Showing papers by "University of Los Andes published in 2009"
TL;DR: In an effort to unify the nomenclature of Trypanosoma cruzi, the causative agent of Chagas disease, an updated system was agreed upon at the Second Satellite Meeting that T. cruzi strains should be referred to by six discrete typing units.
Abstract: In an effort to unify the nomenclature of Trypanosoma cruzi, the causative agent of Chagas disease, an updated system was agreed upon at the Second Satellite Meeting. A consensus was reached that T. cruzi strains should be referred to by six discrete typing units (T. cruzi I-VI). The goal of a unified nomenclature is to improve communication within the scientific community involved in T. cruzi research. The justification and implications will be presented in a subsequent detailed report.
900 citations
TL;DR: In this article, the authors examined how road facility designs, like street density, connectivity, and proximity to Ciclovia lanes, are associated with physical activity, while other attributes of the built environment, like density and land-use mixtures, are not.
652 citations
University of California, Santa Cruz1, National Institutes of Health2, Broad Institute3, University of Los Andes4, University of Guelph5, University of Nottingham6, University of California, Berkeley7, Pennsylvania State University8, Royal Ontario Museum9, Texas A&M University10, Louisiana State University11, Agency for Science, Technology and Research12, University of Kansas13, University of Montana14, American Museum of Natural History15, Oregon State University16, Villanova University17, University of Porto18, Smithsonian Institution19, Oswaldo Cruz Foundation20, Okinawa Institute of Science and Technology21, University of Sheffield22, Harvard University23, Swedish Museum of Natural History24, University of Copenhagen25, Novosibirsk State University26, Australian National University27, Max Planck Society28, Field Museum of Natural History29, Commonwealth Scientific and Industrial Research Organisation30, Science Applications International Corporation31, Stanford University32, University of Illinois at Urbana–Champaign33, George Washington University34, Global Viral35, University of Bedfordshire36, Federal University of Rio de Janeiro37, University of California, Davis38, University of California, Riverside39, Museum Victoria40, University College Dublin41, Monterey Bay Aquarium Research Institute42, Washington University in St. Louis43, University of California, Los Angeles44, Kunming Institute of Zoology45
TL;DR: A precipitous drop in costs and increase in sequencing efficiency is anticipated, with concomitant development of improved annotation technology, and it is proposed to create a collection of tissue and DNA specimens for 10,000 vertebrate species specifically designated for whole-genome sequencing in the very near future.
Abstract: American Genetic Association, Gordon and Betty Moore Foundation, NHGRI Intramural Sequencing Center, and UCSC Alumni Association to cost of the Genome 10K workshop; Howard Hughes Medical Institute to D. H.; Gordon and Betty Moore Foundation to S. C. S.; A
545 citations
Erasmus University Rotterdam1, Graz University of Technology2, Pompeu Fabra University3, Technical University of Madrid4, Princeton University5, University of Florida6, Leiden University7, University of Los Andes8, University of Lyon9, Linköping University10, University of North Carolina at Chapel Hill11, Colorado School of Mines12, Boston Children's Hospital13, VRVis14, Houston Methodist Hospital15, Delft University of Technology16
TL;DR: A standardized evaluation methodology and reference database for the quantitative evaluation of coronary artery centerline extraction algorithms and a database containing 32 cardiac CTA datasets with corresponding reference standard is described and made available.
365 citations
TL;DR: O observation of the electroweak production of single top quarks in pp[over ] collisions at sqrt[s]=1.96 TeV based on 2.3 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider is reported.
Abstract: We report observation of the electroweak production of single top quarks in pp collisions at s=1.96 TeV based on 2.3 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure a cross section of sigma(pp -> tb+X,tqb+X)=3.94 +/- 0.88 pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.5x10(-7), corresponding to a 5.0 standard deviation significance for the observation.
316 citations
TL;DR: The tolerance to As, Hg, Co, Fe and Cr was determined in different Colombian Bacillus sphaericus native strains, as well as the biosorption and bioaccumulation in living biomass and dead cells, and S-layer proteins may possibly have the ability to entrap metallic ions, either on living or dead cells.
282 citations
TL;DR: In this article, a mixed-integer optimization model that incorporates design and budget constraints while maximizing the number of credits reached under the Leadership in Energy and Environmental Design (LEED) rating system is proposed.
255 citations
22 Jun 2009
TL;DR: Tickner and Waever as mentioned in this paper discuss the role of race in the development of IR in the Middle East and present a Geocultural Epistemic Epistemology of IR.
Abstract: 1. Introduction: Geocultural Epistemologies Arlene B. Tickner and Ole Waever 2. Latin America: Still Policy Dependant after all these Years? Arlene B. Tickner 3. South Africa: Between History and a Hard Place Maxi Schoeman 4. Africa: Teaching IR Where its Not Supposed to Be Cirino Hiteng Ofuho 5. Japan, Korea and Taiwan: Are One Hundred Flowers about to Bloom? Takashi Inoguchi 6. China: Between Copying and Constructing Yiwei Wang 7. Southeast Asia: Theory and Praxis in International Relations See Seng Tan 8. South Asia: A "Realist" Past and Alternative Futures Navnita Chadha Behera 9. Iran: Accomplishments and Limitations in IR Mahmood Sariolghalam 10. Arab World Baghat Korany and Karim Makidisi 11. Israel: The Development of a Discipline in a Unique Setting Arie M. Kacowicz 12. Turkey: Towards Homebrown Theorizing and Building a Disciplinary Community Ersel Aydinli and Julie Mathews 13. Russia: IR at a Cross-Road Alexander Sergounin 14. Central and Eastern Europe: Between Continuity and Change Petr Drulak, Jans Karlas and Lucie Konigova 15. Western Europe: Structure and Strategy at the National and Regional Levels Jorg Freidrichs and Ole Waever 16. The "Crimson World": The Anglo Core, the Post-Imperial Non-Core, and the Hegemony of American IR Wayne S. Cox and Kim Richard Nossal 17. The Parochialism of Hegemony: Challenges for "American" International Relations Tom J. Biersteker 18. Conclusion: Worlding Where the West Once Was Arlene B. Tickner and Ole Waever
249 citations
TL;DR: A Fortran 90 library for multitaper spectrum estimation, a state-of-the-art method that has been shown to outperform the standard methods.
234 citations
TL;DR: This work proposes a unified model of human insurgency that reproduces commonalities across wars, explains conflict-specific variations quantitatively in terms of underlying rules of engagement, and establishes a quantitative connection between human insurgency, global terrorism and ecology.
Abstract: Many collective human activities, including violence, have been shown to exhibit universal patterns1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19. The size distributions of casualties both in whole wars from 1816 to 1980 and terrorist attacks have separately been shown to follow approximate power-law distributions6, 7, 9, 10. However, the possibility of universal patterns ranging across wars in the size distribution or timing of within-conflict events has barely been explored. Here we show that the sizes and timing of violent events within different insurgent conflicts exhibit remarkable similarities. We propose a unified model of human insurgency that reproduces these commonalities, and explains conflict-specific variations quantitatively in terms of underlying rules of engagement. Our model treats each insurgent population as an ecology of dynamically evolving, self-organized groups following common decision-making processes. Our model is consistent with several recent hypotheses about modern insurgency18, 19, 20, is robust to many generalizations21, and establishes a quantitative connection between human insurgency, global terrorism10 and ecology13, 14, 15, 16, 17, 22, 23. Its similarity to financial market models24, 25, 26 provides a surprising link between violent and non-violent forms of human behaviour.
231 citations
TL;DR: In this article, the authors demonstrate the relationship between the spatial coherency of the ambient field and the elastodynamic Green's function in both time and frequency domains, and sequentially recover phase velocities and attenuation coefficients.
Abstract: [1] Cross correlation of the ambient seismic field is now routinely used to measure seismic wave travel times; however, relatively little attention has been paid to other information that could be extracted from these signals. In this paper we demonstrate the relationship between the spatial coherency of the ambient field and the elastodynamic Green's function in both time and frequency domains. Through measurement of the frequency domain coherency as a function of distance, we sequentially recover phase velocities and attenuation coefficients. From these measurements we generate 1-D shear wave velocity and attenuation models for southern California. The ambient field measurements of attenuation and the exceptional path coverage that results from the many possible interstation measurements allow us to extend Q estimates over a range of frequencies that has previously been difficult to analyze using earthquake data. Measurements from paths that cross major sedimentary basins show both lower wave speeds and lower-quality factors than other paths, as expected. Our results indicate that there is a wealth of information available in the spatial coherency of the ambient seismic field.
TL;DR: Higher levels of school bullying were related to more males in the schools, lower levels of empathy, more authoritarian and violent families, higher levels of community violence, better socio-economic conditions, hostile attributional biases and more beliefs supporting aggression.
Abstract: Why do some countries, regions and schools have more bullying than others? What socio-economic, socio-political and other larger contextual factors predict school bullying? These open questions inspired this study with 53.316 5th- and 9th-grade students (5% of the national student population in these grades), from 1,000 schools in Colombia. Students completed a national test of citizenship competencies, which included questions about bullying and about families, neighborhoods and their own socio-emotional competencies. We combined these data with community violence and socio-economic conditions of all Colombian municipalities, which allowed us to conduct multilevel analyses to identify municipality- and school-level variables predicting school bullying. Most variance was found at the school level. Higher levels of school bullying were related to more males in the schools, lower levels of empathy, more authoritarian and violent families, higher levels of community violence, better socio-economic conditions, hostile attributional biases and more beliefs supporting aggression. These results might reflect student, classroom and school contributions because student-level variables were aggregated at the school level. Although in small portions, violence from the decades-old-armed conflict among guerrillas, paramilitaries and governmental forces predicted school bullying at the municipal level for 5th graders. For 9th graders, inequality in land ownership predicted school bullying. Neither poverty, nor population density or homicide rates contributed to explaining bullying. These results may help us advance toward understanding how the larger context relates to school bullying, and what socio-emotional competencies may help us prevent the negative effects of a violent and unequal environment. Aggr. Behav. 35:1-10, 2009. (c) 2009 Wiley-Liss, Inc. Language: en
TL;DR: In this article, the authors explored the contribution of spirituality and religiosity to life satisfaction, from a eudaimonic (from the Greek, it consists of the word "eu" (good or well-being) and the word “daemon” (spirit)) point of view, led to test the importance of this new domain in the prediction of the Personal Well-being Index (PWI) in Bogota, Colombia.
Abstract: Subjective well-being explores the evaluations, both positive and negative, of how people experience their lives. Research in the field inquires how people perceive their well-being in different settings, including different cultures, regions and cities. A large number of different measures have been designed to capture subjective well-being. One of the most used SWB measure is the Personal Well-being Index (PWI), an evaluation of life developed by Cummins et al [(2003). Social Indicators Research, 64, 159–190] which proposes that satisfaction with life consists of seven different life-domains. Theoretical considerations of the contribution of spirituality and religiosity to life satisfaction, from a eudaimonic (from the Greek, it consists of the word "eu" (good or well-being) and the word “daemon” (spirit)) point of view, led to test the contribution of this new domain in the prediction of the Personal Well-being Index (PWI) in Bogota, Colombia. Empirical results confirm the construct validity and reliability of the scale. The contribution of the new domain—satisfaction with spirituality and religiosity—to PWI was found significant. Based on these results the paper explores conceptually the role of spirituality contributing to satisfaction with life. The finding stresses the importance of interpreting satisfaction with life as a whole from the Aristotelian concept of eudaimonia. New questions for research in this important area are proposed
TL;DR: In this paper, the authors proposed a new model to assess the lifetime of RC structures subject to corrosion-fatigue deterioration processes, which is applied to the reliability analysis of bridge girders located in various chloride-contaminated environments.
TL;DR: Studies centered on trypanosome-triatomine interaction may allow identification of co-evolutionary processes, which could consolidate hypotheses of the evolution and the distribution of T. cruzi/T.
TL;DR: This review discusses the following questions: when does food produce a natural addiction?
Abstract: The distinction between natural addiction and drug addiction is interesting from many points of view, including scientific and medical perspectives. "Natural addictions" are those based on activation of a physiobehavioral system, such as the one that controls metabolism, foraging, and eating to achieve energy balance. "Drug addictions" activate many systems based on their pharmacology. This review discusses the following questions: (1) When does food produce a natural addiction? Sugar causes signs of addiction if the scheduling conditions are appropriate to cause binge eating. (2) Why does addictive-like behavior result? Bingeing on a 10% sucrose solution repeatedly releases dopamine in the nucleus accumbens, and it delays the release of acetylcholine, thereby postponing satiety. Opioid involvement is shown by withdrawal caused by naloxone or food deprivation. Bingeing, withdrawal, and abstinence-induced motivation are described as the basis for a vicious cycle leading to excessive eating. (3) Which foods can lead to natural addiction? A variety of sugars, saccharin, and sham feeding are compared with bingeing on high-fat diets, which seem to lack sugar's opioid-withdrawal characteristic. (4) How does natural food addiction relate to obesity? Low basal dopamine may be a common factor, leading to "eating for dopamine." (5) In a neural model, the accumbens is depicted as having separate GABA output pathways for approach and avoidance, both controlled by dopamine and acetylcholine. These outputs, in turn, control lateral hypothalamic glutamate release, which starts a meal, and GABA release, which stops it.
TL;DR: In this paper, the authors present a search for charged Higgs bosons in top quark decays, using data from about 1${\text{fb}}^{-1}$ of integrated luminosity recorded by the Fermilab Tevatron Collider.
TL;DR: Evidence is presented that tropical mockingbirds decrease the variation between renditions of each syllable type as they grow older and that more consistent males in this species tend to have higher dominance status and reproductive success and it is hypothesized that syllabletype consistency may also be an indicator of the integrity of brain function in birds analogous to the tests used for neuropsychological assessment in humans.
Liverpool School of Tropical Medicine1, Universidad Autónoma de Nuevo León2, University of California, Davis3, Mahidol University4, University of Los Andes5, Kenya Medical Research Institute6, University of the East7, Universidad Autónoma de Yucatán8, World Health Organization9, Institute of Tropical Medicine Antwerp10
TL;DR: It is proposed to test the non‐inferiority hypothesis that a vector control approach targeting only the most productive water container types gives the same or greater reduction of the vector population as a non‐targeted approach in different ecological settings.
Abstract: Summary objectives To test the non-inferiority hypothesis that a vector control approach targeting only the most productive water container types gives the same or greater reduction of the vector population as a non-targeted approach in different ecological settings and to analyse whether the targeted intervention is less costly. methods Cluster randomized trial in eight study sites (Venezuela, Mexico, Peru, Kenya, Thailand, Myanmar, Vietnam, Philippines), with each study area divided into 18–20 clusters (sectors or neighbourhoods) of approximately 50–100 households each. Using a baseline pupal-demographic survey, the most productive container types were identified which produced ‡55% of all Ae. aegypti pupae. Clusters were then paired based on similar pupae per person indices. One cluster from each pair was randomly allocated to receive the targeted vector control intervention; the other received the ‘blanket’ (nontargeted) intervention attempting to reach all water holding containers. results The pupal-demographic baseline survey showed a large variation of productive container types across all study sites. In four sites the vector control interventions in both study arms were insecticidal and in the other four sites, non-insecticidal (environmental management and ⁄ or biological control methods). Both approaches were associated with a reduction of outcome indicators in the targeted and non-targeted intervention arm of the six study sites where the follow up study was conducted (PPI, Pupae per Person Index and BI, Breteau Index). Targeted interventions were as effective as non-targeted ones in terms of PPI. The direct costs per house reached were lower in targeted intervention clusters than in non-targeted intervention clusters with only one exception, where the targeted intervention was delivered through staff-intensive social mobilization. conclusions Targeting only the most productive water container types (roughly half of all water holding container types) was as effective in lowering entomological indices as targeting all water holding containers at lower implementation costs. Further research is required to establish the most efficacious method or combination of methods for targeted dengue vector interventions.
TL;DR: The ICAST-R is based on consensus from international experts, translates clearly and has satisfactory properties for adoption as a survey tool to estimate prevalence and describe perpetrators and other contextual aspects of child abuse.
TL;DR: In this article, the authors studied the dynamic interfacial tension and rheology of interfaces between water and either crude oil diluted in toluene or in a model oil consisting of asphaltenes were redissolved.
Abstract: We have performed a study of dynamic interfacial tension and rheology of interfaces between water and either crude oil diluted in toluene or in a model oil consisting of toluene, in which pentane-extracted asphaltenes were redissolved. We show that the break point of the curve interfacial tension versus asphaltene concentration is not related to an eventual critical aggregation concentration but rather to the collapse of the asphaltene surface layer. As for other amphiphilic species that adsorb irreversibly at an oil−water interface, the corresponding emulsion stability increases with the amphiphile concentration, even above the collapse point. The behavior of diluted crude oil and model oil are quite similar. However, the surface layers evolve over longer time scales in the case of diluted crude oil, probably because of the contribution of resins that form less polar aggregates with asphaltenes. This results in less stable emulsions, especially before the collapse point.
TL;DR: The results obtained depict a complex evolutionary scenario and emphasize the importance of considering multiple traits when disentangling the forces behind allopatric divergence in the Amazonian frog, Allobates femoralis.
Abstract: Evolutionary divergence in behavioural traits related to mating may represent the initial stage of speciation. Direct selective forces are usually invoked to explain divergence in mate-recognition traits, often neglecting a role for neutral processes or concomitant differentiation in ecological traits. We adopted a multi-trait approach to obtain a deeper understanding of the mechanisms behind allopatric divergence in the Amazonian frog, Allobates femoralis. We tested the null hypothesis that geographic distance between populations correlates with genetic and phenotypic divergence, and compared divergence between mate-recognition (acoustic) and ecological (coloration, body-shape) traits. We quantified geographic variation in 39 phenotypic traits and a mitochondrial DNA marker among 125 individuals representing eight populations. Geographic variation in acoustic traits was pronounced and tracked the spatial genetic variation, which appeared to be neutral. Thus, the evolution of acoustic traits tracked the shared history of the populations, which is unexpected for pan-Amazonian taxa or for mate-recognition traits. Divergence in coloration appeared uncorrelated with genetic distance, and might be partly attributed to local selective pressures, and perhaps to Batesian mimicry. Divergence in body-shape traits was low. The results obtained depict a complex evolutionary scenario and emphasize the importance of considering multiple traits when disentangling the forces behind allopatric divergence. ©2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 826-838.
TL;DR: In this paper, a probabilistic approach to compute the life-cycle cost (LCC) of corroding reinforced concrete (RC) bridges in earthquake-prone regions was developed by combining cumulative seismic damage and damage associated with corrosion.
Abstract: Bridge design should take into account not only safety and functionality, but also the cost effectiveness of investments throughout a bridge life-cycle. This paper presents a probabilistic approach to compute the life-cycle cost (LCC) of corroding reinforced concrete (RC) bridges in earthquake-prone regions. The approach is developed by combining cumulative seismic damage and damage associated with corrosion due to environmental conditions. Cumulative seismic damage is obtained from a low-cycle fatigue analysis. Chloride-induced corrosion of steel reinforcement is computed based on Fick's second law of diffusion. The proposed methodology accounts for the uncertainties in the ground motion parameters, the distance from the source, the seismic demand on the bridge, and the corrosion initiation time. The statistics of the accumulated damage and the cost of repairs throughout the bridge life-cycle are obtained by Monte-Carlo simulation. As an illustration of the proposed approach, the effects of design parameters on the LCC of an example RC bridge are studied. The results are valuable in better estimating the condition of existing bridges and, therefore, can help to schedule inspection and maintenance programs. In addition, by taking into consideration the two deterioration processes over a bridge life-cycle, it is possible to estimate the optimal design parameters by minimizing, for example, the expected cost throughout the life of the structure. A comparison between the effects of the two deterioration processes shows that, in seismic regions, the cumulative seismic damage affects the reliability of bridges over time more than the corrosion even for corrosive environments. Copyright © 2008 John Wiley & Sons, Ltd.
TL;DR: A new vector-based cellular automata (VecGCA) model is described to overcome the scale sensitivity of the raster-based CA models and produces realistic spatial patterns similar to reference land-use maps.
TL;DR: In order to demonstrate that the circulating T. cruzi I isolates in Colombia can be classified in the four proposed haplotypes, specific primers were designed on polymorphic regions of the miniexon gene's intergenic sequences that allowed the molecular characterization of 33 Colombian isolates.
TL;DR: In this paper, a parametric study was conducted to examine the influence of different parameters in some reduced scale models made of Expanded polystyrene (EPS) isolation barriers within Fontainebleau sand in order to determine geofoam isolation efficiency.
TL;DR: The International Society for the Prevention of Child Abuse and Neglect has developed instrumentation that may be used with cross-cultural and cross-national benchmarking by local investigators as mentioned in this paper.
TL;DR: The EAR instrumento unidimensional que se contesta en a 4 alternativas, i.e., "muyde acuerdo" a " muy en desacurate" as mentioned in this paper.
Abstract: entiende la autoestima como unsentimiento hacia uno mismo, que puede serpositivo o negativo, el cual se construye pormedio de una evaluacion de las propias caracteris-ticas. La escala fue dirigida en un principio aadolescentes, hoy se usa con otros grupos etarios.Su aplicacion es simple y rapida. Cuenta con 10items, divididos equitativamente en positivos ynegativos (ejemplos, sentimiento positivo: “creoque tengo un buen numero de cualidades”,sentimiento negativo: “siento que no tengo mu-chos motivos para sentirme orgulloso de mi”). Esun instrumento unidimensional que se contesta enuna escala de 4 alternativas, que va desde “muyde acuerdo” a “muy en desacuerdo”.La EAR es ampliamente utilizada en Chile,pero no existe evidencia de un proceso devalidacion publicado, por tanto el proposito deeste estudio fue determinar su confiabilidad yvalidez en una muestra chilena.M
National University of Colombia1, University of Leeds2, Max Planck Society3, University of Brasília4, University of California, Irvine5, District University of Bogotá6, University of Göttingen7, Institut national de la recherche agronomique8, Centre national de la recherche scientifique9, Conservation International10, Museu Paraense Emílio Goeldi11, University of Edinburgh12, Duke University13, Alexander von Humboldt Biological Resources Research Institute14, University of Georgia15, Center for International Forestry Research16, Empresa Brasileira de Pesquisa Agropecuária17, Universidade Federal do Acre18, University of Los Andes19, University of Oxford20
TL;DR: In this paper, branch xylem density is measured for 1653 trees representing 598 species, sampled from 87 sites across the Amazon basin and found significant differences in average ρx across regions and sampled plots as well as significant differences between families, genera and species.
Abstract: Xylem density is a physical property of wood that varies between individuals, species and environments. It reflects the physiological strategies of trees that lead to growth, survival and reproduction. Measurements of branch xylem density, ρx, were made for 1653 trees representing 598 species, sampled from 87 sites across the Amazon basin. Measured values ranged from 218 kg m−3 for a Cordia sagotii (Boraginaceae) from Mountagne de Tortue, French Guiana to 1130 kg m−3 for an Aiouea sp. (Lauraceae) from Caxiuana, Central Para, Brazil. Analysis of variance showed significant differences in average ρx across regions and sampled plots as well as significant differences between families, genera and species. A partitioning of the total variance in the dataset showed that species identity (family, genera and species) accounted for 33% with environment (geographic location and plot) accounting for an additional 26%; the remaining "residual" variance accounted for 41% of the total variance. Variations in plot means, were, however, not only accountable by differences in species composition because xylem density of the most widely distributed species in our dataset varied systematically from plot to plot. Thus, as well as having a genetic component, branch xylem density is a plastic trait that, for any given species, varies according to where the tree is growing in a predictable manner. Within the analysed taxa, exceptions to this general rule seem to be pioneer species belonging for example to the Urticaceae whose branch xylem density is more constrained than most species sampled in this study. These patterns of variation of branch xylem density across Amazonia suggest a large functional diversity amongst Amazonian trees which is not well understood.
TL;DR: In this paper, the top quark pair production cross section in p (p) over bar collisions in the l + jets, ll, and tau l final states (where l is an electron or muon) at a center of mass energy of root s = 1.96 TeV in 1 fb(-1) of data collected with the D0 detector.
Abstract: We combine measurements of the top quark pair production cross section in p (p) over bar collisions in the l + jets, ll, and tau l final states ( where l is an electron or muon) at a center of mass energy of root s = 1.96 TeV in 1 fb(-1) of data collected with the D0 detector. For a top quark mass of 170 GeV/c(2), we obtain sigma(t (t) over bar) = 8.18(-0.87)(+0.98) pb in agreement with the theoretical prediction. Based on predictions from higher order quantum chromodynamics, we extract a mass for the top quark from the combined t (t) over bar cross section, consistent with the world average of the top quark mass. In addition, the ratios of t (t) over bar cross sections in different final states are used to set upper limits on the branching fractions B(t -> H(+)b -> tau(+) vb) and B(t -> H(+)b -> c (s) over barb) as a function of the charged Higgs boson mass.