Moving Mugabe's Mountain: Zimbabwe's Path to Arrears Clearance and Debt Relief

Zimbabwe is embarking on a long, complex, and difficult journey to rebuild its economy, which has been shattered by years of neglect and destructive government policies. If the final political hurdles are overcome? hopefully sooner rather than later—the new coalition government will be faced with making politically difficult decisions and addressing conclusively the economic ghosts of the past. One of those ghosts is more than $5 billion owed to external creditors, of which nearly 80 percent is arrears. Clearing Zimbabwe’s external debt arrears and securing comprehensive debt relief will be a critical step in eventual recovery. By doing so, the government will remove a crippling burden on its budget, investment climate, and overall macroeconomic environment. More important to the success of the coalition government, it will unlock hundreds of millions of dollars in new external assistance for critical reconstruction programs that will improve the Zimbabwean people’s quality of life. This paper provides a detailed overview of the arrears clearance and debt relief processes. The purpose is to spark a debate in creditor capitals and hopefully to buttress the government’s analytical foundation. With a strong dedicated team of experts—and support from relevant donor agencies— the Zimbabwean government will one day conclusively address its crushing debt burden and proceed with the rebuilding of a once vibrant and proud nation.zimbabwe; reconstruction; external debt; economic development; debt relief

Transgenerational Effects of Parental Drought Stress on Germination Time and Gene Expression in Arabidopsis Thaliana

Uniform germination among crops produces greater yields at harvest. Understanding the mechanisms underlying seed performance could provide strategies to maximize agricultural efficiency and mitigate the effects of adverse climatic conditions. Seeds produced by Arabidopsis thaliana plants that have undergone drought stress have been previously shown to exhibit delayed germination. It has been posited that epigenetic inhibition of growth-promoting genes during gametophyte development could be the cause of this phenomenon. Such inhibition is likely mediated by methylation, a common epigenetic modification. In prior studies, seeds produced by drought-stressed plants have been shown to contain increased genome-wide methylation levels. This study aimed to determine if germination delay is associated with hypermethylation of genes expressed in seeds, and if either the male or female parent plant is disproportionately associated with these transgenerational effects. Reciprocal crosses were performed between drought stressed and control plants and within each treatment groups to create seeds with varying levels of parental stress. Germination delay was found in offspring of drought-stressed plants compared to control. Interestingly, germination occurred more quickly in offspring of a drought-stressed male parent with a control female parent compared to offspring of two control parents. Expression of Tryptophan Aminotransferase 1 (TAA1) was found to be lower in the offspring of drought-stressed plants, suggesting that TAA1 could be a possible target of epigenetic modification. There was no statistical difference in Early Responsive to Dehydration 10 (ERD10) expression between treatment and control offspring. Bisulfite converted DNA was produced for TAA1 and ERD10 for future studies into specific methylation sites in these gene

The Facilitation of Sound Waves Using Mathematical and Scientific Methods of Digital Signal Processing

Mathematics and music have been lifelong partners since the beginning of time. Rhythm and time are two fundamental aspects of music which rely solely on counting, an under-appreciated skill in mathematics, yet recognized by all mathematically-minded people as the foundation of some of the most important mathematical findings; as John B. Fraleigh would say, “Never underestimate a theorem that counts something!” However, music recordings have evolved through the use of technology further than merely possessing the capabilities to quantify and archive the notes that were played in the recording. In the days before digital recordings, the only way to ensure better sound quality was by modifications to the recording equipment and acoustical adjustments to the setting of the recording. It is an indisputable fact that the overwhelming majority of recordings in our modern day are produced using digital technology. The discovery that sound is quantified by a sum of the disturbances the source of the perturbations created by changes in air pressure, known as sound waves, preceded the use of digital technology, but it was this amazing observation that first shaped how mathematicians and scientists utilized mathematical methods in audio engineering. This group of mathematicians and scientists, known as acousticians, aspire to utilize digital signal processing techniques to reproduce the sound created by a source and enhance the sound quality of the recording. There are many ways this can be accomplished. However, one of the most important methods available to acousticians is filtering. Filtering is the process of accentuating or attenuating certain frequencies in the content of the signal. The focus of this paper is digital filtration techniques and the fundamental workings of the mathematical methods that allow these techniques to be possible, as well as the various kinds of software that utilize these techniques. In addition to detailed explanations of the processes by which these methods were born, there is also a case study comparing the effect of a piece of hardware used for filtration with the effect of a digital filter modeled to exhibit the same behavior and functionality as the analog filter. This intensive and comprehensive study of digital signal processing and the mathematical methods acousticians used to create this field of science has been something I have been interested in for many years since first learning of my passion for mathematics. I am excited to share my research and data with the science and math community

The Facilitation of Sound Waves Using Mathematical and Scientific Methods of Digital Signal Processing

Mathematics and music have been lifelong partners since the beginning of time. Rhythm and time are two fundamental aspects of music which rely solely on counting, an under-appreciated skill in mathematics, yet recognized by all mathematically-minded people as the foundation of some of the most important mathematical findings; as John B. Fraleigh would say, “Never underestimate a theorem that counts something!” However, music recordings have evolved through the use of technology further than merely possessing the capabilities to quantify and archive the notes that were played in the recording. In the days before digital recordings, the only way to ensure better sound quality was by modifications to the recording equipment and acoustical adjustments to the setting of the recording. It is an indisputable fact that the overwhelming majority of recordings in our modern day are produced using digital technology. The discovery that sound is quantified by a sum of the disturbances the source of the perturbations created by changes in air pressure, known as sound waves, preceded the use of digital technology, but it was this amazing observation that first shaped how mathematicians and scientists utilized mathematical methods in audio engineering. This group of mathematicians and scientists, known as acousticians, aspire to utilize digital signal processing techniques to reproduce the sound created by a source and enhance the sound quality of the recording. There are many ways this can be accomplished. However, one of the most important methods available to acousticians is filtering. Filtering is the process of accentuating or attenuating certain frequencies in the content of the signal. The focus of this paper is digital filtration techniques and the fundamental workings of the mathematical methods that allow these techniques to be possible, as well as the various kinds of software that utilize these techniques. In addition to detailed explanations of the processes by which these methods were born, there is also a case study comparing the effect of a piece of hardware used for filtration with the effect of a digital filter modeled to exhibit the same behavior and functionality as the analog filter. This intensive and comprehensive study of digital signal processing and the mathematical methods acousticians used to create this field of science has been something I have been interested in for many years since first learning of my passion for mathematics. I am excited to share my research and data with the science and math community

Supercongruences and Complex Multiplication

We study congruences involving truncated hypergeometric series of the form_rF_{r-1}(1/2,...,1/2;1,...,1;\lambda)_{(mp^s-1)/2} = \sum_{k=0}^{(mp^s-1)/2} ((1/2)_k/k!)^r \lambda^k where p is a prime and m, s, r are positive integers. These truncated hypergeometric series are related to the arithmetic of a family of algebraic varieties and exhibit Atkin and Swinnerton-Dyer type congruences. In particular, when r=3, they are related to K3 surfaces. For special values of \lambda, with s=1 and r=3, our congruences are stronger than what can be predicted by the theory of formal groups because of the presence of elliptic curves with complex multiplications. They generalize a conjecture made by Rodriguez-Villegas for the \lambda=1 case and confirm some other supercongruence conjectures at special values of \lambda.Comment: 19 page

The Moderated Relationship of Appearance Valence on Appearance Self Consciousness: Development and Testing of New Measures of Appearance Schema Components

This paper describes the creation and psychometric properties of two independent measures of aspects of appearance schematicity - appearance salience and valence, assessed by the CARSAL and CARVAL, and their relation to appearance self-consciousness. Five hundred and ninety two participants provided data in a web based task. The results demonstrate the sound psychometric properties of both scales. This was demonstrated by good item total characteristics, good internal reliability of each scale, and the independence of the two scales shown through principal components analysis. Furthermore, the scales show independent and moderated relationships with valid measures of appearance related psychosocial distress. Negatively valenced appearance information was associated with increased appearance self-consciousness. More crucially, the impact of negative valence on appearance self-consciousness was exacerbated by the moderating effect increased salience of appearance. © 2012 Moss, Rosser

Quantifying triplet formation in conjugated polymer/non-fullerene acceptor blends

Triplet formation is generally regarded as an energy loss process in organic photovoltaics. Understanding charge photogeneration and triplet formation mechanisms in non-fullerene acceptor blends is essential for deepening understanding of photophysics in these important organic photovoltaic materials. Here, we present a comprehensive spectroscopy and morphology study on non-fullerene acceptors ITIC, ITIC-Th, ITIC-2F and Y6, both pristine and blended with reference polymer PffBT4T-C9C13. Atomic force microscopy and grazing-incidence X-ray diffraction provided information regarding the morphology of the films while spectroelectrochemistry combined with microsecond transient absorption spectroscopy allowed triplets and charge carriers to be investigated in detail. Crucially, we used triplet sensitisation to determine molar extinction coefficients of the non-fullerene acceptor triplets (2.7–6.5 × 104 L mol−1 cm−1), allowing triplet populations to be quantified in the blends. Intriguingly, no consistent trends were found in the photophysics of the studied blend systems, with each presenting its own unique mechanism. PffBT4T-C9C13:Y6 showed no triplet formation, only charge carriers that decayed rapidly in a relatively crystalline environment, consistent with the observed highly segregated morphology. In contrast, all blends in the ITIC series produced evidence of considerable triplet formation in addition to charge carriers. PffBT4T-C9C13:ITIC-Th blend produced acceptor triplets irrespective of excitation wavelength, and these were formed via intersystem crossing and/or energy transfer. Conversely, both ITIC and ITIC-2F blends displayed triplet formation via non-geminate recombination of charge carriers, with both NFA and polymer triplets observed. However, PffBT4T-C9C13:ITIC-2F produced a substantially higher charge carrier population than the ITIC blend. Because its triplet formation mechanism relies on the presence of charge carriers, PffBT4T-C9C13:ITIC-2F, with the highest charge carrier population, also had the highest triplet population. These results exemplify the prevalence of triplet states across a range of NFA blend systems, despite the varying formation mechanisms. Furthermore, they showcase that triplet populations can reach very high levels, particularly in cases of concomitantly high charge populations. Since high charge carrier densities correlate with large short circuit currents, this has significant ramifications for organic photovoltaic performance

High-speed modulation of resonant CMOS photonic modulators in deep-submicron bulk-CMOS

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 71-72).Processor manufacturers have turned to parallelism to continue to improve processor performance, and the bandwidth demands of these systems have risen. Silicon photonics can lower the energy-per-bit of core-to-core and core-to-memory interconnects to help alleviate bandwidth bottlenecks. In this thesis, methods of controlling the amount of charge entering the PiN-diode structure of a photonic ring modulator are investigated to achieve high energy-efficiency in a constrained monolithic process. A digital modulator driver circuit is designed, simulated, fabricated and partially tested. This circuit uses a push-pull topology with pre emphasis to reduce the energy per bit and to prevent the ring's optical passband from shifting to the next optical channel. A flexible driver test circuit for in-situ device characterization has been developed with a device-to-circuit modeling framework. There are many tradeoffs that must be analyzed from the system, circuit, and device levels.by Benjamin Moss.S.M

Regulating and Supervising Systemic Risk in the European Union: Results of the Post-Crisis Structural Reforms

This thesis contributes new and unique perspectives on the post 2007-09 crisis reform agenda established in the European Union. The focus of the thesis will be specifically on reform of the regulatory and the supervisory framework aimed at mitigating the effects of systemic risk. The starting point will be a review of the literature on the concept of systemic risk which will demonstrate that its unpredictable nature requires a malleable regulatory response. In light of the suggested areas of concern by the pivotal ‘de Larosiere report’, analysis will be provided on the progress achieved so far. On the regulatory front, the systemic risk aspects of the various legislative measures introduced are assessed in terms of their relevance and potential effectiveness. The reformed supervisory framework under the new European System of Financial Supervision (ESFS) requires close scrutiny due to the transfer of power to centralised authorities. Although the reform should be considered a success in terms of reaching its objectives in a timely manner, some critiques and suggestions will be provided on how to carry the framework forward. The thesis will also argue that taking the framework to the next step may require testing the boundaries of European Treaties and its case law in relation to delegation of powers. The measured success of the new framework could however be jeopardised by the recent introduction of the first steps towards a banking union in the Eurozone. By creating a new supervisory dynamic within the EU, it will be argued that such a move raises the potential of creating a ‘two speed’ model of financial supervision in the EU. Additionally it risks polarising the supervisory debate between the European Central Bank and the Bank of England at the detriment of the EU