290 research outputs found
RedescripciĂłn de Cetopsorhamdia nasus Eigenmann y Fisher, 1916 (Siluriformes: Heptapteridae)
To increase our knowledge of the morphology of the genus Cetopsorhamdia, a redescription of the type species C. nasus is presented. External morphology, configuration of the skull, complex vertebrae, free vertebrae and associated structures, pectoral and pelvic girdles, dorsal fin, and caudal skeleton are described in detail. A diagnosis for the species, based on comparisons with other valid species in the genus, is proposed. A previous description is discussed, and the position of the genus within the family Heptapteridae and sub-clade Nemuroglanis is validated.A fin de contribuir con el conocimiento morfolĂłgico del gĂ©nero Cetopsorhamdia, se presenta la redescripciĂłn de la especie tipo Cetopsorhamdia nasus. Se describe detalladamente la morfologĂa externa, configuraciĂłn del cráneo, vĂ©rtebra compleja, vĂ©rtebras libres y estructuras asociadas, las cinturas pectoral y pĂ©lvica, la aleta dorsal y el esqueleto caudal. Con base en la comparaciĂłn con las otras especies consideradas válidas para el gĂ©nero, se propone una diagnosis para la especie. Se discute una redescripciĂłn precedente y se valida la pertenencia del gĂ©nero dentro de la familia Heptapteridae y el sub-clado Nemuroglanis
Rediscovery of the holotype of Characidium sanctjohanni Dahl 1960 (Characiformes: Crenuchidae) from the Colombian Pacific slope
We report the rediscovery of the holotype of Characidium sanctjohanni Dahl, previously considered as lost in the ICN collections. We present counts, measurements and photographs, also offering a comparison between the holotype and the original description.Presentamos el redescubrimiento de la especie Characidium sanctjohanni descrita por Dahl (1960), lote que se encontraba perdido en el ICN. Tomamos conteos, medidas y fotografĂas para comparar los datos del holotipo con la descripciĂłn original
Peces de la subcuenca del rĂo Catatumbo, cuenca del Lago de Maracaibo, Colombia y Venezuela
Records from the literature supplemented by reviewing reference collection specimens of fish in the Humboldt Institute - IAvH-P, Rancho Grande Biological Station - EBRG and Museum of Natural Sciences Guanare -MCNG, show 109 freshwater native species and 14 of marine estuarine origin living in the Catatumbo river basin, making it the system with the highest diversity of fish species on Maracaibo Lake. These species belong to 10 orders, 39 families and 91 genera. The taxonomic orders with the highest number of families, genera and species were Siluriformes with 12 families, 42 genera and 61 species and Characiformes with 11 families, 24 genera and 32 species. The richest families were Loricariidae (16 genera and 25 species), Characidae (13 genera and 18 species) and Pimelodidae (6 genera and 8 species), there were between one and five species recorded in each of the remaining 37 families. Of the 123 species registered, 69 were collected and cataloged as sampling results of this study and 11 are new registers for Colombia. As for the Catatumbo 61 of the 68 species are considered endemic to the Maracaibo Lake basin and 40 were established themselves as commonly fished species for commercial purposes, six marine - estuarine and 34 freshwater. This paper discusses changes in the number of species registered in the different lists and their implications for species richness Catatumbo basin
Peces de la subcuenca del rĂo Catatumbo, cuenca del Lago de Maracaibo, Colombia y Venezuela
Records from the literature supplemented by reviewing reference collection specimens of fish in the Humboldt Institute - IAvH-P, Rancho Grande Biological Station - EBRG and Museum of Natural Sciences Guanare -MCNG, show 109 freshwater native species and 14 of marine estuarine origin living in the Catatumbo river basin, making it the system with the highest diversity of fish species on Maracaibo Lake. These species belong to 10 orders, 39 families and 91 genera. The taxonomic orders with the highest number of families, genera and species were Siluriformes with 12 families, 42 genera and 61 species and Characiformes with 11 families, 24 genera and 32 species. The richest families were Loricariidae (16 genera and 25 species), Characidae (13 genera and 18 species) and Pimelodidae (6 genera and 8 species), there were between one and five species recorded in each of the remaining 37 families. Of the 123 species registered, 69 were collected and cataloged as sampling results of this study and 11 are new registers for Colombia. As for the Catatumbo 61 of the 68 species are considered endemic to the Maracaibo Lake basin and 40 were established themselves as commonly fished species for commercial purposes, six marine - estuarine and 34 freshwater. This paper discusses changes in the number of species registered in the different lists and their implications for species richness Catatumbo basin.Registros de literatura, complementados con la revisiĂłn de ejemplares de colecciĂłn de referencia de peces del Instituto Humboldt - IAvH-P (Colombia), EstaciĂłn BiolĂłgica de Rancho Grande - EBRG y Museo de Ciencias Naturales de Guanare - MCNG (Venezuela), muestran que 109 especies nativas de agua dulce y 14 de origen marino y estuarino habitan la subcuenca el rĂo Catatumbo, constituyĂ©ndose en el sistema con mayor diversidad de especies de peces de la cuenca del Lago de Maracaibo. Estas especies pertenecen a 10 Ăłrdenes, 39 familias y 91 gĂ©neros. Los Ăłrdenes con mayor nĂşmero de familias, gĂ©neros y especies fueron Siluriformes con 12 familias, 42 gĂ©neros y 60 especies, y Characiformes 11 familias, 24 gĂ©neros y 32 especies. Las familias con mayor riqueza fueron Loricariidae (16 gĂ©neros y 25 especies), Characidae (13 gĂ©neros y 18 especies) y Pimelodidae (6 gĂ©neros y 8 especies); presentando las restantes 37 familias entre una y cinco especies. De las 123 especies registradas, 69 fueron capturadas y catalogadas como resultados de los muestreos durante el presente estudio y 11 corresponden a nuevos registros para Colombia. Para el rĂo Catatumbo se registraron 61 especies de las 68 consideradas endĂ©micas para la cuenca del Lago de Maracaibo y se establecieron como especies pesqueras 40, de las cuales seis fueron marino-estuarinas y 34 dulceacuĂcolas. Se discute las variaciones del nĂşmero de especies registradas en los diferentes listados y sus implicaciones en la riqueza de especies para la subcuenca del Catatumbo
Substrate-induced dimerization of engineered monomeric variants of triosephosphate isomerase from Trichomonas vaginalis
"The dimeric nature of triosephosphate isomerases (TIMs) is maintained by an extensive surface area interface of more than 1600 angstrom 2. TIMs from Trichomonas vaginalis (TvTIM) are held in their dimeric state by two mechanisms: a ball and socket interaction of residue 45 of one subunit that fits into the hydrophobic pocket of the complementary subunit and by swapping of loop 3 between subunits. TvTIMs differ from other TIMs in their unfolding energetics. In TvTIMs the energy necessary to unfold a monomer is greater than the energy necessary to dissociate the dimer. Herein we found that the character of residue I45 controls the dimer-monomer equilibrium in TvTIMs. Unfolding experiments employing monomeric and dimeric mutants led us to conclude that dimeric TvTIMs unfold following a four state model denaturation process whereas monomeric TvTIMs follow a three state model. In contrast to other monomeric TIMs, monomeric variants of TvTIM1 are stable and unexpectedly one of them (I45A) is only 29-fold less active than wild-type TvTIM1. The high enzymatic activity of monomeric TvTIMs contrast with the marginal catalytic activity of diverse monomeric TIMs variants. The stability of the monomeric variants of TvTIM1 and the use of cross-linking and analytical ultracentrifugation experiments permit us to understand the differences between the catalytic activities of TvTIMs and other marginally active monomeric TIMs. As TvTIMs do not unfold upon dimer dissociation, herein we found that the high enzymatic activity of monomeric TvTIM variants is explained by the formation of catalytic dimeric competent species assisted by substrate binding.
Long-term effects of coronavirus disease 2019 on the cardiovascular system, CV COVID registry: A structured summary of a study protocol
Background: Patients presenting with the coronavirus-2019 disease (COVID-19) may have a high risk of cardiovascular adverse events, including death from cardiovascular causes. The long-term cardiovascular outcomes of these patients are entirely unknown. We aim to perform a registry of patients who have undergone a diagnostic nasopharyngeal swab for SARS-CoV-2 and to determine their long-term cardiovascular outcomes. Study and design: This is a multicenter, observational, retrospective registry to be conducted at 17 centers in Spain and Italy (ClinicalTrials.gov number: NCT04359927). Consecutive patients older than 18 years, who underwent a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for SARS-CoV2 in the participating institutions, will be included since March 2020, to August 2020. Patients will be classified into two groups, according to the results of the RT-PCR: COVID-19 positive or negative. The primary outcome will be cardiovascular mortality at 1 year. The secondary outcomes will be acute myocardial infarction, stroke, heart failure hospitalization, pulmonary embolism, and serious cardiac arrhythmias, at 1 year. Outcomes will be compared between the two groups. Events will be adjudicated by an independent clinical event committee. Conclusion: The results of this registry will contribute to a better understanding of the long-term cardiovascular implications of the COVID19
Peces de la cuenca del rĂo Orinoco. Parte I: Lista de especies y distribuciĂłn por subcuencas
Para efectos del presente trabajo y en funciĂłn de los datos disponibles hasta la fecha, se consideran las siguientes subcuencas y/o regiones para la cuenca del Orinoco, desde su nacimiento hasta su desembocadura en el ocĂ©ano Atlántico: Alto Orinoco, Casiquiare, Ventuari, Atabapo, InĂrida, Guaviare, Vichada, Sipapo, Tomo, Cataniapo, Bita, Meta, Parguaza, Cinaruco, Suapure, Capanaparo, Arauca, Apure, Cuchivero, Manapiare, Zuata, Caura, Pao, Aro, Caris, CaronĂ, Morichal Largo, Delta y Orinoco (Mapa)
Peces de la estrella fluvial inĂrida: rĂos Guaviare, InĂrida, Atabapo y Orinoco (OrinoquĂa colombiana)
Data derived from the literature supplemented with new collections made in the InĂrida Fluvial Star (15th to 27th February 2008) reveal a species richness of 470 fishes species grouped in 224 genera, 40 families, and 10 orders. Its represents the higher species richness in the Orinoco River Basin. Orders with the largest numbers of species in the Star were Characiformes (237 species), Siluriformes (136 species), Perciformes (60 species), and Gymnotiformes (19 species), with the remaining 6 orders having from 1 to 7 species. At the family level, the Characidae has the greatest number of species (141 species), followed by the Cichlidae (55 species), Loricariidae (39 species), Pimelodidae (23 species), and Anostomidae (21 species); the remaining 35 families have 1 to 18 species. Present data indicate that 4 species are new records for the Orinoco River Basin and 19 are new for Colombia. The species richness by river was: 280 for the InĂrida, 238 for Atabapo, 224 for Guaviare, and 82 for the Orinoco. In the InĂrida Fluvial Star 335 species have commercial value as ornamentals, and 132 are harvested for food
Inside the Outbreak of the 2009 Influenza A (H1N1)v Virus in Mexico
Influenza viruses pose a threat to human health because of their potential to cause global disease. Between mid March and mid April a pandemic influenza A virus emerged in Mexico. This report details 202 cases of infection of humans with the 2009 influenza A virus (H1N1)v which occurred in Mexico City as well as the spread of the virus throughout the entire country.From May 1st to May 5th nasopharyngeal swabs, derived from 751 patients, were collected at 220 outpatient clinics and 28 hospitals distributed throughout Mexico City. Analysis of samples using real time RT-PCR revealed that 202 patients out of the 751 subjects (26.9%) were confirmed to be infected with the new virus. All confirmed cases of human infection with the strain influenza (H1N1)v suffered respiratory symptoms. The greatest number of confirmed cases during the outbreak of the 2009 influenza A (H1N1)v were seen in neighbourhoods on the northeast side of Mexico City including Iztapalapa, Gustavo A. Madero, Iztacalco, and Tlahuac which are the most populated areas in Mexico City. Using these data, together with data reported by the Mexican Secretariat of Health (MSH) to date, we plot the course of influenza (H1N1)v activity throughout Mexico.Our data, which is backed up by MSH data, show that the greatest numbers of the 2009 influenza A (H1N1) cases were seen in the most populated areas. We speculate on conditions in Mexico which may have sparked this flu pandemic, the first in 41 years. We accept the hypothesis that high population density and a mass gathering which took in Iztapalapa contributed to the rapid spread of the disease which developed in three peaks of activity throughout the Country
- …