Estudio del estado del arte sobre la predicción de deserción universitaria usando machine learning

La deserción universitaria trae como principal consecuencia el aumento del número de estudiantes con educación superior incompleta. Por lo cual se ha implementado técnicas predictivas que han ayudado a detectar patrones que sirven para el estudio del tema. Existen varias técnicas utilizadas para el análisis predictivo como: La Regresión Logística, El Análisis Bayesiano, Árboles de Decisión, entre otras, que han logrado ser de suma importancia al momento de arrojar resultados favorables que ayuden a llevar un control estadístico sobre los casos de estudiantes desertores. Es importante señalar que el uso de técnicas predictivas como la minería de datos en donde se pueda visualizar las razones por las que los estudiantes desertan según los patrones expresados estadísticamente para que las autoridades institucionales puedan tomar decisiones basándose en esta información y disminuir la deserción de los estudiantes universitarios. Este artículo recopila información sobre los diferentes algoritmos de predicción utilizados en el tema de la deserción universitaria y analiza los datos sobre técnicas, algoritmos, datasets, usados para la predicción de la deserción universitaria, con el objetivo de encontrar la técnica de mejor rendimiento al momento de realizar el estudio mediante métricas de evaluación como son el Accuracy, Recall y F-Score.The main consequence of university desertion is the increase in the number of students with incomplete higher education. Therefore, predictive techniques have been implemented that have helped to detect patterns that are useful for the study of the subject. There are several techniques used for predictive analysis such as: Logistic Regression, Bayesian Analysis, Decision Trees, among others, which have become extremely important when it comes to yielding favorable results that help to keep statistical control over student cases. deserters. It is important to point out that the use of predictive techniques such as data mining where it can be visualized the reasons why students drop out according to patterns expressed statistically so that institutional authorities can make decisions based on this information and reduce the dropout rate of university students. This article collects information on the different prediction algorithms used in the subject of university dropout and analyzes the data on techniques, algorithms, datasets, used for the prediction of university dropout, with the aim of finding the technique with the best performance at the moment. to carry out the study on university desertion through evaluation metrics such as Accuracy, Recall and F-Score

Behaviour and social organization of the African Jacana Actophilornis africanus.

Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1997.The behaviour, nesting, food resources and mating system of the African Jacana Actophilornis africanus were studied at Muzi Swamp, northern KwaZulu-Natal and at Darvill Sewerage Works, KwaZulu-Natal. African Jacanas show highly polyandrous behaviour associated with a marked reversed sexual size dimorphism. A high clutch loss was recorded because of predation and weather conditions. Contact behaviour was recorded, which is unusual in Charadriiformes. Vocalization and visual displays were distinctive and closely related to territorial and sexual behaviour. Unlike the Wattled Jacana Jacana jacana, the African Jacana practises male guarding behaviour. Rich food concentration in the African Jacana habitat was shown by field tests and this may be a reason for this species evolving in a floating environment. The presence of simultaneous polyandry in the African Jacana was analyzed mathematically and by computer modelling in order to determine possible advantages of polyandry

The role of visual adaptation in cichlid fish speciation

D. Shane Wright (1) , Ole Seehausen (2), Ton G.G. Groothuis (1), Martine E. Maan (1) (1) University of Groningen; GELIFES; EGDB(2) Department of Fish Ecology & Evolution, EAWAG Centre for Ecology, Evolution and Biogeochemistry, Kastanienbaum AND Institute of Ecology and Evolution, Aquatic Ecology, University of Bern.In less than 15,000 years, Lake Victoria cichlid fishes have radiated into as many as 500 different species. Ecological and sexual sel ection are thought to contribute to this ongoing speciation process, but genetic differentiation remains low. However, recent work in visual pigment genes, opsins, has shown more diversity. Unlike neighboring Lakes Malawi and Tanganyika, Lake Victoria is highly turbid, resulting in a long wavelength shift in the light spectrum with increasing depth, providing an environmental gradient for exploring divergent coevolution in sensory systems and colour signals via sensory drive. Pundamilia pundamila and Pundamilia nyererei are two sympatric species found at rocky islands across southern portions of Lake Victoria, differing in male colouration and the depth they reside. Previous work has shown species differentiation in colour discrimination, corresponding to divergent female preferences for conspecific male colouration. A mechanistic link between colour vision and preference would provide a rapid route to reproductive isolation between divergently adapting populations. This link is tested by experimental manip ulation of colour vision - raising both species and their hybrids under light conditions mimicking shallow and deep habitats. We quantify the expression of retinal opsins and test behaviours important for speciation: mate choice, habitat preference, and fo raging performance

An investigation into the biosynthesis of proximicins

PhD ThesisThe proximicins are a family of three compounds – A-C – produced by two marine Actinomycete Verrucosispora strains – V. maris AB18-032 and V. sp. str. 37 - and are characterised by the presence of 2,4-disubstituted furan rings. Proximicins demonstrate cell-arresting and antimicrobial ability, making them interesting leads for clinical drug development. Proximicin research has been largely overshadowed by other Verrucosispora strain secondary metabolites (SM), and despite the publication of the V. maris AB18-032 draft, the enzymatic machinery responsible for their production has not been established. It has been noted in related research into a pyrrole-containing homolog – congocidine –due to the structural similarity exhibited, proximicins likely utilise a similar biosynthetic route. The initial aim of this research was to confirm the presumed pathway to proximicin biosynthesis. Following the sequencing, assembly and annotation of the second proximicin producer, Verrucosispora sp. str. MG37, and genome mining of V. maris AB18-032, no common clusters mimicked that of congocidine, casting doubt on the previously assumed analogous biosynthetic routes. A putative proximicin biosynthesis (ppb) cluster was identified, containing non-ribosomal peptide synthetase (NRPS) enzymes, exhibiting some homology with congocidine. NRPSsystems represent a network of interacting proteins, which act as a SM assembly line: crucially, adenylation (A)- domain enzymes act as the ‘gate-keeper’, determining which precursors are included into the elongating peptide. To elucidate the route to proximicins, activity characterisation of the four A-domains present in ppb cluster was attempted. The A-domain Ppb120 was shown to possess novel activity, demonstrating a high promiscuity towards heterocycle containing precursors, in addition to the absence of an apparent essential domain. This discovery refutes previous work outlining the core residues which dictate A-domain activity, while also presenting a facile route to novel heterocycle-containing compounds. Despite extensive work, A-domains ppb195 and ppb210, were ineffectively purified in the active form – informing future work into A-domains activity characterisation. Finally, the ppb220 A-domain which lies at the border of ppb, was inactive suggesting over-estimation of the cluster margins. To confirm ppb220 redundancy and confirm ppb boundaries, CRISPR/Cas gene editing studies were done. The gene responsible for the orange pigment of Verrucosispora strains was initially targeted and successfully deleted, and ppb studies commenced. The research here refutes the previously presumed route to proximicin biosynthesis; the ppb cluster instead comprises enzymes exhibiting unique activity and structure. The findings represent the foundations for allowing exploitation of chemistry exhibited within the proximicin family. The novelty exhibited can be utilised in the search for antimicrobial clinical leads, by allowing the production of compounds containing previously inaccessible heterocycle chemistry

From population to individual: colony dynamics and structure in time and space of a highly social seabird

Understanding why populations change in size and distribution can help us assess a species’ vulnerability to future environmental change (e.g. climate warming) and their conservation status. This thesis focuses on a population of sooty terns, a small seabird, that breed in huge numbers on Ascension Island in the South Atlantic. By combining long-term data on population size and breeding movements with genetic relatedness and chick survival, we explore the effects of environmental and social processes that may underlie population trends. We found evidence for a shift in population size between two breeding sites on the island. Despite high population genetic diversity and low levels of relatedness we found fine-scale genetic structure between neighbours. There was evidence that birds breeding earlier were genetically different to those breeding over one month later. Chick sociality was a key factor influencing daily survival together with the use of habitat cover, both of which are likely responses to predation risk. The shift in population size between breeding sites suggests instability in habitat quality, with potential declines in breeding success driving breeder movements. Overall our findings suggest differences in animal behaviour can have significant effects on population ecology, genetic structure, breeding timing and breeding outcomes

Abstracts of Papers, 77th Annual Meeting of the Virginia Academy of Science, May 26-28, 1999, Old Dominion University, Norfolk, Virginia

This document is a list of abstracts presented at the 77th annual meeting of the Virginia Academy of Science, between May 26 and May 28th, 1999, at Old Dominion University