815 resultados para Mathematical thinking
Resumo:
The recognition and protection of constitutional rights is a fundamental precept. In Ireland, the right to marry is provided for in the equality provisions of Article 40 of the Irish Constitution (1937). However, lesbians and gay men are denied the right to marry in Ireland. The ‘last word’ on this issue came into being in the High Court in 2006, when Katherine Zappone and Ann Louise Gilligan sought, but failed, to have their Canadian marriage recognised in Ireland. My thesis centres on this constitutional court ruling. So as to contextualise the pursuit of marriage equality in Ireland, I provide details of the Irish trajectory vis-à-vis relationship and family recognition for same-sex couples. In Chapter One, I discuss the methodological orientation of my research, which derives from a critical perspective. Chapter Two denotes my theorisation of the principle of equality and the concept of difference. In Chapter Three, I discuss the history of the institution of marriage in the West with its legislative underpinning. Marriage also has a constitutional underpinning in Ireland, which derives from Article 41 of our Constitution. In Chapter Four, I discuss ways in which marriage and family were conceptualised in Ireland, by looking at historical controversies surrounding the legalisation of contraception and divorce. Chapter Five denotes a Critical Discourse Analysis of the High Court ruling in Zappone and Gilligan. In Chapter Six, I critique text from three genres of discourse, i.e. ‘Letters to the Editor’ regarding same-sex marriage in Ireland, communication from legislators vis-à-vis the 2004 legislative impediment to same-sex marriage in Ireland, and parliamentary debates surrounding the 2010 enactment of civil partnership legislation in Ireland. I conclude my research by reflecting on my methodological and theoretical considerations with a view to answering my research questions. Author’s Update: Following the outcome of the 2015 constitutional referendum vis-à-vis Article 41, marriage equality has been realised in Ireland.
Resumo:
This portfolio of exploration explores the role of transformative thinking and practice in a property entrepreneur’s response to the financial crisis which swept over Ireland from 2008. The complexity of this challenge and the mental capacity to meet its demands is at the core of the exploration. This inquiry emerged from the challenges the financial crisis presented to my values, beliefs, assumptions, and theories, i.e. the interpretive lens through which I make meaning of my experiences. Given the issue identified, this inquiry is grounded in aspects of theories of constructive developmental psychology, applied developmental science, and philosophy. Integrating and linking these elements to business practice is the applied element of the Portfolio. As the 2008 crisis unfolded I realised I was at the limits of my way of knowing. I came to understand that the underlying structure of a way of knowing is the ‘subject-object relationship’ i.e. what a way of knowing can reflect upon, look at, have perspective on, in other words, make object, as against what is it embedded in, attached to, identified within, or subject to. My goal became enhancing my awareness of how I made meaning and how new insights, which would transform a way of knowing, are created. The focus was on enhancing my practice. This Portfolio is structured into three essays. Essay One reported on my self-reflection and external evaluation out of which emerged my developmental goals. In Essay Two I undertake a reading for change programme in which different meaning making systems were confronted in order to challenge me as a meaning maker. Essay Three reported on my experiment which concerned the question whether it was possible for me as a property entrepreneur, and for others alike, to retain bank finance in the face of the overwhelming objective of the bank to deleverage their balance sheet of property loans. The output of my research can be grouped into General Developmental and Specific Business Implications. Firstly I address those who are interested in a transformational-based response to the challenges of operating in the property sector in Ireland during a crisis. I outline the apparatus of thought that I used to create insight, and thus transform how I thought, these are Awareness, Subject-object separation, Exploring other’s perspectives from the position of incompleteness, Dialectical thinking and Collingwood’s Questioning activity. Secondly I set out my learnings from the crisis and their impact on entrepreneurial behaviour and the business of property development. I identify ten key insights that have emerged from leading a property company through the crisis. Many of these are grounded in common sense, however, in my experience these were, to borrow Shakespeare’s words, “More honor'd in the breach than the observance” in pre Crisis Ireland. Finally I set out a four-step approach for forging a strategy. This requires my peer practitioners to identify (i) what they are subject to, (ii) Assess the Opportunity or challenge in a Systemic Context, (iii) Explore Multiple Perspectives on the opportunity or Challenge with an Orientation to change how you know and (iv) Using the Questioning Activity to create Knowledge. Based on my experience I conclude that transformative thinking and practice is a key enabler for a property entrepreneur, in responding to a major collapse of traditional (bank debt) funding.
A mathematical theory of stochastic microlensing. II. Random images, shear, and the Kac-Rice formula
Resumo:
Continuing our development of a mathematical theory of stochastic microlensing, we study the random shear and expected number of random lensed images of different types. In particular, we characterize the first three leading terms in the asymptotic expression of the joint probability density function (pdf) of the random shear tensor due to point masses in the limit of an infinite number of stars. Up to this order, the pdf depends on the magnitude of the shear tensor, the optical depth, and the mean number of stars through a combination of radial position and the star's mass. As a consequence, the pdf's of the shear components are seen to converge, in the limit of an infinite number of stars, to shifted Cauchy distributions, which shows that the shear components have heavy tails in that limit. The asymptotic pdf of the shear magnitude in the limit of an infinite number of stars is also presented. All the results on the random microlensing shear are given for a general point in the lens plane. Extending to the general random distributions (not necessarily uniform) of the lenses, we employ the Kac-Rice formula and Morse theory to deduce general formulas for the expected total number of images and the expected number of saddle images. We further generalize these results by considering random sources defined on a countable compact covering of the light source plane. This is done to introduce the notion of global expected number of positive parity images due to a general lensing map. Applying the result to microlensing, we calculate the asymptotic global expected number of minimum images in the limit of an infinite number of stars, where the stars are uniformly distributed. This global expectation is bounded, while the global expected number of images and the global expected number of saddle images diverge as the order of the number of stars. © 2009 American Institute of Physics.
Resumo:
BACKGROUND: Serotonin is a neurotransmitter that has been linked to a wide variety of behaviors including feeding and body-weight regulation, social hierarchies, aggression and suicidality, obsessive compulsive disorder, alcoholism, anxiety, and affective disorders. Full understanding of serotonergic systems in the central nervous system involves genomics, neurochemistry, electrophysiology, and behavior. Though associations have been found between functions at these different levels, in most cases the causal mechanisms are unknown. The scientific issues are daunting but important for human health because of the use of selective serotonin reuptake inhibitors and other pharmacological agents to treat disorders in the serotonergic signaling system. METHODS: We construct a mathematical model of serotonin synthesis, release, and reuptake in a single serotonergic neuron terminal. The model includes the effects of autoreceptors, the transport of tryptophan into the terminal, and the metabolism of serotonin, as well as the dependence of release on the firing rate. The model is based on real physiology determined experimentally and is compared to experimental data. RESULTS: We compare the variations in serotonin and dopamine synthesis due to meals and find that dopamine synthesis is insensitive to the availability of tyrosine but serotonin synthesis is sensitive to the availability of tryptophan. We conduct in silico experiments on the clearance of extracellular serotonin, normally and in the presence of fluoxetine, and compare to experimental data. We study the effects of various polymorphisms in the genes for the serotonin transporter and for tryptophan hydroxylase on synthesis, release, and reuptake. We find that, because of the homeostatic feedback mechanisms of the autoreceptors, the polymorphisms have smaller effects than one expects. We compute the expected steady concentrations of serotonin transporter knockout mice and compare to experimental data. Finally, we study how the properties of the the serotonin transporter and the autoreceptors give rise to the time courses of extracellular serotonin in various projection regions after a dose of fluoxetine. CONCLUSIONS: Serotonergic systems must respond robustly to important biological signals, while at the same time maintaining homeostasis in the face of normal biological fluctuations in inputs, expression levels, and firing rates. This is accomplished through the cooperative effect of many different homeostatic mechanisms including special properties of the serotonin transporters and the serotonin autoreceptors. Many difficult questions remain in order to fully understand how serotonin biochemistry affects serotonin electrophysiology and vice versa, and how both are changed in the presence of selective serotonin reuptake inhibitors. Mathematical models are useful tools for investigating some of these questions.
Resumo:
PURPOSE: To develop a mathematical model that can predict refractive changes after Descemet stripping endothelial keratoplasty (DSEK). METHODS: A mathematical formula based on the Gullstrand eye model was generated to estimate the change in refractive power of the eye after DSEK. This model was applied to four DSEK cases retrospectively, to compare measured and predicted refractive changes after DSEK. RESULTS: The refractive change after DSEK is determined by calculating the difference in the power of the eye before and after DSEK surgery. The power of the eye post-DSEK surgery can be calculated with modified Gullstrand eye model equations that incorporate the change in the posterior radius of curvature and change in the distance between the principal planes of the cornea and lens after DSEK. Analysis of this model suggests that the ratio of central to peripheral graft thickness (CP ratio) and central thickness can have significant effect on refractive change where smaller CP ratios and larger graft thicknesses result in larger hyperopic shifts. This model was applied to four patients, and the average predicted hyperopic shift in the overall power of the eye was calculated to be 0.83 D. This change reflected in a mean of 93% (range, 75%-110%) of patients' measured refractive shifts. CONCLUSIONS: This simplified DSEK mathematical model can be used as a first step for estimating the hyperopic shift after DSEK. Further studies are necessary to refine the validity of this model.
Resumo:
This volume originated in HASTAC’s first international conference, “Electronic Techtonics: Thinking at the Interface,” held at Duke University during April 19-21, 2007. “Electronic Techtonics” was the site of truly unforgettable conversations and encounters that traversed domains, disciplines, and media – conversations that explored the fluidity of technology both as interface as well as at the interface. This hardcopy version of the conference proceedings is published in conjunction with its electronic counterpart (found at www.hastac.org). Both versions exist as records of the range and depth of conversations that took place at the conference. Some of the papers in this volume are almost exact records of talks given at the conference, while others are versions that were revised and reworked some time after the conference. These papers are drawn from a variety of fields and we have not made an effort to homogenize them in any way, but have instead retained the individual format and style of each author.
Resumo:
In three related experiments, 250 participants rated properties of their autobiographical memory of a very negative event before and after writing about either their deepest thoughts and emotions of the event or a control topic. Levels of emotional intensity of the event, distress associated with the event, intrusive symptoms, and other phenomenological memory properties decreased over the course of the experiment, but did not differ by writing condition. We argue that the act of answering our extensive questions about a very negative event led to the decrease, thereby masking the effects of expressive writing. To show that the changes could not be explained by the mere passage of time, we replicated our findings in a fourth experiment in which all 208 participants nominated a very negative event, but only half the participants rated properties of their memory in the first session. Implications for reducing the effects of negative autobiographical memories are discussed.
Resumo:
Idioms of distress communicate suffering via reference to shared ethnopsychologies, and better understanding of idioms of distress can contribute to effective clinical and public health communication. This systematic review is a qualitative synthesis of "thinking too much" idioms globally, to determine their applicability and variability across cultures. We searched eight databases and retained publications if they included empirical quantitative, qualitative, or mixed-methods research regarding a "thinking too much" idiom and were in English. In total, 138 publications from 1979 to 2014 met inclusion criteria. We examined the descriptive epidemiology, phenomenology, etiology, and course of "thinking too much" idioms and compared them to psychiatric constructs. "Thinking too much" idioms typically reference ruminative, intrusive, and anxious thoughts and result in a range of perceived complications, physical and mental illnesses, or even death. These idioms appear to have variable overlap with common psychiatric constructs, including depression, anxiety, and PTSD. However, "thinking too much" idioms reflect aspects of experience, distress, and social positioning not captured by psychiatric diagnoses and often show wide within-cultural variation, in addition to between-cultural differences. Taken together, these findings suggest that "thinking too much" should not be interpreted as a gloss for psychiatric disorder nor assumed to be a unitary symptom or syndrome within a culture. We suggest five key ways in which engagement with "thinking too much" idioms can improve global mental health research and interventions: it (1) incorporates a key idiom of distress into measurement and screening to improve validity of efforts at identifying those in need of services and tracking treatment outcomes; (2) facilitates exploration of ethnopsychology in order to bolster cultural appropriateness of interventions; (3) strengthens public health communication to encourage engagement in treatment; (4) reduces stigma by enhancing understanding, promoting treatment-seeking, and avoiding unintentionally contributing to stigmatization; and (5) identifies a key locally salient treatment target.
Resumo:
The management of acute heart failure is shifting toward treatment approaches outside of a traditional hospital setting. Many heart failure providers are now treating patients in less familiar health care settings, such as acute care clinics, emergency departments, and skilled nursing facilities. In this review we describe the current pressures driving change in the delivery of acute heart failure and summarize the evidence regarding treatments for acute heart failure outside of the inpatient setting. We also provide considerations for the design of future treatment strategies to be implemented in alternative care settings.
Resumo:
En este trabajo se describe una experiencia llevada a cabo con profesores de matemáticas en formación, sobre el papel que pueden desarrollar las nuevas tecnologías para llevar a cabo procesos de demostración y prueba en el aula de secundaria.
Resumo:
En este trabajo se describe detalladamente una experiencia llevada a cabo con profesores de matemáticas en formación, sobre el papel que pueden desarrollar las nuevas tecnologías para llevar a cabo procesos de demostración y prueba en el aula de secundaria.
Resumo:
Dai ethnic mathematical culture is an important part of Dai ethnic culture. Mathematical elements show in their daily life. Through a research project of the Yunnan Dehong Dai people in southwest China, We collected the first-hand information, tried to do a small investigative study, and collected mathematics teaching resources that is useful to primary and secondary schools students on mathematics learning in this minority areas. Keyword: Dai ethnic; Mathematical culture; Primary and secondary schools; Teaching resources.
Resumo:
The phrase “not much mathematics required” can imply a variety of skill levels. When this phrase is applied to computer scientists, software engineers, and clients in the area of formal specification, the word “much” can be widely misinterpreted with disastrous consequences. A small experiment in reading specifications revealed that students already trained in discrete mathematics and the specification notation performed very poorly; much worse than could reasonably be expected if formal methods proponents are to be believed.
Resumo:
It is well known that during alloy solidification, convection currents close to the so-lidification front have an influence on the structure of dendrites, the local solute concentration, the pattern of solid segregation, and eventually the microstructure of the casting and hence its mechanical properties. Controlled stirring of the melt in continuous casting or in ingot solidification is thought to have a beneficial effect. Free convection currents occur naturally due to temperature differences in the melt and for any given configuration, their strength is a function of the degree of superheat present. A more controlled forced convection current can be induced using electro-magnetic stirring. The authors have applied their Control-Volume based MHD method [1, 2] to the problem of tin solidification in an annular crucible with a water-cooled inner wall and a resistance heated outer one, for both free and forced convection situations and for various degrees of superheat. This problem was studied experimentally by Vives and Perry [3] who obtained temperature measurements, front positions and maps of electro-magnetic body force for a range of superheat values. The results of the mathematical model are compared critically against the experimental ones, in order to validate the model and also to demonstrate the usefulness of the coupled solution technique followed, as a predictive tool and a design aid. Figs 6, refs 19.
Resumo:
Computer based mathematical models describing aircraft fire have a role to play in the design and development of safer aircraft, in the implementation of safer and more rigorous certification criteria and in post mortuum accident investigation. As the cost involved in performing large-scale fire experiments for the next generation 'Ultra High Capacity Aircraft' (UHCA) are expected to be prohibitively high, the development and use of these modelling tools may become essential if these aircraft are to prove a safe and viable reality. By describing the present capabilities and limitations of aircraft fire models, this paper will examine the future development of these models in the areas of large scale applications through parallel computing, combustion modelling and extinguishment modelling.