The University of Cundinamarca , is a public, departmental, coeducational university located primarily in the city of Fusagasugá in Cundinamarca, Colombia. The university has satellite campuses across the department in the cities of Chía, Chocontá, Facatativá, Girardot, Soacha, Ubaté and Zipaquirá. Wikipedia.
Hernandez-Fernandez J.,Jorge Tadeo Lozano University, Bogotá |
Ramirez L.,Jorge Tadeo Lozano University, Bogotá |
Ramirez N.,Jorge Tadeo Lozano University, Bogotá |
Fuentes L.S.,University of Cundinamarca |
Jimenez J.,University of Cundinamarca
World Journal of Microbiology and Biotechnology | Year: 2011
Twenty-eight soil samples were obtained from open fields and greenhouses used for tomato cultivation in various regions of Colombia. For functional characterization, 99 Bacillus thuringiensis (Bt) strains were isolated and characterized by abundance and morphology of microscopic crystals, SDS-PAGE of protein extracts and M-PCR analyses of genes of the cry1 family, as well as for their insecticidal activity against Tuta absoluta second instar larvae. Native Bt strains had amorphous (5%), bi-pyramidal (27%), square (8%), spherical (38%) and triangular (22%) crystal forms. Based on the presence of 1-4 different crystal forms, 18 different profiles were established. The SDS-PAGE analyses of protein extracts established ten different strain groups based on their protein band weight and potential biological activity. The M-PCR technique identified 35 native Bt strains based on the presence of the 6 genes cry1Aa, cry1Ab, cry1Ac, cry1B, cry1C and cry1D, whose frequency of occurrence was 76, 26, 21, 35, 32 and 8.8%, respectively. Thirteen different PCR profiles were found in native Bt strains. Several gene combinations tended to co-occur with elevated frequency, such as the pairs cry1Ac/cry1C, cry1Ab/cry1Ac and cry1Ab/cry1B, for which Pearson correlation coefficients were 0.69, 0.52 and 0.54, respectively. Native strains ZBUJTL39 and ZCUJTL11 had up to three times higher biological activity against T. absoluta second instar larvae than the reference strain Bt var. kurstaki HD1, with an LD50 of 2.4 μg/ml (P<0.05) for native Bt strain ZCUJTL11. This study suggests a high biodiversity of native Bt strains from tomato growing regions in Colombia, which has important implications for designing biological control strategies for T. absoluta. © 2010 Springer Science+Business Media B.V.
Acero A.,University of Cundinamarca |
Muir J.P.,Texas AgriLife Research Center |
Wolfe R.M.,Texas AgriLife Research Center
Journal of the Science of Food and Agriculture | Year: 2010
The role of condensed tannins (CT) in ruminant nutrition and health makes changes in leaf litter (LL) after abscission of interest. This study compared the effect of different drying methods of green leaves (GL) with that of natural drying of LL on CT, fibre, crude protein (CP) and phosphorus (P) concentrations in nine Texas browse species. Leaves harvested before autumn shedding were oven-dried (OD) or freeze-dried (FD). RESULTS: Where different (P < 0.05), extractable CT concentrations were higher while protein- and fibre-bound CT concentrations were lower in GL-FD than in LL. Drying method changed total CT concentration in three species. Where different, fibre fraction concentrations were greater in LL than in GL, regardless of drying method. In some species, CP and P concentrations were lower in LL than in GL, but in five species they did not change (P > 0.05) from GL to LL, with CP concentrations ranging from 63 to 151 g kg-1 in the latter. CONCLUSION: Browse LL had high nutritive value and CT concentrations, explaining why browsing ruminants utilise this feed resource. However, changes in nutrient and CT concentrations as leaves become litter in some species mean that information on one is not necessarily applicable to the other. © 2010 Society of Chemical Industry.
Guerrero E.R.,University of Cundinamarca |
Benavides G.M.,University of San Buenaventura
2014 IEEE Colombian Conference on Communications and Computing, COLCOM 2014 - Conference Proceedings | Year: 2014
Farming of Hass-variety-avocado has become an important economic activity in Colombian agriculture for covering local market requirements but also for exporting high quality fruits to foreign markets. Many processes still need to be improved in different regions of Colombia where Hass variety is cultivated in order to increase the efficiency during harvesting, transportation and storage. Human-performed classification of avocados takes time that could be used by farm's personnel to perform other activities aimed to achieve higher quality standards and production efficiency. Product price and target market depends to a large extent on classification stage. We propose a system based on image processing of avocados' pictures for their classification after they have been picked off the tree. The classifying algorithm runs on a computer which receives fruit's images wirelessly from a camera, the result is transmitted using IEEE 802.15.4 packets and avocados are placed in conveyor belt rails according to their categories. Matching percentage of the image processing algorithm for selecting avocados was of 88% compared to the test set classified by expert farmers. Confusion matrix showed 82.22% accuracy when classifying avocados. © 2014 IEEE.
Li G.,Chinese Academy of Agricultural Sciences |
Li G.,Henan Academy of Agricultural science |
Feng H.,Henan Academy of Agricultural science |
Gao Y.,Chinese Academy of Agricultural Sciences |
And 2 more authors.
Environmental Entomology | Year: 2010
Helicoverpa armigera Hbner (Lepidoptera: Noctuidae) is a key insect pest of cotton in Xinjiang cotton-planting region of northwest China. In this region, cotton is grown on average ∼1.65 million ha (1.53∼1.80 million ha) annually in largely monoculture agricultural landscapes, similarly to cropping systems in the United States or Australia. Under such cropping regimes, naturally occurring refuges (with non-Bt crops) may be insufficient to prevent H. armigera resistance development to Bt toxins. Therefore, we assessed frequency of alleles conferring resistance to Cry1Ac toxin of F1 and F2 offspring of H. armigera isofemale lines from two distinct localities in the region during 2005-2009. More specifically, a total of 224 isofemale lines was collected from Korla County (≈70% Bt cotton adoption) and 402 lines from Shache County (≈5% Bt cotton planting). Subsequent offspring was screened on Cry1Ac artificial diet. From 2005 to 2009, resistance gene frequency in Korla fluctuated between 0.0000 and 0.0040, while being 0.0000-0.0008 in individuals collected from Shache, and there were no significant increases in both counties from 2005 to 2009. Relative average development rates (RADRs) of larvae in F1 tests showed significant increases from Korla, but not in Shache. RADR of F1 larvae is significantly correlated with RADR of F2 offspring, indicating genetic variation in response to toxin in field H. armigera population. Although the occurrence of Cry1Ac resistance alleles was low in Xinjiang cotton-planting region of China, particular attention should be given to H. armigera resistance development in Korla County. © 2010 Entomological Society of America.
Orjuela-Matta H.M.,University of Cundinamarca |
Sanabria Y.R.,National University of Colombia |
Camacho-Tamayo J.H.,National University of Colombia
Chilean Journal of Agricultural Research | Year: 2012
Studies that involve soil attributes variability help the analysis of the behavior of hydrophysical attributes in space, to support the decision-making process within the conception of precision agriculture. The aim of the present paper was to characterize the spatial variability of the surface infiltration and its relation to some soil physical attributes. The sampling was done with a rectangular mesh of 64 points with perpendicular distances of 52 m × 45 m between sampling points. The attributes studied were bulk density, contents of sand, silt and clay, soil moisture, cumulative infiltration, basic infiltration, sorptivity, and saturated hydraulic conductivity (Ks). Data were analyzed using descriptive statistics and geostatistics, identifying the relationship between attributes, using the Pearson correlation and cluster analysis. Results suggest a behavior of parameters close to normal, attributes related to soil water movement had greater variability, with low basic infiltration (1.46 cm h-1) and Ks (0.80 cm h-1), which together with high values of bulk density (1.87 g cm-3) show limitations by compaction. Cumulative infiltration and Ks attributes did not fit to models of spatial distribution, finding ranges of 150 m for the other attributes, distance to optimize future sampling for the study of spatial variability. Pearson correlation and cluster analysis allowed establishing relationships between soil attributes; spatial relationships were corroborated in contour maps, where we observed the influence of clay and sand content in the behavior of bulk density, and the influence of these attributes in processes of water infiltration into the soil.
Celis-F A.,University of Cundinamarca |
Mendoza-F C.,University of Cundinamarca |
Pachon-S M.E.,University of Cundinamarca
Acta Horticulturae | Year: 2012
Piperaceae family plants have secondary metabolites with potential use in medicine for preventing and curing diseases and in agriculture to control plant disease problems. Due to the expansion of agricultural borders and development of roads and infrastructure, these species tend to disappear. This study was conducted at the farm "La Esperanza" at the University of Cundinamarca (Colombia), whose goal was study the propagation and subsequent maintenance in a garden in in vivo and ex situ Piperaceae species collected in the Sumapaz province. Among the results is emphasized that these wild plants can be propagated using basal stem cuttings softwood and semi-hardwood with a sand substrate in greater higher fraction. The plant material propagated needs a hardening-off phase to allow plant acclimation before being transplanted to final place. In the garden fourteen species were included of the genus Piper: P. aduncum, P. arboreum, P. artanthe, P. bogotense, P. cumanense, P. dilatatum, P. el-bancoanum, P. eriopodon, P. eriocladum, P. holtonii, P. marginatum, P. peltatum, P. septulinervium and P. subtomentosum. And six species of the genus Peperomia: P. griseoargentea, P. leucostachia, P. tetraphylla, P. peltoidea, P. obtusifolia, P. sp Accession CMF 043. The garden is fundamental to conserve genetic diversity of the family, for mass propagation of these species and search for new secondary metabolites.
Rios Rivera M.J.,University of Cundinamarca |
Mujica L.R.,University of Cundinamarca
2015 IEEE Colombian Conference on Communications and Computing, COLCOM 2015 - Conference Proceedings | Year: 2015
There are special challenges about the construction of rural communications network, mainly by the cost of establishing them. This is due to the conditions of rural population, which is generally low paying capacities, and present a high dispersion, due to the low population density, hence it requires special considerations about coverage, particularly by the cost to establish a communication network. An important parameter cost rural networks is to build towers that support the antennas at a height that allows to set a link, this cost is highest than the costs attributed to communications equipment, therefore you have special attention. In this paper are explained the conditions about the height of the communications antennas towers and feasibility to the use of tubular steel masts and guyed towers to define the problem about the minimum cost towers. Panigrahi-Duttat-Naiswal-Naidu-Rastogi cost optimization algorithm which aims to solve the problem of network topology in rural areas, establishing the best communication tower height that allows to have an optimal cost-benefit ratio. Then numerical simulation of the proposed algorithm have been made an algorithm simple heuristics, in order to compare it with a simple heuristics algorithm and to do evident a better performance to reducing costs matters. © 2015 IEEE.
Escobar N.,University of Cundinamarca |
Espejo J.,University of Cundinamarca |
Rodriguez L.,University of Cundinamarca
WIT Transactions on Ecology and the Environment | Year: 2014
Current production of seasonal crops needs to have more efficient integrated handling to obtain expected returns, contribute to sustainability and the environment, as an alternative incorporating in bio-agricultural inputs. The aim of this research was to evaluate the effect of diatomaceous earth (TDDA) as bioinput, fertilization and biological control in commercial crops: corn (Zea mays), bean (Phaseolus vulgaris L.), carrot (Daucus carota L.) and yellow potato (Solanum phureja). We compared the following treatments: TDDA + commercial compost, TDDA + chemical fertilizer, TDDA + compost and control (traditional chemical). The fieldwork was conducted in private property located in Guchipas, a municipality of Pasca, (Cundinamarca department). We performed a Latin square design for each crop. Chemical analyses were made at the private Calderon's soil laboratory. For data processing we used MEANS in SAS statistical package (version 9.0). When a significant effect (α=0.05) was shown by the Tukey means test, significant differences between crops for physiological variables (leaf area index, relative growth rate, dry weight, fresh weight and height) were found (P<0.05). The best results for phenological variables and productivity were obtained for TDDA + chemical fertilizer, and TDDA + compost treatments. Pests as whitefly (T. vaporariorum) and thrips (Thrips tabaci) were controlled. Diatomaceous earth application allows the dose of chemical fertilizers, thereby promoting healthier environmental management. © 2014 WIT Press.
PubMed | Instituto Nacional Of Salud, University of Cundinamarca, Industrial University of Santander, University of Los Andes, Colombia and El Rosario University
Type: Journal Article | Journal: Archives of environmental & occupational health | Year: 2016
This study describes the use of pesticides mixtures and their potential association with comet assay results in 223 rice field workers in Colombia. Thirty-one pesticides were quantified in blood, serum, and urine (15 organochlorines, 10 organophosphorus, 5 carbamates, and ethylenethiourea), and the comet assay was performed. Twenty-four (77.42%) pesticides were present in the workers. The use of the maximum-likelihood factor analysis identified 8 different mixtures. Afterwards, robust regressions were used to explore associations between the factors identified and the comet assay. Two groups of mixtures---benzene hexachloride (-BHC), hexachlorobenzene (HCB), and -BHC (: 1.21, 95% confidence interval [CI]: 0.33-2.10) and pirimiphos-methyl, malathion, bromophos-methyl, and bromophos-ethyl (: 11.97, 95% CI: 2.34-21.60)--were associated with a higher percentage of DNA damage and comet tail length, respectively. The findings suggest that exposure to pesticides varies greatly among rice field workers.
PubMed | Utopia.de and University of Cundinamarca
Type: Journal Article | Journal: Neotropical entomology | Year: 2016
Melipona eburnea Friese is a stingless bee kept in some regions of Colombia, where it is reported to be vulnerable to extinction due to habitat disturbance. To contribute to raising conservation strategies, the aim of this study was to identify the floral preferences of this species using melissopalynological analysis. A total of 31 pollen pot samples and 37 honey samples were taken from March 2009 through March 2010 from four colonies in Fusagasuga, Colombia. We found 92 pollen types: 17 from pollen pot samples, 39 from honey samples (indicating the sources of nectar), and 36 in both types of samples. The most frequent pollen types in the pollen pot samples were Myrcia type (100%), Eucalyptus globulus (96.9%), and Fraxinus uhdei (96.9%). The most frequent pollen types in honey samples were E. globulus (97.4%) and Myrcia type (94.9%). The pollen types corresponded mainly to native plants (68%), trees (44.5%), plants whose sexual system is hermaphroditic (56.5%), and plants with inflorescences (76.2%). The most frequent shapes of the flowers were brush-like (type Myrtaceae) and dish-like (type Asteraceae), and the preferred flower colors were white or cream (52.2%). In general, we found that M. eburnea showed a strong preference for trees of the family Myrtaceae to obtain nectar and pollen, including native and introduced species. Some other families are contributing significantly, such as Melastomataceae for pollen collection and Asteraceae for nectar. These results highlight the key plant species for the diet of M. eburnea.