93 research outputs found

    Compound distribution, structural analysis and nanomechanical properties of nanofibers loaded with high-oleic palm oil nanoemulsions for packaging application

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    The effect of the HOPO concentration on the morphology, fiber diameter, oil load and distribution, protein structure, protein-oil colocalization, and nanomechanical properties of the NFs were evaluated. We obtained smooth and defect-free NFs with diameters in range of 77–94 nm. Fourier-transform infrared spectroscopy was used as a reliable method to confirm oil load and protein structure after electrospinning. β-turn, β-sheet, α-helix, and triple helical structures were quantified. Confocal laser scanning microscopy was used to analyze colocalization, and results revealed a high distribution of NE droplets along the NFs and high oil-protein colocalization (overlap coefficient of ~ 0.63). The nanomechanical properties of the NE-loaded NFs demonstrated that at higher HOPO concentrations, the elastic modulus decreased. Likewise, homogeneity and synergy between compounds were observed. The adhesion properties of NE-loaded NFs were associated with their sticky surface, which was attributed to presence of HOPO. The NE-loaded NFs presented suitable physical properties for edible packaging.Fil: Ricaurte, Leidy. Universidad de la Sabana; ColombiaFil: Perea Flores, María de Jesús. INSTITUTO POLITÉCNICO NACIONAL (IPN);Fil: Méndez Méndez, Juan Vicente. INSTITUTO POLITÉCNICO NACIONAL (IPN);Fil: Santagapita, Patricio Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Quintanilla Carvajal, María Ximena. Universidad de la Sabana; Colombi

    Dynamical features of reaction-diffusion fronts in fractals

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    The speed of front propagation in fractals is studied by using (i) the reduction of the reaction-transport equation into a Hamilton-Jacobi equation and (ii) the local-equilibrium approach. Different equations proposed for describing transport in fractal media, together with logistic reaction kinetics, are considered. Finally, we analyze the main features of wave fronts resulting from this dynamic process, i.e., why they are accelerated and what is the exact form of this acceleration

    Electrochemical Properties of Diluted Al-Mg Alloys With Columnar-To-Equiaxed Transition

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    The objective of the present research is to study the corrosion susceptibility of two Al-Mg diluted alloys (Al-0.5wt.%Mg and Al-2wt.%Mg) with different grains structures obtained by directional solidification (columnar, equiaxed and columnar-to-equiaxed transition, CET) in 0.5% NaCl solution, at room temperature. The corrosion resistance is analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques in both longitudinal and transversal sections of the samples. The columnar grain zone presents higher corrosion resistance than the equiaxed grain zone. In addition, the transversal section shows higher corrosion resistance than the longitudinal section of the samples. Then, the Al-0.5wt.% Mg alloy displays higher corrosion resistance than the Al-2wt.% Mg alloy. The values of the polarization resistance are used as a basic criterion for the evaluation of the corrosion resistance of both alloys. In this way, when the polarization resistance decreases with the increasing in the distance from the base, the grain size, secondary dendritic arm spacings and hardness increases. In addition, when the polarization resistance increases, the critical temperature gradient decreases.Fil: Roman, Alejandra Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Ibañez, Edgar Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Méndez, Marcela Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Pedrozo, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Kramer, Gustavo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Zadorozne, Natalia Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Alonso, Paula Regina. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Ares, Alicia Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentin

    The spiral structure of the Galaxy revealed by CS sources and evidence for the 4:1 resonance

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    We present a map of the spiral structure of the Galaxy, as traced by molecular CS emission associated with IRAS sources which are believed to be compact HII regions. The CS line velocities are used to determine the kinematic distances of the sources, in order to investigate their distribution in the galactic plane. This allows us to use 870 objects to trace the arms, a number larger than that of previous studies based on classical HII regions. The distance ambiguity of the kinematic distances, when it exists, is solved by different procedures, including the latitude distribution and an analysis of the longitude-velocity diagram. The well defined spiral arms are seen to be confined inside the co-rotation radius, as is often the case in spiral galaxies. We identify a square-shaped sub-structure in the CS map with that predicted by stellar orbits at the 4:1 resonance (4 epicycle oscillations in one turn around the galactic center). The sub-structure is found at the expected radius, based on the known pattern rotation speed and epicycle frequency curve. An inner arm presents an end with strong inward curvature and intense star formation that we tentatively associate with the region where this arm surrounds the extremity of the bar, as seen in many barred galaxies. Finally, a new arm with concave curvature is found in the Sagitta to Cepheus region of the sky

    Proceedings - U.S.A Agroecology Summit 2023

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    This docket is a memory of the meeting held in Kansas City from May 22-25 called the 2023 USA Agroecology Summit and contains all the documents generated before, during, and after the meeting

    Determinación de la curva de lactancia en conejas, empleando la función beta modificada

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    The purpose of this research was to characterize the lactation curve in rabbits; important aspect to adjust rations and obtain maximum performance in production systems. A modified beta function was used, with estimators of: height (κ), ascent (α) and descent (β) of 374.60 ± 10.271; 0.5616 ± 0.015 and 0.4369 ± 0.014 respectively. The day of maximum production (DMP) and the maximum production (PM) of the average curve was achieved at 16.78 d with a volume of 189.01 g.d-1. Parameter estimators, as well as WMD and PM of individual lactations, were analyzed using the mixed model with repeated measures, which included the fixed effects: genotype (G), number of parity (P) and litter size. (C), and the random effect of the animal nested within genotype A(G). For κ, significant differences were found (p ≤ 0.05), increasing its value with the size of the litter. In α, significant differences were only detected in P with the highest parameter value in primiparous females (p ≤ 0.05). The β parameter was only affected by C. The WMD and PM were affected (p ≤ 0.05) by P and C. The PM was higher in multiparous rabbits and increased with C (p ≤ 0.05). The modified beta function adequately describes the lactation curve of rabbits.El propósito de esta investigación fue caracterizar la curva de lactancia en conejas; aspecto importante para ajustar las raciones y obtener máximo rendimiento en los sistemas de producción. Se usó una función beta modificada, con estimadores de: altura (κ), ascenso (α) y descenso (β) de 374,60 ± 10,271; 0,5616 ± 0,015 y 0,4369 ± 0,014 respectivamente. El día de máxima producción (DMP) y la producción máxima (PM) de la curva promedio se logró a los 16,78 d con volumen de 189,01 g.d-1. Los estimadores de los parámetros, así como, DMP y la PM de las lactancias individuales, fueron analizadas usando el modelo mixto con medidas repetidas, que incluyó los efectos fijos: genotipo (G), número de partos (P) y tamaño de la camada (C), y el efecto aleatorio del animal anidado dentro de genotipo A(G). Para κ se encontraron diferencias significativas (p ≤ 0,05), incrementando su valor con el del tamaño de la camada. En α solo se detectaron diferencias significativas en P con el valor del parámetro más alto en las primíparas (p ≤ 0,05). El parámetro β solo fue afectado por C. El DMP y PM, fueron afectados (p ≤ 0,05) por P y C. La PM fue mayor en conejas multíparas y aumentó con C (p ≤ 0,05). La función beta modificada describe adecuadamente la curva de lactancia de las conejas

    Long-term results of sirolimus treatment in lymphangioleiomyomatosis: a single referral centre experience

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    There are few published data on long-term treatment with sirolimus in lymphangioleiomyomatosis (LAM). The objective of this study was to describe the long-term effect of sirolimus in a series of LAM patients followed up in a referral centre, focusing on pulmonary function. We retrospectively reviewed a series of 48 patients with LAM diagnosed, followed up and treated with sirolimus in a single centre. Response to sirolimus was evaluated at 1 and 5 years. A negative sirolimus response was defined as an FEV1 decline greater than - 75 ml/year. A mixed-effects model was used to estimate the longitudinal changes in FEV1 (average slope), both as absolute (ml/year) and as predicted values (%predicted/year). From a total of 48 patients, 9 patients underwent lung transplantation and 4 died during the study. Mean (95% CI) FEV1 slope over 5 years was - 0.14 (- 26.13 to 25.85) ml/year in the whole LAM group, 42.55 (14.87 to 70.22) ml/year in the responder group, - 54.00 (- 71.60 to - 36.39) ml/year in the partial responder group and - 84.19 (- 113.5 to - 54.0) ml/year in the non-responder group. After 5 years of sirolimus treatment 59% had a positive response, 30% had a partial response and 11% had a negative response. Our study found that sirolimus treatment had a positive long-term effect on most LAM patients

    Staphylococcus aureus Nasal Colonization in Spanish Children. The COSACO Nationwide Surveillance Study

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    Objective: To assess the prevalence and risk factors for S. aureus and methicillin-resistant S. aureus (MRSA) nasal colonization in Spanish children. Methods: Cross-sectional study of patients <14 years from primary care centers all over Spain. Clinical data and nasal aspirates were collected from March to July 2018. Results: A total of 1876 patients were enrolled. Prevalence of S. aureus and MRSA colonization were 33% (95% CI 30.9-35.1) and 1.44% (95% CI 0.9-2), respectively. Thirty-three percent of the children (633/1876) presented chronic conditions, mainly atopic dermatitis, asthma and/or allergy (524/633). Factors associated with S. aureus colonization were age ≥5 years (OR 1.10, 95% CI 1.07-1.12), male sex (OR 1.43, 95% CI 1.17-1.76), urban setting (OR 1.46, 95% CI 1.08-1.97) and the presence of asthma, atopic dermatitis or allergies (OR 1.25; 95% CI: 1.093-1.43). Rural residence was the only factor associated with MRSA colonization (OR 3.62, 95% CI 1.57-8.36). MRSA was more frequently resistant than methicillin-susceptible S. aureus to ciprofloxacin [41.2% vs 2.6%; p<0.0001], clindamycin [26% vs 16.9%; p=0.39], and mupirocin [14.3% vs 6.7%; p=0.18]. None of the MRSA strains was resistant to tetracycline, fosfomycin, vancomycin or daptomycin. Conclusions: The main risk factors for S. aureus colonization in Spanish children are being above five years of age, male gender, atopic dermatitis, asthma or allergy, and residence in urban areas. MRSA colonization is low, but higher than in other European countries and is associated with rural settings.This study has been supported by The Spanish Ministry of Science and Innovation – Instituto de Salud Carlos III, and Fondos FEDER of the EU, Grant Nº PI18CIII/00372 [Fondo de Investigaciones Sanitarias-Spanish Health Research Fund (ISCIII)]; Grant Award “Jose María Corretger” from the Spanish Society for Pediatric Infectious Diseases; Grant Research Award from the Spanish Association of Pediatric Primary Care; and a Small Grant Award from the European Society for Pediatric Infectious Diseases.S

    Asociación entre características reproductivas y producción de leche, en novillas mestizas

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    This research was carried out in heifers from a crisscrossing program between the red Holstein and Brahman breeds, in Venezuela. (Co)variance components were estimated and the relationship between milk yield (P305), age (AGE1) and fertility at first service (FERT1) in virgin heifers was investigated. The analysis methodology was restricted maximum likelihood (REML), under a multivariate animal model. The mixed model included: the random effect of the animal; and the fixed effects of racial group, year-seasons of the event occurrence; for P305, the duration of lactation was also included as a covariate in quadratic form. Heritabilities were: 0.498 ± 0.022; 0.436 ± 0.020 and 0.024 ± 0.008, for P305, AGE1 and FERT1 respectively. Genetic correlations between: P305-AGE1; P305-FERT1 and AGE1-FERT1, were: -0.281±0.040; 0.238 ± 0.117 and -0.076 ± 0.123, these results suggest a favorable genetic association between P305-AGE1, as well as, between P305-FERT1. Weighted regression analysis of the averages breeding values on years, showed an improvement in P305 of 10.85 kg/year and a reduction of -0.1150 month/year in AGE1 representing 0.60 and 0.41% of the population means for those traits (p &lt; 0.01); the annual genetic change for FERT1 was not significant (p &gt; 0.05). The phenotypic changes in P305 and AGE1 were not significant (p &gt; 0.05). It is concluded that there is no genetic antagonism between P305 and FERT1 and that it is possible to reduce AGE1 for decreasing the costs for generating replacement heifers, improving the rate of genetic change in P305. &nbsp;Esta investigación se realizó con novillas de un programa de cruzamiento entre las razas Holstein y Brahman roja, en Venezuela. Se estimaron los componentes de (co)varianza y se investigó la relación entre producción de leche (P305), edad (AGE1) y fertilidad al primer servicio (FERT1) en novillas vírgenes. La metodología de análisis fue bajo máxima verosimilitud restringida (REML), bajo un modelo animal multivariado. El modelo lineal incluía: el efecto aleatorio del animal; y los efectos fijos de grupo racial, años-temporadas de ocurrencia del evento; para P305, la duración de la lactancia también se incluyó como covariable en forma cuadrática. Las heredabilidades fueron: 0,498 ± 0,022; 0,436 ± 0,020 y 0,024 ± 0,008, para P305, AGE1 y FERT1 respectivamente. Las correlaciones genéticas entre: P305-AGE1; P305-FERT1 y AGE1-FERT1, fueron: -0,281±0,040; 0,238 ± 0,117 y -0,076 ± 0,123, estos resultados sugieren una asociación genética favorable entre P305-AGE1, así como entre P305-FERT1. El análisis de regresión ponderada de los valores genéticos promedios en años, mostró una mejora en P305 de 10.85 kg/año y una reducción de -0.1150 mes/año en AGE1 lo cual representa 0.60 y 0.41% de las medias poblacionales para esos rasgos (p &lt; 0.05), el cambio genético anual para FERT1 no fue significativo (p &gt; 0,05). Los cambios fenotípicos en P305 y AGE1 no fueron significativos (p &gt; 0,01). Se concluye que no existe antagonismo genético entre P305 y FERT1 y que es posible reducir AGE1 para disminuir los costos de generación de vaquillas, mejorando la tasa de cambio genético en P305

    Gas absorption and dust extinction towards the Orion Nebula Cluster

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    B. Hasenberger, et al, 'Gas absorption and dust extinction towards the Orion Nebula Cluster', Astronomy & Astrophysics, 593, A7, 2016. The version of record is available online at DOI: 10.1051/0004-6361/201628517. Published by EDP Sciences. © ESO, 2016We characterise the relation between the gas and dust content of the interstellar medium towards young stellar objects in the Orion Nebula Cluster. X-ray observations provide estimates of the absorbing equivalent hydrogen column density N_H based on spectral fits. Near-infrared extinction values are calculated from intrinsic and observed colour magnitudes (J-H) and (H-K_s) as given by the VISTA Orion A survey. A linear fit of the correlation between column density and extinction values A_V yields an estimate of the N_H/A_V ratio. We investigate systematic uncertainties of the results by describing and (if possible) quantifying the influence of circumstellar material and the adopted extinction law, X-ray models, and elemental abundances on the N_H/A_V ratio. Assuming a Galactic extinction law with R_V=3.1 and solar abundances by Anders & Grevesse (1989), we deduce an N_H/A_V ratio of (1.39 +- 0.14) x 10^21 cm^-2 mag^-1 for Class III sources in the Orion Nebula Cluster where the given error does not include systematic uncertainties. This ratio is consistent with similar studies in other star-forming regions and approximately 31% lower than the Galactic value. We find no obvious trends in the spatial distribution of N_H/A_V ratios. Changes in the assumed extinction law and elemental abundances are demonstrated to have a relevant impact on deduced A_V and N_H values, respectively. Large systematic uncertainties associated with metal abundances in the Orion Nebula Cluster represent the primary limitation for the deduction of a definitive N_H/A_V ratio and the physical interpretation of these results.Peer reviewe
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