72 results on '"Gutiérrez, Marco"'
Search Results
52. Análisis de protección para casco de ciclista sometido a impacto virtual por método de elemento finito.
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Armendáriz Mireles, Eddie Nahúm, Castillo Robles, José Adalberto, López Gutiérrez, Marco Antonio, and Rangel, Enrique Rocha
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Bikes involve great risk of injury from falls; among the major risks are head injuries. Therefore, it is essential to use protective elements. This project focuses on a study to analyze protection for a helmet for cyclists using the finite element method; the entire methodology of this work was based on the Snell standards. The percentage of absorbed tension was determined by simulating a frontal impact by varying the thickness of the material of the helmet (30 mm, 20 mm and 10 mm) that protects a 4.7kg sphere of solid aluminum, emulating the head of a bicyclist. From the results it was determined that the helmet can absorb more than 90% of the tensions, the helmet with 20mm of thickness presents the best results. [ABSTRACT FROM AUTHOR]
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- 2017
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53. Early Tremadocian graptolites from the Arivechi area, Sonora, northern Mexico.
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Raquel Reyes-Montoya, Dulce, Javier Cuen-Romero, Francisco, Navas-Parejo, Pilar, Gámez-Meza, Nohemí, José Palafox-Reyes, Juan, and Carlos Gutiérrez-Marco, Juan
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GRAPTOLITES , *CONTINENTAL shelf , *CONTINENTAL margins ,LAURENTIA (Continent) - Abstract
Graptolites from the early Tremadocian Anisograptus matanensis Biozone are identified from east-central Sonora, northwestern Mexico, within a carbonate-shelf succession deposited on the southwestern continental shelf margin of Laurentia. This is the second occurrence of typical anisograptid graptolites in Mexico, after its original record in the Oaxaca area, which belongs to a Gondwana-related paleogeographical realm. The graptolites from Sonora represent the second global occurrence of any member of the Rhabdinopora flabelliformis group in the Ordovician equatorial shelf region. [ABSTRACT FROM AUTHOR]
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- 2023
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54. Early Tremadocian graptolites from the Arivechi area, Sonora, northern Mexico.
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Raquel Reyes-Montoya, Dulce, Javier Cuen-Romero, Francisco, Navas-Parejo, Pilar, Gámez-Meza, Nohemí, José Palafox-Reyes, Juan, and Carlos Gutiérrez-Marco, Juan
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GRAPTOLITES , *CONTINENTAL shelf , *CONTINENTAL margins ,LAURENTIA (Continent) - Abstract
Graptolites from the early Tremadocian Anisograptus matanensis Biozone are identified from east-central Sonora, northwestern Mexico, within a carbonate-shelf succession deposited on the southwestern continental shelf margin of Laurentia. This is the second occurrence of typical anisograptid graptolites in Mexico, after its original record in the Oaxaca area, which belongs to a Gondwana-related paleogeographical realm. The graptolites from Sonora represent the second global occurrence of any member of the Rhabdinopora flabelliformis group in the Ordovician equatorial shelf region. [ABSTRACT FROM AUTHOR]
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- 2023
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55. New fossil assemblages from the Early Ordovician Fezouata Biota.
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Saleh, Farid, Vaucher, Romain, Vidal, Muriel, Hariri, Khadija El, Laibl, Lukáš, Daley, Allison C., Gutiérrez-Marco, Juan Carlos, Candela, Yves, Harper, David A. T., Ortega-Hernández, Javier, Ma, Xiaoya, Rida, Ariba, Vizcaïno, Daniel, and Lefebvre, Bertrand
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BIOTIC communities , *FOSSILS , *LIFE history theory , *SHALE - Abstract
The Fezouata Biota (Morocco) is a unique Early Ordovician fossil assemblage. The discovery of this biota revolutionized our understanding of Earth's early animal diversifications—the Cambrian Explosion and the Ordovician Radiation—by suggesting an evolutionary continuum between both events. Herein, we describe Taichoute, a new fossil locality from the Fezouata Shale. This locality extends the temporal distribution of fossil preservation from this formation into the upper Floian, while also expanding the range of depositional environments to more distal parts of the shelf. In Taichoute, most animals were transported by density flows, unlike the in-situ preservation of animals recovered in previously investigated Fezouata sites. Taichoute is dominated by three-dimensionally preserved, and heavily sclerotized fragments of large euarthropods—possibly representing nektobenthic/nektic bivalved taxa and/or hurdiid radiodonts. Resolving whether this dominance reflects a legitimate aspect of the original ecosystem or a preservational bias requires an in-depth assessment of the environmental conditions at this site. Nevertheless, Taichoute provides novel preservational and palaeontological insights during a key evolutionary transition in the history of life on Earth. [ABSTRACT FROM AUTHOR]
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- 2022
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56. Inequalities and Asymmetries in the Development of Angola's Provinces: The Impact of Colonialism and Civil War.
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Catoto Capitango, João Adolfo, Garat de Marin, Mirtha Silvana, Soriano Flores, Emmanuel, Rojo Gutiérrez, Marco Antonio, Gracia Villar, Mónica, and Durántez Prados, Frigdiano Álvaro
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CIVIL war , *FISHING villages , *SMALL-scale fisheries , *PROVINCES , *COLONIAL administration , *EQUALITY ,PORTUGUESE colonies - Abstract
Angola, as with many countries on the African continent, has great inequalities or asymmetries between its provinces. At the economic, financial, and technological level, there is a great disparity between them, where it is observed that the province of Luanda is the largest financial business center to the detriment of others, such as Moxico, Zaire, and Cabinda. In the latter, despite the advantages of high oil production, from a regional point of view, they remain almost stagnant in time, in a social dysfunction where the population lives on extractivism and artisanal fishing. This article analyzes the most important events in contemporary regional history, the Portuguese occupation that was the Portuguese colonial rule over Angola (1890–1930) and the civil war that was a struggle between Angolans for control of the country (1975–2002), in the consolidation of the asymmetries between provinces. For this work, a theoretical-reflective study was conducted based on the reading of books, articles, and previous investigations on the phenomenon studied. Considering the interpretation and analysis of the theoretical content obtained through the bibliographic research conducted, this theoretical construction approaches the qualitative approach. We conclude that the deep inequalities between regions and within them, between the provinces studied, originated historically in the form of exploitation of the regions and from the consequences of the war. The asymmetries, observed through the variables studied show that the provinces historically explored and considered object regions present a lower growth compared to those that were considered subject regions in which the applied geopolitical strategy, as they are centers of primary production flows, was different. We also observe that, due to the conflicts of the civil war in the less developed regions, the inequalities have deepened, contributing seriously to a higher level of poverty and a lower development of the provinces where these conflicts took place. [ABSTRACT FROM AUTHOR]
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- 2022
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57. Late Ordovician brachiopods from Peru and their palaeobiogeographical relationships.
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Villas, Enrique, Colmenar, Jorge, Gutiérrez‐Marco, Juan C., and Alvarez, Fernando
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ORDOVICIAN paleoecology , *BRACHIOPODA , *CLUSTER analysis (Statistics) , *CORRESPONDENCE analysis (Statistics) ,GONDWANA (Continent) ,LAKE Titicaca (Peru & Bolivia) - Abstract
A Sandbian brachiopod association from the Calapuja Formation, in the Peruvian Altiplano, north-west of Lake Titicaca, has allowed a re-examination of the palaeobiogeographical relationships between Gondwana and Avalonia during the Late Ordovician, when the palaeocontinents are considered to be already very distant from one another. The brachiopod fauna includes the new species Onnizetina calapujensis sp. nov., Horderleyella chacaltanai sp. nov., Drabovinella minuscula sp. nov. and Tasmanella curtiseptata sp. nov., as well as Caeroplecia sp., Dinorthis cf. flabellulum and Tunariorthis cardocanalis. In addition, Colaptomena expansa expansa and Heterorthis retrorsistria, known from the British Burrellian Stage of the Caradoc Series (late Sandbian) in Wales and the Welsh Borderlands, have also been identified. The brachiopod collection is the most diverse known from a single locality in the whole Central Andean Basin. Within it, forms with clear Gondwanan links occur, such as the new species of Onnizetina, Drabovinella and Horderleyella, and typical representatives of the Avalonian faunas, such as the Welsh Colaptomena expansa expansa and Heterorthis retrorsistria. The brachiopod species exchange between the Proto- Andean margin of Gondwana and Avalonia, now believed to be possible during the late Sandbian, allows a reconsideration of the global taxonomic affinities of both regions. With this in mind, detrended correspondence analysis ( DCA) and cluster analysis have been applied to an updated rhynchonelliformean brachiopod matrix consisting of presence/absence data. The scatter plot resulting from the DCA allows a vivid visualization of the grouping and geographical trends of the South American localities with respect to Avalonia- Baltica and the Mediterranean margin of Gondwana during the Sandbian. Our results agree with previous palaeogeographical reconstructions, depicting Avalonia very close to Baltica and already distant from Gondwana. As a few brachiopod species, with low dispersal potential, would have been able to migrate between those distant palaeocontinents, the existence of intermediate islands in the Rheic Ocean, permitting the transit by island hopping of eurythermal species, must be considered. [ABSTRACT FROM AUTHOR]
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- 2015
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58. Ordovician graptolites from the basal part of the Palaeozoic transgressive sequence in the Karadere area, Zonguldak Terrane, NW Turkey.
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Göncöglu, M. Cemal, Sachanski, Valeri, Gutiérrez-Marco, Juan Carlos, and Okuyucu, Cengiz
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GRAPTOLITES , *GEOLOGICAL formations , *ORDOVICIAN stratigraphic geology , *ORDOVICIAN Period - Abstract
The Karadere area to the east of Safranbolu in NW Anatolia is one of the very few localities in Turkey where the contact between the Cadomian basement and the Lower Palaeozoic transgressive succession is well exposed. The Ordovician graptolite Rhabdinopora flabelliformis (Eichwald) ssp. was found in the basal part of the Bakacak Formation, indicating an Early to early Late Tremadocian age for the beginning of the Palaeozoic transgression in the Zonguldak terrane. A few metres above this occurrence, another horizon contains Paradelograptus cf. antiquus (T. S. Hall), which mainly ranges into the Late Tremadocian. Higher up in the Ordovician succession, a new graptolite bed confirms an early Darriwilian (Dw1) age for the middle part of the Karadere Formation with the occurrence of the biozonal index Levisograptus austrodentatus (Harris & Keble) and the first record of Tetragraptus cor (Strandmark) in the area. The palaeobiogeographic distribution of these Karadere fossils is in agreement with a peri-Gondwanan affinity of the Zonguldak Terrane of the Pontides, NW Anatolia, during the Early-Middle Ordovician. [ABSTRACT FROM AUTHOR]
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- 2014
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59. Middle Ordovician harknessellid brachiopods (Dalmanellidina) from the Mediterranean margin of Gondwana.
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REYES-ABRIL, JAIME, VILLAS, ENRIQUE, GUTIÉRREZ-MARCO, JUAN CARLOS, JIMÉNEZ-SÁNCHEZ, ANDREA, and COLMENAR, JORGE
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BRACHIOPODA , *ORDOVICIAN Period , *PHYLOGENY , *DALMANELLIDAE ,GONDWANA (Continent) - Abstract
The family Harknessellidae Bancroft, 1928 (Orthida, Dalmanellidina) was designed to embrace an assemblage of species referred previously to Harknessella Reed, 1917, and included five genera known mainly from the Middle and Upper Ordovician of England. Herein, we suggest reassigning to this family the genus Cacemia Mitchell, 1974, widespread in the middle Darriwilian (upper Middle Ordovician) of the Iberian and Armorican massifs. Since its designation, Cacemia was placed among the dalmanellidin heterorthids, in spite of its strongly mucronate hinge line, which is totally unknown within this Mediterranean family. A new harknessellid has been identified from the upper Darriwilian beds of the Central Iberian Zone (Central Spain): Isabelella fascicostellata Reyes-Abril & Villas gen. et sp. nov. It is similar to Horderleyella Bancroft, 1928 for its coarsely fascicostellate radial ornamentation and obtuse cardinal angles, although its convexoplane to convexoconcave profile allows discrimination from the typically dorsibiconvex Horderieyella. A phylogenetic analysis of the family places both Cacemia and Isabelella in basal positions of their clades, which fits with their early stratigraphic record. Based on our study, the family Harknessellidae appears to have originated in the high latitude Mediterranean margins of Gondwana during pre-Darriwilian times, before the detachment of Avalonia from Gondwana. The family reached its highest diversification in Avalonia throughout the Late Ordovician, keeping connections with the Mediterranean and Proto-Andean margins of Gondwana, as well as with the mid-latitude palaeocontinents of Baltica and South China. [ABSTRACT FROM AUTHOR]
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- 2013
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60. The new chronostratigraphic classification of the Ordovician System and its relations to major regional series and stages and to δ13C chemostratigraphy.
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BERGSTRÖM, STIG M., XU CHEN, GUTIÉRREZ-MARCO, JUAN CARLOS, and DRONOV, ANDREI
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GRAPTOLITES , *CONODONTS , *ORDOVICIAN stratigraphic geology , *CARBONATES , *SHALE - Abstract
The extensive work carried out during more than a decade by the International Subcommission on Ordovician Stratigraphy has resulted in a new global classification of the Ordovician System into three series and seven stages. Formal Global Boundary Stratotype Section and Points (GSSPs) for all stages have been selected and these and the new stage names have been ratified by the International Commission on Stratigraphy. Based on a variety of biostratigraphic data, these new units are correlated with chronostratigraphic series and stages in the standard regional classifications used in the UK, North America, Baltoscandia, Australia, China, Siberia and the Mediterranean-North Gondwana region. Furthermore, based mainly on graptolite and conodont zones, the Ordovician is subdivided into 20 stage slices (SS) that have potential for precise correlations in both carbonate and shale facies. The new chronostratigraphic scheme is also tied to a new composite δ13C curve through the entire Ordovician. [ABSTRACT FROM AUTHOR]
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- 2009
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61. Microbiología de secreciones bronquiales en una unidad de cuidados intensivos.
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Casanova-Cardiel, Luis Javier, Castañón-González, Jorge Alberto, León-Gutiérrez, Marco Antonio, Becerra-Lara, Juan José, Calyeca-Sánchez, María Verónica, Franco-Contreras, Ana Elizabeth, Polanco-Flores, Esther, González-Green, Isabel, and Martínez-Gutiérrez, Miguel
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DRUG resistance in microorganisms , *PNEUMONIA , *MECHANICAL ventilators , *INTENSIVE care units , *NOSOCOMIAL infections , *PSEUDOMONAS aeruginosa , *STAPHYLOCOCCUS - Abstract
Objective: to know patterns of antimicrobial resistance of bacterial isolates from tracheal aspirates in an Intensive Care Unit and to evaluate the cases of ventilator-associated pneumonia. Methods: antibiotic sensitivity test was done. A comparison was made between patients with nosocomial pneumonia reported by infection surveillance team against those reported by the attending physician with the infectious disease consultant. Results: Pseudomonas aeruginosa was the bacteria most frequently reported with 134 isolates (26 %), 71 were multiple-drug-resistant; followed by Staphylococcus with 122 isolates (24 %), of which 88 were S. aureus with 62 of them (70 %) methicillin-resistant. Enterobacteriaceae, E. coli, K. pneumoniae, E. cloacae, S. marcescens, as well as Acinetobacter sp. and S. maltophilia were occasionally isolated. Candida represented 17 % of the isolates. Three peaks of isolates of S. aureus and P. aeruginosa were identified during the two years of surveillance. There were differences in cases of ventilator associated pneumonia reported by the hospital based epidemiology team and the attending clinicians in collaboration with an Infectious disease consultant. Conclusions: prevalence of Multiple-drug-resistant Pseudomonas aeruginosa (53 %) and methicillin resistant Staphylococcus (70 %) isolated from the airway is high in our Intensive Care Unit. Enterobacterias, Acinetobacter sp. and Stenotrophomonas maltophilia colonization are low in our Intensive Care Unit. [ABSTRACT FROM AUTHOR]
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- 2008
62. NEW AND REVISED OCCURRENCES OF ORDOVICIAN CRINOIDS FROM SOUTHWESTERN EUROPE.
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Ausich, William I., Sá, Artur A., and Gutiérrez-Marco, Juan C.
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FOSSIL crinoidea , *FOSSIL pelmatozoa , *STRATIGRAPHIC paleontology , *ORDOVICIAN paleontology - Abstract
A comprehensive treatment of Ordovician crinoids from southwestern Europe is presented, including taxa based on articulated crowns and stems. This summary incorporates new material, new localities, and a revision of some southwestern Europe occurrences. The first record of an Ordovician crinoid from Portugal, Delgadocrinus oportovinum n. gen. and sp., is reported, and this is the oldest known crinoid from the Iberian Peninsula (Arenigian/Oretanian boundary, early Darriwilian). Geographic and temporal ranges of several crinoids are revised from peri-Gondwanan areas in southwestern Europe and northern Africa or modified with new Iberian material. The Spanish range of Heviacrinus melendezi Gil Cid et al., 1996 is extended down into the lower upper Oretanian, and Merocrinus millanae Ausich et al., 2002 is restricted to the upper lower Dobrotivian. The stratigraphic position of Ortsaecrinus cocae Gil Cid et al., 1999b is restricted to the early middle Berounian, and the range of Visocrinus castelli Ausich et al., 2002 is restricted to the late middle Berounian (see Fig. 2). New topotype material of Morenacrinus silvani Ausich et al., 2002 is reported that furthers understanding of the occurrence this taxon, which was previously only positively known from the holotype. [ABSTRACT FROM AUTHOR]
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- 2007
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63. Hirnantia Fauna from the Condroz Inlier, Belgium: another case of a relict Ordovician shelly fauna in the Silurian?
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Pereira, Sofia, Colmenar, Jorge, Mortier, Jan, Vanmeirhaeghe, Jan, Verniers, Jacques, Štorch, Petr, Taylor Harper, David Alexander, and Gutiérrez-Marco, Juan Carlos
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BRACHIOPODA , *MASS extinctions , *ABSOLUTE sea level change , *TRILOBITES , *BIOTIC communities , *GLACIATION - Abstract
The end-Ordovician mass extinction, linked to a major glaciation, led to deep changes in Hirnantian–Rhuddanian biotas. The Hirnantia Fauna, the first of two Hirnantian survival brachiopod-dominated communities, characterizes the lower–mid Hirnantian deposits globally, and its distribution is essential to understand how the extinction took place. In this paper, we describe, illustrate, and discuss the first macrofossiliferous Hirnantia Fauna assemblage from Belgium, occurring in the Tihange Member of the Fosses Formation at Tihange (Huy), within the Central Condroz Inlier. Six fossiliferous beds have yielded a low-diversity, brachiopod-dominated association. In addition to the brachiopods (Eostropheodonta hirnantensis, Plectothyrella crassicosta, Hirnantia sp., and Trucizetina? sp.), one trilobite (Mucronaspis sp.), four pelmatozoans (Xenocrinus sp., Cyclocharax [col.] paucicrenulatus, Conspectocrinus [col.] celticus, and Pentagonocyclicus [col.] sp.), three graptolites (Cystograptus ancestralis, Normalograptus normalis, and ?Metabolograptus sp.), together with indeterminate machaeridians and bryozoans were identified. The graptolite assemblage, from the Akidograptus ascensus-Parakidograptus acuminatus Biozone, indicates an early Rhuddanian (Silurian) age, and thus, an unexpectedly late occurrence of a typical Hirnantia Fauna. This Belgian association may represent an additional example of relict Hirnantia Fauna in the Silurian, sharing characteristics with the only other known from Rhuddanian rocks at Yewdale Beck (Lake District, England), although reworking has not been completely ruled out. The survival of these Hirnantian taxa into the Silurian might be linked to delayed post-glacial effects of rising temperature and sea-level, which may have favored the establishment of refugia in these two particular regions that were paleogeographically close during the Late Ordovician–early Silurian. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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64. Allele Frequency of ACE2 Intron Variants and Its Association with Blood Pressure.
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Lozano-Gonzalez, Karla, Padilla-Rodríguez, Elba, Texis, Tomas, Gutiérrez, Marco N., Rodríguez-Dorantes, Mauricio, Cuevas-Córdoba, Betzaida, Ramírez-García, Eliseo, Mino-León, Dolores, Sánchez-García, Sergio, and Gonzalez-Covarrubias, Vanessa
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BLOOD pressure , *SYSTOLIC blood pressure , *GENE frequency , *HYPERTENSION , *RENIN-angiotensin system , *ANGIOTENSIN II - Abstract
Angiotensin-converting enzyme 2 (ACE2) is known as the counter-regulator of the renin–angiotensin system, it cleaves angiotensin II to render Ag 1–7, a potent vasodilator with multiple roles in cardiovascular protection. A few studies have pinpointed ACE2 polymorphisms and their relationship with heart function and hypertension in a sex-dependent manner. These observations still lack replication mostly for admixed populations. This study aimed to report minor allele frequencies of four ACE2 intron variants, rs2285666, rs2048683, rs2106809, and rs4240157, derived from previous research using the GSA, v1.0, microarray in 1231 hypertensive and nonhypertensive patients. Logistic and multiple linear regression models were developed to identify potential associations with hypertension status and systolic and diastolic blood pressure (SBP and DBP). Allele frequency differences were identified for ACE2 rs2048683 and rs4240157 in populations with European ancestry and people of the Americas. Regression analyses identified a significant association of ACE2 rs2048683 and rs4240157 with SBP/DBP in males or females. Our observations confirm sex differences in ACE2 genetic associations with SBP and DBP and contribute to the collection of genetic variation in ACE2 for admixed populations. [ABSTRACT FROM AUTHOR]
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- 2020
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65. Innate Lymphoid Cells Have Decreased HLA-DR Expression but Retain Their Responsiveness to TLR Ligands during Sepsis.
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Cruz-Zárate, David, Cabrera-Rivera, Graciela Libier, Ruiz-Sánchez, Bibiana Patricia, Serafín-López, Jeanet, Chacón-Salinas, Rommel, López-Macías, Constantino, Isibasi, Armando, Gallegos-Pérez, Humberto, León-Gutiérrez, Marco Antonio, Ferat-Osorio, Eduardo, Arriaga-Pizano, Lourdes, Estrada-García, Iris, and Wong-Baeza, Isabel
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SEPSIS , *INNATE lymphoid cells , *MONOCYTES , *IMMUNOSUPPRESSION , *CASPASES - Abstract
Sepsis, one of the leading causes of death in intensive care units, is caused by a dysregulated host response to infection that leads to life-threatening organ dysfunction. The proinflammatory and anti-inflammatory responses activated by the infecting microorganism become systemic, and the sustained anti-inflammatory response induces a state of immunosuppression that is characterized by decreased expression of HLA-DR on monocytes, T cell apoptosis, and reduced production of TNF-a by monocytes and macrophages in response to TLR ligands. Innate lymphoid cells (ILCs) are lymphocytes that lack Ag-specific receptors and lineage-specific markers; they express HLA-DR and are activated by cytokines and by direct recognition of microbial molecules. In this study, we evaluated if ILCs are affected by the anti-inflammatory response during sepsis. We found that the number of peripheral blood ILCs was decreased in septic patients compared with healthy volunteers; this decrease was caused by a reduction in ILC1 and ILC3 and is associated with apoptosis, because ILCs from septic patients expressed active caspase 3. ILCs from septic patients had decreased HLA-DR expression but increased expression of the activating receptors NKp46 and NKp44; they also showed a sustained expression of CD127 (IL-7R α-chain) and retained their capacity to produce TNF-α in response to TLR ligands. These results indicate that during sepsis, ILCs have decreased HLA-DR expression and die via apoptosis, similar to monocytes and T cells, respectively. However, other effector functions of ILCs (activation through NKp46 and NKp44, TNF-α production) may remain unaffected by the immunosuppressive environment prevailing in septic patients. [ABSTRACT FROM AUTHOR]
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- 2018
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66. Conodonts from the Lower Ordovician of Morocco — Contributions to age and faunal diversity of the Fezouata Lagerstätte and peri-Gondwana biogeography.
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Lehnert, Oliver, Nowak, Hendrik, Sarmiento, Graciela N., Gutiérrez-Marco, Juan Carlos, Akodad, Mustapha, and Servais, Thomas
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CONODONTS , *ORDOVICIAN paleoecology , *ANIMAL diversity , *BIOGEOGRAPHY , *BIOTIC communities , *PROTOPANDERODUS ,GONDWANA (Continent) - Abstract
This study documents conodont faunas of the Fezouata Formation, recovered from the AZ-1 borehole at Adrar Zouggar Mountain and from outcrops near Zagora in south-eastern Morocco. The Fezouata Formation was deposited on the peri-Gondwanan shelf near the South Pole during Early Ordovician times. It is composed of mostly fine-grained siliciclastics and is well known for including beds displaying the exceptionally well preserved Fezouata Biota. Studies on different microfossil groups, including conodonts, increase the diversity recorded from this exceptional ecosystem. Strongly recrystallised conodont elements were extracted from the fine-grained siliciclastic sediments by diluted hydrofluoric acid (HF), which was used for isolating palynomorphs. The material is dominated by simple cone taxa such as Parapaltodus , Semiacontiodus , Scolopodus , Scalpellodus , Drepanoistodus , Acodus , Paltodus , and Cornuodus . In addition, a few elements of early Prioniodus are recovered. This composition allows an estimation of uppermost Tremadocian through basal Floian ages for the fragmented elements because characteristic elements of younger assemblages, including ramiform (e.g., Oepikodus , Baltoniodus ) or coniform (e.g., Tropodus , Protopanderodus ) apparatuses, have not been recorded. The association is devoid of any warm/tropical and temperate water taxa and is typical for faunas in the cold water environments of the subpolar siliciclastic shelves during Early Ordovician times. The new term of ‘subpolar faunal domain’ is proposed for these conodont associations of low diversity that occur at high southern latitudes during the Early Ordovician. Ecological implications and palaeobiogeographical relationships of the conodont faunas are discussed. [ABSTRACT FROM AUTHOR]
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- 2016
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67. Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize.
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Baltazar, Baltazar M., Castro Espinoza, Luciano, Espinoza Banda, Armando, de la Fuente Martínez, Juan Manuel, Garzón Tiznado, José Antonio, González García, Juvencio, Gutiérrez, Marco Antonio, Guzmán Rodríguez, José Luis, Heredia Díaz, Oscar, Horak, Michael J., Madueño Martínez, Jesús Ignacio, Schapaugh, Adam W., Stojšin, Duška, Uribe Montes, Hugo Raúl, and Zavala García, Francisco
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POLLEN , *GENE flow , *GENE flow in plants , *PLANT diversity - Abstract
Mexico, the center of origin of maize (Zea mays L.), has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient) of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance). The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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68. First Furongian (late Cambrian) trilobites from the Cantabrian Zone (north-western Spain).
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ACEŇOLAZA, GUILLERMO F., ALBANI, ROBERTO, BERNÁRDEZ, ENRIQUE, GARCÍA-BELLIDO, DIEGO C., GUTIÉRREZ-MARCO, JUAN CARLOS, RÁBANO, ISABEL, and SÁ, ARTUR A.
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CRUSTACEA , *TRILOBITES , *ACRITARCHS , *TRACE fossils , *ORDOVICIAN paleontology , *CANTABRIANS - Abstract
The first Furongian trilobites are described herein from the Cambrian of the Cantabrian Zone, NW Spain. They were collected during the construction of the "Túnel Ordovícico del Fabar" from the shales of "El Fabar Beds" in the La Matosa member of the Barrios Formation. The assemblage includes the aphelaspidine genus Maladioidella, with a specimen identified as M. cf. colcheni, a species previously known from Sierra de la Demanda (Spain), and possibly Sardinia and Oman. Fragments of an indeterminate olenid trilobite and phyllocarid crustaceans have also been recorded. Based on the acritarch assemblage, these beds are considered as late Jiangshanian or earliest Stage 10 of the Cambrian System. The ichnofossil Cruziana semiplicata has also been collected in the tunnel from the upper part of the Ligueria Member (Tremadocian) of the Barrios Formation, clearly postdating the occurrence of Maladioidella colcheni, its supposed tracemarker according to some authors. The separate record of both taxa (a Furongian trilobite and a Cambro-Ordovician trace fossil) does not support this statement, so their relationship would be refuted in this case. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
69. Pseudoobstrucción colónica aguda (síndrome de Ogilvie). Informe de dos casos.
- Author
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Abraján-Hernández, Octavio Iván, Castañón-González, Jorge Alberto, León-Gutiérrez, Marco Antonio, Tejeda-Huezo, Brigette, Sánchez-Hurtado, Luis, Serrano-Cuevas, Leonor, and Hernández-Ramírez, Daniel Alejandro
- Subjects
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GASTROINTESTINAL motility disorders , *DILATATION & extraction abortion , *METABOLIC disorders , *CENTRAL nervous system abnormalities , *PROSTAGLANDINS , *COLONOSCOPY , *CHOLINESTERASE inhibitors - Published
- 2009
70. Diagnóstico del sistema turístico en la cuenca del Lago Ranco.
- Author
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Peña-Cortés, Fernando, Hermosilla, Katherine, Escalona-Ulloa, Miguel, Rebolledo, Gonzalo, and Gutiérrez, Marco
- Subjects
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CRATER lakes , *WATERSHEDS , *HUILLICHE (South American people) , *MAPUCHE (South American people) , *TOURISM development offices (Government) , *TOURIST attractions , *HERITAGE tourism , *INDIGENOUS peoples of South America - Abstract
In this essay the tourism system of the Ranco lake watershed is characterized and some potential tourist products are described for the comunas of Futrono and Lago Ranco. These analyses form part of the Plan de Ordenamiento Territorial de la Cuenca del Lago Ranco (LPT-UCT 2007), which is based on secondary informative data recollected, the implementation of participative workshops, and interviews with local actors, which has made it possible to quantify the primary tourist attractions of the watershed. The results show that for the comuna of Futrono, has 45 attractions in four tourism units (Futrono, Huapi, Llifén, and Maihue), while for the comuna of Lago Ranco's 47 attractions were identified in four units (Nilahue, Rupumeika, Illahuape and Ranco). Among these attractions, those that are particularly unique are the volcanic systems, the Maihue and Ranco lakes, and the presence of the mapuche huilliche culture. We conclude that the Ranko Lake watershed possesses a potential for touristic development as much for its natural resources as for its historical-cultural patrimony. [ABSTRACT FROM AUTHOR]
- Published
- 2010
71. Graptolite and conodont biostratigraphy of the upper Telychian-lower Sheinwoodian (Llandovery-Wenlock) strata, Jabalón River section, Corral de Calatrava, central Spain.
- Author
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LOYDELL, D. K., SARMIENTO, G. N., ŠTORCH, P., and GUTIÉRREZ-MARCO, J. C.
- Subjects
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GRAPTOLITES , *CONODONTS , *BIOSTRATIGRAPHY , *FOSSIL animals - Abstract
A graptolite biostratigraphy is erected for the upper Telychian (upper crenulata Biozone) to lower Sheinwoodian (riccartonensisor dubiusBiozone) strata of the Jabalón River section, Spain. Two unconformities are recognized in the section: one between the lapworthiand murchisonibiozones; the other between the murchisoniand riccartonensisbiozones. These unconformities coincide with intervals of lowered eustatic sea-level. Graptolite assemblages include both cosmopolitan taxa and some which have been recorded previously from Morocco and/or other Spanish sections. At some stratigraphical levels Pristiograptusor Euroclimacisspecies are abundant; Monoclimacis, Streptograptusand Mediograptusspecies are generally uncommon. Conodonts were examined from the upper spiralisthrough to lower murchisoniBiozone; the occurrences of Pterospathodus amorphognathoidesare consistent with the species' known range elsewhere. Four new graptolite species are described: Euroclimacis jabalonensis, E. hamata, Monoclimacis flexaand Stimulograptus pradoi. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
72. Impact of Opuntia species plant bio-battery in a semi-arid environment: Demonstration of their applications.
- Author
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Apollon, Wilgince, Kamaraj, Sathish-Kumar, Silos-Espino, Héctor, Perales-Segovia, Catarino, Valera-Montero, Luis L., Maldonado-Ruelas, Víctor A., Vázquez-Gutiérrez, Marco A., Ortiz-Medina, Raúl A., Flores-Benítez, Silvia, and Gómez-Leyva, Juan F.
- Subjects
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OPUNTIA , *BATTERY storage plants , *PLANT species , *MICROBIAL fuel cells , *CACTUS , *SUCCULENT plants , *ELECTRIC power production , *OPUNTIA ficus-indica - Abstract
Impact of power on Cactus Growth. • A novel vertically plug-in ceramic stick based plant bio-battery was constructed. • Higher total electricity production of 285.12 J was achieved in Opuntia albicarpa. • Opuntia ficus-indica and Opuntia albicarpa showed a significantly improved biomass. • We demonstrated the feasibility of plant bio-battery in the semi-arid area. The plant microbial fuel cell (P-MFC) is a novel bioelectrochemical device that is commonly used in highly water-saturated ecosystems to produce sustainable energy. However, the use of this system in arid or semi-arid areas has been less well explored to date. This would involve, the use of plants such as prickly pear, which adapts to these adverse conditions and could be an alternative to expand the application of P-MFC. The objective of this research is to use four Opuntia species (succulent plants) for the generation of sustainable electricity via plant-based biobattery design, under open environment and unsaturated water conditions. A Novel vertically integrated plug-in ceramic stick based P-MFCs was constructed, this could reduce the usage of the top-soil surface and aid the possible potential of scale-up design. For a long operating time (30 days), the results showed an average power density of 103.6 mW m−3 with reactors using Opuntia albicarpa , followed by Opuntia ficus-indica (10.63 mW m−3) > Opuntia robusta (7.46 mW m−3) > Opuntia joconostle (0.46 mW m−3), with 1000 Ohms resistance. Higher total electricity production of 285.12 J was achieved in Opuntia albicarpa over four weeks. In addition, the energy generation of 3.66 Wh m−2 was achieved in this study. Notably, Opuntia ficus-indica and Opuntia albicarpa species showed a significant height in the first two months (P-value < 0.05). This finding opened the avenue for the electricity generation impact on plant growth. The P-MFC also shows the potential to be used in a semi-arid area. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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