Respuesta de la comunidad microbiana del suelo a manejos agrícolas diferentes en Santa Clara, Cuba

Seven farms (two state, two cooperatives, and three private farms) were selected for assessing effects of farm management on the microbial biomass and the structure of the microbial community, as well as, the responses to seasonality on these two bio-indicators in these three representative farming systems. All farms are located on brown calcareous soil. Soil samples from the 0-20 cm depth were collected from two fields of each farm. Soil microbial community was assessed through two analyses: microbial biomass carbon and phospholipid fatty acid. The technological differences in soil management, among the three farming systems, affected both microbial biomass carbon and the microbial community composition. The differences were most pronounced between the private and the state farms. The statistical analyses demonstrated that the total of phospholipid fatty-acid were significantly higher in cooperative farms. The use of fallow in these farms seems to have positive effects on soil microbial communities. Seasonality has a clear effect on both indicators. Summarizing, both indicators demonstrated sensible responses to disturbances caused by farm management and seasonality in the conditions of Cuban agriculture. Keywords:  farming systems, microbial biomass carbon, phospholipid fatty-acid analysis (PLFA), soil qualitySiete fincas (dos estatales, dos cooperativas y tres privadas) fueron seleccionadas para evaluar los efectos del manejo agrícola en la biomasa microbiana y en la estructura de la comunidad microbiana, así como, la respuesta a la estacionalidad de estos dos bio-indicadores en los tres sistemas agrícolas. Todas las fincas se encontraban sobre suelos pardos con carbonatos. Las muestras fueron colectadas en dos campos de cada finca a una profundidad de 0-20 cm. La comunidad microbiana fue evaluada a través de dos análisis: carbono de la biomasa microbiana y los fosfolípidos. Las diferencias tecnológicas en el manejo de los suelos, entre los tres sistemas agrícolas, afectaron el carbono de la biomasa microbiana y la estructura de la comunidad microbiana. Las diferencias fueron más pronunciadas entre los sistemas privados y estatales. Los análisis estadísticos demostraron que el total de los fosfolípidos fue significativamente superior en los campos de las cooperativas. El uso del barbecho en estas fincas parece tener efectos positivos en la comunidad microbiana del suelo. La estacionalidad tuvo un claro efecto en los dos indicadores. En resumen, estos bioindicadores demostraron respuestas sensibles a los disturbios causados por el manejo y la estacionalidad en las condiciones de la agricultura cubana. Palabras clave: análisis de ácidos grasos fosfolípidos (PLFA), calidad del suelo, carbono de la biomasa microbiana, sistemas agrícola

Foveal avascular zone and choroidal thickness are decreased in subjects with hard drusen and without high genetic risk of developing Alzheimer’s disease

A family history (FH+) of Alzheimer’s disease (AD) and ɛ4 allele of the ApoE gene are the main genetic risk factors for developing AD, whereas ɛ4 allele plays a protective role in age-related macular degeneration. Ocular vascular changes have been reported in both pathologies. We analyzed the choroidal thickness using optical coherence tomography (OCT) and the foveal avascular zone (FAZ) using OCT-angiography and compared the results with ApoE gene expression, AD FH+, and the presence or absence of hard drusen (HD) in 184 cognitively healthy subjects. Choroidal thickness was statistically significantly different in the (FH−, ɛ4−, HD+) group compared with (i) both the (FH−, ɛ4−, HD−) and the (FH+, ɛ4+, HD+) groups in the superior and inferior points at 1500 μm, and (ii) the (FH+, ɛ4−, HD+) group in the superior point at 1500 μm. There were statistically significant differences in the superficial FAZ between the (FH+, ɛ4−, HD+) group and (i) the (FH+, ɛ4−, HD−) group and (ii) the (FH+, ɛ4+, HD−) group. In conclusion, ocular vascular changes are not yet evident in participants with a genetic risk of developing AD

Resolvamos problemas 5, Secundaria : cuaderno de trabajo de Matemática 2020

Cuaderno de trabajo empleado para el quinto grado de Educación Secundaria para el año 2020

Microhardness, Structure, and Morphology of Primary Enamel after Phosphoric Acid, Self-Etching Adhesive, and Er:YAG Laser Etching

Background. Phosphoric acid is the traditional etching agent; self-etching adhesives and Er:YAG laser are alternative methods. Knowledge of deciduous enamel etching is required. Aim. To evaluate primary enamel microhardness, structure, and morphology after phosphoric acid, self-etching, and Er:YAG laser etching. Design. Seventy primary incisors were assigned to five groups (n=14): I (control), II (35% phosphoric acid), III (self-etching adhesive), IV (Er:YAG laser at 15 J/cm2), and V (Er:YAG laser at 19.1 J/cm2). Microhardness was evaluated by Vickers indentation. Chemical composition was analyzed by energy dispersive X-ray spectroscopy and morphological changes by scanning electron microscopy. One-way ANOVA, Kruskal–Wallis, Mann–Whitney U, and Pearson bivariate correlation were employed (α=0.05). Results. Vickers microhardness showed differences and no correlation with Ca/P ratio. Group II showed differences in carbon, oxygen, and phosphorus atomic percent and group V in Ca/P ratio. Morphological changes included exposed prisms, fractures, craters, and fusion. Conclusions. Enamel treated with phosphoric acid showed different chemical characterization among groups. Self-etching and Er:YAG laser irradiation at 19.1 J/cm2 showed similar microhardness and chemical characterization. Er:YAG laser irradiation at 15 J/cm2 maintained microhardness as untreated enamel. Er:YAG laser irradiation at 19.1 J/cm2 enhanced mineral content. Morphological retentive changes were specific to each type of etching protocol

Oseltamivir-Resistant Pandemic (H1N1) 2009 Virus, Mexico

During May 2009–April 2010, we analyzed 692 samples of pandemic (H1N1) 2009 virus from patients in Mexico. We detected the H275Y substitution of the neuraminidase gene in a specimen from an infant with pandemic (H1N1) 2009 who was treated with oseltamivir. This virus was susceptible to zanamivir and resistant to adamantanes and oseltamivir

A Ribosomal Misincorporation of Lys for Arg in Human Triosephosphate Isomerase Expressed in Escherichia coli Gives Rise to Two Protein Populations

We previously observed that human homodimeric triosephosphate isomerase (HsTIM) expressed in Escherichia coli and purified to apparent homogeneity exhibits two significantly different thermal transitions. A detailed exploration of the phenomenon showed that the preparations contain two proteins; one has the expected theoretical mass, while the mass of the other is 28 Da lower. The two proteins were separated by size exclusion chromatography in 3 M urea. Both proteins correspond to HsTIM as shown by Tandem Mass Spectrometry (LC/ESI-MS/MS). The two proteins were present in nearly equimolar amounts under certain growth conditions. They were catalytically active, but differed in molecular mass, thermostability, susceptibility to urea and proteinase K. An analysis of the nucleotides in the human TIM gene revealed the presence of six codons that are not commonly used in E. coli. We examined if they were related to the formation of the two proteins. We found that expression of the enzyme in a strain that contains extra copies of genes that encode for tRNAs that frequently limit translation of heterologous proteins (Arg, Ile, Leu), as well as silent mutations of two consecutive rare Arg codons (positions 98 and 99), led to the exclusive production of the more stable protein. Further analysis by LC/ESI-MS/MS showed that the 28 Da mass difference is due to the substitution of a Lys for an Arg residue at position 99. Overall, our work shows that two proteins with different biochemical and biophysical properties that coexist in the same cell environment are translated from the same nucleotide sequence frame

Genetic Ancestry, Race, and Severity of Acutely Decompensated Cirrhosis in Latin America

Background & Aims: Genetic ancestry or racial differences in health outcomes exist in diseases associated with systemic inflammation (eg, COVID-19). This study aimed to investigate the association of genetic ancestry and race with acute-on-chronic liver failure (ACLF), which is characterized by acute systemic inflammation, multi-organ failure, and high risk of short-term death. / Methods: This prospective cohort study analyzed a comprehensive set of data, including genetic ancestry and race among several others, in 1274 patients with acutely decompensated cirrhosis who were nonelectively admitted to 44 hospitals from 7 Latin American countries. / Results: Three hundred ninety-five patients (31.0%) had ACLF of any grade at enrollment. Patients with ACLF had a higher median percentage of Native American genetic ancestry and lower median percentage of European ancestry than patients without ACLF (22.6% vs 12.9% and 53.4% vs 59.6%, respectively). The median percentage of African genetic ancestry was low among patients with ACLF and among those without ACLF. In terms of race, a higher percentage of patients with ACLF than patients without ACLF were Native American and a lower percentage of patients with ACLF than patients without ACLF were European American or African American. In multivariable analyses that adjusted for differences in sociodemographic and clinical characteristics, the odds ratio for ACLF at enrollment was 1.08 (95% CI, 1.03–1.13) with Native American genetic ancestry and 2.57 (95% CI, 1.84–3.58) for Native American race vs European American race. / Conclusions: In a large cohort of Latin American patients with acutely decompensated cirrhosis, increasing percentages of Native American ancestry and Native American race were factors independently associated with ACLF at enrollment

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Curso de redacción técnica

Muestra elementos que se requiere conocer para el diseño, redacción y elaboración de informes, memorandos,oficios, sobre cualquier tema, mediante una serie de ejercicios lógicos objetivos, así como la presentación física del materia