Santa Marta, Colombia
Santa Marta, Colombia

The University of Magdalena , is a public, departmental, coeducational, research university based in the city of Santa Marta, Magdalena, Colombia. Wikipedia.

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Arango-Argoty G.A.,University of Magdalena
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference | Year: 2011

Predict the function of unknown proteins is one of the principal goals in computational biology. The subcellular localization of a protein allows further understanding its structure and molecular function. Numerous prediction techniques have been developed, usually focusing on global information of the protein. But, predictions can be done through the identification of functional sub-sequence patterns known as motifs. For motifs discovery problem, many methods requires a predefined fixed window size in advance and aligned sequences. To confront these problems we proposed a method based on variable length motifs characterization and detection using the continuous wavelet transform (CWT) and a dissimilarity space representation. For analyzing the motifs results generated by our approach, we divide the entire dataset into training (60%) and validation (40%). A Support Vector Machine (SVM) classifier is used as predictor for validation set. The highest Sn = 82.58% and Sp = 92.86%, across 10-fold cross validation, is obtained for endosome proteins. Average results Sn = 74% and Sp = 75.58% are comparable to current state of the art. For data sets whose identity is low (< 40%), the motifs characterization and localization based on CWT shows a good performance and the interpretability of the subsequences in each subcellular localization.

Kotov A.A.,RAS Severtsov Institute of Ecology | Fuentes-Reines J.M.,University of Magdalena
Zootaxa | Year: 2014

A new species of Leydigia Kurz, 1875 (Cladocera: Chydoridae) is described based on the material from Ciénaga Grande de Santa Marta, Magdalena Department, Colombia. L. lourdesae sp. nov. is a member of the subgenus Leydigia (Neoley-digia) Kotov, 2009, having all diagnostic characters of the latter. It could be the closest relative to L. iberica Kotov & Alon-so, 2010, having five setae on exopodite III, a unique for the genus character. But new taxon differs from the latter in a series of characters of the head pores, armature of valve ventral margin, postabdomen, antenna I and II, and limbs I-III. We believe that the basal taxa of L. (Neoleydigia) (including L. lourdesae sp. nov.) are remains of an antique pan-conti-nental group, probably of Mesozoic age, partly survived after the mass extinction and represented now by a series of lo-cally distributed taxa in very distant localities of the planet. Copyright © 2014 Magnolia Press.

Fuentes-Reines J.M.,University of Magdalena | de Roa E.Z.,Central University of Colombia
Check List | Year: 2013

Nine species of cladocerans are newly recorded from the Ciénaga Grande de Santa Marta Magdalena Department and of these, five of them are new to Colombia (Dunhevedia crassa, Simocephalus vetuloides, Ilyocriptus paranaensis paranaensis, Nicsmirnovius fitzpatricki and Coronatella monacantha). The known number of Cladocera (45 species) in Ciénaga Grande de Santa Marta represents about the half of reported species in Colombia. Brief descriptions and illustrations of species, including distribution, are given. © 2013 Check List and Authors.

Alvarez A.E.,University of Magdalena | Ovalles E.,University of Magdalena | Caro S.,University of Los Andes, Colombia
Construction and Building Materials | Year: 2012

The material properties of hot mix asphalt (HMA) are modified by the amount and properties of the mineral filler (or filler) incorporated in the HMA. This paper focuses on the analysis of the filler effect on asphalt-aggregate interfaces of HMA based on thermodynamic properties (i.e., measurements of surface free energy, SFE, performed on asphalts, mastics (asphalt-filler combinations), and aggregates). Seven asphalts, three different mineral fillers added at different proportions, and six aggregates were assessed. The analysis was conducted in terms of energy parameters computed by using the SFE components of the materials evaluated. Corresponding results suggest that the inclusion of filler in the asphalt led to changes in the resistance to both fracture and moisture damage of the mastic-aggregate systems, and the wettability of the mastic over the aggregate as evaluated in terms of the energy parameters. Since these particular effects are not comprehensively captured based on conventional tests currently used for filler characterization - which mainly evaluate particle size, presence of harmful fines, and morphological properties, the HMA mix design can benefit from characterization of fillers and mastics in terms of the SFE and subsequent computation of the energy parameters included in this study. © 2011 Elsevier Ltd. All rights reserved.

Alvarez A.E.,University of Magdalena | Ovalles E.,University of Magdalena | Epps Martin A.,Texas A&M University
Construction and Building Materials | Year: 2012

The surface free energy (SFE) is a material property that can be used to identify optimum asphalt-aggregate combinations (i.e., interfaces) for improved design of hot mix asphalt (HMA) and to characterize the HMA performance through the use of micromechanical models. Based on SFE measurements, and subsequent calculation of energy indices, this paper compares asphalt-aggregate interfaces formed with asphalt rubber (AR) and polymer modified (PM) asphalt binders (or asphalts) specified for fabrication of permeable friction course (PFC) mixtures in Texas. Six PM asphalts and four AR asphalts with five different aggregates were assessed. Corresponding results suggest that, in terms of the energy indices computed, the fracture resistance, moisture damage susceptibility, and the wettability of the asphalt over the aggregate of AR asphalt-aggregate systems can be comparable to that developed by PM asphalt-aggregate systems. However, this conclusion is restricted by the variability encountered for both asphalt groups analyzed (i.e., AR and PM). Additional research is recommended to analyze the effect of lime in PM asphalts (since PFC mixtures fabricated with PM asphalts often include lime) and the effect of mineral fillers on both PM- and AR-aggregate systems. © 2012 Elsevier Ltd. All rights reserved.

Alvarez A.E.,University of Magdalena | Martin A.E.,Texas A&M University | Estakhri C.,Texas A&M University
Construction and Building Materials | Year: 2011

Permeable friction course (PFC) mixtures constitute one of the best options for surface paving, since they offer advantages (as compared to dense-graded hot mix asphalt) in terms of safety, economy, and environment. However, mix design and evaluation of PFC mixtures still require improvement and standardization to further promote the reliable use of these mixtures. This paper summarizes an extensive literature review focused on the basic aspects integrated in the mix design and evaluation of PFC mixtures. Although substantial advances related to these topics were reported since implementation of PFC mixtures in the 1990's, there is still a need for integration of several of these advances in an improved mix design procedure. The paper also identifies areas that require additional research, including the optimization of the balance between mixture functionality and durability and replacement of the indirect assessment of these important aspects. © 2010 Elsevier Ltd. All rights reserved.

Castro L.R.,University of Magdalena | Colgan D.J.,Research Branch
Molecular Phylogenetics and Evolution | Year: 2010

This is the first report of the mitochondrial gene order and almost-complete DNA sequence of a representative of the Neritimorpha, the highest-ranking gastropod clade lacking such data. Mitochondrial gene order in Nerita is largely plesiomorphic. Its only difference from the cephalopod Octopus vulgaris is a tRNA transposition shared by Vetigastropoda and Caenogastropoda. Genome arrangements were not informative enough to resolve the evolutionary relationships of Neritimorpha, Vetigastropoda and Caenogastropoda. The sister-group taxon of Neritimorpha varied in sequence-based analyses. Some suggested that Neritimorpha is the sister group of Caenogastropoda plus Heterobranchia and some that Neritimorpha and Caenogastropoda are sister groups. No analysis significantly supported the hypothesis that Vetigastroda is more closely related to Caenogastropoda than is Neritimorpha. © 2010 Elsevier Inc.

Berdugo G.O.,University of Magdalena | Barandica J.C.N.,University of Magdalena
Genetics and Molecular Biology | Year: 2014

Prochilodus magdalenae is an endemic freshwater fish that occurs in the Magdalena, Sinú and Atrato hydrographic basins. It has an important economic role and is a food resource for the artisanal fishing communities. Its socioeconomic importance contrasts with the current status of its fisheries, where stocks are being depleted. Considering its importance and lack of information on its genetic structure, we used seven microsatellite markers to assess the genetic structure of wild populations of P. magdalenae. The genetic diversity was assessed and the population genetic structure was estimated through Fst, analysis of molecular variance and Bayesian analysis. A total of 290 alleles were found in all loci throughout all population. The high polymorphism contrasts with the levels of observed heterozygosity (Ho = 0.276), which are the lowest values recorded for the family. We found three populations of bocachico coexisting throughout the studied system, contradicting the hypothesis that freshwater migratory fish form panmictic populations. These results on the genetic structure of P. magdalenae constitute tools for a better understanding of the behavior and biology of this species, contributing to fish management and conservation programs. © 2014, Sociedade Brasileira de Genética.

Barba-Ortega J.,National University of Colombia | Gonzalez J.D.,University of Magdalena | Sardella E.,São Paulo State University
Journal of Low Temperature Physics | Year: 2014

We study the influence of a pentagonal (hexagonal) trench or barrier on the superconducting properties of a perforated disk. Effects associated to the pinning (anti-pinning) force of the central hole and the trench (barrier) and the interplay between the boundary conditions and the shape of the inner defects on the vortex configuration are studied for a thin disk. Also, we considered two cases for the value of the order parameter at the surface. The first one is ψs ≠0; this is the usual supercondutor/vacuum interface, for which the deGennes parameter is b→∞. The second one is ψs =0, which is the surface of the sample in a complete normal state, simulated by b=0. The vorticity, Gibbs free energy, magnetic induction, supercurrent density, magnetization and Cooper pairs density as a function of the external magnetic field are calculated. We show that in our sample new phenomena are possible due to the competing interactions of the boundary and the geometry of the sample and the added geometry of the nanoengineered trench and barrier. © 2013 Springer Science+Business Media New York.

Fuentes-Reines J.M.,University of Magdalena | Suarez-Morales E.,Colegio de Mexico
Crustaceana | Year: 2014

The harpacticoid copepod fauna of the Laguna Navío Quebrado, La Guajira, a protected area of the northern Colombian coast, was studied from plankton samples obtained at littoral areas covered by vegetation (macrophytes and mangroves), and at limnetic habitats close to an oyster bank. A total of 14 species of harpacticoid copepods are reported from the surveyed area. Nine of these species are new to the Colombian copepod fauna: Schizopera knabeni Lang, 1965, Cletocamptus helobius Fleeger, 1980, Quinquelaophonte quinquespinosa (Sewell, 1924), Sarsamphiascus hirtus (Gurney, 1927), Parategastes herteli Jacobi, 1953, Enhydrosoma lacunae Jakubisiak, 1933, Metis holothuriae (Edwards, 1891), Robertsonia propinqua (T. Scott, 1894) and Nitokra taylori Gómez, Carrasco & Morales-Serna, 2012. The first two species have not been hitherto recorded from South America and the last one is reported for the Americas for the first time. Nine of these species are also new records for the Caribbean Sea. This is the first report on the marine benthic harpacticoid Copepoda from northern Colombia. A complete species list plus brief diagnostic descriptions of the new records for the Colombian harpacticoid copepod fauna are provided together with morphologic remarks, notes on the variability of some species and their distribution. © Koninklijke Brill NV, Leiden, 2014.

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