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2.
Materials (Basel) ; 14(10)2021 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-34064575

RESUMEN

Whey in large quantities can cause environmental problems when discarded, because it reduces dissolved oxygen and aquatic life. Nonetheless, it could be used as an easily available and economical alternative to reduce culture medium costs in microbially induced calcium carbonate precipitation (MICP). In this work, a native Sporosarcina pasteurii was isolated and then cultured by using different proportions of whey (W) in nutrient broth (NB). The solids were characterized by XRD, FT-IR, TGA, and SEM. The potential applications in bioconsolidation were also studied. Whey concentration was directly related to CaCO3 production. Higher whey concentrations reduced calcium carbonate purity to nearly 80%. All experiments showed calcite and vaterite fractions, where a whey increment in the media increased calcite content and decreased vaterite content, causing a decrease in crystal size. MICP improved compressive strength (CS) in sand and fly ash. The best CS results were obtained by fly ash treated with 25 W-75 NB (37.2 kPa) and sand with 75 W-25 NB (32.1 kPa). Whey changed crystal polymorphism in biogenic CaCO3 production. Material bioconsolidation depends on the CaCO3 polymorph, thus fly ash was effectively bioconsolidated by crystallization of vaterite and sand by crystallization of calcite.

3.
Rev. iberoam. psicol. (En línea) ; 13(3): 109-118, 2020.
Artículo en Español | LILACS, COLNAL | ID: biblio-1224677

RESUMEN

La sensibilidad se refiere a la capacidad del cuidador para percibir las señales del niño, interpretarlas correctamente y responder a ellas de manera contingente y apropiada. El Q Set del Comportamiento Materno (MBQS) fue creado a partir de descripciones teóricas y empíricas de la sensibilidad. Los Q-sorts se asocian con la metodología cuantitativa debido a que asignan puntajes; además, combinan la metodología cualitativa al hacer un estudio sistemático de la subjetividad. Son pocos los artículos que se ocupan de explorar el análisis, la validez interna, la confiabilidad o la replicabilidad externa de los Q-sorts. Usualmente los datos se reducen por medio de un análisis de componentes principales o análisis factorial. Sin embargo, en los Q-sorts se correlacionan los participantes para dilucidar las relaciones entre ellos en lugar de correlacionar las variables. El objetivo de la presente investigación fue encontrar evidencia respecto a la validez basada en la estructura interna del MBQS con el apoyo del software R y el paquete qmethod. Colaboraron 37 díadas mexicanas mamá-bebés, 35 colombianas y 24 uruguayas. En el 2002, Posada y colaboradores propusieron siete escalas. Las escalas en las que nuestro modelo factorial presentó un buen ajuste son las que tienen menos ítems, lo cual puede ser indicativo de que la falta de ajuste tiene que ver con la identificación del modelo debido a que se cuenta con pocas observaciones. Consideramos que tanto el uso del MBQS para evaluar la sensibilidad como del paquete qmethod para realizar el análisis resulta novedoso, relevante y pertinente


Sensitivity refers to the caregiver's ability to perceive infant's cues, interpret them correctly, and respond to them in a contingent and appropriate way. The Maternal Behavior Q Set (MBQS) was created from theoretical and empirical descriptions of sensitivity. Q-methodology is associated with the quantitative methodology because it assigns scores; in addition, it combines qualitative methodology by making a systematic study of subjectivity. Few papers are concerned with exploring the analysis, internal validity, reliability, or external replicability of Q studies. Usually analyses reduce data to a few summarizing factors, based on principal component analysis or centroid factor analysis. Q-factor analysis method was developed especially for q-sorted data; it is a by-person factor analysis which is used to identify groups of participants who make sense of a pool of items in comparable way. The aim of this study was to find evidence regarding the validity based on the internal structure of the MBQS using the R software and the qmethod package. Thirty-seven Mexican, 35 Colombian and 24 Uruguayan mother-baby dyads collaborated. In 2002, Posada et al. proposed seven scales. The scales in which our factorial model presented a good fit are those with the fewest items, which may be indicative that the lack of fit has to do with the identification of the model because there are few observations. We consider that both the use of the MBQS to assess sensitivity and the qmethod package to perform the analysis is novel, relevant and pertinent.


Asunto(s)
Humanos , Cuidadores , Conducta Materna , Aptitud , Uruguay , Conducta , Sensibilidad y Especificidad , Colombia , Señales (Psicología) , México , Madres
4.
Open AIDS J ; 6: 239-44, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23115608

RESUMEN

BACKGROUND: A number of studies have demonstrated that receptor and co-receptor expression levels which may affect viral entry, promoting cervical HIV infection. The aim was to evaluate the expression levels of CCR5, CXCR4and DC-SIGN mRNA in a sample of heterosexually HIV infected Mexican women. METHODS: We enrolled twenty-six HIV heterosexual infected women attending a local infectious diseases medical unit.RNA was isolated from the cervix and gene expression analysis was performed using real-time PCR. RESULTS: Expression rates for mRNA of CCR5 (median 1.82; range 0.003-2934) were higher than those observed for CXCR4 (0.79; 0.0061-3312) and DC-SIGN (0.33; 0.006-532) receptors (p < 0.05). A high correlation was found between the mRNA expression levels of these three receptors (rs = 0.52 to 0.85, p < 0.01). CONCLUSION: Levels of expression of the tested chemokine receptors in the cervix are different from each other and alsovary from woman to woman, and seem to support the suggestion that chemokine receptor expression in genital tissues may be playing a role in the HIV transmission.

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