An investigation of machine-learning algorithms for the estimation of galaxy redshift

The next wave of large radio telescopes is being commissioned, with plans to observe deeper, in wider areas than ever before. The Evolutionary Map of the Universe (EMU) project is expected to increase the number of known radio galaxies from ∼2.5 million to ∼70 million, allowing for statistical studies of unprecedented size in the radio regime. However, most of the studies planned by the EMU project require redshift estimates. While the redshift measurements required don’t need to be measured to excellent resolution and can be roughly binned, they do require a low level of outliers. Even with recent advancements in multi-object spectroscopy, spectroscopic redshifts will only be possible for a small fraction of sources. The majority of the newly discovered radio sources will have limited multi-wavelength photometry, whereas traditional photometric template fitting methods requires high-quality, complete multiwavelength photometry. Previous research has used machine learning (ML) to estimate redshift, but has primarily focused on trying to match the best results provided by photometric template fitting, using the best, and most complete data available. For the most part, the datasets used are not radio-selected – which typically fail using photometric template fitting methods – and are limited in redshift. While Machine Learning (ML) techniques have proved to be effective, most have not been conclusively tested on radio-selected datasets, at the higher redshift ranges expected from the EMU project. In this thesis, I examine the utility of the k-NearestNeighbours (kNN) and Random Forest (RF) regression and classification algorithms for estimating the redshift of a source from its features. The kNN tests include using five different distance metrics. I use a radio-selected dataset, built from the Australia Telescope Large Area Survey (ATLAS) 1.4 GHz radio survey which was completed in anticipation of the EMU project, and has been observed to around the depth of the EMU project. The 1.4 GHz flux –measured by ATLAS – was combined with Infrared (IR) fluxes from the Spitzer Wide-area Infrared Extragalactic Survey (SWIRE), optical magnitudes from the DES, and spectroscopic redshi. measurements from the OzDES. Based on the combined multi-wavelength catalogue, I create three datasets. Dataset A consists of all sources with a spectroscopic redshift, with the sources with missing observations included, and those missing values filled with the mean of that feature across the entire dataset. Dataset B is a subset of Dataset A, with those sources without complete multi-wavelength photometry removed. Dataset C is a subset of Dataset B, with the sources removed that have optical or IR photometry below the detection limits of all-sky surveys. To test the generalisation of the algorithms across the sky, I use three different training and test sets. Set 1 uses a training set randomly selected from the dataset. Set 2 uses a training set made up entirely of sources from the European Large Area ISO Survey-South 1 (ELAIS-S1) field, with the test set made up from the Extended Chandra Deep Field South (eCDFS) field. Set 3 uses a training sample made up entirely of sources from the eCDFS field, with the test set made up from the ELAIS-S1 field. This thesis shows that traditionally simple ML algorithms like kNN and RFs can provide acceptable redshift estimations on radio selected data, with the best results coming from redshift binned to a lower resolution. By extending the algorithms to suit the data, the kNN classification algorithm using the Largest Margin Nearest Neighbour (LMNN) learned distance metric provided a decrease in the number of outliers, reaching, an ƞ0:15 outlier rate of ∼5%, with accuracies of σ∆z/(1+zspec) ≈ 0.09. Once completed, the EMU project is expected to have optical and IR counterparts for ≈ 40% of the 70 million detected radio galaxies. By 2020, this is expected to increase to ≈ 70% of the galaxies detected by the EMU project. This thesis shows that the EMU project can be provided with reliable redshift for ≈ 95% of sources with optical and IR photometry – ∼ 27 million sources when the EMU project is completed, increasing to ∼ 47 million sources by 2020. This will enable many of the key science goals of the EMU project to be completed

Alcance de la integración relacional con los españoles en las redes personales de inmigrantes en parejas mixtas y endógamas

Resultados anteriores de dos proyectos de investigación[1] sobre inmigrantes y los diferentes procesos de integración que experimentan en función de que tengan pareja del mismo origen o pareja española muestran una mayor presencia de españoles en las redes personales de aquellas personas en uniones mixtas. Se podría deducir que, en este sentido, estas están mejor integradas con la población autóctona en términos relacionales. Sin embargo, para explorar la cuestión con mayor profundidad, es útil valorar hasta qué punto y de qué manera esta mayor representación de población de origen español en sus redes personales afecta también a los otros inmigrantes que las constituyen. ¿Es más probable que se establezcan vínculos entre españoles y no españoles en las redes de personas en uniones mixtas que en las de aquellas en uniones endógamas? ¿Se produce una especie de efecto contagio en las relaciones español-inmigrante en las redes de inmigrantes con pareja española? En este trabajo, se pretende analizar qué factores inciden en que la aparente mejor integración relacional de los inmigrantes en uniones mixtas se extienda a sus conocidos inmigrantes. Es decir, en qué medida se producen más interacciones entre personas de diferentes orígenes como consecuencia de esas uniones mixtas. Si esta hipótesis se verifica, entonces los encuestados en uniones mixtas estarían más relacionados con españoles que a su vez estarían más relacionados con otros inmigrantes, apuntando a que los efectos de la exogamia en la integración trascienden sus propios límites. Para estudiarlo, se realiza un meta-análisis de los resultados de cada uno de los modelos de grafos aleatorios exponenciales (ERGM) aplicado a cada una de las redes personales recogidas, de manera que se pueda cuestionar la generalidad de dichos resultados.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Ghana Irrigation Sector Mapping

The irrigation sector of Ghana was mapped with the purpose to inform private sector parties on the potential for developing small-scale irrigation. It is shown that offcial schemes only amount 17,000 ha, wheras the area under farmer-led irrigation development is estimated 189,000 ha. Large potentials remain untapped and another 700,000 households could benefit from support to invest in irrigation equipment. The reports shows key information in figures, maps and other visuals

The ecological boundaries of six Carolina bays: Community composition and ecotone distribution

Community and environmental gradients within the ecological boundaries of Carolina bay wetlands may provide important information on the interaction between Carolina bays and associated uplands, and may also provide guidance for improved management. We established twelve 30-m transects on the sloping rims of each of six Carolina bays in northeastern South Carolina to characterize the community gradient, as well as important environmental factors producing this gradient. Mid-points of the transects were placed on jurisdictional wetland boundaries. Hydrology, soil properties, and plant species composition were measured within these transects. On average, transects included an elevation change of 0.6 m that corresponded with gradients of hydrology, soil properties, and community characteristics. Decreasing surface soil moisture (i.e., fewer flood events) and decreasing soil nutrients were associated with a shift from shrub-bog vegetation with relatively low alpha diversity and prominence of evergreens to a relatively diverse and heterogeneous community characterized by grasses, herbs, low shrubs, and vines. Ecotones, identified by abrupt changes in community composition, were more frequently found outside jurisdictional wetland boundaries. Likewise, five near-endemic and endemic plant species were found outside the wetland boundaries. Our data reinforce the need for better understanding of how Carolina bays interact with adjacent landscape elements, and specifically how ecological boundaries are influenced by this interaction

Inmigración, uniones mixtas e integración sociocultural en Cataluña: hacia un análisis complejo multimétodo

Des de principis de la darrera dècada, coincidint amb la important arribada d’immigració estrangera a Espanya, les unions mixtes o binacionals han augmentat considerablement. Malgrat això, encara se sap ben poc sobre l’abast, les dinàmiques internes, els significats i les conseqüències d’aquesta realitat. En aquest article presentem els avenços de dos projectes de recerca en curs on s’està intentant clarificar la relació entre unions/llars mixtes i integració/cohesió social, a partir de l’estudi d’unions mixtes i no mixtes de set col·lectius immigrats residents a Catalunya, aplicant una aproximació multimètode (quantitativa i qualitativa), que inclou la explotació de fonts estadístiques administratives i l’anàlisi de 94 xarxes personals/socials. Les dades que presentem aquí corresponen a l’anàlisi d’una de les fonts estadístiques més significatives (ENI) i a l’anàlisi descriptiva d’alguns casos de xarxes personals. Tot apunta a una relació entre «mixicitat» i integració multidireccional o segmentada, més complexa del que tradicionalment s’ha teoritzat.Since the beginning of the last decade, coinciding with the arrival of a considerable number of foreign immigrants to Spain, the amount of mixed or bi-national unions has grown considerably. However, very little is still actually known about the scope, internal dynamics, meanings and social consequences of this situation. In this paper we present the preliminary findings of two research projects in progress, in which the relationship between mixed unions and social integration/cohesion is being analyzed, from the study of seven immigrant origins forming mixed and non-mixed unions residing in Catalonia (Spain), and using a multi-method approach that includes the analysis of administrative data sources and 94 personal/social networks. The data presented here correspond to the analysis of one significant data source (ENI) and the descriptive analysis of some personal networks. Our results suggest a multi-directional or segmented relationship between mixedness and social integration, which is much more complex than it has traditionally been theorized.Desde principios de la última década, coincidiendo con la importante llegada de inmigración extranjera a España, las uniones mixtas o binacionales han aumentado considerablemente. Sin embargo, todavía se sabe muy poco sobre el alcance, las dinámicas internas, los significados y las consecuencias sociales de esta realidad. Presentamos aquí los avances de dos proyectos de investigación en curso donde se está intentando clarificar la relación entre uniones/hogares mixtos e integración/cohesión social, a partir del estudio de uniones mixtas y no mixtas de siete colectivos inmigrados residentes en Cataluña, aplicando una aproximación multimétodo que incluye la explotación de fuentes estadísticas administrativas y el análisis de 94 redes personales/sociales. Los datos que presentamos corresponden al análisis de una de las fuentes estadísticas más significativas (ENI) y al análisis descriptivo de algunos casos de redes personales. Todo apunta a una relación entre «mixicidad» e integración multidireccional o segmentada, más compleja de lo que tradicionalmente se ha teorizado

Immigració, unions mixtes i integració sociocultural : cap a una anàlisi complexa multimètode

Des de principis de la darrera dècada, coincidint amb la important arribada d'immigració estrangera a Espanya, les unions mixtes o binacionals han augmentat considerablement. Malgrat això, encara se sap ben poc sobre l'abast, les dinàmiques internes, els significats i les conseqüències d'aquesta realitat. En aquest article presentem els avenços de dos projectes de recerca en curs on s'està intentant clarificar la relació entre unions/llars mixtes i integració/cohesió social, a partir de l'estudi d'unions mixtes i no mixtes de set col·lectius immigrats residents a Catalunya, aplicant una aproximació multimètode (quantitativa i qualitativa), que inclou la explotació de fonts estadístiques administratives i l'anàlisi de 94 xarxes personals/socials. Les dades que presentem aquí corresponen a l'anàlisi d'una de les fonts estadístiques més significatives (ENI) i a l'anàlisi descriptiva d'alguns casos de xarxes personals. Tot apunta a una relació entre «mixicitat» i integració multidireccional o segmentada, més complexa del que tradicionalment s'ha teoritzat.Desde principios de la última década, coincidiendo con la importante llegada de inmigración extranjera a España, las uniones mixtas o binacionales han aumentado considerablemente. Sin embargo, todavía se sabe muy poco sobre el alcance, las dinámicas internas, los significados y las consecuencias sociales de esta realidad. Presentamos aquí los avances de dos proyectos de investigación en curso donde se está intentando clarificar la relación entre uniones/hogares mixtos e integración/cohesión social, a partir del estudio de uniones mixtas y no mixtas de siete colectivos inmigrados residentes en Cataluña, aplicando una aproximación multimétodo que incluye la explotación de fuentes estadísticas administrativas y el análisis de 94 redes personales/sociales. Los datos que presentamos corresponden al análisis de una de las fuentes estadísticas más significativas (ENI) y al análisis descriptivo de algunos casos de redes personales. Todo apunta a una relación entre «mixicidad» e integración multidireccional o segmentada, más compleja de lo que tradicionalmente se ha teorizado.Depuis le début de la dernière décennie, qui coïncide avec l'arrivée importante de l'immigration étrangère en Espagne, les mariages mixtes ou bi-nationaux ont considérablement augmenté. Cependant, on en sait encore très peu sur la dimension, la dynamique interne, les significations et les conséquences sociales de cette réalité. Nous présentons ici les résultats de deux projets de recherche en cours, où nous tentons de clarifier la relation entre unions mixtes et intégration/cohésion sociale à partir de l'étude de sept groupes d'immigrés en unions mixtes et non-mixtes résidant en Catalogne, ainsi qu'une approche multi-méthode qui comprend l'exploitation des sources de données statistiques et l'analyse de 94 réseaux personnels/sociaux. Les données présentées ici correspondent à l'analyse de l'une des sources statistiques les plus importantes (ENI) ainsi que de l'analyse descriptive de certains cas de réseaux personnels. Tout indique une relation entre mixité et intégration multidirectionnelle ou segmentée, plus complexe que ce qui a traditionnellement été théorisé.Since the beginning of the last decade, coinciding with the arrival of a considerable number of foreign immigrants to Spain, the amount of mixed or bi-national unions has grown considerably. However, very little is still actually known about the scope, internal dynamics, meanings and social consequences of this situation. In this paper we present the preliminary findings of two research projects in progress, in which the relationship between mixed unions and social integration/cohesion is being analyzed, from the study of seven immigrant origins forming mixed and non-mixed unions residing in Catalonia (Spain), and using a multi-method approach that includes the analysis of administrative data sources and 94 personal/social networks. The data presented here correspond to the analysis of one significant data source (ENI) and the descriptive analysis of some personal networks. Our results suggest a multi-directional or segmented relationship between mixedness and social integration, which is much more complex than it has traditionally been theorized

Evaluación de la integración relacional de los inmigrantes en uniones mixtas a partir del análisis de redes personales

Desde principios de la última década el número de matrimonios mixtos ha crecido considerablemente. En este artículo presentamos resultados que intentan clarificar la relación entre uniones mixtas e integración social, a partir del análisis de datos primarios de entrevistas en profundidad con delineación de redes personales. Los resultados sobre composición y estructura de las redes muestran una presencia más numerosa de españoles en las redes de uniones mixtas, en gran parte familiares agregados por la pareja, que se incorporan antes y tienen más vínculos con otros inmigrantes. Sin embargo, el papel de la pareja española no es más central que el de la inmigrada, ni la proximidad emocional a los autóctonos es mayor en el caso de las uniones mixtas. Los análisis de dos redes particulares sugieren procesos diversos y complejos en la configuración de los entramados de relaciones en el destino.Since the beginning of the last decade the number of mixed unions has increased considerably. This study presents some findings that aim to clarify the relationship between mixed unions and social integration. Primary data have been collected through in-depth interviews with information on personal networks. Results regarding network composition and structure suggest a higher presence of Spaniards in the networks of mixed unions, mainly relatives of the native partner, who enter sooner the networks and have more links to other immigrants. However, the role of the Spanish partner is not more central than that of the immigrant partner, nor the emotional proximity to native actors is higher in the case of mixed unions. The analysis of two particular networks suggests diverse and complex processes in the confi guration of the relationships knits at destination

Exploring Entrepreneurial Skills and Competencies in Farm Tourism

Diversification to farm tourism is increasingly seen as a viable development strategy to promote a more diverse and sustainable rural economy and to counter declining farm incomes. However, our understanding of the dynamics of the modern farm tourism business and the entrepreneurial and competitive skills farmers require in making the transition from agriculture to a diversified - and service based - enterprise remains limited. Hence, the aim of this paper is to explore the range of skills and competencies that farmers in the North West of England identify as important when adopting a diversification strategy to farm tourism. With the findings indicating that that whilst a range of managerial skills are valued by farmers, they lack many of the additional business and entrepreneurial competencies required for success. Moreover, this paper acknowledges the need to generate consensus on the requisite skill-set that farm tourism operators require, along with a need for a currently fragmented rural tourism literature to acknowledge the significance of rural entrepreneurship and the characteristics of successful farmers and farm tourism ventures

Macroinvertebrates associated with water hyacinth roots and a root analog

Abstract: The ecological effects of water hyacinth (Eichhornia crassipes), an introduced macrophyte, in freshwater systems depend on the growth and extent of floating mats. We studied macroinvertebrates associated with roots of water hyacinth in the Waccamaw River, a blackwater, tidal river in northeastern South Carolina, USA. In this system, water hyacinth is limited to a few protected bays and backwaters where the ecological effect is unknown. Our goal was to assess whether water hyacinth roots provided unique habitat. Plants representing ambient conditions, plants with defaunated roots, and a root analog (cotton mop strands = mop) were secured to floating frames in open water adjacent to water hyacinth mats. Samples were collected every 2 wk for 2 mo, and invertebrates were identified and quantified. Colonization of defaunated roots began within 2 wk, and invertebrate assemblages differed between roots and mops. The most common taxa on water hyacinth roots were Branchiopoda, Oligochaeta, Talitridae, and Chironomidae (Diptera), whereas Oligochaeta and Chironomidae were predominant on mops. Berosus sp.(Hydrophilidae) was the top-ranked taxon by proportional biomass on roots and mops. Total abundance and taxon richness of macroinvertebrates were greater on roots than on mops. Collector-gatherers were the most abundant functional feeding group (FFG) on mops, whereas distributions of abundance were relatively even among FFGs on ambient and defaunated roots. Predators dominated invertebrate biomass of all treatments, and shredder biomass was higher on roots than on mops. These data suggest that water hyacinth roots provide habitat for a diverse assemblage of macroinvertebrates, a function that should be weighed and assessed with other impacts before management actions are initiated

Factors Facilitating Acceptable Mammography Services for Women with Disabilities

Prior research has described general barriers to breast cancer screening for women with disabilities (WWD). We explored specific accommodations described as necessary by WWD who have accessed screening services, and the presence of such accommodations in community based screening programs