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Understanding the mechanisms driving community assembly has been a major focus of ecological research for nearly a century, yet little is known about these mechanisms in commensal communities, particularly with respect to their historical/evolutionary components. Here, we use a large-scale dataset of 4,440 vascular plant species to explore the relationship between the evolutionary distinctiveness (ED) (as measured by the 'species evolutionary history' (SEH)) of host species and the phylogenetic diversity (PD) of their associated epiphyte species. Although there was considerable variation across hosts and their associated epiphyte species, they were largely unrelated to host SEH. Our results mostly support the idea that the determinants of epiphyte colonization success might involve host characteristics that are unrelated to host SEH (e.g., architectural differences between hosts). While determinants of PD of epiphyte assemblages are poorly known, they do not appear to be related to the evolutionary history of host species. Instead, they might be better explained by neutral processes of colonization and extinction. However, the high level of phylogenetic signal in epiphyte PD (independent of SEH) suggests it might still be influenced by yet unrecognized evolutionary determinants. This study highlights how little is still known about the phylogenetic determinants of epiphyte communities.
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Evolução Biológica , Traqueófitas , Filogenia , Simbiose , Especificidade de HospedeiroRESUMO
The Bromeliaceae family has been used as a model to study adaptive radiation due to its terrestrial, epilithic, and epiphytic habits with wide morpho-physiological variation. Functional groups described by Pittendrigh in 1948 have been an integral part of ecophysiological studies. In the current study, we revisited the functional groups of epiphytic bromeliads using a 204 species trait database sampled throughout the Americas. Our objective was to define epiphytic functional groups within bromeliads based on unsupervised classification, including species from the dry to the wet end of the Neotropics. We performed a hierarchical cluster analysis with 16 functional traits and a discriminant analysis, to test for the separation between these groups. Herbarium records were used to map species distributions and to analyze the climate and ecosystems inhabited. The clustering supported five groups, C3 tank and CAM tank bromeliads with deep tanks, while the atmospheric group (according to Pittendrigh) was divided into nebulophytes, bromeliads with shallow tanks, and bromeliads with pseudobulbs. The two former groups showed distinct traits related to resource (water) acquisition, such as fog (nebulophytes) and dew (shallow tanks). We discuss how the functional traits relate to the ecosystems inhabited and the relevance of acknowledging the new functional groups.
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We identify changes in the functional composition of vascular epiphytes along a tropical elevational gradient with the aim of quantifying the role of climate in determining the assembly of epiphyte communities. We measured seven leaf functional traits (leaf area, specific leaf area, leaf dry-matter content, leaf thickness, force to punch, stomatal density, and potential conductance index) in the 163 most abundant epiphyte species recorded across 10 sites located along an elevational gradient between 60 and 2,900 m above sea level in the Colombian Andes. We grouped the epiphyte species into seven hierarchical functional groups according to their most characteristic leaf traits. Along the elevational gradient, the two main independent leaf trait dimensions that distinguished community assemblages were defined primarily by leaf area-photosynthetic (LAPS) and mass-carbon (LMCS) gradients. Mean annual temperature was the main determinant of species position along LAPS. In contrast, local changes in specific leaf area due to variation in the epiphytes' relative height of attachment was the main determinant of their position along the LMCS. Our findings indicate that epiphytic plant leaves have evolved to optimize and enhance photosynthesis through a leaf area-based strategy and carbon acquisition through investments in construction costs of leaf area per unit of biomass that aim to regulate light capture and tissue development. Given that most studies of plant functional traits neglect vascular epiphytes, our quantification of the multiple dimensions of epiphyte leaf traits greatly augments our understanding of vascular plant function and adaptation to changing environments.
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Fotossíntese , Folhas de Planta , Clima , Colômbia , Plantas , Clima TropicalRESUMO
In the new era of functional magnetic resonance imaging (MRI), the utility of chest MRI is increasing exponentially due to several advances, including absence of ionizing radiation, excellent tissue contrast and high capability for lesion characterization and treatment monitoring. The application of several of these diagnostic weapons in a multiparametric fashion enables to better characterize thymic epithelial tumors and other mediastinal tumoral lesions, accurate assessment of the invasion of adjacent structures and detection of pathologic lymph nodes and metastasis. Also, "do not touch lesions" could be identified with the associated impact in the management of those patients. One of the hot-spots of the multiparametric chest MR is its ability to detect with acuity early response to treatment in patients with mediastinal malignant neoplasms. This has been related with higher rates of overall survival and progression free survival. Therefore, in this review we will analyze the current functional imaging techniques available (18F-Fluorodeoxiglucose positron emission tomography/computed tomography, diffusion-weighted imaging, dynamic contrast-enhanced MRI, diffusion tensor imaging and MR spectroscopy) for the evaluation of mediastinal lesions, with a focus in their correct acquisition and post-processing. Also, to review the clinical applications of these techniques in the diagnostic approach of benign and malignant conditions of the mediastinum.
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OBJECTIVE: To compare the percentage of patients at risk for obstructive sleep apnea (OSA) in open-angle glaucoma (OAG) versus controls using the STOP-Bang questionnaire. METHODS: This study used a cross-sectional survey. Patients with OAG and controls completed the STOP-Bang questionnaire-a validated tool to identify patients at high risk for OSA. Patients were considered at risk if they scored 3 or more points or at high risk for moderate/severe OSA if they scored 5 or more out of the maximum 8 points. Demographic information, medical history, and previous diagnosis of OSA were recorded. Details regarding the patients' glaucoma were obtained from their medical records. RESULTS: A total of 437 patients with OAG and 441 controls were included. The mean STOP-Bang score was 3.01 ± 1.3 for the glaucoma group and 3.03 ± 1.4 for the control group (p = 0.92). There was no significant difference between the percentage of subjects considered at risk for OSA (62.7% OAG vs 59.4% controls, p = 0.37) or at high risk for moderate/severe OSA (12.6% OAG vs 16.5% controls, p = 0.1). Significantly more patients in the control group had a previous diagnosis of OSA (p = 0.01). More patients with OAG reported feeling tired compared with controls (p = 0.003). A risk/high risk for OSA was not associated with glaucoma severity, progression, intraocular pressure control, or glaucoma type. CONCLUSIONS: Our results indicate that a risk or high risk for moderate/severe OSA as measured by the STOP-Bang questionnaire is not correlated with the presence or absence of glaucoma (regardless of the type), glaucoma severity, glaucoma progression, or IOP control.
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Glaucoma de Ângulo Aberto/complicações , Programas de Rastreamento/métodos , Apneia Obstrutiva do Sono/epidemiologia , Inquéritos e Questionários , Idoso , Estudos Transversais , Feminino , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Incidência , Masculino , Ontário/epidemiologia , Polissonografia , Fatores de Risco , Apneia Obstrutiva do Sono/etiologiaRESUMO
RESUMEN Las actividades académicas, como los congresos, son muy importantes para la investigación y el desarrollo; sin embargo, las emisiones de carbono derivadas de la realización de eventos presenciales han mostrado estar muy por encima de las que producen eventos en línea. El objetivo de este trabajo fue estimar las emisiones generadas por el 5º Congreso Nacional y 1º Internacional de Ciencias Ambientales "Las Ciencias Ambientales en el Antropoceno", celebrado virtualmente, en su mayor parte. Se estimaron las emisiones del uso directo de computadores y de software (emisiones de los computadores, emisiones de la transferencia de los datos) y las emisiones de otras fuentes (reuniones de los organizadores, búsquedas y visitas a la página Web, uso de monitores externos y lámparas), así como las emisiones evitadas por transporte aéreo y terrestre. El congreso emitió 4,8 tCO2eq y evitó 33 tCO2eq. El desarrollo de eventos online o híbridos es más sostenible ambientalmente y podría ser más accesibles, a un mayor número de personas.
ABSTRACT Academic activities such as conferences are very important for research and development, however, carbon emissions derived from face-to-face events have been shown to be much higher than those produced by online events. The aim of this work was to estimate CO2 emissions generated by the 5th National Congress and 1st International Congress of Environmental Sciences "Environmental Sciences in the Anthropocene". Emissions from direct use of computers and software (emissions from computers, emissions from data transfer) and emissions from other sources (meetings of the organizers, searches and visits to the website, use of external monitors and lamps), as well as emissions avoided by air and land transport. The congress emitted 4.8 tCO2eq and avoided 33 tCO2eq. The development of online or hybrid events is more environmentally sustainable and could be more accessible to a greater number of people.
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Los quistes tímicos multiloculados son lesiones generalmente adquiridas, que se diagnostican de manera incidental en la mayoría de pacientes y se asocian con condiciones de naturaleza diversa, como: inflamación, infección, trauma y radioterapia. Se presenta el caso de una mujer de 55 años con un quiste tímico multiloculado, sin antecedentes de importancia o condición clínica particular al momento del diagnóstico.
Multiloculated thymic cysts are acquired lesions, diagnosed incidentally in most patients and associated with other conditions such as inflammation, infection, trauma and radiothera. We present the case of a 55-year-old woman with a multilocular thymic cyst, with no relevant history or particular clinical condition at the time of diagnosis.
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Humanos , Neoplasias do Timo , Timo , Tomografia Computadorizada por Raios X , Cisto MediastínicoRESUMO
Resumen Los tumores pardos son una forma localizada de osteítis fibrosa no neoplásica, secundaria a hiperparatiroidismo (primario o secundario). Hacen parte de las alteraciones del metabolismo mineral y óseo de la enfermedad renal crónica (ERC). Se manifiestan como lesiones líticas, expansivas, asociadas a masas de tejidos blandos, que pueden estar localizadas en cualquier parte del esqueleto, con predilección por las costillas, clavículas, pelvis, fémur, huesos faciales y mandíbula. Reportamos dos casos de paciente con ERC en terapia de reemplazo renal (TRR), con hiperparatiroidismo secundario y tumores pardos localizados en mandíbula, arcos costales y cuerpos vertebrales, con manifestaciones radiológicas atípicas. Conclusión: los tumores pardos hacen parte de las alteraciones óseas de los pacientes con ERC. El aspecto benigno en los estudios de imágenes (lesiones expansivas sin destrucción de la cortical) en el contexto de un paciente con hiperparatiroidismo, pueden sugerir el diagnóstico. (Acta Med Colomb 2018; 43: 221-225).
Abstract Brown tumors are a localized form of non-neoplastic osteitis fibrosa, secondary to hyperparathyroidism (primary or secondary). They are part of the alterations of the mineral and bone metabolism of chronic kidney disease (CKD). They manifest as lytic, expansive lesions associated to soft tissue masses that can be located in any part of the skeleton with predilection for the ribs, clavicles, pelvis, femur, facial bones and jaw. Two cases of patients with CKD in renal replacement therapy (RRT), with secondary hyperparathyroidism and brown tumors located in the jaw, costal arches and vertebral bodies, with atypical radiological manifestations are described. Conclusion: brown tumors are part of the bone disorders of patients with CKD. The benign appearance in imaging studies (expansive lesions without destruction of the cortex) in the context of a patient with hyperparathyroidism, may suggest the diagnosis. (Acta Med Colomb 2018; 43: 221-225).
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Humanos , Feminino , Adulto , Insuficiência Renal Crônica , Densidade Óssea , HiperparatireoidismoRESUMO
El linfoma de células del manto hace parte del subgrupo de linfomas no Hodgkin (LNH). Este se manifiesta con adenopatías, esplenomegalia, síntomas B y compromiso cutáneo asociado a enfermedad diseminada. El compromiso esplénico se presenta como: Esplenomegalia sin lesión focal; lesiones sólidas únicas o múltiples e infiltración del bazo sin cambios morfológicos ni lesiones focales. La aparición de linfoma con lesiones quísticas es extremadamente rara, se encuentran solo unos cuantos casos en la literatura, ninguno de ellos en el bazo. Se expone el caso de una paciente de 59 años de edad, quien consultó por dolor abdominal intermitente. En los estudios diagnósticos se observó esplenomegalia con lesiones sólidas y quísticas. Se realizó esplenectomía con estudio histopatológico que confirmó compromiso por linfoma de células del manto.
Mantle cell lymphoma is a Non-Hodgkin Lymphoma (NHL). In cases of disseminated disease, lymphadenopathy, splenomegaly, B-symptoms and skin disease are present. Lymphoma affecting the spleen has several radiologic presentations, ranging from normal appearance, to splenomegaly or multiples focal solid lesions. Cystic presentation of lymphoma is rare and few cases have been reported, none of them involving the spleen. We report a case of a 59-year old female patient with cystic spleen lesions that after splenectomy were diagnosed as Mantle cell lymphoma.