148 research outputs found

    Urohidrosis as an overlooked cooling mechanism in long-legged birds

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    Behavioural thermoregulation could buffer the impacts of climate warming on vertebrates. Specifically, the wetting of body surfaces and the resulting evaporation of body fluids serves as a cooling mechanism in a number of vertebrates coping with heat. Storks (Ciconiidae) frequently excrete onto their legs to prevent overheating, a phenomenon known as urohidrosis. Despite the increasingly recognised role of bare and highly vascularised body parts in heat exchange, the ecological and evolutionary determinants of urohidrosis have been largely ignored. We combine urohidrosis data from a scientifically curated media repository with microclimate and ecological data to investigate the determinants of urohidrosis in all extant stork species. Our phylogenetic generalised linear mixed models show that high temperature, humidity and solar radiation, and low wind speed, promote the use of urohidrosis across species. Moreover, species that typically forage in open landscapes exhibit a more pronounced use of urohidrosis than those mainly foraging in waterbodies. Substantial interspecific variation in temperature thresholds for urohidrosis prevalence points to different species vulnerabilities to high temperatures. This integrated approach that uses online data sources and methods to model microclimates should provide insight into animal thermoregulation and improve our capacity to make accurate predictions of climate change’s impact on biodiversityinfo:eu-repo/semantics/publishedVersio

    Efeito da dietílnitrosamína, associada ou não a fenobarbital e diazepam, sobre fígado de gerbil (Meriones unguiculatus)

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    Foram estudadas as alterações hepáticas induzidas quimicamente em gerbil, através de tratamento crônico com dietilnitrosamina subcutânea, associada ou não a fenobarbital oral e diazepam intraperitoneal. As observações foram realizadas a partir da 25ª semana, quando o tratamento foi suspenso, até a 50ª semana. A dietilnitrosamina exerceu efeito hematotóxico acentuado, evidenciado por citomegalia, necrose multifocal, proliferação ductular e fibrose. Este diminuiu intensamente com a administração simultânea de fenobarbital, mas o mesmo não aconteceu com a administração concomitante de diazepam. O tratamento concomitante de fenobarbital não anulou a ação carcinogênica da dietilnitrosamina, e a partir da 36ª semana ocorreram hepatocarcinomas, predominando o padrão trabecular; Já o diazepam parece ter diminuído o efeito hepatocarcinógeno e na 50ª semana registraram-se apenas lesões pré-neoplásicas

    The sources of variation for individual prey-to-predator size ratios

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    The relative body size at which predators are willing to attack prey, a key trait for predator-prey interactions, is usually considered invariant. However, this ratio can vary widely among individuals or populations. Identifying the range and origin of such variation is key to understanding the strength and constraints on selection in both predators and prey. Still, these sources of variation remain largely unknown. We filled this gap by measuring the genetic, maternal and environmental variation of the maximum prey-to-predator size ratio (PPSRmax) in juveniles of the wolf spider Lycosa fasciiventris using a paternal half-sib split-brood design, in which each male was paired with two females and the offspring reared in two food environments: poor and rich. Each juvenile spider was then sequentially offered crickets of decreasing size and the maximum prey size killed was determined. We also measured body size and body condition of spiders upon emergence and just before the trial. We found low, but significant heritability (h2 = 0.069) and dominance and common environmental variance (d2 + 4c2 = 0.056). PPSRmax was also partially explained by body condition (during trial) but there was no effect of the rearing food environment. Finally, a maternal correlation between body size early in life and PPSRmax indicated that offspring born larger were less predisposed to feed on larger prey later in life. Therefore, PPSRmax, a central trait in ecosystems, can vary widely and this variation is due to different sources, with important consequences for changes in this trait in the short and long terms.info:eu-repo/semantics/publishedVersio

    Assessment of Child, Mother, and Environmental Factors Associated with Undernutrition in Children Less than Five Years Old in a Maya Community in Yucatan, Mexico

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    The objective of this study was to examine child, mother, and environmental factors associated with undernutrition in children less than five years old in a Maya community in Yucatan, Mexico. This investigation was designed as a case-control study. All cases (n=42) of undernutrition were included, and a sample of 52 controls was randomly selected from the study population. The frequency of investigated exposure factors was compared between cases and controls by using logistic regression. Undernutrition was associated with child’s age (> 36 months old; OR = 3.53; 95% CI = 1.04, 18.40) and mother’s marital status (married; OR = 0.29; 95% CI = 0.09, 0.90). The odds of undernutrition were 2.81 times higher in children infected with Giardia spp, but this association was not significant (P = 0.18) after controlling for child’s age and mother’s marital status. In conclusion, child’s age and mother’s marital status were associated with child undernutrition in study subjects. Futures studies on undernutrition in children should examine more carefully how mother’s marital status alone or in combination with other factors (e.g. socio-economic, psychological factors) can influence child nutrition

    Recursos y estrategias para la enseñanza de la estadística y la analítica de datos en la educación superior

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    The purpose of this study is to present a literature review analysis on the teaching of statistics and data analytics in higher education. The assessment includes examining the role played by specific factors as mediators of teaching-learning processes. These factors include: disciplinary and pedagogical training of teachers, teaching styles, classroom experiences, use of didactic resources, and context. The literature review revealed that there is a need to create and develop innovative learning environments that transform the teaching of statistics at the university level, starting from rethinking the contents and curricula to favor the social dimension and the humanistic and complex thinking of students. It is concluded that, currently, the generalization of digital media and social networks imposes new challenges for teaching statistics and data analytics in the context of data science, machine learning, and big data.El propósito de este estudio es presentar una reflexión documentada frente a la enseñanza de la estadística y la analítica de datos en la educación superior. Se analiza el papel que cumplen factores como la formación disciplinar y pedagógica de los docentes, sus estilos de enseñanza, las experiencias en el aula de clase, el uso de recursos didácticos y el contexto, como mediadores de los procesos de enseñanza-aprendizaje. Como resultado de la referenciación de autores realizada, se expone frente a la necesidad de crear y desarrollar ambientes de aprendizaje innovadores que transformen la enseñanza de la estadística a nivel universitario, a partir de repensar los contenidos y currículos para favorecer la dimensión socio humanística y el pensamiento complejo de los estudiantes. Se concluye que actualmente la generalización de medios digitales y las redes sociales constituyen un nuevo reto para la enseñanza de la estadística y la analítica de datos en su integración con ciencia de datos, aprendizaje automático y macrodatos

    Characterization of water uptake by organic coatings used for the corrosion protection of steel as determined from capacitance measurements

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    Water absorption by a coating on a metal is a major factor affecting its corrosion protection efficiency. It is usually determined from the increase of coating capacity with time, which is taken as a measure of the water volume ratio in the system. In this communication, the early stages of water uptake by three paint systems applied on galvanized steel have been investigated. The models proposed by Brasher and Kingsbury (BK), and the discrete (DM) and the continuous (CM) models proposed by Bellucci and Nicodemo, were employed to evaluate water absorption. It has been found that the amount of water adsorbed in the coating depended on both the nature and the thickness of the film, though different results were delivered by these methods, with convergence occurring only in the saturation stage. Next, water diffusion coefficients were determined, and they were observed to vary with the thickness of the polymer film regardless their actual composition. The time evolution of the diffusion coefficients could be adequately described using the DM model

    A novel HPV 16 L1-based chimeric virus-like particle containing E6 and E7 seroreactive epitopes permits highly specific detection of antibodies in patients with CIN 1 and HPV-16 infection

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    <p>Abstract</p> <p>Background</p> <p>The presence of IgG antibodies to HPV-16 L1-virus like particles (VLPs) in serum has been reported as a result of persistent exposure to the virus and as a marker of disease progression. However, detection of VLP-specific antibodies in sera does not always indicate a malignant lesion as positive results may also be due to a nonmalignant viral infection. Furthermore, malignant lesions are associated with an increased antibody titer for E6 and E7 proteins. The aim of this study was to develop an ELISA using a novel chimeric virus-like particle (cVLP) encoding an L1 protein fused with a string of HPV-16 E6 and E7 seroreactive epitopes to its C-terminus to be used for detection of HPV-16 specific antibodies in patients with cervical intraepithelial lesion grade 1 (CIN 1).</p> <p>Results</p> <p>The sera of 30 patients with CIN 1 who also tested positive for HPV-16 DNA and of 30 age-matched normal donors negative for HPV infection were tested for the presence of IgG antibodies specific for either VLP-L1 (HPV-16 L1), gVLP (derived from Gardasil), or cVLP by ELISA. The cVLP-reactive sera yielded two distinct groups of results: (H) reactivity levels that presented very strong cVLP-specific titers, and (L) reactivity levels with significantly lower titers similar to those obtained with VLP-L1 and gVLP antigens. Additionally, the sera that presented the higher cVLP titers closely matched those that had significantly stronger reactivity to E6 and E7 epitopes. Interestingly, the samples with the highest titers corresponded to patients with the higher numbers of sexual partners and pregnancies. On the other hand only 4 out of the 12 sera that harbored antibodies with VLP neutralizing ability corresponded to the group with high cVLP antibody titers.</p> <p>Conclusion</p> <p>We report for the first time that chimeric particles containing HPV-16 L1 protein fused with E6 and E7 seroreactive epitopes enable much better detection of IgG antibodies in the sera of CIN 1 patients positive for HPV-16 infection than those obtained with VLPs containing only the HPV-16 L1 protein. We also found that the sera with higher cVLP antibody titers corresponded to patients with more sexual partners and pregnancies, and not always with to those with a high neutralizing activity. This novel assay could help in the development of a tool to evaluate cervical cancer risk.</p

    Caracterización del subsistema de plantas me-dicinales en los patios traseros (Patyotyoty) de la comunidad de Amado Nervo, Municipio de Yajalón, Chiapas; México

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    Se realizó un estudio con el propósito de hacer una caracterización de los traspatios (PATY OTYOTY), en la comunidad Amado Nervo, municipio de Yajalón Chiapas, que contempló un inventario de las plantas medicinales que se encuentran en ellos, además del uso y manejo de las mismas. El estudio hace una descripción en general de los recursos naturales con que cuentan los PATY OTYOTY (atrás de la casa) y aborda con mayor minuciosidad las plantas medicinales. Para recabar la información se utilizó la técnica de entrevista semi estructurada, observación directa y diario de campo. El tamaño de la muestra se calculó por muestreo aleatorio simple (Zar, 1999), y se aplicó a 39 traspatios. Los resultados indican que en la comunidad de Amado Nervo cuenta con 1391 habitantes y 277 familias, existen siete parteras que se encuentran registradas por la clínica del IMSS. El inventario realizado indica que las plantas son para uso familiar, no hay comercialización con fines de lucro y las más frecuentemente encontradas son: albaca, ajenjo, ajo, cempasúchil, chanita, hierbabuena, hinojo, maguey morado, chaya, orozúz, árnica, yäxbak, orégano, poleo, ruda, té de zacate, sábila y perejil. Se encontró que el 26% de los Paty Otyoty no tienen plantas medicinales mientras que el 61 % aplican abono orgánico para la producción. Se concluye que el uso de medicamentos alópatas como el de plantas medicinales es utilizado con frecuencia para recuperar el estado de salud de las personas, se reconoce que el 39% de los habitantes recurre a ellas como única alternativa debido a la escases de recursos económicos

    Perfusion Decellularization of Extrahepatic Bile Duct Allows Tissue-Engineered Scaffold Generation by Preserving Matrix Architecture and Cytocompatibility

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    Reconstruction of bile ducts damaged remains a vexing medical problem. Surgeons have few options when it comes to a long segment reconstruction of the bile duct. Biological scaffolds of decellularized biliary origin may offer an approach to support the replace of bile ducts. Our objective was to obtain an extracellular matrix scaffold derived from porcine extrahepatic bile ducts (dECM-BD) and to analyze its biological and biochemical properties. The efficiency of the tailored perfusion decellularization process was assessed through histology stainings. Results from 4’-6-diamidino-2-phenylindole (DAPI), Hematoxylin and Eosin (H&E) stainings, and deoxyribonucleic acid (DNA) quantification showed proper extracellular matrix (ECM) decellularization with an effectiveness of 98%. Immunohistochemistry results indicate an effective decrease in immunogenic marker as human leukocyte antigens (HLA-A) and Cytokeratin 7 (CK7) proteins. The ECM of the bile duct was preserved according to Masson and Herovici stainings. Data derived from scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) showed the preservation of the dECM-BD hierarchical structures. Cytotoxicity of dECM-BD was null, with cells able to infiltrate the scaffold. In this work, we standardized a decellularization method that allows one to obtain a natural bile duct scaffold with hierarchical ultrastructure preservation and adequate cytocompatibility

    Reversal of SARS-CoV2-Induced Hypoxia by Nebulized Sodium Ibuprofenate in a Compassionate Use Program

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    Introduction: Sodium ibuprofenate in hypertonic saline (NaIHS) administered directly to the lungs by nebulization and inhalation has antibacterial and anti-inflammatory effects, with the potential to deliver these benefits to hypoxic patients. We describe a compassionate use program that offered this therapy to hospitalized COVID-19 patients. Methods: NaIHS (50 mg ibuprofen, tid) was provided in addition to standard of care (SOC) to hospitalized COVID-19 patients until oxygen saturation levels of > 94% were achieved on ambient air. Patients wore a containment hood to diminish aerosolization. Outcome data from participating patients treated at multiple hospitals in Argentina between April 4 and October 31, 2020, are summarized. Results were compared with a retrospective contemporaneous control (CC) group of hospitalized COVID-19 patients with SOC alone during the same time frame from a subset of participating hospitals from Córdoba and Buenos Aires. Results: The evolution of 383 patients treated with SOC + NaIHS [56 on mechanical ventilation (MV) at baseline] and 195 CC (21 on MV at baseline) are summarized. At baseline, NaIHS-treated patients had basal oxygen saturation of 90.7 ± 0.2% (74.3% were on supplemental oxygen at baseline) and a basal respiratory rate of 22.7 ± 0.3 breath/min. In the CC group, basal oxygen saturation was 92.6 ± 0.4% (52.1% were on oxygen supplementation at baseline) and respiratory rate was 19.3 ± 0.3 breath/min. Despite greater pulmonary compromise at baseline in the NaIHS-treated group, the length of treatment (LOT) was 9.1 ± 0.2 gs with an average length of stay (ALOS) of 11.5 ± 0.3 days, in comparison with an ALOS of 13.3 ± 0.9 days in the CC group. In patients on MV who received NaIHS, the ALOS was lower than in the CC group. In both NaIHS-treated groups, a rapid reversal of deterioration in oxygenation and NEWS2 scores was observed acutely after initiation of NaIHS therapy. No serious adverse events were considered related to ibuprofen therapy. Mortality was lower in both NaIHS groups compared with CC groups. Conclusions: Treatment of COVID-19 pneumonitis with inhalational nebulized NaIHS was associated with rapid improvement in hypoxia and vital signs, with no serious adverse events attributed to therapy. Nebulized NaIHS s worthy of further study in randomized, placebo-controlled trials (ClinicalTrials.gov: NCT04382768).Fil: Salva, Oscar. Clínica Independencia; ArgentinaFil: Doreski, Pablo A.. Fundación Respirar; ArgentinaFil: Giler, Celia S.. Clínica Independencia; ArgentinaFil: Quinodoz, Dario C.. Sanatorio de la Cañada; ArgentinaFil: Guzmán, Lucia G.. Sanatorio de la Cañada; ArgentinaFil: Muñoz, Sonia Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Carrillo, Mariana Norma del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Porta, Daniela Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Ambasch, Germán. Sanatorio Privado Mayo; ArgentinaFil: Coscia, Esteban. Sanatorio Privado Mayo; ArgentinaFil: Tambini Diaz, Jorge L.. Sanatorio Privado Mayo; ArgentinaFil: Bueno, Germán D.. Sanatorio Privado Mayo; ArgentinaFil: Fandi, Jorge O.. Clínica Independencia; ArgentinaFil: Maldonado, Miriam A.. Sanatorio San Roque; ArgentinaFil: Peña Chiappero, Leandro E.. Sanatori San Roque; ArgentinaFil: Fournier, Fernando. Clínica Francesa; ArgentinaFil: Pérez, Hernán A.. Sanatorio Alive; Argentina. University of Maryland; Estados UnidosFil: Quiroga, Mauro A.. Instituto Modelo de Cardiología; ArgentinaFil: Sala Mercado, Javier Agustin. Instituto Modelo de Cardiología; ArgentinaFil: Martínez Picco, Carlos. Clínica del Sol; ArgentinaFil: Beltrán, Marcelo Alejandro. Hospital Dr. Alberto Duhau; ArgentinaFil: Castillo Argañarás, Luis Fernando. Hospital Dr. Alberto Duhau; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ríos, Nicolás Martínez. Quimica Luar Srl; ArgentinaFil: Kalayan, Galia I.. Provincia de Córdoba. Ministerio de Ciencia y Técnica. Centro de Excelencia en Productos y Procesos de Córdoba; ArgentinaFil: Beltramo, Dante Miguel. Provincia de Córdoba. Ministerio de Ciencia y Técnica. Centro de Excelencia en Productos y Procesos de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Garcia, Nestor Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentina. Provincia de Córdoba. Ministerio de Ciencia y Técnica. Centro de Excelencia en Productos y Procesos de Córdoba; Argentin
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