213 research outputs found
Culture conditions for zinc- and pH-regulated gene expression studies in Aspergillus fumigatus
In Aspergillus fumigatus, the regulation of zinc homeostasis is strongly influenced by environmental pH. Thus, the study of zinc-regulated gene expression in A. fumigatus requires controlling variations in culture pH, as this may affect zinc availability. However, depending on the nitrogen source, the pH of the culture can change dramatically over time. In addition, due to the ubiquitous distribution of zinc and that it is an essential micronutrient required in minute amounts for optimal fungal growth, neither buffering of the culture media to prevent pH variations nor the use of chelating agents is advisable if
mycelium is to be used for expression analyses. In this work, the growth of A. fumigatus in several culture media was examined in order to determine the conditions yielding mycelia suitable for gene expression analyses in acid and neutral media, regardless of zinc availability. Our results showed that a zinc-limiting synthetic basal medium could be readily converted into a zinc-replete one and subsequently into acid or neutral medium by using, respectively, ammonium or nitrate as nitrogen source. [Int Microbiol 2007; 10(3):187-192
Introduction to protein folding for physicists
The prediction of the three-dimensional native structure of proteins from the
knowledge of their amino acid sequence, known as the protein folding problem,
is one of the most important yet unsolved issues of modern science. Since the
conformational behaviour of flexible molecules is nothing more than a complex
physical problem, increasingly more physicists are moving into the study of
protein systems, bringing with them powerful mathematical and computational
tools, as well as the sharp intuition and deep images inherent to the physics
discipline. This work attempts to facilitate the first steps of such a
transition. In order to achieve this goal, we provide an exhaustive account of
the reasons underlying the protein folding problem enormous relevance and
summarize the present-day status of the methods aimed to solving it. We also
provide an introduction to the particular structure of these biological
heteropolymers, and we physically define the problem stating the assumptions
behind this (commonly implicit) definition. Finally, we review the 'special
flavor' of statistical mechanics that is typically used to study the
astronomically large phase spaces of macromolecules. Throughout the whole work,
much material that is found scattered in the literature has been put together
here to improve comprehension and to serve as a handy reference.Comment: 53 pages, 18 figures, the figures are at a low resolution due to
arXiv restrictions, for high-res figures, go to http://www.pabloechenique.co
Transformational and Transactional Behaviors as Predictors of Quality Education
This study determined the leadership behaviors that predict quality education as perceived by teachers in elementary Southern Asia with at least three years of teaching experience. Quality education utilized the dimensions: strategic planning, customer focus, measurement, analysis and knowledge management, workforce focus, operation focus, and results. The investigation used correlation design utilizing a random sample of 395 respondents. The respondents answered the validated survey questionnaire generate the findings of this study. The descriptive results revealed that the prevalent leadership behavior used by the principals was transformational and transactional. The respondents perceived that high quality education was also observed in their institution. Moreover, the study found that the dimensions of leadership behavior: inspirational motivation, contingent reward, intellectual stimulation, idealized influence, individualized consideration, and management-by-exemption were significant predictors of quality education. The study proffered a number of recommendations to maintain and improve the quality of education among Adventist Institutions in the Southern Asia pacific region
Sesquiterpenoids lactones: benefits to plants and people
Sesquiterpenoids, and specifically sesquiterpene lactones from Asteraceae, may play a highly significant role in human health, both as part of a balanced diet and as pharmaceutical agents, due to their potential for the treatment of cardiovascular disease and cancer. This review highlights the role of sesquiterpene lactones endogenously in the plants that produce them, and explores mechanisms by which they interact in animal and human consumers of these plants. Several mechanisms are proposed for the reduction of inflammation and tumorigenesis at potentially achievable levels in humans. Plants can be classified by their specific array of produced sesquiterpene lactones, showing high levels of translational control. Studies of folk medicines implicate sesquiterpene lactones as the active ingredient in many treatments for other ailments such as diarrhea, burns, influenza, and neurodegradation. In addition to the anti-inflammatory response, sesquiterpene lactones have been found to sensitize tumor cells to conventional drug treatments. This review explores the varied ecological roles of sesquiterpenes in the plant producer, depending upon the plant and the compound. These include allelopathy with other plants, insects, and microbes, thereby causing behavioural or developmental modification to these secondary organisms to the benefit of the sesquiterpenoid producer. Some sesquiterpenoid lactones are antimicrobial, disrupting the cell wall of fungi and invasive bacteria, whereas others protect the plant from environmental stresses that would otherwise cause oxidative damage. Many of the compounds are effective due to their bitter flavor, which has obvious implications for human consumers. The implications of sesquiterpenoid lactone qualitiesfor future crop production are discussed
Riesgo químico: estrategias de intervención social
Production, use, marketing and emission of chemical substances display the strong links between chemical risks at the workplace, healthcare and environmental pollution. In spite of this fact, the policies for the management of chemical risk are far from being coherent and unified in the different sectors. (Nutritional safety, agriculture, healthcare, environment and occupational health).The Commission of European Communities (EC) has elaborated a White Document on the future policy on chemicals that recognizes the existing lack of control in this domain. We are facing a deep crisis of traditional strategies that are supposed to control chemical risks.It becomes essential to diversify the strategies. Some of them must aim at the improvement of information, others at the assessment of risk situations and some strategies must be directed to evaluate the possible alternatives for the solution of problems.La producción, utilización, comercialización y emisión de sustancias químicas pone de manifiesto los fuertes vínculos existentes entre el riesgo químico en el lugar de trabajo, la salud pública y la contaminación ambiental. A pesar de ello, las políticas de gestión del riesgo químico no han sido coherentes y unificadas en las diferentes áreas (seguridad alimentaria, agricultura, salud pública, medio ambiente y salud laboral).La Comisión de las Comunidades Europeas ha elaborado un Libro Blanco sobre la futura política en materia de sustancias químicas en el que reconoce un importante grado de descontrol. Realmente estamos ante una profunda crisis de ineficacia de las estrategias tradicionales que debían servir supuestamente para controlar el riesgo químico.Se hace necesario utilizar estrategias diversificadas: unas destinadas a mejorar los niveles de información; otras dirigidas a la evaluación de las situaciones de riesgo y otras, de mucho mayor calado, que tengan como objetivo la evaluación de alternativas orientadas a la resolución de los problemas
Gene expression profiling and its use in adenocarcinomas of unknown primary origin: A case report
Carcinomas of unknown primary origin account for 3-5% of all malignancies. The current literature suggests that metastatic dissemination is able to occur in the absence of primary tumor growth. In metastatic disease that is difficult to diagnose, the origin usually remains unknown even after an exhaustive evaluation of immunohistochemistry (IHC) markers. In the current study, a 49-year-old male presented with lymph nodes metastases of unknown origin. The exci- sional biopsy of an inguinal node revealed an adenocarcinoma growth pattern, but the IHC could not determine the primary origin. A gene profiling test was performed to complete the diagnosis and a salivary gland adenocarcinoma was diagnosed with 90% probability. Subsequently, the patient underwent appropriate chemotherapy for salivary gland adenocarcinoma, and exhibited an improved partial response. The present case study highlights the importance of an accurate diagnosis of the primary tumor and the use of all the current tools available in order to provide patients with the best treatment possibl
Seguimiento de los flujos de calor sensible y calor latente en vid mediante la aplicación del balance de energía METRIC
Revista oficial de la Asociación Española de Teledetección[EN] The monitoring of the energy fluxes over vineyard applying the one source energy balance model METRIC (Allen et al., 2007b) are shown in this work. This model is considered operaive because it uses an internalized calibration method derived from the selection of two extreme pixels in the scene, from the minimum ET values such as the bare soil to a maximum that corresponds to full cover active vegetation. The model provides the maps of net radiation (Rn), soil heat flux (G), sensible heat (H), latent heat (LE), evapotranspiration (ET) and crop coefficient (Kc). The flux values have been validated with a flux tower installed in the plot, providing a RMSE for instantaneous fluxes of 43 W m2, 33 W m2, 55 W m2 y 40 W m2 on Rn, G, H and LE. In relative terms are 8%, 29%, 21% and 20% respectively. The RMSE at daily scale for the ET is 0.58 mm day-1, with a value in the crop coefficient for the mid stage of 0.42±0.08. These results allow considering the model adequate for crop monitoring and irrigation purposes in vineyard. The values obtained have been compared to other studies over vineyard and with alternative energy balance models showing similar results.
Guardar / Salir Siguiente >[ES] En este trabajo se presenta el seguimiento de los flujos de energía en un cultivo de vid bajo riego, obtenidos a partir del modelo de balance de energía METRIC (Allen et al., 2007b). Este modelo resulta operativo al utilizar un método de calibración interna definido a partir de la selección de píxeles con valores extremos dentro de la escena. De esta manera se obtuvieron mapas de radiación neta (Rn), flujo de calor en suelo (G), calor sensible (H), calor latente (LE), evapotranspiración (ET) y coeficiente de cultivo (Kc). Estos valores fueron validados con registros obtenidos en el sitio, utilizando una torre de flujos turbulentos (covarianza de torbellinos). El RMSE fue 43 W m-2, 33 W m-2, 55 W m-2 y 40 W m-2 en Rn, G, H y LE, los cuales en términos relativos representan un 8%, 29 %, 21% y 20% respectivamente. A escala diaria el RMSE para la ET fue de 0,58 mm día-1, con un valor de Kc máximo y estable de 0,42±0,08. Estos re-sultados permiten considerar que el método es adecuado y operativo para el seguimiento de la evapotranspiración y cálculo de las necesidades hídricas del viñedo evaluadoAl proyecto CERESS (Coupling land surface Energy and water balance from Remote sensing for mapping Evapotranspiration, water Stress and Soil moisture, ref: AGL2011-30498-C02-01) financiado por el Ministerio de Ciencia e Innovación español. El co-autor C. Balbontín N. agradece el financiamiento del Ministerio de Educación de Chile a través de su proyecto FONDECYT Iniciación Cod. 11140843.González-Piqueras, J.; Villodre, J.; Campos, I.; Calera, A.; Balbontín, C. (2015). Monitoring the latent and sensible heat fluxes in vineyard by applying the energy balance model METRIC. Revista de Teledetección. (43):43-54. https://doi.org/10.4995/raet.2015.2310SWORD435443Allen, R., Irmak, A., Trezza, R., Hendrickx, J. M. H., Bastiaanssen, W., & Kjaersgaard, J. (2011). Satellite-based ET estimation in agriculture using SEBAL and METRIC. Hydrological Processes, 25(26), 4011-4027. doi:10.1002/hyp.8408Allen, R. G., Pereira, L. S., Raes, D., Smith, M. 1998. Crop Evapotranspiration. Guidelines for computing crop water requirements. (Vol. 56), Food and Agriculture Organization.Balbontin-Nesvara, C., Calera-Belmonte, A., González-Piqueras, J., Campos-Rodríguez, I., López-González, M. L., Torres-Prieto, E. 2011. Vineyard Evapotranspiration Measurements in a Semiarid Environment: Eddy Covariance and Bowen Ratio Comparison. Agrociencia, 45, 87-103.González-Dugo, M. P., González-Piqueras, J., Campos, I., Balbontín, C., Calera, A. 2012b. Estimation of surface energy fluxes in vineyard using field measurements of canopy and soil temperature. In C. M. U. Neale & M. H. Cosh (Eds.), Remote Sensing and Hydrology (Vol. 352, pp. 59-62). Wallingford: Int Assoc Hydrological Sciences.INM. 2004. Guía resumida del clima de Espa-a 1971-2000. In I. N. d. Meteorología (Ed.). Madrid
Francisco del Castillo, autor de la fachada de la Chancillería de Granada
En la larga lista de personajes que ocuparon la presidencia de la Real Chancillería de Granada, en el primer siglo de su funcionamiento en esta ciudad, cada uno se distingui6 en su mandato por aspectos diferentes, lo que les hizo dejar una importante huella per sonal en la ciudad
PREDICCIÓN DE LAS NECESIDADES HÍDRICAS CON UNA SEMANA DE ANTELACIÓN MEDIANTE TELEDETECCIÓN Y METEOROLOGÍA EN LA FINCA EXPERIMENTAL DEL CENTER PARA CULTIVOS DE MAÍZ
[ES] Determinar las necesidades hídricas que los cultivos demandarán a corto plazo juega
un papel fundamental en la gestión de explotaciones agrícolas de regadío. De su precisión
depende la obtención de mejores rendimientos productivos, económicos y
medioambientales. La experiencia llevada a cabo en la finca experimental de la DGDRPF –
CENTER del MAGRAMA, obtuvo la predicción de las necesidades hídricas con una semana
de antelación durante todo el periodo de monitorización. Basados en la ecuación del
coeficiente de cultivo único (Kc), de la metodología FAO56, se predijo la evapotranspiración
del cultivo (ETc) en parcelas de maíz en regadío. Para ello, se emplearon técnicas
meteorológicas que predijeron la evapotranspiración de referencia (ETo), y técnicas de
teledetección basadas en secuencias temporales de índices de vegetación (IV) mediante las
cuales se predijo el Kc. Los resultados obtenidos produjeron una ligera sobre estimación de
la ETc a final de campaña (8%). Paralelamente, los riegos aplicados fueron validados
externamente mediante el empleo de sondas de humedad. En resumen, la experiencia
proporcionó resultados adecuados con un bajo número de recursos. Así, la programación
del riego se realizó mediante la combinación de técnicas de teledetección y meteorológicas.Garrido-Rubio, J.; González Gómez, L.; Arellano Alcazar, I.; Madurga Del Cura, C.; Navarro Comalrena De Sobregrau, M.; López Tapia, J.; Calera Belmonte, A. (2015). PREDICCIÓN DE LAS NECESIDADES HÍDRICAS CON UNA SEMANA DE ANTELACIÓN MEDIANTE TELEDETECCIÓN Y METEOROLOGÍA EN LA FINCA EXPERIMENTAL DEL CENTER PARA CULTIVOS DE MAÍZ. En XXXIII CONGRESO NACIONAL DE RIEGOS. Valencia 16-18 junio de 2015. Editorial Universitat Politècnica de València. https://doi.org/10.4995/CNRiegos.2015.1496OC
First Human Model of In Vitro Candida albicans Persistence within Granuloma for the Reliable Study of Host-Fungi Interactions
BACKGROUND: The balance between human innate immune system and Candida albicans virulence signaling mechanisms ultimately dictates the outcome of fungal invasiveness and its pathology. To better understand the pathophysiology and to identify fungal virulence-associated factors in the context of persistence in humans, complex models are indispensable. Although fungal virulence factors have been extensively studied in vitro and in vivo using different immune cell subsets and cell lines, it is unclear how C. albicans survives inside complex tissue granulomas. METHODOLOGY/PRINCIPAL FINDING: We developed an original model of in vitro human granuloma, reproducing the natural granulomatous response to C. albicans. Persistent granulomas were obtained when the ratio of phagocytes to fungi was high. This in vitro fungal granuloma mimics natural granulomas, with infected macrophages surrounded by helper and cytotoxic T lymphocytes. A small proportion of granulomas exhibited C. albicans hyphae. Histological and time-lapse analysis showed that C. albicans blastoconidia were located within the granulomas before hyphae formation. Using staining techniques, fungal load calculations, as well as confocal and scanning electron microscopy, we describe the kinetics of fungal granuloma formation. We provide the first direct evidence that C. albicans are not eliminated by immunocompetent cells inside in vitro human granulomas. In fact, after an initial candicidal period, the remaining yeast proliferate and persist under very complex immune responses. CONCLUSIONS/SIGNIFICANCE: Using an original in vitro model of human fungal granuloma, we herein present the evidence that C. albicans persist and grow into immunocompetent granulomatous structures. These results will guide us towards a better understanding of fungal invasiveness and, henceforth, will also help in the development of better strategies for its control in human physiological conditions
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