63 research outputs found
Hemisystems of small flock generalized quadrangles
In this paper, we describe a complete computer classification of the
hemisystems in the two known flock generalized quadrangles of order
and give numerous further examples of hemisystems in all the known flock
generalized quadrangles of order for . By analysing the
computational data, we identify two possible new infinite families of
hemisystems in the classical generalized quadrangle .Comment: slight revisions made following referee's reports, and included raw
dat
The role of Comprehension in Requirements and Implications for Use Case Descriptions
Within requirements engineering it is generally accepted that in writing specifications (or indeed any requirements phase document), one attempts to produce an artefact which will be simple to comprehend for the user. That is, whether the document is intended for customers to validate requirements, or engineers to understand what the design must deliver, comprehension is an important goal for the author. Indeed, advice on producing âreadableâ or âunderstandableâ documents is often included in courses on requirements engineering. However, few researchers, particularly within the software engineering domain, have attempted either to define or to understand the nature of comprehension and itâs implications for guidance on the production of quality requirements.
Therefore, this paper examines thoroughly the nature of textual comprehension, drawing heavily from research in discourse process, and suggests some implications for requirements (and other) software documentation. In essence, we find that the guidance on writing requirements, often prevalent within software engineering, may be based upon assumptions which are an oversimplification of the nature of comprehension. Hence, the paper examines guidelines which have been proposed, in this case for use case descriptions, and the extent to which they agree with discourse process theory; before suggesting refinements to the guidelines which attempt to utilise lessons learned from our richer understanding of the underlying discourse process theory. For example, we suggest subtly different sets of writing guidelines for the different tasks of requirements, specification and design
Corporate governance and financial constraints on strategic turnarounds
The paper extends the Robbins and Pearce (1992) two-stage turnaround response model to include governance factors. In addition to the retrenchment and recovery, the paper proposes the addition of a realignment stage, referring specifically to the re-alignment of expectations of principal and agent groups. The realignment stage imposes a threshold that must be crossed before the retrenchment and hence recovery stage can be entered. Crossing this threshold is problematic to the extent that the interests of governance-stakeholder groups diverge in a crisis situation. The severity of the crisis impacts on the bases of strategy contingent asset valuation leading to the fragmentation of stakeholder interests. In some cases the consequence may be that management are prevented from carrying out turnarounds by governance constraints. The paper uses a case study to illustrate these dynamics, and like the Robbins and Pearce study, it focuses on the textile industry. A longitudinal approach is used to show the impact of the removal of governance constraints. The empirical evidence suggests that such financial constraints become less serious to the extent that there is a functioning market for corporate control. Building on governance research and turnaround literature, the paper also outlines the general case necessary and sufficient conditions for successful turnarounds
Kinetic modeling of tumor growth and dissemination in the craniospinal axis: implications for craniospinal irradiation
BACKGROUND: Medulloblastoma and other types of tumors that gain access to the cerebrospinal fluid can spread throughout the craniospinal axis. The purpose of this study was to devise a simple multi-compartment kinetic model using established tumor cell growth and treatment sensitivity parameters to model the complications of this spread as well as the impact of treatment with craniospinal radiotherapy. METHODS: A two-compartment mathematical model was constructed. Rate constants were derived from previously published work and the model used to predict outcomes for various clinical scenarios. RESULTS: The model is simple and with the use of known and estimated clinical parameters is consistent with known clinical outcomes. Treatment outcomes are critically dependent upon the duration of the treatment break and the radiosensitivity of the tumor. Cross-plot analyses serve as an estimate of likelihood of cure as a function of these and other factors. CONCLUSION: The model accurately describes known clinical outcomes for patients with medulloblastoma. It can help guide treatment decisions for radiation oncologists treating patients with this disease. Incorporation of other treatment modalities, such as chemotherapy, that enhance radiation sensitivity and/or reduce tumor burden, are predicted to significantly increase the probability of cure
Reproductive inequality in humans and other mammals
To address claims of human exceptionalism, we determine where humans fit within the greater mammalian distribution of reproductive inequality. We show that humans exhibit lower reproductive skew (i.e., inequality in the number of surviving offspring) among males and smaller sex differences in reproductive skew than most other mammals, while nevertheless falling within the mammalian range. Additionally, female reproductive skew is higher in polygynous human populations than in polygynous nonhumans mammals on average. This patterning of skew can be attributed in part to the prevalence of monogamy in humans compared to the predominance of polygyny in nonhuman mammals, to the limited degree of polygyny in the human societies that practice it, and to the importance of unequally held rival resources to womenâs fitness. The muted reproductive inequality observed in humans appears to be linked to several unusual characteristics of our speciesâincluding high levels of cooperation among males, high dependence on unequally held rival resources, complementarities between maternal and paternal investment, as well as social and legal institutions that enforce monogamous norms
Endurance, resistance and resilience in the South African health care system: case studies to demonstrate mechanisms of coping within a constrained system
BACKGROUND: South Africa is at present undertaking a series of reforms to transform public health services to make them more effective and responsive to patient and provider needs. A key focus of these reforms is primary care and its overburdened, somewhat dysfunctional and hierarchical nature. This comparative case study examines how patients and providers respond in this system and cope with its systemic demands through mechanisms of endurance, resistance and resilience, using coping and agency literatures as the theoretical lenses. METHODS: As part of a larger research project carried out between 2009 and 2010, this study conducted semi-structured interviews and observations at health facilities in three South African provinces. This study explored patient experiences of access to health care, in particular, ways of coping and how health care providers cope with the health care systemâs realities. From this interpretive base, four cases (two patients, two providers) were selected as they best informed on endurance, resistance and resilience. Some commentary from other respondents is added to underline the more ubiquitous nature of these coping mechanisms. RESULTS: The cases of four individuals highlight the complexity of different forms of endurance and passivity, emotion- and problem-based coping with health care interactions in an overburdened, under-resourced and, in some instances, poorly managed system. Patientsâ narratives show the micro-practices they use to cope with their treatment, by not recognizing victimhood and sometimes practising unhealthy behaviours. Providers indicate how they cope in their work situations by using peer support and becoming knowledgeable in providing good service. CONCLUSIONS: Resistance and resilience narratives show the adaptive power of individuals in dealing with difficult illness, circumstances or treatment settings. They permit individuals to do more than endure (itself a coping mechanism) their circumstances, though resistance and resilience may be limited. These are individual responses to systemic forces. To transform health care, mutually supportive interactions are required among and between both patients and providers but their nature, as micro-practices, may show a way forward for system change
'You give us rangoli, we give you talk': using an art-based activity to elicit data from a seldom heard group
<p>Abstract</p> <p>Background</p> <p>The exclusion from health research of groups most affected by poor health is an issue not only of poor science, but also of ethics and social justice. Even if exclusion is inadvertent and unplanned, policy makers will be uninformed by the data and experiences of these groups. The effect on the allocation of resources is likely to be an exacerbation of health inequalities.</p> <p>Discussion</p> <p>We subject to critical analysis the notion that certain groups, by virtue of sharing a particular identity, are inaccessible to researchers - a phenomenon often problematically referred to as 'hard to reach'. We use the term 'seldom heard' to move the emphasis from a perceived innate characteristic of these groups to a consideration of the methods we choose as researchers. Drawing on a study exploring the intersections of faith, culture, health and food, we describe a process of recruitment, data collection and analysis in which we sought to overcome barriers to participation. As we were interested in the voices of South Asian women, many of whom are largely invisible in public life, we adopted an approach to data collection which was culturally in tune with the women's lives and values. A collaborative activity mirroring food preparation provided a focus for talk and created an environment conducive to data collection. We discuss the importance of what we term 'shoe leather research' which involves visiting the local area, meeting potential gatekeepers, and attending public events in order to develop our profile as researchers in the community. We examine issues of ethics, data quality, management and analysis which were raised by our choice of method.</p> <p>Summary</p> <p>In order to work towards a more theoretical understanding of how material, social and cultural factors are connected and influence each other in ways that have effects on health, researchers must attend to the quality of the data they collect to generate finely grained and contextually relevant findings. This in turn will inform the design of culturally sensitive health care services. To achieve this, researchers need to consider methods of recruitment; the makeup of the research team; issues of gender, faith and culture; and data quality, management and analysis.</p
- âŠ