Maximum likelihood geometry in the presence of data zeros

Given a statistical model, the maximum likelihood degree is the number of complex solutions to the likelihood equations for generic data. We consider discrete algebraic statistical models and study the solutions to the likelihood equations when the data contain zeros and are no longer generic. Focusing on sampling and model zeros, we show that, in these cases, the solutions to the likelihood equations are contained in a previously studied variety, the likelihood correspondence. The number of these solutions give a lower bound on the ML degree, and the problem of finding critical points to the likelihood function can be partitioned into smaller and computationally easier problems involving sampling and model zeros. We use this technique to compute a lower bound on the ML degree for $2 \times 2 \times 2 \times 2$ tensors of border rank $\leq 2$ and $3 \times n$ tables of rank $\leq 2$ for $n=11, 12, 13, 14$, the first four values of $n$ for which the ML degree was previously unknown

Farmers' Use of Improved Seed Selection Practices in Mexican Maize: Evidence and Issues from the Sierra de Santa Marta

The principal advantage of in situ conservation is that it allows adaptive evolutionary processes to continue in the species that are being conserved. For a cultivated crop species, in situ conservation involves farmers' management of their own genetic resources even as the farmers themselves adapt to a changing environment. Improved seed selection practices and other on-farm breeding strategies have been proposed as a means of providing economic incentives for farmers to continue growing traditional varieties or landraces identified as important for conservation. This paper describes a pilot study among a group of indigenous farmers in the Sierra de Santa Marta, Veracruz, Mexico, who have collaborated in such efforts. The findings raise key issues about the potential impact of such an approach, as well as some useful methodological points for applied economists. In the study area, there is a high frequency of experimentation, exchange, loss, and replacement of seed over time -- seed of the same varieties, including both modern and traditional varieties. This poses a challenge for economists' models of varietal choice, which tend to be based on static perceptions of a 'variety' as well as simplistic distinctions between 'modern' and 'traditional' varieties. Seed selection in the study area is not a single event but an iterative, continuous process. Women may be more involved in seed selection than previously thought, which may have implications for the welfare impact of new seed selection practices. Other implications of the study are that (1) the impact of introducing practices to enhance farmers' varieties is likely to be diffuse and difficult to observe, predict, or measure, and (2) in developing analytical models of farmer decision-making as it affects the diversity of genetic resources on the farm, the most appropriate unit of analysis for predicting the effects of some policy interventions is not likely to be the individual farmer or the individual farm household. A better understanding of the 'social infrastructure' shaping seed and information flows is needed, since in the diffusion of innovations of this type, the seed system is based entirely on farmers and their interactions.Crop Production/Industries,

Continuous Time Models of Interest Rate: Testing the Mexican Data (1998-2006)

Distinct parametric models in continuous time for the interest rates are tested by means of a comparative analysis of the implied parametric and nonparametric densities. In this research the statistic developed by Ait-Sahalia (1996a) has been applied to the Mexican CETES (28 days) interest rate in the period 1998-2006. With this technique, the discrete approximation to the continuous model is unnecessary even when the data are discrete. The results allow to affirm that the models of interest rate shown in this paper are unable to describe the data of the Mexican CETES.

Experiences from the academic training. Study about the identity of the novice teacher, second part.

We present some progresses of the current research project we are developing called "The professional identity of teacher studies”. It aims to analyse the training received by students in the faculties of education in the Autonomous Community of Andalusia, especially in the degrees of pre-school education and primary education. To that effect we enquiry about the influence of the experience as school student in their training and what kind of professional identity they are generating along the formation period and after five years of activity as teachers. We present some results from the second phase of the research project: The analysis of the teacher students experience accounts in the collegeUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Ethnography inquiry and teacher education. The use of diaries for the comprehension of educational practice

We present in this communication a work of inquiry carried our using the diaries of students participating an educational experience in a primary school. Along a semester, a group of 10 students was workomg with a community learning project. These students were engaged with a teacher training experience which is being developed in the Education College at the University of Málaga. In this experience some teacher students attended two subjects of his education as collaborators in this school. His experience was collected systematically in field diaries in which they reflected their everyday experience in the school, as well as his insights, assessments, feelings, etc. These diaries become into the working material to study the school functioning and their experience. For that reason, working meetings were held with teachers of their subjects at the university. Collaboratively, diaries were analyzed, categorized and interpreted in an attempt to understand the school practice, and thus, progress their training process.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The military coup in Chile in 1973, the immediate reaction of international organisations, and the founding of the first rehabilitation program for torture victims in 1977

This paper documents the historical steps of the immediate  reactions of the United Nations, Amnesty International, the World Council of Churches (WCC), the Inter-American Commission on Human Rights, and lawyers’ organisations in support of the victims of torture and others suffering gross violations of their human rights, as perpetrated by the Chilean military from 1973 to 1990. This article is also the history of the founding of the first rehabilitation programs for torture victims in Chile in 1977 and the other care programs for victims under local and international churches’ protection during the worst period of the militarydictatorship. The actions of denunciation and defense of the victims were possible through national and international networks sustained in collaborative work from inside and outside Chile, which lasted for 17 years. The results and lessons learned projected the creation of new commissions, funds, and international networks that continue today in the international arena. The rehabilitation programs under the dictatorship began as a  solidarity response to the needs of victims The rehabilitation programs, born during the dictatorship, projected their practice and experience to create a comprehensive health program as part of the State’s reparation measures. The testimonies of the victims made it possible to understand the consequences of human rightsviolations on individuals and society. State policies and civil society actions have sought to contribute to the reparation of victims through rehabilitation actions directly. This paper is part of the memory of that past by reconstructing the solidarity actions of denunciation and rehabilitation, and the details of which are often unknown

A phylogeny of Setaria (Poaceae, Panicoideae, Paniceae) and related genera based on the chloroplast gene ndhF

The genus Setaria is the largest genus in the so-called bristle clade, a monophyletic group of panicoid grasses distinguished by the presence of sterile branches, or bristles, in their inflorescences. The clade includes both foxtail millet and pearl millet, the latter an important cereal crop in dry parts of the world. Other members of the clade are weeds that are widespread agricultural pests. Previous molecular phylogenetic studies have suggested that Setaria might not be monophyletic but did not have a large enough sample of species to test this rigorously. In addition, taxonomic studies have suggested a close relationship between Setaria and Paspalidium, with some authors combining them into a single genus, but molecular studies included too few Paspalidium accessions for a meaningful conclusion. Accordingly, we have produced 77 new sequences of the chloroplast gene ndhF for 52 species not in previous analyses. These were added to available sequences for 35 species in 10 genera of the bristle clade and four outgroup taxa. We find that Setaria species fall into several moderately to strongly supported clades that correlate with geography but not with the existing subgeneric classification. Relationships among these clades and among other genera within the bristle clade are unclear. Constraint experiments using the approximately unbiased test reject the monophyly of Pennisetum, Setaria, and Setaria plus Paspalidium, as well as several other groupings, although the test may be overly sensitive and prone to Type I error. The more conservative Shimodaira-Hasegawa test fails to reject monophyly of any of the tested clades.Fil: Kellogg, Elizabeth Anne. University of Missouri; Estados UnidosFil: Aliscioni, Sandra Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica Agrícola; ArgentinaFil: Morrone, Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Pensiero, Jose Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Zuloaga, Fernando Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentin

Ethnography, visual narratives and learning ecologies. The 'Universidad Rural Paulo Freire' case.

In this paper, we present some of the results of the R&D Project called "Ecologies of learning in multiple contexts: analysis of expanded education projects and citizenship configurations" funded by Minister of Economy and Competitiveness (Spain). The interest of this project arises after considering that much of the individual and organizational learnings have been turning invisible in different educational spaces. Therefore, our purpose is to study the different socio-educational mechanisms that individuals and organizations put into play in different scenarios: schools, asociations, virtual academical contexts, etc. On this ocassion, we present some of the methodological issues and results of a specific case: "La Universidad Rural Paulo Freire de la Serranía de Ronda" (onwards URPF), a rural socio-educative organization. The ethnography is being developed in Benalauría (Ronda mountain range). This organization is focused in the recovery of traditional learnings that people used to have around the rural world. It is settled in a critical perspective that connects their educational actions under the approaches of sustainability, dignity, feminism, etc. The general objectives we consider for this project are the following: - To know life style of people in Benalauría context. - To understand the configuration of URPF group and its impact in the territory. - To promote learning communities of practice with other organizations. As specific objectives, we emphasize: - To review the conceptual frameworks those allow us to understand the practices of invisible learning in this experience. - To generate visual narratives those evidence the work and identity features of the URPF. - To analyse the life stories of the people who are part of this experience (as well as the collective story), for the understanding of socio-educational action in rural contexts through dialogue of knowledge, generation of democratic practices and collaborative participation. - To generate spaces for dialogue with other organizations, groups and people for the creation of networks and learning communities.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech