no microbial products have achieved marketability for this weed, we believe their reasoning for this is erroneous, and likely due to lack of distinction between two biocontrol approaches, specifically classical biocontrol, and innundative biocontrol (often referred to as the biopesticide approach). These two different types of biocontrol have different goals, and are applied in different ways