Dalmacio Velez Sarsfield, Argentina

Catholic University of Santiago del Estero

Dalmacio Velez Sarsfield, Argentina

The Catholic University of Santiago del Estero is an institution created by a group of lay Catholics in collaboration with the Congregation of the Brothers of Mercy, and was inaugurated on June 21, 1960, as the Instituto Universitario San José de Ciencias Políticas, Sociales y Económicas.Its main, Santiago del Estero campus was built in 1979, and the institution maintains campuses in San Salvador de Jujuy , Olivos , and Rafaela . The main campus is known for its arboretum, the Estación Experimental Fernández, which features over 15,000 trees . Wikipedia.

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Roser L.G.,University of Buenos Aires | Roser L.G.,National University of San Martín of Argentina | Ferreyra L.I.,University of Buenos Aires | Ewens M.,Catholic University of Santiago del Estero | And 2 more authors.
American Journal of Botany | Year: 2017

PREMISE OF THE STUDY: Gene flow through dispersal of seeds and pollen is a fundamental determinant of spatial genetic structure (SGS) in natural populations of trees at different spatial scales. Within continuous populations, restrictions to gene flow should be manifested in a process of local genetic differentiation, known as isolation by distance. The present work examines the SGS of a Prosopis alba population in a patchy region where urban, forest, and agricultural areas coexist. The analysis discussed here expands our knowledge about the processes affecting the distribution of the genetic variability in populations of disturbed landscapes. METHODS: Three sites with different landscape and demographic characteristics were analyzed. Seven highly variable microsatellite markers were used to survey the relevance of both isolation by distance and stochastic migration in the SGS of the population. KEY RESULTS: The analyses showed that (1) the genetic similarity declined with increasing geographic distance, (2) the population may be conceived as a single genetically continuous unit showing spatial differentiation as consequence of isolation by distance, rather than a structured population following the island model, and (3) there is evidence supporting a past immigration event into one of the study sites, which promoted a local pattern of genetic structure. CONCLUSIONS: These results indicate that in spite of the population fragmentation produced by land-use changes, P. alba maintains the genetic cohesion and a continuous genetic structure in the analyzed area. © 2017 Botanical Society of America.

Villavicencio G.,Catholic University of Santiago del Estero
Proceedings of the ACM SIGSOFT Symposium on the Foundations of Software Engineering | Year: 2014

Software maintenance exhibits many differences regarding how other engineering disciplines carry out maintenance on their artifacts. Such dissimilarity is caused due to the fact that it is easy to get a copy from the original artifact to be used in maintenance, and also because the flat dimension of the software text facilitates access to the components by simply using a text editor. Other engineering disciplines resort to different artifact 'versions' (obtained by dissassembling) where the introduction of modifications (previous comprehension) is easier. After which the artifact is reassembled. In software engineering this approach can be simulated by combining program transformation techniques, search-based software engineering technology and design attributes. © Copyright 2014 ACM.

Bessega C.,University of Buenos Aires | Pometti C.,University of Buenos Aires | Ewens M.,Catholic University of Santiago del Estero | Saidman B.O.,University of Buenos Aires | Vilardi J.C.,University of Buenos Aires
Genetica | Year: 2015

Signals of selection on quantitative traits can be detected by the comparison between the genetic differentiation of molecular (neutral) markers and quantitative traits, by multivariate extensions of the same model and by the observation of the additive covariance among relatives. We studied, by three different tests, signals of occurrence of selection in Prosopis alba populations over 15 quantitative traits: three economically important life history traits: height, basal diameter and biomass, 11 leaf morphology traits that may be related with heat-tolerance and physiological responses and spine length that is very important from silvicultural purposes. We analyzed 172 G1-generation trees growing in a common garden belonging to 32 open pollinated families from eight sampling sites in Argentina. The multivariate phenotypes differ significantly among origins, and the highest differentiation corresponded to foliar traits. Molecular genetic markers (SSR) exhibited significant differentiation and allowed us to provide convincing evidence that natural selection is responsible for the patterns of morphological differentiation. The heterogeneous selection over phenotypic traits observed suggested different optima in each population and has important implications for gene resource management. The results suggest that the adaptive significance of traits should be considered together with population provenance in breeding program as a crucial point prior to any selecting program, especially in Prosopis where the first steps are under development. © 2014, Springer International Publishing Switzerland.

Villavicencio G.,Catholic University of Santiago del Estero
ACM International Conference Proceeding Series | Year: 2011

One affective way to carry out a program comprehension process is by refactoring the source code. In this paper we explore this approach in the functional programming paradigm, on Haskell programs specifically. As result, we have identified many correlations between the traditional (procedural and object-oriented) program comprehension process and the so called understanding-oriented refactorings, in the functional programming context. Besides, we have identified a catalog of refactorings used to improve program efficiency which, applied in reverse order, are valuable for program understanding purposes. Coupled to these refactorings, there is a calculational process by (means of) which we obtain a full formal description of program functionality. All together, a bottom-up program comprehension strategy in the functional setting is described. © 2011 ACM.

Olivera G.C.,Instituto Nacional Of Parasitologia Dr Mario Fatala Chaben | Albareda M.C.,Instituto Nacional Of Parasitologia Dr Mario Fatala Chaben | Alvarez M.G.,Hospital Eva Peron | De Rissio A.M.,Instituto Nacional Of Parasitologia Dr Mario Fatala Chaben | And 8 more authors.
Microbes and Infection | Year: 2010

Trypanosoma cruzi-specific immune responses were evaluated in a total of 88 subjects living in areas endemic of Chagas disease of Argentina by IFN-γ ELISPOT assays and immunoblotting. Positive T. cruzi antigen-induced IFN-γ responses were detected in 42% of subjects evaluated (15/26 positive by conventional serology and 22/62 seronegative subjects). Using immunoblotting, T. cruzi-specific IgG reactivity was detected in all seropositive subjects and in 11% (7/61) of subjects negative by conventional serology. Measurements of T cell responses and antibodies by immunoblotting, in conjunction with conventional serology, might enhance the capability of detection of exposure to T. cruzi in endemic areas. © 2010 Elsevier Masson SAS. All rights reserved.

Ewens M.,Catholic University of Santiago del Estero | Gezan S.,University of Florida | Felker P.,Catholic University of Santiago del Estero
Forests | Year: 2012

Prosopis alba seedlings, that grew at the 45 dS m -1 salinity level in a previous study of growth and survival of Argentine and Peruvian Prosopis, were propagated by rooting cuttings and established in a seed orchard/long term evaluation trial on soils with low salinity (EC 5.1-7.5 dS m -1) but high pH (8.9 to 10.2). A pH gradient occurred in the field with values ranging from pH 9.4 in block 1 to pH 10.3 in block 5. After five years growth, almost all of the clones had a mean height greater than 4 m and one clone was more than 5 m. Ten of the 21 tested clones had significantly greater biomass growth than the three seed propagated check varieties. The broad-sense (i.e., clone mean) heritability was estimated to be 0.45 for biomass, 0.53 for diameter and 0.59 for height indicating that strong genetic gains should be possible by selecting and vegetatively propagating the best genotypes. In the block with the highest pH values, two clones that appear to be P. alba × P. ruscifolia hybrids (i.e., P. vinallilo) had the greatest biomass. Correlations between growth during the last two months in the high salinity hydroponic greenhouse selection system and growth in the field were significant (R 2 = 0.262) and positive, although the relationship was negative for putative P. vinallilo clones (R 2 = 0.938). The several fold increase in biomass of some of the clones over the three check varieties, suggests that the greenhouse screen was successful in identifying superior salt tolerant clones. Apparently whether the greenhouse seedlings had lesser (~1 cm) to greater (~3 cm) height growth was not as important as just having a healthy live apical meristem. The observed salt tolerance of the putative P. vinalillo clones may prove useful as rootstocks for recently described high pod producing P. alba clones. © 2012 by the authors.

Villavicencio G.,Catholic University of Santiago del Estero
Proceedings of the European Conference on Software Maintenance and Reengineering, CSMR | Year: 2012

This research line proposes the classification of refactoring techniques according to two opposite program properties: understanding and efficiency, being the former useful for maintenance while the latter for executing. Understanding-oriented refactoring and efficiency-oriented refactoring are considered the inverses of each other. Thus, through the application of the first sort of refactoring, understanding can be improved but efficiency can be affected. On the other hand, by applying the second sort of refactoring, efficiency can be improved but understanding can be damaged. So, the challenge to be faced here is to transform a software artifact through the application of a sequence of understanding-oriented refactoring, and to execute maintenance with the most appropriate version obtained. After that, we plan to restore its original efficiency by the application of the opposite sequence of refactorings, i.e. efficiency-oriented refactoring. In this way, a new maintenance scenario is outlined. Up to now, this ongoing research is being carried out in the functional setting. © 2012 IEEE.

Herrera S.I.,Catholic University of Santiago del Estero | Clusella M.M.,Catholic University of Santiago del Estero | Mitre M.G.,Catholic University of Santiago del Estero | Santillan M.A.,Catholic University of Santiago del Estero | Garcia C.M.,Catholic University of Santiago del Estero
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

This study proposes the design of a web interactive information system for promoting cultures. It is a result of a relevant research on Santiago del Estero's culture1 and human-computer interaction topics; which began about five years ago2. Culture is a hypercomplex phenomenon, that's why it is studied from two different and complementary approaches: Cultural Studies and Systemics. In regard with the methodology, retroprospectivation is used to design the e-culture system. This strategy involves a systemic modelling process evolving from an existed model (ancient Santiago's culture) to an existing model (current Santiago's culture), then to an operating model (interactive model for Santiago's culture) and finally to a meta model. Retroprospectivation allows changing the order of the described evolution. The operating model is useful for the e-culture system analysis and design. It is based both on an interaction model for knowledge management (guiding the analysis) and on the emotional system design (mainly guiding user interface design). The full validation of the operating model is still in process. Once sufficiently validated it-by adapting it to other cultures - the development of the meta model is expected. It would be a cross-culture web application model that contributes to promoting cultural identities for academic, sporting, trade and tourism purposes. © Springer-Verlag Berlin Heidelberg 2011.

Bessega C.,University of Buenos Aires | Pometti C.L.,University of Buenos Aires | Ewens M.,Catholic University of Santiago del Estero | Saidman B.O.,University of Buenos Aires | Vilardi J.C.,University of Buenos Aires
European Journal of Forest Research | Year: 2016

Spatial genetic structure (SGS) in plants is primarily determined by the interaction between pollen and seed dispersal, but it is strongly affected by both evolutionary and ecological processes. SGS studies in forest species also allow evaluating the consequences of human-mediated disturbance on pollen and seed movement and designing strategies of sustainable use of native forest resources. The present paper compares fine-scale SGS between two populations of Prosopis alba: Fernandez-Forres (FF) and Campo Duran (CD), based on the variation of 12 SSR markers. Populations show different history, management, and levels of disturbance. FF is highly disturbed and fragmented by agricultural activity and stock-breeding. Although no significant differences were observed in genetic variability parameters, highly significant genetic differentiation was detected with virtually no admixture between populations. SGS was positive and significant at short distances only in the non-disturbed population of CD. Accordingly, estimated neighborhood size and effective gene dispersal are higher in FF than in CD. This result might be explained by the higher incidence of livestock in seed dispersal and the patchy structure favoring longer pollen movement and artificial thinning and selection in FF. The results are relevant to conservation and breeding programs, suggesting that the distance between seed trees to be sampled should be larger than 22 m, the estimated distance of significant SGS in P. alba. © 2016 Springer-Verlag Berlin Heidelberg

Ewens M.,Catholic University of Santiago del Estero | Felker P.,Catholic University of Santiago del Estero
Forest Ecology and Management | Year: 2010

Semi-arid adapted nitrogen fixing trees of the genus Prosopis have been extensively used in Argentina for soil improvement, luxury quality lumber production and sweet (35% sucrose) pods for humans and livestock. Due to the great demand of Prosopis alba for lumber, erect, tall, high pod producing trees of this species have been greatly overharvested, leading to erosion of the gene pool. A previous progeny trial with 57 half sib families identified 12 trees with promise for rapid growth, high production of pods and sweet pods. This trial, on a site with a salinity of 8.6dSm-1EC and a pH of 7.7, examined clones of these 12 trees in a randomized complete block trial with 8 single tree replications for height, basal diameter, canopy height and diameter, production of pods, sensory characteristics of the pods, disease resistance and insect resistance. In the 5th year of production and 7th year from planting, three clones produced more than 50kg pods per tree versus 32kg for check. At this 10m×10m spacing, this yield of 5000kg/ha compares favorably to many other semi-arid crops, especially given the unfavorable salinity and pH. In contrast to genetic improvement in pod production, the clones had lower diameter, height and canopy growth than the check. The lower biomass production may be due to fibrous root system produced from cuttings, since some of the clones blew over in high winds but none of the checks produced from seed blew over. Companion seed orchards of salt tolerant clones may provide rootstock for these high pod production clones. Significant differences in insect and disease resistance of the clones were observed and full sib crosses were made to study the genetics of the resistance. All clones had good sensory properties for use in human food. This is the first replicated trial with multipurpose clones useful for lumber and human food. The annual diameter growth rates ranged from 2.8 to 4.1cmyear-1 which was estimated to produce an internal return of approximately 20% from lumber alone. © 2010 Elsevier B.V.

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