Investigating bias in Music Recommender Systems

Music Recommender Systems (MRS) are software applications that provide personalized music recommendations based on user preferences and listening history. They analyze data to suggest music that aligns with individual tastes, enhancing the music discovery experience. This thesis aims to investigate the influence of record labels across different music recommendation datasets and evaluate their impact on recommender systems. Additionally, it seeks to expand the scope and experimentation of prior research on bias within feedback loops of MRS. To study their effect, the datasets are preprocessed and fed into a multi-stage web crawler that retrieves record label information for individual albums as well as an assignment to a major record company (Universal, Sony, Warner) or independent. This crawler is used to enrich our dataset collection. Based on the additional information, we can show different characteristics and identify particular biases in their user-generated music collections of playlists and listening profiles. Moreover, recommender system experiments are conducted, presenting results of feedback loop simulations, where the stability of record label distribution in longitudinal recommendations are studied. All findings and gathered record label information are made publicly available to the research community.Els Sistemes de Recomanació Musical (MRS) són aplicacions de software que proporcionen recomanacions de música personalitzades basades en les preferències i el històric d'escolta de l'usuari. Analitzen dades per suggerir música que s'ajusti als gustos individuals, millorant així l'experiència de descobriment musical. Aquesta tesi té com a objectiu investigar la influència de les discogràfiques en diferents conjunts de dades de recomanació musical i avaluar el seu impacte en els sistemes de recomanació. A més, busca ampliar l'abast i l'experimentació de recerques prèvies sobre biaixos en els bucles de retroalimentació dels MRS. Per estudiar el seu efecte, els conjunts de dades es pre-processen i s'insereixen a un rastrejador web de diverses etapes que recopila informació sobre les discogràfiques dels àlbums individuals, així com la seva classificació en una discogràfica principal (Universal, Sony, Warner) o independent. Aquest rastrejador s'utilitza per enriquir la nostra col·lecció de dades. Basant-nos en la informació addicional, podem mostrar diferents característiques i identificar biaixos particulars en les col·leccions de música generades pels usuaris, com ara llistes de reproducció i perfils d'escolta. A més, es fan experiments en un entorn simulat de recomanacions, presentant els primers resultats de la simulació de bucles de retroalimentació on s'estudia l'estabilitat de la distribució de segells discogràfics en recomanacions longitudinals. Totes les troballes i la informació recopilada de segells discogràfics es posa a la disposició del públic per a la comunitat investigadora

Food Choice by a Free-ranging Antillean Manatee (Trichechus manatus manatus) in Tabasco, Mexico

Understanding foraging ecology is an important element of effective conservation strategies. While West Indian manatees (Trichechus manatus) have been documented to consume a wide variety of vascular plants and algae, little is known about the diet of the Endangered Antillean subspecies (T. m. manatus) at freshwater sites such as the wetlands of Tabasco, the largest manatee habitat in Mexico. Here we present the results of a study of wild manatee diet in a freshwater site in Mexico. Controlled food choice experiments were conducted on a wild adult manatee during the dry seasons of 2011 and 2012. Plant species tested were representative of the habitat and included 14 of the 15 most common species. A total of 54 plant species, representing 25 families and 43 genera, were systematically tested during seven days of experiments. The manatee selected 27 (from 11 families and 20 genera) of the 54 species. Ten of the 20 genera are new reports from the previously known freshwater genera consumed by West Indian manatees, an increase of 12.8%. Results from this study support the literature indicating that manatees are generalists (i.e. feed on a wide variety of plant species); however, this manatee was also very selective in the food items it consumed, both rejecting and selecting an equal amount of species. Both this large dietary breadth and selectivity must be taken into consideration when developing conservation strategies for wild manatees in freshwater habitats and protocols for captive rehabilitation of orphaned and stranded manatees that will be reintroduced into the wild in the region

Spin-orbit transitions in the N+^+(3PJA^3P_{J_A}) + H2_2 →\rightarrow NH+^+(X2ΠX^2\Pi, 4Σ−^4\Sigma^-)+ H(2S^2S) reaction, using adiabatic and mixed quantum-adiabatic statistical approaches

The cross section and rate constants for the title reaction are calculated for all the spin-orbit states of N$^+$($^3P_{J_A}$) using two statistical approaches, one purely adiabatic and the other one mixing quantum capture for the entrance channel and adiabatic treatment for the products channel. This is made by using a symmetry adapted basis set combining electronic (spin and orbital) and nuclear angular momenta in the reactants channel. To this aim, accurate {\it ab initio} calculations are performed separately for reactants and products. In the reactants channel, the three lowest electronic states (without spin-orbit couplings) have been diabatized, and the spin-orbit couplings have been introduced through a model localizing the spin-orbit interactions in the N$^+$ atom, which yields accurate results as compared to {\it ab initio} calculations including spin-orbit couplings. For the products, eleven purely adiabatic spin-orbit states have been determined with {\it ab initio} calculations. The reactive rate constants thus obtained are in very good agreement with the available experimental data for several ortho-H$_2$ fractions, assuming a thermal initial distribution of spin-orbit states. The rate constants for selected spin-orbit $J_A$ states are obtained, to provide a proper validation of the spin-orbit effects to obtain the experimental rate constants.Comment: 14 pages, 10 figures, submitted to J. Chem. Phy

Elaboracion de prototipo viable de una Organizacion Asociativa Turistica Privada para la Region del Maule

95 p.El presente es parte del Proyecto de Investigación y Desarrollo del Turismo Cidetur, Programa de vínculos académicos, Universidad de Talca, Universidad de Nottingham y Universidad de South Bank, patrocinado por el Reino Unido. Tiene como objetivo diseñar una propuesta viable de organización asociativa turística regional, para abordar de mejor manera los problemas y carencias actuales de esta industria en el Maule, considerando especialmente el potencial de la zona para el desarrollo de las nuevas tendencias en turismo, como son el turismo rural (Agroturismo, Ecoturismo, Turismo de aventura), histórico y cultural. La metodología se basa en método Delphi, es decir se usaran las opiniones de expertos en los temas que se quiere desarrollar. Con estas ideas se confeccionara un prototipo de Consorcio, que incluirá desde la estructura administrativa legal, hasta la definición de sus principales actividades. Luego de creado este prototipo, se presentara a los potenciales integrantes para que emitan su opinión basándose en los beneficios y desventajas que esta organización pudiere proveerles. Entonces se dará cabida a que hagan recomendaciones y comentarios, de acuerdo al grado de aporte del modelo para satisfacer sus necesidades e intereses. El resultado final revela que la figura legal que mas se adapta a sus fines es la de Corporación de Derecho Privado (sin fines de lucro). Esta compuesta por varias categorías de miembros, los socios activos seran los empresarios y sus agrupaciones (asociaciones gremiales), sobre los cuales recaerá la mayor responsabilidad. Entre ellos se elegirá el Directorio y tendrán derecho a voz y voto en las asambleas según la ley y los estatutos definidos. Los socios Cooperadores asistirán las actuaciones de la Corporación con asistencia técnica y apoyo de gestión. Finalmente las instituciones de gobierno participaran como miembros de apoyo y consulta, en las mismas condiciones que los miembros anteriores (se denominara Corporación Turística del Maule, CTM). La CTM desarrollara actividades de fomento y proyección de la industria turística regional, especialmente en área donde se han detectado debilidades, como son: Marketing regional, sistemas de calidad, sistemas de información, de capacitación, sustentabilidad ambiental y desarrollo de nuevos productos, entre otras

Daily very low UV dose exposure enhances adaptive immunity, compared with a single high‐dose exposure. Consequences for the control of a skin infection

Ultraviolet radiation (UVr) promotes several well‐known molecular changes, which may ultimately impact on health. Some of these effects are detrimental, like inflammation, carcinogenesis and immunosuppression. On the other hand, UVr also promotes vitamin D synthesis and other beneficial effects. We recently demonstrated that exposure to very low doses of UVr on four consecutive days [repetitive low UVd (rlUVd)] does not promote an inflammatory state, nor the recruitment of neutrophils or lymphocytes, as the exposure to a single high UV dose (shUVd) does. Moreover, rlUVd reinforce the epithelium by increasing antimicrobial peptides transcription and epidermal thickness. The aim of this study was to evaluate the adaptive immune response after shUVd and rlUVd, determining T‐cell and B‐cell responses. Finally, we challenged animals exposed to both irradiation procedures with Staphylococcus aureus to study the overall effects of both innate and adaptive immunity during a cutaneous infection. We observed, as expected, a marked suppression of T‐cell and B‐cell responses after exposure to an shUVd but a novel and significant increase in both specific responses after exposure to rlUVd. However, the control of the cutaneous S. aureus infection was defective in this last group, suggesting that responses against pathogens cannot be ruled out from isolated stimuli.Fil: Cela, Eliana Maiten. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Gonzalez, Cintia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; ArgentinaFil: Friedrich, Adrián David. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Inmunología; ArgentinaFil: Ledo, Camila. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Paz, Mariela Laura. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Leoni, Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Gomez, Marisa Ines. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Gonzalez Maglio, Daniel Horacio. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentin

Dutch social entrepreneurs in international development : Defying existing micro and macro characterizations

In this paper we aim to contribute to the literature on social entrepreneurship by nuancing both existing micro-level characterizations as well as its presumed macro level societal impacts. Moreover, we explore connections between the micro and macro levels of analysis to see which types of social entrepreneurs are more likely to achieve what kinds of societal impacts. We present findings from an illustrative sample of 28 interviews with Dutch social entrepreneurs working in International Development. At the micro level, our qualitative findings do not support a perception of social entrepreneurs – often found in the Anglo Saxon literature - as heroic ‘lone rangers’ who ‘go it alone’ and with ‘dogged determination’ fight for a self-defined social cause. Instead, most social entrepreneurs in our study are acutely aware of the need to cooperate with other stakeholders and often use existing ‘off the shelf’ social causes and theories of change, even when they do develop innovative ways to try and achieve these goals. At the macro level, two starkly contrasting views exist on the possible societal impacts of social entrepreneurs. The first is an, often implicit, extension of the ‘lone-ranger’ perception of social entrepreneurs as people who ‘change the world’ or at least significantly contribute to social and economic transformation. At the other end of the spectrum in the literature we find those who argue that social entrepreneurs are potentially counterproductive to international development interventions as their social mission is not the result of a ‘collective deliberative process’, their activities are likely to displace NGO and/or government interventions and might even give governments an excuse to not intervene and ignore deeper levels of political contestation and societal inequalities. The paper is structured as follows. We first explain the rise in social entrepreneurship in international development, and we introduce the central assumptions in the literature on how social entrepreneurs define their social mission and on their likely societal impact. Next we present our data to show that our interviews do not support existing assumptions about the characteristics of social entrepreneurs nor about their possible societal impacts. Finally, we explore the usefulness of the typology proposed by Zahra et al, and we conclude that this typology indeed helps to further systematize a more nuanced understanding of the characteristics and likely roles of social entrepreneurs

First Successful Capture and Satellite Tracking of a West Indian Manatee (Trichechus manatus) in Panama: Feasibility of Capture and Telemetry Techniques

It is currently unknown how important the Central American countries south of Belize are as a link between manatee populations in the north (Belize and Mexico) and populations in South America. Therefore, apart from knowing where manatees are found, it is important to understand how manatees are using these habitats and if they are moving between countries or distinct population centers. Here we report the results of a multi-national and multiinstitutional collaboration resulting in the first successful capture and satellite tracking of a West Indian manatee in southern Central America

Genetic variability and structure of an isolated population of Ambystoma altamirani, a mole salamander that lives in the mountains of one of the largest urban areas in the world

Amphibians are globally threatened by habitat loss and fragmentation; species within the order Ambystoma are not the exception, as there are 18 species of mole salamanders in México, of which 16 are endemic and all species are under some national or international status of protection. The mole salamander, Ambystoma altamirani is a microendemic species, which is distributed in central México, within the trans-Mexican volcanic belt, and is one of the most threatened species due to habitat destruction and the introduction of exotic species. Nine microsatellite markers were used to determine the genetic structure, genetic variability, effective population size, presence of bottlenecks and inbreeding coefficient of one population of A. altamirani to generate information which might help to protect and conserve this threatened species. We found two genetic subpopulations with significant level of genetic structure (FST = 0.005) and high levels of genetic variability (Ho = 0.883; He = 0.621); we also found a small population size (Ne = 8.8), the presence of historical (M = 0.486) and recent bottlenecks under IAM and TPM models, with a low, but significant coefficient of inbreeding (FIS = −0.451). This information will help us to raise conservation strategies of this microendemic mole salamander species

Influence of aquaculture waste on fatty acid profiles and gonad maturation of wild fish aggregations at fish farms

Wild fish belonging to four species belonging to different trophic groups were captured at three distances from fish farm facilities: long distance (>5 Km), medium distance (1.5 Km) and close to sea-cages. Flesh, brain, liver and gonads were sampled for fatty acid analysis. Fish aggregated near sea-cages showed accumulation of fatty acids of vegetable origin in the studied tissues, due to surplus feed consumption or via predation of fish that consumed the feed. Gonads accumulated vegetable fatty acids in different manner in the different species, and the species least and most influenced by fish-feeds were selected for gonad histological examination. Results showed an acceleration of the final stages of the oocyte development in fish aggregated near fish farms compared to fish captured at long distance. Differences in oocyte development were more acute in the species which incorporated higher quantities of vegetable fatty acids.This work was funded by the project FATFISH (ref: CTM 2009-14362-C02-02) and FPI predoctoral grant (ref: BES-2010-033391) from Ministerio de Economía y Competitividad (Government of Spain)

Precipitation of Phosphate Minerals by Microorganisms Isolated from a Fixed-Biofilm Reactor Used for the Treatment of Domestic Wastewater

The ability of bacteria isolated from a fixed-film bioreactor to precipitate phosphate crystals for the treatment of domestic wastewater in both artificial and natural media was studied. When this was demonstrated in artificial solid media for crystal formation, precipitation took place rapidly, and crystal formation began 3 days after inoculation. The percentage of phosphate-forming bacteria was slightly higher than 75%. Twelve major colonies with phosphate precipitation capacity were the dominant heterotrophic platable bacteria growing aerobically in artificial media. According to their taxonomic affiliations (based on partial sequencing of the 16S rRNA), the 12 strains belonged to the following genera of Gram-negative bacteria: Rhodobacter, Pseudoxanthobacter, Escherichia, Alcaligenes, Roseobacter, Ochrobactrum, Agromyce, Sphingomonas and Paracoccus. The phylogenetic tree shows that most of the identified populations were evolutionarily related to the Alphaproteobacteria (91.66% of sequences). The minerals formed were studied by X-ray diffraction, scanning electron microscopy (SEM), and energy dispersive X-ray microanalysis (EDX). All of these strains formed phosphate crystals and precipitated struvite (MgNH4PO4·6H2O), bobierrite [Mg3(PO4)2·8H2O] and baricite [(MgFe)3(PO4)2·8H2O]. The results obtained in this study show that struvite and spherulite crystals did not show any cell marks. Moreover, phosphate precipitation was observed in the bacterial mass but also near the colonies. Our results suggest that the microbial population contributed to phosphate precipitation by changing the media as a consequence of their metabolic activity. Moreover, the results of this research suggest that bacteria play an active role in the mineral precipitation of soluble phosphate from urban wastewater in submerged fixed-film bioreactors.This investigation was funded by the CTM 2009-11929-CO2-02 of the Spanish Ministerio de Educación y Ciencia