57 research outputs found
Effect of ground-cover management on predatory mites (Acari: Phytoseiidae) in a Mediterranean vineyard
Most predatory mites belong to the family Phytoseiidae (Acari). Throughout the world, phytoseiids are involved in the biological control of phytophagous mites in vineyards. Conservative strategies, including cover-vegetation management, are essential to achieve environmentally friendly viticulture. The abundance and diversity of phytoseiid mites in the grapevine canopy and the vegetal ground cover of a Mediterranean vineyard were surveyed by weekly samplings, from early May until the end of September for two years (2016 and 2017). Three types of soil management without herbicide application were analysed and referred to as "Tillage", "Spontaneous Cover", and "Flower-driven Cover" treatments. Six phytoseiid species were collected on the grapevine canopy, with Typhlodromus pyri being the dominant species (99.5 %). Five phytoseiid species were recorded in the ground cover, with Typhlodromus and Neoseiulus as the major genera. The Flower-driven Cover treatment showed the highest abundance of phytoseiids in the grapevine canopy. However, both species richness and abundance of phytoseiid mites on the ground-cover vegetation were highest in the Spontaneous Cover treatment. These observations suggest that improving vegetation cover would promote both the abundance and diversity of phytoseiid mites in vineyards because the greater supply of pollen would enhance their survival. Therefore, the use of cover crops in vineyards represents a means of improving vineyard ecosystems by conservative biological control
Identification of plasmodium vivax proteins with potential role in invasion using sequence redundancy reduction and profile hidden markov models
Background: This study describes a bioinformatics approach designed to identify Plasmodium vivax proteins potentially involved in reticulocyte invasion. Specifically, different protein training sets were built and tuned based on different biological parameters, such as experimental evidence of secretion and/or involvement in invasion-related processes. A profile-based sequence method supported by hidden Markov models (HMMs) was then used to build classifiers to search for biologically-related proteins. The transcriptional profile of the P. vivax intra-erythrocyte developmental cycle was then screened using these classifiers.
Results: A bioinformatics methodology for identifying potentially secreted P. vivax proteins was designed using sequence redundancy reduction and probabilistic profiles. This methodology led to identifying a set of 45 proteins that are potentially secreted during the P. vivax intra-erythrocyte development cycle and could be involved in cell invasion. Thirteen of the 45 proteins have already been described as vaccine candidates; there is experimental evidence of protein expression for 7 of the 32 remaining ones, while no previous studies of expression, function or immunology have been carried out for the additional 25.
Conclusions: The results support the idea that probabilistic techniques like profile HMMs improve similarity searches. Also, different adjustments such as sequence redundancy reduction using Pisces or Cd-Hit allowed data clustering based on rational reproducible measurements. This kind of approach for selecting proteins with specific functions is highly important for supporting large-scale analyses that could aid in the identification of genes encoding potential new target antigens for vaccine development and drug design. The present study has led to targeting 32 proteins for further testing regarding their ability to induce protective immune responses against P. vivax malaria
Identification of Plasmodium vivax Proteins with Potential Role in Invasion Using Sequence Redundancy Reduction and Profile Hidden Markov Models
BACKGROUND: This study describes a bioinformatics approach designed to identify Plasmodium vivax proteins potentially involved in reticulocyte invasion. Specifically, different protein training sets were built and tuned based on different biological parameters, such as experimental evidence of secretion and/or involvement in invasion-related processes. A profile-based sequence method supported by hidden Markov models (HMMs) was then used to build classifiers to search for biologically-related proteins. The transcriptional profile of the P. vivax intra-erythrocyte developmental cycle was then screened using these classifiers. RESULTS: A bioinformatics methodology for identifying potentially secreted P. vivax proteins was designed using sequence redundancy reduction and probabilistic profiles. This methodology led to identifying a set of 45 proteins that are potentially secreted during the P. vivax intra-erythrocyte development cycle and could be involved in cell invasion. Thirteen of the 45 proteins have already been described as vaccine candidates; there is experimental evidence of protein expression for 7 of the 32 remaining ones, while no previous studies of expression, function or immunology have been carried out for the additional 25. CONCLUSIONS: The results support the idea that probabilistic techniques like profile HMMs improve similarity searches. Also, different adjustments such as sequence redundancy reduction using Pisces or Cd-Hit allowed data clustering based on rational reproducible measurements. This kind of approach for selecting proteins with specific functions is highly important for supporting large-scale analyses that could aid in the identification of genes encoding potential new target antigens for vaccine development and drug design. The present study has led to targeting 32 proteins for further testing regarding their ability to induce protective immune responses against P. vivax malaria
Morphological and molecular description of Blastocrithidia cyrtomeni sp. nov. (Kinetoplastea: Trypanosomatidae) associated with Cyrtomenus bergi Froeschner (Hemiptera: Cydnidae) from Colombia
A new trypanosomatid species, Blastocrithidia cyrtomeni, is herein described using morphological and molecular data. It was found parasitising the alimentary tract of the insect host Cyrtomenus bergi, a polyphagous pest. The morphology of B. cyrtomeni was investigated using light and transmission microscopy and molecular phylogeny was inferred from the sequences of spliced leader RNA (SL rRNA) - 5S rRNA gene repeats and the 18S small subunit (SSU) rRNA gene. Epimastigotes of variable size with straphanger cysts adhering to the middle of the flagellum were observed in the intestinal tract, hemolymph and Malpighian tubules. Kinetoplasts were always observed anterior to the nucleus. The ultrastructure of longitudinal sections of epimastigotes showed the flagellum arising laterally from a relatively shallow flagellar pocket near the kinetoplast. SL RNA and 5S rRNA gene repeats were positive in all cases, producing a 0.8-kb band. The amplicons were 797-803 bp long with > 98.5% identity, indicating that they originated from the same organism. According to the sequence analysis of the SL-5S rRNA gene repeats and the 18S SSU rRNA gene, B. cyrtomeni is different from all other known species or isolates of Trypanosomatidae. Both analyses indicate that among known species, it is most closely related to Blastocrithidia triatomae
SELNET clinical practice guidelines for bone sarcoma
Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context
Malaria vector species in Colombia: a review
Here we present a comprehensive review of the literature on the vectorial importance of the major Anopheles malaria vectors in Colombia. We provide basic information on the geographical distribution, altitudinal range, immature habitats, adult behaviour, feeding preferences and anthropophily, endophily and infectivity rates. We additionally review information on the life cycle, longevity and population fluctuation of Colombian Anopheles species. Emphasis was placed on the primary vectors that have been epidemiologically incriminated in malaria transmission: Anopheles darlingi, Anopheles albimanus and Anopheles nuneztovari. The role of a selection of local, regional or secondary vectors (e.g., Anopheles pseudopunctipennis and Anopheles neivai) is also discussed. We highlight the importance of combining biological, morphological and molecular data for the correct taxonomical determination of a given species, particularly for members of the species complexes. We likewise emphasise the importance of studying the bionomics of primary and secondary vectors along with an examination of the local conditions affecting the transmission of malaria. The presence and spread of the major vectors and the emergence of secondary species capable of transmitting human Plasmodia are of great interest. When selecting control measures, the anopheline diversity in the region must be considered. Variation in macroclimate conditions over a species' geographical range must be well understood and targeted to plan effective control measures based on the population dynamics of the local Anopheles species
Efectos de la combinación de salinidad y exceso de boro en las relaciones hídricas del tomate (Solanum lycopersicum L.) tolerante cv. Poncho Negro y su relación con la funcionalidad de las acuaporinas
As elevated levels of boron (B) are accompanied by conditions of excessive salinity with drastic consequences for crops,it is crucial to find a crop that is tolerant to these conditions. In this work, the interaction between salinity and excess Bwith respect to aquaporin-mediated changes by blockade of mercury and water relations were studied as well as the osmotic adjustment of the plants. The treatments, for tomato ‘Poncho Negro’ cultivated hydroponically in a controlled environment chamber, were control (75 and 150 mM) NaCl and/or 5 mg L–1 or 20 mg L–1 B. Hydraulic conductance (L0) of detached exuding root systems exhibits large variations in response to abiotic stimuli. No additive (synergic) effects of B and salinity were observed. Under salinity, the plants increased their turgor, compensating for the decrease in the leaf water potential through the reduction in the leaf osmotic potential by the accumulation of soluble sugars and proline. The involvement of Hg2+-insensitive aquaporins or the osmotic gradient as the main force for water flow through the apoplastic pathway must be contemplated. Finally, all the data reveal the tomato cv. Poncho Negro to be a germplasm of agronomic interest and a good alternative for cultivation areas with high content of salts and the excess B of the soil and irrigation water.En muchas ocasiones niveles elevados de boro (B) van acompañados de condiciones de excesiva salinidad, cuyasconsecuencias pueden ser drásticas para los cultivos, por lo que es fundamental encontrar variedades que puedan tolerarestas condiciones. En este trabajo, se estudió cómo la interacción entre la salinidad y el exceso de B afecta a laactividad de las acuaporinas y a las relaciones hídricas, así como al ajuste osmótico de las plantas. Se cultivó en hidroponíatomate cv Poncho Negro en una cámara de crecimiento con ambiente controlado con los tratamientos control, NaCl (75 y 150 mM) y/o B (5 ó 20 mg L–1). No se observó ningún efecto aditivo (sinergia) del exceso de B y lasalinidad. Las plantas aumentaron su turgencia en condiciones salinas, compensando así la disminución del potencial hídrico foliar, a través de la reducción de su potencial osmótico por la acumulación de azúcares solubles y prolina. La participación de acuaporinas insensibles al Hg+2 o del gradiente osmótico, como la principal fuerza impulsora del flujo del agua, a través de la vía apoplástica, deben ser contemplados. Finalmente, todos los datos revelan que el tomate cv. Poncho Negro puede ser un germoplasma de interés agronómico y una buena alternativa para cultivar en condiciones de alto contenido de sales y exceso de B del suelo y del agua de riego
Color prediction in ceramic enamels using the Kubelka Munk Model
In the present research, the Kubelka-Munk model was applied for predicting color in glazes used in ceramic decoration. The model relates the absorption coefficient, scattering coefficient and the diffuse reflectance expected for a mixture of three ceramic pigments in the visible spectrum. The concentrations of each enamel were also considered making possible predict a particular tone. It was used visible spectrophotometry to obtain the absorption and scattering coefficients of pigments chosen on ceramic substrates for their use in pottery, and also for the diffuse reflectance spectra of mixtures selected for burned enamels. The results showed a good prediction in some regions of the visible spectrum, concluding that the model could be used for quality control of products manufactured in the ceramic industry.En este trabajo se muestra la aplicación del modelo de Kubelka-Munk para la predicción de color en esmaltes utilizados en decoración cerámica. El modelo relaciona los coeficientes de absorción y de dispersión de reflectancia difusa esperados para una mezcla de tres pigmentos cerámicos en el espectro visible, con las respectivas concentraciones de la composición de cada esmalte, con lo cual es posible predecir un tono determinado. Se empleó espectrofotometría visible con el fin de obtener los coeficientes de absorción y dispersión de los pigmentos elegidos sobre sustratos cerámicos para locería y también para los espectros de reflectancia difusa de las mezclas elegidas para los esmaltes calcinados. Los resultados obtenidos mostraron una buena predicción en algunas regiones del espectro visible, concluyéndose que el modelo podría utilizarse para el control de calidad de los productos fabricados en la industria cerámica
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