Llegó La Luz: a case study of the impacts of solar photovoltaic electricity in Las Balsas, Ecuador

textIn this thesis I study the impact of electrification using solar photovoltaic panels in the rural Ecuadorian community of Las Balsas. Many large-scale development organizations like the World Bank promote small-scale renewable energy technologies like solar photovoltaics as being crucial in helping poor rural communities generate more income. My research however, both in the field and in the literature, shows income generation from these projects tends to be minimal. I find that the introduction of solar electrification is most important for social applications like music, movies, cell phones, and lighting. FEDETA, the NGO that installed the solar photovoltaics, promotes the development project not as a neoliberal market-based income-generation project, but rather as a humanistic improvement in the “quality of life” of local residents. I analyze this goal of the project in light of the development theories developed over the past few decades. I question how well solar photovoltaics fits into the “small is beautiful” appropriate technology sector. While solar photovoltaic systems have the potential to build small-scale islands of autonomous electricity production in a more environmentally sustainable manner than grid electricity based on fossil fuels, I caution that this is not necessarily the most equitable way to provide electricity to the rural poor in developing countries. While solar home systems have much potential to provide (often minimal amounts of) electricity to extremely rural areas, the service provided is in many cases inferior to grid electricity. While solar photovoltaic technology does provide many potential benefits in areas not reached by grid electricity, NGOs and policy makers should be wary of seeing the technology as a panacea for sustainable development. Solar photovoltaics as a technology has a long way to go to provide energy services comparable to that offered by most grid systems. As with any technology its actual use is not predetermined, but rather is influenced by the local social and cultural contexts.Latin American Studie

Triply mixed coverings of arbitrary base curves: Quasimodularity, quantum curves and a mysterious topological recursions

Simple Hurwitz numbers enumerate branched morphisms between Riemann surfaces with fixed ramification data. In recent years, several variants of this notion for genus $0$ base curves have appeared in the literature. Among them are so-called monotone Hurwitz numbers, which are related to the HCIZ integral in random matrix theory and strictly monotone Hurwitz numbers which count certain Grothendieck dessins d'enfants. We generalise the notion of Hurwitz numbers to interpolations between simple, monotone and strictly monotone Hurwitz numbers to any genus and any number of arbitrary but fixed ramification profiles. This yields generalisations of several results known for Hurwitz numbers. When the target surface is of genus one, we show that the generating series of these interpolated Hurwitz numbers are quasimodular forms. In the case that all ramification is simple, we refine this result by writing this series as a sum of quasimodular forms corresonding to tropical covers weighted by Gromov-Witten invariants. Moreover, we derive a quantum curve for monotone and Grothendieck dessins d'enfants Hurwitz numbers for arbitrary genera and one arbitrary but fixed ramification profile. Thus, we obtain spectral curves via the semiclassical limit as input data for the CEO topological recursion. Astonishingly, we find that the CEO topological recursion for the genus $1$ spectral curve of the strictly monotone Hurwitz numbers compute the monotone Hurwitz numbers in genus $0$. Thus, we give a new proof that monotone Hurwitz numbers satisfy CEO topological recursion. This points to an unknown relation between those enumerants. Finally, specializing to target surface $\mathbb{P}^1$, we find recursions for monotone and Grothendieck dessins d'enfants double Hurwitz numbers, which enables the computation of the respective Hurwitz numbers for any genera with one arbitrary but fixed ramification profile.Comment: 41 page

The Effect of Gamma Irradiation on Growth of Seven Strains of Trypanosoma avium

The prime motivating factor in the present study was the desire to show significant differences in radio-sensitivities within six strains of Trypanosoma avium. A seventh strain was later added for the last two irradiation treatments. Gross morphology and differences in growth curves associated with varying temperatures suggested that the strains being cultured were not the same. With these differences in mind, the strains were subjected to different dosage levels of gamma irradiation

An Early T Cell Lineage Commitment Checkpoint Dependent on the Transcription Factor Bcl11b

The identities of the regulators that mediate commitment of hematopoietic precursors to the T lymphocyte lineage have been unknown. The last stage of T lineage commitment in vivo involves mechanisms to suppress natural killer cell potential, to suppress myeloid and dendritic cell potential, and to silence the stem cell or progenitor cell regulatory functions that initially provide T cell receptor–independent self-renewal capability. The zinc finger transcription factor Bcl11b is T cell–specific in expression among hematopoietic cell types and is first expressed in precursors immediately before T lineage commitment. We found that Bcl11b is necessary for T lineage commitment in mice and is specifically required both to repress natural killer cell–associated genes and to down-regulate a battery of stem cell or progenitor cell genes at the pivotal stage of commitment

Triply mixed coverings of arbitrary base curves : quasimodularity, quantum curves and a mysterious topological recursions

Simple Hurwitz numbers are classical invariants in enumerative geometry counting branched morphisms between Riemann surfaces with fixed ramification data. In recent years, several modifications of this notion for genus 0 base curves have appeared in the literature. Among them are so-called monotone Hurwitz numbers, which are related to the Harish–Chandra–Itzykson–Zuber integral in random matrix theory and strictly monotone Hurwitz numbers which enumerate certain Grothendieck dessins d’enfants. We generalise the notion of Hurwitz numbers to interpolations between simple, monotone and strictly monotone Hurwitz numbers for arbitrary genera and any number of arbitrary but fixed ramification profiles. This yields generalisations of several results known for Hurwitz numbers. When the target surface is of genus one, we show that the generating series of these interpolated Hurwitz numbers are quasimodular forms. In the case that all ramification is simple, we refine this result by writing this series as a sum of quasimodular forms corresponding to tropical covers weighted by Gromov–Witten invariants. Moreover, we derive a quantum curve for monotone and Grothendieck dessins d’enfants Hurwitz numbers for arbitrary genera and one arbitrary but fixed ramification profile. Thus, we obtain spectral curves via the semi-classical limit as input data for the Chekhov–Eynard–Orantin (CEO) topological recursion. Astonishingly, we find that the CEO topological recursion for the genus 1 spectral curve of the strictly monotone Hurwitz numbers computes the monotone Hurwitz numbers in genus 0. Thus, we give a new proof that monotone Hurwitz numbers satisfy CEO topological recursion. This points to an unknown relation between those enumerative invariants. Finally, specializing to target surface ℙ1, we find recursions for monotone and Grothendieck dessins d’enfants double Hurwitz numbers, which enables the computation of the respective Hurwitz numbers for any genera with one arbitrary but fixed ramification profile

a big data approach

Purpose: The purpose of this paper is to propose and demonstrate how Tourism2vec, an adaptation of a natural language processing technique Word2vec, can serve as a tool to investigate tourism spatio-temporal behavior and quantifying tourism dynamics. Design/methodology/approach: Tourism2vec, the proposed destination-tourist embedding model that learns from tourist spatio-temporal behavior is introduced, assessed and applied. Mobile positioning data from international tourists visiting Tuscany are used to construct travel itineraries, which are subsequently analyzed by applying the proposed algorithm. Locations and tourist types are then clustered according to travel patterns. Findings: Municipalities that are similar in terms of their scores of their neural embeddings tend to have a greater number of attractions than those geographically close. Moreover, clusters of municipalities obtained from the K-means algorithm do not entirely align with the provincial administrative segmentation.authorsversionpublishe

Inside the virtuous circle between productivity, profitability, investment and corporate growth: An anatomy of Chinese industrialization

This work explores the dynamics of the "virtuous circle" driving the impressive Chinese catching-up and growth by investigating the micro relationships linking productivity, profitability, investment and growth, based on China's manufacturing firm-level dataset over the period 1998-2007. Interestingly and somewhat puzzlingly, we find that productivity variations, rather than relative levels, are the prevalent productivity-related determinant of firm growth. Moreover, the direct relation between profitability and firm growth is much weaker and its contribution to the explanation of the different rates of firm growth is almost negligible. The only visible profitability-growth relationship is mediated via investment. Firm's contemporaneous and lagged profitabilities display positive and significant effect on the probability to report an investment spike, and, in turn, investment activities are related to higher firm growth

Patient innovation under rare diseases and chronic needs

info:eu-repo/semantics/publishedVersio

Color/magnitude calibration for National Aeronautics and Space Administration (NASA) standard Fixed-Head Star Trackers (FHST)

This paper characterizes and analyzes the spectral response of Ball Aerospace fixed-head star trackers, (FHST's) currently in use on some three-axis stabilized spacecraft. The FHST output is a function of the frequency and intensity of the incident light and the position of the star image in the field of view. The FHST's on board the Extreme Ultraviolet Explorer (EUVE) have had occasional problems identifying stars with a high B-V value. These problems are characterized by inaccurate intensity counts observed by the tracker. The inaccuracies are due to errors in the observed star magnitude values. These errors are unique to each individual FHST. For this reason, data were also collected and analyzed from the Upper Atmosphere Research Satellite (UARS). As a consequence of this work, the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) hopes to improve the attitude accuracy on these missions and to adopt better star selection procedures for catalogs