Boundary‐Value Problems of Linear‐Transport Theory—Green's Function Approach

Case's technique utilizing Green's functions for dealing with boundary‐value problems of the neutron linear‐transport theory is exploited. We show that the Fourier coefficients of the Green's function over the Case spectrum are precisely the normal modes. In particular, if we assume that the scattering kernel is rotationally invariant (which indeed we do assume) and approximate it by a degenerate kernel consisting of spherical harmonics, the set of modes is deficient for problems lacking azimuthal symmetry. We also show that the expansion of the scattering kernel, in terms of spherical harmonics (or any set of orthogonal functions for that matter), permits the linear factorization of the Fourier coefficients of the Green's function in terms of the lowest element, with the proportionality functions consisting of complete orthogonal polynomials. As a consequence of this attribute of Fourier coefficients, the eigenfunctions (continuum and discrete) also factorize, which then permits decoupling of the appropriate singular integral equations. To illustrate our idea, we solve half‐space and slab problems. However, the basic procedure is kept sufficiently general so that the extension to problems involving other geometrics remains straightforward.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71085/2/JMAPAQ-11-10-3042-1.pd

Continuous low dose rate irradiation of the rat brain

The reported median survival time for patients who are diagnosed with high grade astrocytomas and who undergo postoperative radiotherapy is of the order of 24 to 40 weeks. The course of radiotherapy administered to these patients takes up a considerable portion of their expected survival time. Therefore, any means of reducing the treatment time may contribute to an enhanced quality of life for these patients. A potentially useful method for the reduction of the treatment time may be achieved with the use of continuous low dose rate external beam radiotherapy, where the treatment is administered over a 12 to 24 hour period. A relationship between fractionated and continuous low dose rate irradiation has been reported for skin, however, no such relationship has been reported for the brain. Low dose rate protocols that are equivalent in effect to fractionated (conventional) protocols can be derived using the linear quadratic theory, provided that quantitative radiobiological data for normal tissue (brain) is known. Thus, the aim of the current study is to test the radiation tolerance of the rat brain to low dose rate and fractionated radiation in order to establish the values for the parameters of the linear quadratic model

A comparison of three types of orthodontic study models

Magister Scientiae Dentium - MSc(Dent)The aim of this present study was to compare the accuracy of digital and printed study models with plaster study models, that are considered the gold standard. The objectives were to compare the accuracy of measurements obtained from digital and printed study models with those of plaster study models, to establish which type of study model yielded the most accurate measurements in comparison to plaster study models and to identify possible disadvantages and errors that can be made using any of the three types of study models

Investigating the value proposition of advanced metering infrastructure in developed and emerging economies with a focus on South Africa

South Africa’s power utility, Eskom Holdings SOC Limited, is currently working towards implementing aspects of a Smart Grid with the initial introduction of an Advanced Metering Infrastructure (AMI), similar to utilities internationally. The primary reasons for transitioning towards a Smart Grid could be attributed to the challenges of unprecedented capacity constraints experienced on the power networks in 2008, continually increasing demand, aging infrastructure and the need for improved asset management. The global definition of a Smart Grid may however vary for utilities around the world; and can be defined as embedded intelligence through hardware infrastructure built into the existing electrical network to provide visibility, automatic control and intelligent decision making over the entire electrical architecture from generation to the end user with the aim of increasing efficiency, improving reliability and enhancing decision making. AMI provides the foundation for any utility’s vision towards a Smart Grid, as it promotes the direct interaction between a specific customer and the utility. An AMI system is a hardware infrastructure which provides the customer the ability to either pay more for electricity in known peak demand periods or communicates the actual grid demand in real-time to customers so the electricity price increases proportionally with the demand on the grid. This then influences the customer to either manually move electric loads to lower demand periods or implement automated systems that has the ability to make use of electricity according to their preferences. All of this ensures that electricity is used at the lowest possible cost to the customer and that the grid adapts to its constraints at that point in time. AMI incorporates functionality such as time-of-use tariffs, automated meter reading, remote connect or disconnect, bi-directional communication infrastructure, integration with utility backend systems for improved customer care and, has the ability to improve existing operations and maintenance processes. This research focuses on a comparative analysis of the value propositions of AMI in developed and emerging countries, analysing market driving forces and the challenges associated with AMI deployment. The research will also provide for a case study to evaluate Eskom’s AMI deployment and the customer’s reaction and acceptance to the technology, such as behavioural changes, changes in energy usage and relationship with the utility. A qualitative and quantitative analysis of the case study questionnaire responses will be reviewed to determine customer perceptions, behavioural changes, comparative consumption patterns for the traditional conventional meter to that of the AMI smart meter, and the acceptance of the AMI solution in an emerging economy focusing on South Africa

Exploring auto-construction in informal settlements as an alternative housing strategy in Cato Manor, Durban : a proposed incremental housing development.

Master of Art in Architecture. University of KwaZulu-Natal, Durban 2016.By 2030, 71% of the South African population will live in urban areas. Currently, 1 billion people worldwide live in informal settlements. Providing urban dwellers access to adequate housing is an immense challenge throughout the world and particularly in South Africa. Cato Manor is one of the oldest informal settlements in Durban, and is home to 93 000 people. It is characterised by the resident‟s struggle to claim a Right to the City. Many people have settled here due to its proximity to the city. In the South African context, the delivery and availability of housing remains a pressing issue. A long tradition of informal, self-built housing, or auto-construction has undoubtedly shaped the city, yet remains an unacknowledged resource in the strategy for housing. In order to mitigate the socio-economic problems brought about by apartheid, and address the new constitutional right for all to have „access to adequate housing,‟ the post-apartheid government implemented the Reconstruction and Development Programme to build and allocate houses. The RDP project does not fully consider the needs of people, most of which experience financial instability and under-employment. Further the ever-growing backlog for RDP homes means that the average person is on the waiting list for 15-20 years. Adequate housing entails the provision of more than just a house for residents in informal settlements. The incremental approach offers residents more flexibility, and an opportunity for their homes to grow with the family. Through an exploration of the practice of auto-construction as a resource, the aim is to suggest a more holistic approach to housing, infrastructure and community networks in informal settlements. This is achieved by improving the quality, flexibility and satisfaction of living environments for residents of informal settlements

Lisdexamfetamine dimesylate augmentation for adults with major depressive disorder and inadequate response to antidepressant monotherapy: Results from 2 phase 3, multicenter, randomized, double-blind, placebo-controlled studies

AbstractBackgroundThe efficacy, safety, and tolerability of lisdexamfetamine dimesylate (LDX) augmentation of antidepressant monotherapy in adults with major depressive disorder (MDD) from two phase 3 studies are reported.MethodsAcross study 1 (placebo, n=201; LDX, n=201) and study 2 (placebo, n=213; LDX, n=211), most participants (placebo and LDX) in the safety analysis set were female (study 1: 66.2% and 64.2%; study 2: 67.1% and 66.8%); mean±SD ages were 41.8±12.04 with placebo and 42.2±12.32 with LDX in study 1 and 42.6±11.41 with placebo and 42.0±11.63 with LDX in study 2. Participants (18–65 y) had DSM-IV-TR–diagnosed MDD and lead-in baseline Montgomery-Åsberg Depression Rating Scale (MADRS) total scores ≥24. Eight-week antidepressant lead-in phases prospectively assessed antidepressant response. Then, 8 weeks of randomized (1:1), double-blind treatment with dose-optimized LDX (20–70mg) or placebo in participants exhibiting inadequate antidepressant monotherapy responses (augmentation baseline MADRS total scores ≥18 and <50% MADRS total score reductions from lead-in baseline to augmentation baseline) was initiated. The primary endpoint was MADRS total score change from augmentation baseline to week 16. Safety and tolerability measures included the occurrence of treatment-emergent adverse events (TEAEs).ResultsLeast squares mean (95% CI) treatment differences (LDX–placebo) for MADRS total score changes from augmentation baseline to week 16 were not statistically significant in study 1 (0.1 [–1.7, 2.0], P=0.883) or study 2 (–0.5 [–2.3, 1.3], P=0.583). The only TEAE reported by >5% of LDX participants at twice the placebo rate in both studies was dry mouth.LimitationsLimitations include the exclusion of participants with psychiatric comorbidities/active medical disorders, the inability to assess specific MDD symptom domains (eg, anhedonia, cognition) or subtypes, the use of telephone-based depression assessments, and the potential influence of placebo response.ConclusionContrary to expectations, LDX augmentation was not superior to placebo in reducing depressive symptoms in individuals with MDD exhibiting inadequate responses to antidepressant monotherapy

A register-based case-control study of health care utilization and costs in binge-eating disorder

Objective: Capturing trends in healthcare utilization may help to improve efficiencies in the detection and diagnosis of illness, to plan service delivery, and to forecast future health expenditures. For binge-eating disorder (BED), issues include lengthy delays in detection and diagnosis, missed opportunities for recognition and treatment, and morbidity. The study objective was to compare healthcare utilization and expenditure in people with and without BED. Methods: A case-control design and nationwide registers were used. All individuals diagnosed with BED at eating disorder clinics in Sweden between 2005 and 2009 were included (N = 319, 97% female, M age = 22 years). Ten controls (N = 3190) were matched to each case on age-, sex-, and location of birth. Inpatient, hospital-based outpatient, and prescription medication utilization and expenditure were analyzed up to eight years before and four years after the index date (i.e., date of diagnosis of the BED case). Results: Cases had significantly higher inpatient, hospital-based outpatient, and prescription medication utilization and expenditure compared with controls many years prior to and after diagnosis of BED. Utilization and expenditure for controls was relatively stable over time, but for cases followed an inverted U-shape and peaked at the index year. Care for somatic conditions normalized after the index year, but care for psychiatric conditions remained significantly higher. Conclusion: Individuals with BED had substantially higher healthcare utilization and costs in the years prior to and after diagnosis of BED. Since previous research shows a delay in diagnosis, findings indicate clear opportunities for earlier detection and clinical management. Training of providers in detection, diagnosis, and management may help curtail morbidity. A reduction in healthcare utilization was observed after BED diagnosis. This suggests that earlier diagnosis and treatment could improve long-term health outcomes and reduce the economic burden associated with BED

In vivo regulation of interleukin 1β in patients with cryopyrin-associated periodic syndromes

The investigation of interleukin 1β (IL-1β) in human inflammatory diseases is hampered by the fact that it is virtually undetectable in human plasma. We demonstrate that by administering the anti–human IL-1β antibody canakinumab (ACZ885) to humans, the resulting formation of IL-1β–antibody complexes allowed the detection of in vivo–produced IL-1β. A two-compartment mathematical model was generated that predicted a constitutive production rate of 6 ng/d IL-1β in healthy subjects. In contrast, patients with cryopyrin-associated periodic syndromes (CAPS), a rare monogenetic disease driven by uncontrolled caspase-1 activity and IL-1 production, produced a mean of 31 ng/d. Treatment with canakinumab not only induced long-lasting complete clinical response but also reduced the production rate of IL-1β to normal levels within 8 wk of treatment, suggesting that IL-1β production in these patients was mainly IL-1β driven. The model further indicated that IL-1β is the only cytokine driving disease severity and duration of response to canakinumab. A correction for natural IL-1 antagonists was not required to fit the data. Together, the study allowed new insights into the production and regulation of IL-1β in man. It also indicated that CAPS is entirely mediated by IL-1β and that canakinumab treatment restores physiological IL-1β production

Green's Function Technique For Dealing With Boundary Value Problems Of The Linear Transport Theory.

PhDPhysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/188357/2/7014560.pd