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Institution

University of Costa Rica

EducationSan José, Costa Rica
About: University of Costa Rica is a education organization based out in San José, Costa Rica. It is known for research contribution in the topics: Population & Venom. The organization has 9817 authors who have published 16781 publications receiving 238208 citations. The organization is also known as: UCR & Universidad de Costa Rica.


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Book
01 Jan 2003
TL;DR: This book discusses the Workerless Social Parasites of the New World Pheidole, Based on the Queen, and the Species Groups of the Nonparasitic New World pheidole based on the Worker Castes.
Abstract: * Introduction * The Origins of Hyperdiversity * Glossary and Anatomy * Keys * The Workerless Social Parasites of the New World Pheidole, Based on the Queen * The Species Groups of the Nonparasitic New World Pheidole, Based on the Worker Castes * The aberrans Group * The biconstricta Group * The crassicornis Group * The diligens Group * The distorta Group * The fallax Group * The flavens Group * The gertrudae Group * The granulata Group * The lamia Group * The megacephala Group * The perpusilla Group * The pilifera Group * The punctatissima Group * The scrobifera Group * The tachigaliae Group * The teneriffana Group * The transversostriata Group * The tristis Group * The New World Species * Indeterminate Names * References * Acknowledgments * Index

238 citations

Journal ArticleDOI
TL;DR: Findings indicate that deficiency of UBR1 perturbs the pancreas' acinar cells and other organs, presumably owing to metabolic stabilization of specific substrates of the N-end rule pathway.
Abstract: Johanson-Blizzard syndrome (OMIM 243800) is an autosomal recessive disorder that includes congenital exocrine pancreatic insufficiency, multiple malformations such as nasal wing aplasia, and frequent mental retardation. We mapped the disease-associated locus to chromosome 15q14-21.1 and identified mutations, mostly truncating ones, in the gene UBR1 in 12 unrelated families with Johanson-Blizzard syndrome. UBR1 encodes one of at least four functionally overlapping E3 ubiquitin ligases of the N-end rule pathway, a conserved proteolytic system whose substrates include proteins with destabilizing N-terminal residues. Pancreas of individuals with Johanson-Blizzard syndrome did not express UBR1 and had intrauterine-onset destructive pancreatitis. In addition, we found that Ubr1(-/-) mice, whose previously reported phenotypes include reduced weight and behavioral abnormalities, had an exocrine pancreatic insufficiency, with impaired stimulus-secretion coupling and increased susceptibility to pancreatic injury. Our findings indicate that deficiency of UBR1 perturbs the pancreas' acinar cells and other organs, presumably owing to metabolic stabilization of specific substrates of the N-end rule pathway.

236 citations

Journal ArticleDOI
Edgardo Moreno1, E Stackebrandt1, M Dorsch1, J Wolters1, M Busch1, H Mayer1 
TL;DR: The chemical analysis of the lipid A fraction revealed that Brucella species contain both glucosamine and diaminoglucose, thus suggesting the presence of a so-called mixed lipid A type, and the serological analysis with polyclonal and monoclonal antibodies is in agreement with the existence of mixed lipid B type in B. abortus.
Abstract: On the basis of ribosomal 16S sequence comparison, Brucella abortus has been found to be a member of the alpha-2 subdivision of the class Proteobacteria (formerly named purple photosynthetic bacteria and their nonphototrophic relatives). Within the alpha-2 subgroup, brucellae are specifically related to rickettsiae, agrobacteria, and rhizobiae, organisms that also have the faculty or the obligation of living in close association to eucaryotic cells. The composition of Brucella lipid A suggests a close phylogenetical relationship with members of the alpha-2 group. The chemical analysis of the lipid A fraction revealed that Brucella species contain both glucosamine and diaminoglucose, thus suggesting the presence of a so-called mixed lipid A type. The serological analysis with polyclonal and monoclonal antibodies is in agreement with the existence of mixed lipid A type in B. abortus. The amide-linked fatty acid present as acyl-oxyacyl residues were 3-O-C(16:0)12:0, 3-O-C(16:0)13:0, 3-O-C(16:0)14:0, and 3-O-C(18:0)14:0. The only amide-linked unsubstituted fatty acid detected was 3-OH-C16:0. The ester-linked fatty acids are 3-OH-C16:0, 3-OH-C18:0, C16:0, C17:0, and C18:0. Significant amounts of the large-chain 27-OH-C28:0 were detected together with traces of 25-OH-C26:0 and 29-OH-C30:0. Comparison of the Brucella lipid composition with that of the other Proteobacteria also suggests a close phylogenetical relationship with members of the alpha-2 subdivision. The genealogical grouping of Brucella species with pericellular and intracellular plant and animal pathogens as well as with intracellular plant symbionts suggests a possible evolution of Brucella species from plant-arthropod-associated bacteria.

235 citations

Journal ArticleDOI
TL;DR: In this paper, the authors evaluate and compare four different methods commonly used to measure vertical jump performance, including body center of mass displacement (VJPT), vertical takeoff velocity as calculated from the force platform, and time in the air (JUMPAIR).
Abstract: Vertical jump performance tests can give considerably different results, even when different methods are used to analyze the same jump trial from the same subject. To evaluate and compare 4 different methods commonly used to measure vertical jump performance, 52 physically active men each performed 5 maximal vertical jumps. Kinetic and kinematic data were used to analyze each trial using the 4 methods: a criterion test based on body center of mass displacement (VJPT), 2 methods based on vertical takeoff velocity as calculated from the force platform, and 1 method based on time in the air (JUMPAIR). All 4 methods showed excellent reliability (R > .97). Using VJPT as the criterion, the other 3 methods showed excellent coefficients of validity (R > .95) but poor accuracy: The obtained vertical jump height scores were statistically different among all methods (p < .01). JUMPAIR is considered a relatively simple and inexpensive method to obtain valid and reliable measures of vertical jump performance without a...

235 citations

Journal ArticleDOI
TL;DR: A positive correlation between degree of divergence (measured as Nei's genetic distance, D) and degree of postzygotic isolation is found and in anurans, hybrid sterility appears to evolve more quickly than inviability, which is consistent with the conclusions that involved Drosophila species.
Abstract: From literature data on 116 taxa crosses involving 46 species of frogs, we found a positive correlation between degree of divergence (measured as Nei's genetic distance, D) and degree of postzygotic isolation. In anurans, hybrid sterility appears to evolve more quickly than inviability, which is consistent with the conclusions of other studies that involved Drosophila species. The lower threshold of D = 0.30 for evolution of hybrid inviability that we found is similar to that observed for Drosophila. This consistency suggests that there may be a general pattern in the acquisition of reproductive isolation in animals.

234 citations


Authors

Showing all 9922 results

NameH-indexPapersCitations
Alberto Ascherio13646269578
Gervasio Gomez133184499695
Myron M. Levine12378960865
Hong-Cai Zhou11448966320
Edward O. Wilson10140689994
Mary Claire King10033647454
Olga Martín-Belloso8638423428
José María Gutiérrez8460726779
Cesare Montecucco8438227738
Rodolphe Clérac7850622604
Kim R. Dunbar7447020262
Paul J. Hanson7025119504
Hannia Campos6921015164
Jean-Pierre Gorvel6723115005
F. Albert Cotton66102327647
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202325
2022155
2021865
20201,009
2019894
2018834