Over the last four decades, coral reefs have suffered a ~50% decline of across the tropics. Consequently, most research efforts have focused on the impacts of anthropogenic pressures on corals, including ocean warming, ocean acidification, and overfishing. However, recent discoveries indicate that coral reefs are becoming increasingly vulnerable to acute deoxygenation events, which can drive severe and widespread coral bleaching, and in some cases, mortality of corals and other reef organisms. On unimpacted coral reefs, dissolved oxygen (DO) availability can vary between 50% and 200% air saturation, depending on the location, proximity to the open-ocean, and time of the day. During the daytime, Symbiodiniaceae spp. produce more O$_2$ than the coral host can consume, releasing excess O$_2$ to the surrounding tissues. However, at nighttime Symbiodiniaceae spp. cease O$_2$ production. Hence, corals may suffer to O$_2$ deprivation at nighttime when the photosynthesis ceases, and holobiont respiration consumes oxygen. To assess the O$_2$ thresholds and aftereffects of two Red Sea coral species: ${{P. lobata}}$ and ${{G. fascicularis}}$ corals were exposed to reduced DO concentrations. Coral fragments from both species were exposed to one control treatment (6.8 mg O$_2$ l$^{−1}$) and three reduced DO concentrations treatments (5.25 mg O$_2$ l$^{−1}$, 3.5 mg O$_2$ l$^{−1}$, and 1.25 mg O$_2$ l$^{−1}$). Experiments were held at a stable temperature (32°C ± 0.25) and stable pH levels (pH 8.2 ± 0.08). Corals in these experiments displayed different thresholds to low O$_2$ concentrations. ${{P. lobata}}$ coral fragments didn’t exhibit any bleaching symptoms throughout complete experiment. However, ${{G. fascicularis}}$ fragments showed signs of bleaching after the third night of exposure to the low O$_2$ treatment (1.25 mg O$_2$ l$^{−1}$). Physiological variables such as maximum and effective photochemical efficiency, Chl ${{a}}$, cell density, and dark respiration experienced the lowest values under the low O$_2$ treatment for both species. These results highlight the need for further experimental assessments of deoxygenation thresholds for corals across the globe. These assessments are of great importance to create better conservation strategies for the preservation of coral reefs.

Motivation and Approach This thesis seeks to address the alienated urban experience facilitated by Government architecture within the CBD that has become the norm, namely exclusionary “objects as architecture”. The study will seek to counter public exclusion and establish interdepartmental connectivity thus aiding cohesion within Government as well as between Government and the public. Architectural Intention - Definition through Transparency Exploration will happen by redefining views of the public realm through the creation of an architectural experience that tackles legibility within both the public and private domains, thus engaging all users as valued actors in the spatial milieu. / Dissertation (MArch(Prof))--University of Pretoria, 2010. / Architecture / unrestricted

There is a need to identify patients with osteopenia who are at high risk of sustaining fractures and who would benefit from treatment, since many patients with osteopenia do not sustain fractures, in 2008, the WHO unveiled the fracture risk-assessment-tool (FRAX®), which calculates the 10-year probability of a patient sustaining a fracture. It is available on the internet free of charge, and represents a major step forward since it takes into account a number of risk factors and allows clinicians to focus on those patients at high risk of sustaining fractures, in whom the benefits of treating a silent disease outweigh the potential adverse effects and cost. In the USA, the National Osteoporosis Foundation has suggested a fracture threshold to recommend treatment. In this article, the various risk factors included in the FRAX tool are briefly reviewed, and the advantages, potential limitations and possible future developments are discussed.

"Vision is regarded as the most noble of the senses, and the loss of eyesight as the ultimate physical loss" -- Juhani Pallasmaa To see or not to see?   As a child growing up in the Dominican Republic, my vision was blurred by a perception strongly held by my elders.  A perception that have been nurtured and carried out for many centuries.  This perception have kept me away from the 'reality', limiting my vision to what existed in the other side of the borderline.   As my eyes were blindfolded, my ears opened to received words that would slowly construct my own imaginary world.  A particular world, in which hearing was dominant over my other senses.  As one would imagine that a world could painful while living in 'darkness', what was actually painful was living with the existence of the unknown, of the invisible In April 2011, I decided to visit the imaginary line that runs along Dominican Republic and Haiti.  My experience was truly remarkable.  At that present moment, I had a very exciting encounter with a new sense of reality.  As I approached to an unfinished construction, I climbed to a metal stair reaching an altitude of nearly twenty feet.  My eyes witnessed what was hidden for nearly thirty years of my existence. Through the wavy transparent mirage caused by the refraction of the blistering sun, I was able to see the neighboring country of Haiti for the first time.  Along the Massacre River, there was an element that immediately captivated by curiosity.  It was  a thin, blue metal gate located right in the middle of a concrete bridge that expanded east and west uniting the border towns of Dajabon and Ounaminthe. To my eyes, this gate was a visible and an invisible boundary -- A line, a remarkably powerful, and fundamental element in Architecture -- which was strongly visible, by dividing and marking its presence demarcating territories.  Yet, was also transparent uniting two cultures during the market days. My thesis unfolds in the quest of what can exist by the emergence of the visible and the invisible -- what I envisioned while standing at the site, a Binational Market along the imaginary line. / Master of Architecture

The work in this show reflects my interest in the role of the ceramic vessel historically as well as its place in the dialogue of contemporary art. Traditionally thought of as an object of craft and function, the vessel has found footing also as a conceptual container of ideas and artistic expression. It teeters on the threshold between craft and art, between art and life. Because of its strong association with the domestic, I find the vessel to be a fitting form on which to paint ornamental patterns and imagery associated with my own home life and to put into question its role as a strictly functional object.

The purpose of this study was to identify potential threshold concepts in the music industry as perceived by expert music industry professionals; the data collected may possibly inform postsecondary music industry degree program curriculum design. Threshold concept theory emerged in the early 2000s largely due to the research of Meyer & Land (2003, 2005) as a means to illuminate discipline-specific criteria that irreversibly transform a learner’s positionality within a professional discipline. Through the mastery of a threshold concept, a learner becomes aware of discipline specific norms, and may experience a reconstitution of their own identity as a professional. This is the first study to explore threshold concepts within the music industry. This study is also aimed to contribute to a growing body of research at the intersection of threshold concepts and business education. Utilizing qualitative research informed by phenomenology, semi-structured interviews based on the primary tenets of the threshold concept theory framework were conducted. “Expert” music industry professionals were asked to reflect upon their lived experiences regarding their assimilation into the music industry and maintenance of a sustainable career in the discipline. The data collected were aligned with the threshold concept theory framework in order to illuminate potential threshold concepts specific to the music industry. Results indicate that there exist possible dispositional and disciplinary threshold concepts relative to becoming a music industry professional. The identification, prioritization, and utilization of threshold concepts are applicable to curriculum planning at both the macro- (program creation, execution, and evaluation) and micro- (course creation, planning, instruction, and evaluation) levels for post-secondary music industry education.

Masking Level Difference (MLD) tests are an established component of auditory processing test batteries; however, normative data for these tests vary according to procedure. In this study, forty normal, native-English speaking adults between the ages of 18 and 26 were tested for MLD via a newly developed computer software program using both an adaptive procedure (MLDA) and a Bekesy procedure (MLDB). The results from the two procedures were analyzed for sex differences and compared with each other. For both the MLDA and MLDB, the results showed statistically significant sex differences in the masked thresholds used to obtain the MLD (NoSo and NoSπ), but no significant difference in the calculated MLD value (NoSo - NoSπ). These results suggest that since the MLD was similar for both sexes, the normative data need not be reported separately by sex. The results also showed statistically significant differences between procedures, with the MLDA procedure producing higher MLDs than the MLDB procedure. The MLDA procedure lent itself to a d´ analysis, which could not be determined using MLDB due to the nature of a Bekesy assessment. For MLDA, d´ = 1.4, test sensitivity = 96.4%, and test specificity = 60.3%. The results of this study indicate that MLDA is a better testing procedure due to MLDA’s higher MLD average and the statistical data available (d´, and measures of sensitivity and specificity) when using the MLDA procedure.

Recently, investors have asserted that firms' loss contingency disclosures are not adequate to allow them to assess the likelihood of material losses due to litigation (i.e., litigation risk), and a debate has developed over whether the threshold for disclosure should be lowered to provide investors with more information relating to litigation. Using an experiment, I investigate two unintended consequences of lowering a disclosure threshold, as the FASB has recently proposed. First, I find that adding low probability lawsuits to the disclosure of reasonably possible lawsuits lowers prospective investors' perceptions of litigation risk relating to the disclosure, even though more lawsuits are disclosed. Second, lowering the threshold allows firms to portray the entire disclosure opportunistically, diverting attention from higher probability to lower probability lawsuits. I find evidence that firms can use such an opportunistic presentation under a lower threshold to their advantage. Specifically, prospective investors' and even short investors' perceptions were just as favorable to the firm as long investors' when the disclosure threshold was lower and firms adopted an opportunistic disclosure strategy. Thus, my findings suggest that the FASB's proposal to require disclosure of lower probability loss contingencies may have unintended consequences for investors' perceptions of firms' loss exposure.

This thesis contains both Parts A and B. / <p> Xenon induced flux oscillations are possible in large thermal reactors operating at high powers because of the inter-play between the xenon concentration, reactivity, and thermal flux, and the fact that xenon is produced mainly by radioactive decay of I-135, which has a half-life of 6.7 hours. Due to these nuclear characteristics along with size and operating conditions of the Pickering and Bruce cores, these oscillations in flux are inherently unstable with respect to xenon. That is, a local perturbation in reactivity will result in a divergent and cyclic time and space variation in the thermal flux distribution in the core.</p> <p> One group diffusion theory and a simple perturbation analysis yield for a bare thermal reactor, a threshold in the average flux level ∅ which satisfies (1) M^2λij^2 / αxe - αT/αxe ∅ = 1/1+λxe/σxe∅ - μxe / 1+(λxe + λ1)/σxe∅ for oscillations in ijth mode of the flux distribution (see Figure 1) M^2 is the migration area in cm^2, αxe is the reactivity load of Xe-135 at high flux levels; αT is the fuel temperature coefficient expressed in terms of reactivity change per unit flux. The function f(∅) depends only upon the decay constants λxe of Xe-135 and λ1 of I-135; μxe is the fraction of Xe-135 produced directly from the fission of the fuel rather than through iodine decay (which fraction is denoted by μ1). The dimensionless parameter λij^2 depends only upon the shape of the flux distribution and is equal to the difference between the bulking of the ijth mode and the fundamental model.</p> <p> The Bruce and Pickering reactors are used as models in this study to determine the threshold power level at which xenon instability is possible and in which mode this instability occurs.</p> <p> Bruce is found to be unstable in the fundamental and first azimuthal mode for fresh and equilibrium fuel conditions, and stable for the radial, axial and higher azimuthal modes.</p> <p> Pickering, on the other hand, is unstable for the equilibrium fuel condition in the fundamental and first azimuthal modes only and is stable in every mode except the fundamental in the fresh fuel condition.</p> (Part A of Thesis)-------------------------------------------------------------------------------------------------------(Part B of Thesis) </p> Trimming of thin-film resistor components by an electrical arc is investigated in this report as an inexpensive and simple alternative to the laser trim and mechanical scribe methods. A multitude of tests were effected on Garrett Manufacturing Limited production circuits containing nichrome thin film resistors. These tests included Temperature Coefficient of Resistivity, resistance stability, substrate damage, noise performance, dynamic trim with active devices operating, width of cut as compared to mechanical scribe and laser trim techniques, and optimum parameters for trimming. In all cases the trimmed circuits were within the design specifications of the resistor properties under test. It is the conclusion of the author that the obvious attributes of the arc-trim method as well as its outstanding performance in the above tests, warrants its serious consideration as a viable alternative to the laser trim and mechanical scribe methods of altering resistance levels.</p> / Thesis / Master of Engineering (MEngr)

No description available.